忠永 清治 (タダナガ キヨハル)
| 工学研究院 応用化学部門 無機材料化学分野 | 教授 |
Last Updated :2025/03/17
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- C-7260-2008
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論文
- Mixed ion-electron conductive materials: A path to higher energy density all-solid-state lithium-ion batteries
Abdulkadir Kızılaslan, Recep Kızılaslan, Akira Miura, Kiyoharu Tadanaga
Nano Today, 60, 102556, 102556, Elsevier BV, 2025年02月
研究論文（学術雑誌） - Synthesis and catalytic activity of TiN particles by surfactant-modified urea-glass process
Yohei Saika, Sho Ishiyama, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Boletín de la Sociedad Española de Cerámica y Vidrio, Elsevier BV, 2025年01月
研究論文（学術雑誌） - Electrochemical CO<sub>2</sub> reduction reaction catalytic activity of zirconium nitrides synthesized by the urea-glass route using ZrCl<sub>4</sub> as a raw material
Kentaro Tabuchi, Shinji Noguchi, Ryosuke Nakazato, Keeko Matsumoto, Yuta Fujii, Akira Miura, Kiyoharu Tadanaga
Journal of the Ceramic Society of Japan, Ceramic Society of Japan, 2025年
研究論文（学術雑誌） - The Detail Matters: Unveiling Overlooked Parameters in the Mechanochemical Synthesis of Solid Electrolytes
Abdulkadir Kızılaslan, Mustafa Çelik, Yuta Fujii, Zheng Huang, Chikako Moriyoshi, Shogo Kawaguchi, Satoshi Hiroi, Koji Ohara, Mariko Ando, Kiyoharu Tadanaga, Saneyuki Ohno, Akira Miura
ACS Energy Letters, 156, 160, American Chemical Society (ACS), 2024年12月16日
研究論文（学術雑誌） - Rapid In Situ Investigation of Nitride Synthesis: Ambient Atmospheric Nitridation of 3d Metal Oxides Using Dicyandiamide
Momoka Demura, Keigo Ono, Masanori Nagao, Takafumi Yamamoto, Chul-Ho Lee, Aichi Yamashita, Chikako Moriyoshi, Shohei Tada, Yuji Masubuchi, Yuta Fujii, Kiyoharu Tadanaga, Akira Miura
Chemistry of Materials, 36, 23, 11490, 11498, American Chemical Society (ACS), 2024年11月21日
研究論文（学術雑誌） - Efficient Exploratory Synthesis of Quaternary Cesium Chlorides Guided by In Silico Predictions
Akira Miura, Muratahan Aykol, Shumma Kozaki, Chikako Moriyoshi, Shintaro Kobayashi, Shogo Kawaguchi, Chul-Ho Lee, Yongming Wang, Amil Merchant, Simon Batzner, Hiroshi Kageyama, Kiyoharu Tadanaga, Pushmeet Kohli, Ekin Dogus Cubuk
Journal of the American Chemical Society, 146, 43, 29637, 29644, American Chemical Society (ACS), 2024年10月16日
研究論文（学術雑誌） - Inorganic-Organic Hybrid Sulfide Solid Electrolytes Based on the Tetraalkylammonium Iodide-LiI-Li2S-P2S5 System
Tong Fang, Kazuhiro Hikima, Hiroyuki Muto, Atsunori Matsuda, Yuta Fujii, Akira Miura, Kiyoharu Tadanaga
Journal of The Electrochemical Society, The Electrochemical Society, 2024年10月08日
研究論文（学術雑誌）, Abstract
A series of novel inorganic-organic hybrid sulfide solid electrolytes were synthesized by doping Li7P2S8I with a selection of tetraalkylammonium iodides, including tetramethylammonium iodide (TMAI), tetraethylammonium iodide (TEAI), tetrapropylammonium iodide (TPAI), and tetrabutylammonium iodide (TBAI). The electrolytes were prepared in varying compositions represented as (1-x) Li7P2S8I ⸱ x (TMAI, TEAI, TPAI, TBAI), where x values were adjusted to 0, 0.05, 0.1, and 0.2 (molar ratio) to assess their influence on the electrolyte properties. These hybrids exhibited predominantly amorphous structures. Tetraalkylammonium iodides with longer alkyl chain length of the dopants showed lower ionic conductivity. Mechanical characterization via indentation tests indicated that the incorporation of longer alkyl chain length tetraalkylammonium iodides contributes to a reduction in the elastic modulus of the composites. This work underscores a methodological approach to modulate the structural and mechanical properties of sulfide solid electrolytes through strategic organic doping. - Synthesis, Electronic Structure, and Redox Chemistry of Li2MnP2S6, a Candidate High-Voltage Cathode Material
Yi-Ting Cheng, Yuta Fujii, Yu Nomata, Madhulika Mazumder, Nataly Carolina Rosero-Navarro, Aichi Yamashita, Yoshikazu Mizuguchi, Chikako Moriyoshi, Takato Mitsudome, Toshiaki Ina, Kiyofumi Nitta, Kiyoharu Tadanaga, Akira Miura, Christopher J. Bartel
Chemistry of Materials, 36, 19, 9947, 9958, American Chemical Society (ACS), 2024年09月18日
研究論文（学術雑誌） - Stress-Induced Martensitic Transformation in Na
3 YCl6
Akira Miura, Koki Muraoka, Kotaro Maki, Saori Kawaguchi, Kazuhiro Hikima, Hiroyuki Muto, Atsunori Matsuda, Ichiro Yamane, Toshihiro Shimada, Hiroaki Ito, Yoshikazu Mizuguchi, Chikako Moriyoshi, Hiroshi Nakajima, Shigeo Mori, Hiroshi Oike, Akira Nakayama, Wenhao Sun, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga
Journal of the American Chemical Society, 146, 36, 25263, 25269, 2024年09月11日
研究論文（学術雑誌）, Martensitic transformation with volume expansion plays a crucial role in enhancing the mechanical properties of steel and partially stabilized zirconia. We believe that a similar concept could be applied to unexplored nonoxide materials. Herein, we report the stress-induced martensitic transformation of monoclinic Na3YCl6 with an ∼3.4% expansion. In situ synchrotron X-ray diffraction and atomistic simulations showed that anisotropic crystallographic transformation from monoclinic to rhombohedral Na3YCl6 occurs exclusively under uniaxial pressure; no effect is observed under hydrostatic pressure conditions. The uniaxially pressed powder compact of monoclinic Na3YCl6 showed a large indentation impression and low Young’s modulus, in contrast to its high bulk modulus, suggesting that these unique mechanical properties are induced by the martensitic transformation. - Enhanced performance of graphene-incorporated electrodes for solid-state lithium-sulfur batteries through facilitated ionic diffusion pathways
Abdulkadir Kızılaslan, Çağrı Gökhan Türk, Akira Miura, Kiyoharu Tadanaga
Chemical Engineering Journal, 496, 153588, 153588, Elsevier BV, 2024年09月
研究論文（学術雑誌） - Real-Space Visualization of Charged Polymer Network of Hydrogel by Double Network Strategy and Mineral Staining
Shinji Noguchi, Ryuji Kiyama, Masahiro Yoshida, Maradhana Agung Marsudi, Naohiro Kashimura, Kiyoharu Tadanaga, Jian Ping Gong, Takayuki Nonoyama
Nano Letters, American Chemical Society (ACS), 2024年07月09日
研究論文（学術雑誌） - Synthesis of ZrN–SiO2 core–shell particles by a sol–gel process and use as particle‐based structured coloring material
Shinji Noguchi, Akira Miura, Kiyoharu Tadanaga
Journal of the American Ceramic Society, Wiley, 2024年07月, ［査読有り］, ［責任著者］
英語, 研究論文（学術雑誌）, Abstract
ZrN–SiO2 core–shell particles were prepared, where the ZrN core nanoparticles and SiO2 shell were designed to exhibit localized surface plasmon resonances (LSPRs) and structural coloring. The heating of ZrO2 nanoparticles with Mg3N2 under a nitrogen gas flow produced ZrN nanoparticles with a diameter in the range of 10–20 nm. The dispersion of ZrN nanoparticles in water exhibited an absorption maximum at approximately 700 nm owing to LSPRs. An SiO2 shell was formed on the ZrN nanoparticles using a sol–gel process. Scanning transmission electron microscopy confirmed the formation of ZrN–SiO2 core–shell particles containing ZrN particles with a diameter of approximately 10 nm. The SiO2 shell thickness was controlled by varying the reaction time to form SiO2. The use of particles as a structural component of a structural color material owing to the high uniformity of the size of obtained core–shell particles was investigated. The obtained ZrN–SiO2 core–shell particles were arrayed on a glass substrate using a layer‐by‐layer method. The particle‐stacked film of the ZrN–SiO2 core–shell particles exhibited the maximum reflection depending on the particle size of the SiO2 shell. - Insight on Zn-Al LDH as electrocatalyst for CO2 reduction reaction: An in-situ ATR-IR study
Margherita Cavallo, Melodj Dosa, Ryosuke Nakazato, Natale Gabriele Porcaro, Matteo Signorile, Matthias Quintelier, Joke Hadermann, Silvia Bordiga, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga, Valentina Crocellà, Francesca Bonino
Journal of CO2 Utilization, 83, 102804, 102804, Elsevier BV, 2024年05月, ［査読有り］, ［国際共著］, ［国際誌］
英語, 研究論文（学術雑誌）, 33965568 - Structural Color Materials with Color Mixing Effect Using Noble Metal‐Free Plasmonic Particles in SiO2–ZrN System
Shinji Noguchi, Milena Lama, Yuta Fujii, Akira Miura, Kiyoharu Tadanaga
Advanced Optical Materials, 2400287, 2024年04月15日, ［査読有り］, ［責任著者］
英語, 研究論文（学術雑誌） - Nitrogen-Rich Molybdenum Nitride Synthesized in a Crucible under Air
Momoka Demura, Masanori Nagao, Chul-Ho Lee, Yosuke Goto, Yusuke Nambu, Maxim Avdeev, Yuji Masubuchi, Takato Mitsudome, Wenhao Sun, Kiyoharu Tadanaga, Akira Miura
Inorganic Chemistry, 2024年03月18日, ［査読有り］
英語, 研究論文（学術雑誌） - High-pressure phase and pressure-induced phase transition of Ag3YCl6
Kotaro Maki, Koki Muraoka, Saori Kawaguchi, Taku Tanimoto, Akira Nakayama, Seiya Yokokura, Toshihiro Shimada, Kiyoharu Tadanaga, Akira Miura
CrystEngComm, 26, 13, 1814, 1818, Royal Society of Chemistry (RSC), 2024年
研究論文（学術雑誌）, Hexagonal Ag3YCl6 was found to transform into a monoclinic structure above ∼1.5 GPa. - Preparation of carbon–sulphur composite electrodes by solution impregnation and application to all-solid-state lithium–sulphur batteries
Sakura Niwa, Yuta Fujii, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga, Riku Maniwa, Misaki Fujimoto, Harumi Takada, Masahiro Morooka
Energy Advances, 3, 3, 609, 613, Royal Society of Chemistry (RSC), 2024年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Composite electrodes were prepared by impregnating both sulphur and solid electrolyte solutions into the interior of the porous carbon and drying them, and the composites were applied to all solid-state lithium-sulphur batteries. - Stability and Metastability of Li3YCl6 and Li3HoCl6
Hiroaki Ito, Yuki Nakahira, Naoki Ishimatsu, Yosuke Goto, Aichi Yamashita, Yoshikazu Mizuguchi, Chikako Moriyoshi, Takashi Toyao, Ken-ichi Shimizu, Hiroshi Oike, Masanori Enoki, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Bulletin of the Chemical Society of Japan, 96, 11, 1262, 1268, The Chemical Society of Japan, 2023年11月15日
研究論文（学術雑誌） - CO2 Electrochemical Reduction with Zn-Al Layered Double Hydroxide-Loaded Gas-Diffusion Electrode
Ryosuke NAKAZATO, Keeko MATSUMOTO, Noboru YAMAGUCHI, Margherita CAVALLO, Valentina CROCELLÀ, Francesca BONINO, Matthias QUINTELIER, Joke HADERMANN, Nataly Carolina, ROSERO-NAVARRO, Akira MIURA, Kiyoharu TADANAGA
Electrochemistry, 91, 9, 097003, 097003, The Electrochemical Society of Japan, 2023年09月26日, ［査読有り］
英語, 研究論文（学術雑誌）, 33965568 - Synthesis of lithium oxy-thiophosphate solid electrolytes with Li10GeP2S12 structure by a liquid phase process using 2-propanol
Shunichiro Shiba, Akira Miura, Yuta Fujii, Kiyoharu Tadanaga, Kota Terai, Futoshi Utsuno, Hiroyuki Higuchi
RSC Advances, 13, 33, 22895, 22900, Royal Society of Chemistry (RSC), 2023年07月, ［査読有り］, ［責任著者］
研究論文（学術雑誌）, Crystal structure model of lithium oxy-thiophosphates (LPSO) prepared in the present study (a) and Li10GeP2S12 (b). Purple spheres indicate P, yellow spheres indicate S, red spheres indicate O, and green spheres indicate Ge. - Electrocatalytic property of Zn-Al layered double hydroxides for CO2 electrochemical reduction
Noboru Yamaguchi, Ryosuke Nakazato, Keeko Matsumoto, Masako Kakesu, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
JOURNAL OF ASIAN CERAMIC SOCIETIES, 11, 3, 406, 411, TAYLOR & FRANCIS LTD, 2023年07月, ［査読有り］, ［最終著者, 責任著者］
英語, 研究論文（学術雑誌）, Electrocatalytic CO2 reduction reaction (CO2RR) has attracted considerable attention as a technology to recycle carbon dioxide (CO2) into raw materials for chemicals using renewable energies. In this study, the electrocatalytic CO2RR activity of Zn-Al layered double hydroxides (LDHs) was studied. Zn-Al LDHs loaded carbon sheets were prepared, and CO2 RR was performed using CO2-saturated KHCO3 electrolyte to confirm the catalytic ability of Zn-Al LDH. Zn-Al LDHs intercalated with CO32- anion were synthesized using the mixture of metal nitrates with the different molar ratio of Zn2+/Al3+ by the co-precipitation process, whose corresponding products were named as Zn2Al1 LDH, Zn3Al1 LDH, and Zn4Al1 LDH, respectively. Except for Zn2Al1 LDH, ZnO was observed to exist as an impurity. The synthesized Zn-Al LDHs exhibited the electrocatalytic CO2RR activity for CO formation. In the case of the Zn2Al1 LDH, the current density of 15 mA cm(-2) was obtained with 77% selectivity for CO and 94% selectivity for (CO + H-2) at - 1.4 V vs. RHE. Furthermore, Zn3Al1 and Zn4Al1 LDHs showed a significant change relating to ZnO impurities in the XRD patterns and SEM images before and after the CO2RR whereas Zn2Al1 LDH did not show it. These results indicate that Zn-Al LDH is promising as a CO2RR electrocatalyst for CO formation. - Synthesis of manganese nitride doped with rare-earth elements and their oxygen reduction reaction activity
Hayato Sakai, Shigeto Hirai, Masanori Nagao, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Journal of Alloys and Compounds, 935, 167986, 167986, Elsevier BV, 2023年02月, ［査読有り］
研究論文（学術雑誌） - Microwave assisted preparation of LiFePO4/C coated LiMn1.6Ni0.4O4 for Li-ion batteries with superior electrochemical properties
F.A. Vásquez, N.C. Rosero-Navarro, R. Jalem, A. Miura, Y. Goto, Y. Tateyama, J.A. Calderón, K. Tadanaga
Applied Materials Today, 30, 101697, 101697, Elsevier BV, 2023年02月, ［査読有り］
研究論文（学術雑誌） - Inorganic–organic hybrid solid electrolytes in the tetramethylammonium iodide–LiI–Li2S–P2S5 system for all-solid-state lithium batteries
Tong Fang, Hikaru Tokiwa, Akira Miura, Kiyoharu Tadanaga
Sustainable Energy & Fuels, 7, 17, 4297, 4302, Royal Society of Chemistry (RSC), 2023年
研究論文（学術雑誌）, A new type of glassy solid electrolyte was prepared by doping tetramethylammonium iodide (TMAI) in Li7P2S8I. TMAI can suppress the large volume change of a Si electrode during cycling. - Beneficial Effect of LiFePO4/C coating on Li0.9Mn1.6Ni0.4O4 obtained by microwave heating
F.A. Vásquez, N.C. Rosero-Navarro, A. Miura, Y. Goto, K. Tadanaga, J.A. Calderón
Electrochimica Acta, 437, 141544, 2023年01月, ［査読有り］
研究論文（学術雑誌） - Correction to: Preparation of transparent and mechanically hard inorganic-organic hybrid thick films from 3-glycidoxypropyltrimethoxysilane and zirconium propoxide (Journal of Sol-Gel Science and Technology, (2022), 104, 3, (478-483), 10.1007/s10971-022-05836-7)
Takuto Toide, Nataly Carolina Rosero-Navarro, Akira Miura, Hiromitsu Kozuka, Kiyoharu Tadanaga
Journal of Sol-Gel Science and Technology, 104, 3, 484, 2022年12月
研究論文（学術雑誌）, The original version of this article unfortunately contained a mistake. The 5th sentence under 2nd paragraph of “Introduction” section should be changed from “For instance, Katagiri et al. have reported thick films with a thickness up to 8 μm by electrophoretic deposition and subsequent thermal softening of phenyl-silsesquioxane, but the transmittance of these films was <1% in a wide visible range [19]”. to “For instance Katagiri et al. have reported transparent films with a thickness up to 3 μm by electrophoretic deposition and subsequent thermal softening of phenylsilsesquioxane [19]”. The original article has been corrected. - Preparation of transparent and mechanically hard inorganic-organichybrid thick films from 3-glycidoxypropyltrimethoxysilane and zirconium propoxide
Takuto Toide, Nataly Carolina Rosero-Navarro, Akira Miura, Hiromitsu Kozuka, Kiyoharu Tadanaga
Journal of Sol-Gel Science and Technology, 104, 3, 478, 483, Springer Science and Business Media LLC, 2022年12月, ［査読有り］, ［責任著者］
研究論文（学術雑誌） - Impact of Sulfur Infiltration Time and Its Content in an N-doped Mesoporous Carbon for Application in Li-S Batteries
Jennifer Laverde, Nataly C. Rosero-Navarro, Akira Miura, Robison Buitrago-Sierra, Kiyoharu Tadanaga, Diana López
Batteries, 8, 6, 58, 58, MDPI AG, 2022年06月17日, ［査読有り］
研究論文（学術雑誌）, Li-S batteries are ideal candidates to replace current lithium-ion batteries as next-generation energy storage systems thanks to their high specific capacity and theoretical energy density. Composite electrodes based on carbon microstructures are often used as a host for sulfur. However, sulfur lixiviation, insoluble species formation, and how to maximize the sulfur-carbon contact in looking for improved electrochemical performance are still major challenges. In this study, a nitrogen doped mesoporous carbon is used as a host for sulfur. The S/C composite electrodes are prepared by sulfur melting-diffusion process at 155 °C. The effect of the sulfur melting-diffusion time [sulfur infiltration time] (1–24 h) and sulfur content (10–70%) is investigated by using XRD, SEM, TEM and TGA analyses and correlated with the electrochemical performance in Li-S cells. S/C composite electrode with homogeneous sulfur distribution can be reached with 6 h of sulfur melting-diffusion and 10 wt.% of sulfur content. Li-S cell with this composite shows a high use of sulfur and sufficient electronic conductivity achieving an initial discharge capacity of 983 mA h g−1 and Coulombic efficiency of 99% after 100 cycles. - 硫化物固体電解質の液相合成とそのメカニズム
三浦 章, 忠永 清治
粉体および粉末冶金, 69, 3, 95, 98, 一般社団法人 粉体粉末冶金協会, 2022年03月15日
日本語, Sulfide electrolytes are key materials for all-solid-state batteries. However, the synthesis of sulfide electrolytes needs care to avoid moisture and to prevent the loss of sulfur species. In this minireview, we introduce the chronological history, property, and synthesis of sulfide solid electrolytes, especially that using organic solvents. We show our recent achievements in the synthesis mechanism of β-Li3PS4 via solution process by analyzing intermediates. - Two-step liquid-phase synthesis of argyrodite Li6PS5Cl solid electrolyte using nonionic surfactant
Nataly Carolina Rosero-Navarro, Hazuki Niwa, Akira Miura, Kiyoharu Tadanaga
Boletín de la Sociedad Española de Cerámica y Vidrio, Elsevier BV, 2021年12月, ［査読有り］, ［最終著者］
英語, 研究論文（学術雑誌） - Preparation of Cu3N thin films by nitridation of solution process-derived thin films using urea
Yuki Ohigashi, Amon Higuchi, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Journal of Sol-Gel Science and Technology, 101, 24, 28, Springer Science and Business Media LLC, 2021年12月01日, ［査読有り］, ［最終著者, 責任著者］
英語, 研究論文（学術雑誌） - Graphite/Li7P3S11 composite prepared by “seed” process for all-solid-state batteries
Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga, Atsunori Matsuda
Solid State Ionics, 372, 115789, 115789, Elsevier BV, 2021年12月, ［査読有り］, ［最終著者］
英語, 研究論文（学術雑誌） - Preparation of Composite Electrodes for All-Solid-State Batteries Based on Sulfide Electrolytes: An Electrochemical Point of View
Sara Giraldo, Koki Nakagawa, Ferley A. Vásquez, Yuta Fujii, Yongming Wang, Akira Miura, Jorge A. Calderón, Nataly C. Rosero-Navarro, Kiyoharu Tadanaga
Batteries, 7, 4, 77, 77, MDPI AG, 2021年11月11日, ［査読有り］
研究論文（学術雑誌）, All-solid-state batteries (ASSBs) are a promising response to the need for safety and high energy density of large-scale energy storage systems in challenging applications such as electric vehicles and grid integration. ASSBs based on sulfide solid electrolytes (SEs) have attracted much attention because of their high ionic conductivity and wide electrochemical windows of the sulfide SEs. Here, we study the electrochemical performance of ASSBs using composite electrodes prepared via two processes (simple mixture and solution processes) and varying the ionic conductor additive (80Li2S∙20P2S5 and argyrodite-type Li6PS5Cl). The composite electrodes consist of lithium-silicate-coated LiNi1/3Mn1/3Co1/3O2 (NMC), a sulfide SE, and carbon additives. The charge-transfer resistance at the interface of the solid electrolyte and NMC is the main parameter related to the ASSB’s status. This value decreases when the composite electrodes are prepared via a solution process. The lithium silicate coating and the use of a high-Li-ion additive conductor are also important to reduce the interfacial resistance and achieve high initial capacities (140 mAh g−1). - Synthesis of highly Li-ion conductive garnet-type solid ceramic electrolytes by solution-process-derived sintering additives
Nataly Carolina Rosero-Navarro, Haruna Watanabe, Akira Miura, Kiyoharu Tadanaga
Journal of the European Ceramic Society, 41, 13, 6767, 6771, Elsevier BV, 2021年10月, ［査読有り］, ［最終著者］
研究論文（学術雑誌） - Argyrodite solid electrolyte-coated graphite as anode material for all-solid-state batteries
Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Journal of Sol-Gel Science and Technology, Springer Science and Business Media LLC, 2021年09月16日, ［査読有り］, ［最終著者］
研究論文（学術雑誌） - Combustion Reactions between Transition-Metal Chlorides and Sodium Amide and Their Ignition Temperature
Shinji Noguchi, Jin Odahara, Hayato Sakai, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Inorganic Chemistry, 60, 17, 12753, 12758, American Chemical Society (ACS), 2021年09月06日, ［査読有り］, ［最終著者］
研究論文（学術雑誌） - Kinetically Stabilized Cation Arrangement in Li 3 YCl 6 Superionic Conductor during Solid‐State Reaction
Hiroaki Ito, Kazuki Shitara, Yongming Wang, Kotaro Fujii, Masatomo Yashima, Yosuke Goto, Chikako Moriyoshi, Nataly Carolina Rosero‐Navarro, Akira Miura, Kiyoharu Tadanaga
Advanced Science, 8, 15, 2101413, 2101413, Wiley, 2021年08月, ［査読有り］, ［最終著者］
研究論文（学術雑誌） - Hydroxide ion Conduction Mechanism in Mg-Al CO32− Layered Double Hydroxide
Daiju Kubo, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
Journal of Electrochemical Science and Technology, 12, 2, 230, 236, The Korean Electrochemical Society - English Journal, 2021年05月31日, ［査読有り］, ［責任著者］
研究論文（学術雑誌） - Formation Mechanism of β-Li3PS4 through Decomposition of Complexes
Marcela Calpa, Hiroshi Nakajima, Shigeo Mori, Yosuke Goto, Yoshikazu Mizuguchi, Chikako Moriyoshi, Yoshihiro Kuroiwa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Inorganic Chemistry, 60, 10, 6964, 6970, American Chemical Society (ACS), 2021年05月17日, ［査読有り］, ［最終著者］
研究論文（学術雑誌） - Observing and Modeling the Sequential Pairwise Reactions that Drive Solid‐State Ceramic Synthesis
Akira Miura, Christopher J. Bartel, Yosuke Goto, Yoshikazu Mizuguchi, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yongming Wang, Toshie Yaguchi, Manabu Shirai, Masanori Nagao, Nataly Carolina Rosero‐Navarro, Kiyoharu Tadanaga, Gerbrand Ceder, Wenhao Sun
Advanced Materials, 2100312, 2100312, Wiley, 2021年05月05日, ［査読有り］, ［国際共著］
研究論文（学術雑誌） - Phase transition, magnetic, and electronic properties of CeOInS2
Hiroki ITO, Akira MIURA, Yosuke GOTO, Yoshikazu MIZUGUCHI, Chikako MORIYOSHI, Yoshihiro KUROIWA, Nataly Carolina, ROSERO-NAVARRO, Kiyoharu TADANAGA
Journal of the Ceramic Society of Japan, 129, 5, 249, 253, Ceramic Society of Japan, 2021年05月01日, ［査読有り］, ［最終著者］
研究論文（学術雑誌） - Fast discharge–charge properties of FePS3 electrode for all-solid-state batteries using sulfide electrolytes and its stable diffusion path
Yuta Fujii, Hiroaki Ito, Akira Miura, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga, Li Lu
Functional Materials Letters, 14, 03, 2141005, 2141005, World Scientific Pub Co Pte Lt, 2021年04月, ［査読有り］, ［国際共著］
研究論文（学術雑誌）, We report the fast discharge–charge cycle of micro-sized FePS3 electrode particles in all-solid-state batteries (ASSBs) using sulfide electrolytes at 80∘C. At a current density of 2.04 mA cm[Formula: see text], corresponding to approximately 1 C, the capacity of the FePS3 electrodes reached [Formula: see text]180 mAh g[Formula: see text] without any electron or lithium-ion conductive additives. Galvanostatic intermittent titration technique (GITT) measurements showed a stable diffusion path of FePS3 represented by the product of the diffusion coefficient and square of the surface area. These electrochemical properties were compared with those of FeS, whose capacity was lower because of its unstable diffusion path. - Kinetic Control of the Li0.9Mn1.6Ni0.4O4 Spinel Structure with Enhanced Electrochemical Performance
F. A. Vásquez, N. C. Rosero-Navarro, A. Miura, R. Jalem, Y. Goto, M. Nagao, Y. Tateyama, K. Tadanaga, J. A. Calderón
ACS Applied Materials & Interfaces, 13, 12, 14056, 14067, American Chemical Society (ACS), 2021年03月31日, ［査読有り］, ［国際共著］
研究論文（学術雑誌） - Chemical stability of Li4PS4I solid electrolyte against hydrolysis
Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Randy Jalem, Yoshitaka Tateyama, Kiyoharu Tadanaga
Applied Materials Today, 22, 100918, 100918, Elsevier BV, 2021年03月, ［査読有り］, ［最終著者］
研究論文（学術雑誌） - Wet Chemical Processes for the Preparation of Composite Electrodes in All-Solid-State Lithium Battery
Kiyoharu Tadanaga, Nataly Carolina Rosero-Navarro, Akira Miura
Next Generation Batteries, 85, 92, Springer Singapore, 2021年
論文集(書籍)内論文 - Synthesis of sulfide solid electrolytes from Li2S and P2S5 in anisole
Riku Maniwa, Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Journal of Materials Chemistry A, 9, 1, 400, 405, Royal Society of Chemistry (RSC), 2021年, ［査読有り］
研究論文（学術雑誌）,We report the liquid-phase synthesis of sulfide solid electrolytes from Li2S and P2S5 using anisole at 200–300 °C under microwave irradiation, in which β-Li3PS4 and Li7P3S11 were directly precipitated in anisole in 30 min.
- Organic–Inorganic Hybrid Materials for Interface Design in All-Solid-State Batteries with a Garnet-Type Solid Electrolyte
Nataly Carolina Rosero-Navarro, Ryunosuke Kajiura, Akira Miura, Kiyoharu Tadanaga
ACS Applied Energy Materials, 3, 11, 11260, 11268, American Chemical Society (ACS), 2020年11月23日, ［査読有り］
研究論文（学術雑誌） - Formation Mechanism of Thiophosphate Anions in the Liquid-Phase Synthesis of Sulfide Solid Electrolytes Using Polar Aprotic Solvents
Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kota Terai, Futoshi Utsuno, Kiyoharu Tadanaga
Chemistry of Materials, 32, 22, 9627, 9632, American Chemical Society (ACS), 2020年11月05日, ［査読有り］, ［最終著者］
英語, 研究論文（学術雑誌） - Synthesis and ionic conductivity of a high-entropy layered hydroxide
Akira MIURA, Sho ISHIYAMA, Daiju KUBO, Nataly Carolina, ROSERO-NAVARRO, Kiyoharu TADANAGA
Journal of the Ceramic Society of Japan, 128, 7, 336, 339, Ceramic Society of Japan, 2020年07月01日, ［査読有り］, ［最終著者］
英語, 研究論文（学術雑誌） - Significant Reduction in the Interfacial Resistance of Garnet-Type Solid Electrolyte and Lithium Metal by a Thick Amorphous Lithium Silicate Layer
Nataly Carolina Rosero-Navarro, Ryunosuke Kajiura, Randy Jalem, Yoshitaka Tateyama, Akira Miura, Kiyoharu Tadanaga
ACS Applied Energy Materials, 3, 6, 5533, 5541, American Chemical Society (ACS), 2020年05月27日, ［査読有り］
研究論文（学術雑誌） - Fabrication of Mg-Al Layered Double Hydroxide Thin Membrane for All-Solid-State Alkaline Fuel Cell Using Glass Paper as a Support
Daiju Kubo, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
Frontiers in Materials, 7, 117, Frontiers Media SA, 2020年04月30日, ［査読有り］, ［責任著者］
英語, 研究論文（学術雑誌）, © Copyright © 2020 Kubo, Tadanaga, Hayashi and Tatsumisago. Layered double hydroxides (LDHs) are promising solid electrolytes for all solid-state alkaline fuel cells (AFCs) because of inorganic clay-like materials. However, LDHs were usually obtained as powder, and the formation of thin membranes as a separator of a fuel cell is rather difficult. In this study, a glass paper, non-woven fabric of fine glass fibers with more than 90% porosity, was used as a support for Mg-Al LDH powder, and self-standing, thin membranes for all solid-state AFCs were fabricated. Crystals of Mg-Al LDH were deposited in the inside of the glass paper by repeated immersion in Mg-Al LDH-dispersed solution and drying. Thickness of the obtained Mg-Al LDH thin membrane was about 150 μm, and LDH layer showed c-axis orientation because of the plate-like structure. The H2-O2 fuel cell using the Mg-Al LDH thin membrane as an electrolyte showed open circuit voltage of more than 0.9 V, indicating that the Mg-Al LDH thin membrane is dense and has high gas barrier property. The H2-O2 fuel cell using the Mg-Al LDH thin membrane showed higher power density compared with that using pelletized Mg-Al LDH powder as the electrolyte. The glass paper is proved to be very effective support for making thin Mg-Al LDH electrolyte membrane. - Fe-P-S electrodes for all-solid-state lithium secondary batteries using sulfide-based solid electrolytes
Fujii, Yuta, Akira, Miura, Misaki, Kobayashi, Rosero-Navarro, Nataly Carolina, Li, Minchan, Sun, Jianguo, Kotobuki, Masatoshi, Lu, Li, Tadanaga, Kiyoharu
Journal of Power Sources, 449, 15, 227576, 227576, 2020年02月, ［査読有り］, ［国際共著］ - Selective metathesis synthesis of MgCr2S4 by control of thermodynamic driving forces
Akira Miura, Hiroaki Ito, Christopher J. Bartel, Wenhao Sun, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga, Hiroko Nakata, Kazuhiko Maeda, Gerbrand Ceder
Materials Horizons, 7, 5, 1310, 1316, Royal Society of Chemistry (RSC), 2020年, ［査読有り］, ［国際共著］
研究論文（学術雑誌）,By altering the thermodynamic landscape, metathesis enables the rapid and selective synthesis of MgCr2S4 thiospinel, a compelling Mg-cathode material that is laborious to make
via traditional ceramic synthesis routes. - Flux Growth and Superconducting Properties of (Ce,Pr)OBiS2 Single Crystals
Nagao, Masanori, Miura, Akira, Urushihara, Daisuke, Maruyama, Yuki, Goto, Yosuke, Mizuguchi, Yoshikazu, Moriyoshi, Chikako, Kuroiwa, Yoshihiro, Wang, Yongming, Watauchi, Satoshi, Asaka, Toru, Takano, Yoshihiro, Tadanaga, Kiyoharu, Tanaka, Isao
Frontiers in Chemistry, -, Frontiers Media SA, 2020年, ［査読有り］
研究論文（学術雑誌） - Electrical properties of pyrochlore-type silver tantalate and fluorite-type silver niobate
W. I, U. WITHANAGE, Nobuhiro Kumada, Takahiro Takei, Sayaka YANAGIDA, Kiyoharu Tadanaga, Akira Miura, Nataly Carolina Rosero-Navarro, Masaki Azuma
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 128, 1, 46, 50, Ceramic Society of Japan, 2020年01月01日, ［査読有り］
英語, 研究論文（学術雑誌） - Sintering additives for garnet-type electrolytes
Nataly C. Rosero-Navarro, Kiyoharu Tadanaga
Solid Electrolytes for Advanced Applications: Garnets and Competitors, 111, 128, Springer International Publishing, 2019年12月11日
英語, 論文集(書籍)内論文, Producing densified garnet-type solid electrolytes by lowering sintering temperature is an important target, which can prevent not only the lithium loss (controlling chemical stoichiometry) but also make it more compatible with cathode electrode materials. In this chapter, the use of sintering additives for enhancing the densification and microstructure of high conductive garnet-type solid electrolytes at low temperatures of ≤900 °C is reviewed. Sintering additives can modify the grain and grain boundary, both contributing to the optimization of the chemical and electrochemical properties of garnet-type solid electrolytes. - Mg-Al layered double hydroxide as an electrolyte membrane for aqueous ammonia fuel cell
Ishiyama Sho, Rosero-Navarro Nataly Carolina, Miura Akira, Tadanaga Kiyoharu
MATERIALS RESEARCH BULLETIN, 119, 2019年11月, ［査読有り］, ［最終著者, 責任著者］ - Enhanced hydroxide ion conductivity of Mg-Al layered double hydroxide at low humidity by intercalating dodecyl sulfate anion
Kubo Daiju, Igarashi Kohei, Ishiyama Sho, Rosero Navarro, Nataly Carolina, Miura Akira, Higuchi Mikio, Tadanaga Kiyoharu
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 127, 11, 788, 792, 2019年11月, ［査読有り］ - Two-Dimensional Hybrid Halide Perovskite as Electrode Materials for All-Solid-State Lithium Secondary Batteries Based on Sulfide Solid Electrolytes
Yuta Fujii, Daniel Ramirez, Nataly Carolina Rosero-Navarro, Domingo Jullian, Akira Miura, Franklin Jaramillo, Kiyoharu Tadanaga
ACS Applied Energy Materials, American Chemical Society ({ACS}), 2019年08月, ［査読有り］, ［国際共著］ - Growth and transport properties under high pressure of PrOBiS2 single crystals
Nagao, Masanori, Miura, Akira, Matsumoto, Ryo, Maruyama, Yuki, Watauchi, Satoshi, Takano, Yoshihiko, Tadanaga, Kiyoharu, Tanaka, Isao
Solid State Communications, 296, 17, 20, 2019年07月, ［査読有り］ - Catalytic Activity for Oxygen Reduction Reaction of Ni-Mn-Fe Layered Double Hydroxide-Carbon Gel Composite
Iwai, Yu, Ikka, Takuya, Miura, Akira, Rosero-Navarro, N. C, Iwamura, Shinichiroh, Ogino, Isao, Mukai, Shin R, Tadanaga, Kiyoharu
CHEMISTRY LETTERS, 48, 7, 696, 699, The Chemical Society of Japan, 2019年07月, ［査読有り］, ［最終著者］
研究論文（学術雑誌） - Self-Combustion Synthesis of Novel Metastable Ternary Molybdenum Nitrides
Jin Odahara, Wenhao Sun, Akira Miura, Nataly Carolina Rosero-Navarro, Masanori Nagao, Isao Tanaka, Gerbrand Ceder, Kiyoharu Tadanaga
ACS Materials Letters, 64, American Chemical Society ({ACS}), 2019年07月, ［査読有り］, ［国際共著］ - An electronic structure governed by the displacement of the indium site in In–S6 octahedra: LnOInS2 (Ln = La, Ce, and Pr)
Ito, Hiroaki, Miura, Akira, Goto, Yosuke, Mizuguchi, Yoshikazu, Moriyoshi,Chikako, Kuroiwa, Yoshihiro, Azuma, Masaki, Liu, Jinjia, Wen, Xiao-Dong, Nishioka,Shunta, Maeda, Kazuhiko, Masubuchi, Yuji, Rosero-Navarro, Nataly Carolina, Tadanaga, Kiyoharu
Dalton Transactions, 48, 32, 12272, 12278, ROYAL SOC CHEMISTRY, 2019年06月, ［査読有り］
英語, 研究論文（学術雑誌）, An extremely large displacement of the indium site in In-S-6 octahedra in LnOInS(2) (Ln = La, Ce, and Pr) was found in synchrotron X-ray diffraction. LaOInS2 with off-center indium in In-S-6 octahedra exhibited a wider optical band gap than CeOInS2 and PrOInS2 with on-center indium. Therefore, the electronic structure of LnOInS(2) is governed by the indium site with an extremely large displacement. All LnOInS(2) produced H-2 gas under visible light irradiation in the presence of sacrificial electron donors. - Improvement of superconducting properties by high mixing entropy at blocking layers in BiS2-based superconductor REO0. 5F0. 5BiS2
Sogabe,Ryota, Goto, Yosuke, Abe, Tomohiro, Moriyoshi, Chikako, Kuroiwa, Yoshihiro, Miura, Akira, Tadanaga, Kiyoharu, Mizuguchi, Yoshikazu
Solid State Communications, 295, 43, 49, 2019年06月, ［査読有り］ - Porous ZnV2O4 Nanowire for Stable and High-Rate Lithium-Ion Battery Anodes
Lyn Marie, Z. De Juan-Corpuz, Mai Thanh Nguyen, Ryan D. Corpuz, Tetsu Yonezawa, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga, Tomoharu Tokunaga, Soorathep Kheawhom
ACS Applied Nano Materials, American Chemical Society ({ACS}), 2019年06月, ［査読有り］ - Composition, valence and oxygen reduction reaction activity of Mn-based layered double hydroxides
Yu Iwai, Akira Miura, Nataly Carolina Rosero-Navarro, Mikio Higuchi, Kiyoharu Tadanaga
Journal of Asian Ceramic Societies, 1, Informa {UK} Limited, 2019年04月, ［査読有り］ - Liquid-phase syntheses of sulfide electrolytes for all-solid-state lithium battery
Akira Miura, Nataly Carolina Rosero-Navarro, Atsushi Sakuda, Kiyoharu Tadanaga, Nguyen H. H. Phuc, Atsunori Matsuda, Nobuya Machida, Akitoshi Hayashi, Masahiro Tatsumisago
Nature Reviews Chemistry, 3, 3, 189, 198, Springer Nature, 2019年03月, ［査読有り］
Solid sulfide electrolytes are key materials in all-solid-state lithium batteries because of their high lithium-ion conductivity and deformability, which enable the lithium-ion path to be connected between the material’s grain boundaries under pressure near room temperature. However, sulfur species are moisture-sensitive and exhibit high vapour pressures; therefore, syntheses of sulfide electrolytes need to be carefully designed. Liquid-phase reactions can be performed at low temperatures in controlled atmospheres, opening up the prospect of scalable processes for the preparation of sulfide electrolytes. Here, we review liquid-phase syntheses for the preparation of sulfide-based solid electrolytes and composites of electrolytes and electrodes, and we compare the charge–discharge performances of the all-solid-state lithium batteries using these components. - Electrochemical performance of bulk-type all-solid-state batteries using small-sized Li7P3S11 solid electrolyte prepared by liquid phase as the ionic conductor in the composite cathode
Calpa, Marcela, Rosero-Navarro, Nataly Carolina, Miura, Akira, Tadanaga, Kiyoharu
ELECTROCHIMICA ACTA, 296, 473-, 480, 2019年02月, ［査読有り］
英語, 研究論文（学術雑誌） - Ionic conductivity of Pyrochlore-type Silver Tantalate and Fluorite-type Silver Niobate
W. I, U. WITHANAGE, Nobuhiro Kumada, Takahiro Takei, Sayaka YANAGIDA, Kiyoharu Tadanaga, Akira Miuram Nataly Carolina Rosero-Navarro, Masaki Azuma
J. Ceram. Soc. Jpn., in press, 2019年, ［査読有り］
英語, 研究論文（学術雑誌） - Preparation of lithium ion conductive Li6PS5Cl solid electrolyte from solution for the fabrication of composite cathode of all-solid-state lithium battery
Rosero-Navarro, Nataly Carolina, Miura, A, Tadanaga, K
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 89, 1, 303, 309, 2019年01月, ［査読有り］
英語, 研究論文（学術雑誌） - Electrochemical performance of a garnet solid electrolyte based lithium metal battery with interface modification
George V Alexander, Nataly Carolina, Rosero Navarro, Akira Miura, Kiyoharu Tadanaga, Ramaswamy Murugan
Journal of Materials Chemistry A, 6, 21018, 21028, Royal Society of Chemistry ({RSC}), 2018年10月, ［査読有り］, ［国際共著］ - Reaction Mechanism of FePS3 Electrodes in All-Solid-State Lithium Secondary Batteries Using Sulfide-Based Solid Electrolytes
Fujii Y, Miura A, Rosero-Navarro N.C, Mizuguchi Y, Moriyoshi C, Kuroiwa Y, Higuchi M, Tadanaga K
Journal of The Electrochemical Society, 165, A2948, 2018年09月, ［査読有り］ - Composite cathode prepared by argyrodite precursor solution assisted by dispersant agents for bulk-type all-solid-state batteries
Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Journal of Power Sources, 396, 33, 40, Elsevier B.V., 2018年08月31日, ［査読有り］
英語, 研究論文（学術雑誌）, All-solid-state lithium batteries based on sulfide solid electrolytes are potential candidates for large-scale energy storage applications. Here, composite cathode with high content of an active material was prepared by a liquid phase process assisted by a dispersant agent to produce a better electrode and electrolyte interface. Li6PS5Cl sulfide electrolyte derived from a solution containing dispersant showed an argyrodite crystal phase with a better distribution of particle size and higher conductivity compared with those without dispersant. Regular distribution of Li6PS5Cl particles in nanometric scale with a spherical shape below 500 nm and conductivity of 0.6 × 10−3 S cm−1 (ρ = 1.40 g cm−3) at room temperature were obtained. Composite cathode was prepared by the dispersion of LiNi1/3Mn1/3Co1/3O2 particles and carbon additive in the Li6PS5Cl-solution containing dispersant agent and subsequent drying at 180 °C. Bulk-type all-solid-state battery fabricated with the composite cathode containing 89 wt% of the active material showed an initial discharge capacity of 110 mA h g−1 at 25 °C and maintained 95% discharge capacity after 15 cycles. - Sol-gel processing of solid electrolytes for li-ion batteries
Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga
Handbook of Sol-Gel Science and Technology: Processing, Characterization and Applications, 2631, 2648, Springer International Publishing, 2018年07月09日
英語, 論文集(書籍)内論文, Preparation of solid electrolytes for the all-solid-state Li-ion batteries is reviewed. Precursors and preparation procedure for the typical oxide-based Li-ion conductors with NASICON, perovskite, and garnet structures, sulfide-based Li-ion conductors, and organic-inorganic hybrid materials are described. Since these solid electrolytes are usually multicomponent system, the sol-gel process or other solution processes are often used for the better control of chemical composition of the materials and also for the control of morphology of the solid electrolytes. Solution processes are also useful for the formation of favorable solid-solid interface between electrode and electrolyte. - Measurements of gas adsorption and permeability of sol-gel materials
Kiyoharu Tadanaga, Tsutomu Minami
Handbook of Sol-Gel Science and Technology: Processing, Characterization and Applications, 1411, 1423, Springer International Publishing, 2018年07月09日
英語, 論文集(書籍)内論文, Many sol-gel-derived materials are porous. Surface area, pore size, and porosity are very important properties for the application of porous materials, and those properties are studied by gas adsorption measurements. The sol-gel-derived materials are sometimes used as gas separation or gas barrier membranes. In this chapter, background and measurement techniques of gas adsorption for porous sol-gel-derived materials are firstly described. Then mechanism of permeation in porous and nonporous media and gas permeability measurement techniques for membranes prepared by sol-gel processes are described. - Synthesis of Bi2(O,F)S2 superconductors by NaF treatment
Takahashi N, Nagao M, Miura A, Watauchi S, Tadanaga K, Takano Y, Tanaka I
J. Ceram. Soc. Jpn., 126, 7, 591, 593, 2018年07月, ［査読有り］
英語, 研究論文（学術雑誌） - Synthesis of submicron-sized NiPS3 particles and electrochemical properties as active materials in all-solid-state lithium batteries
Suto Y, Fujii Y, Miura A, Rosero-Navarro N.C, Higuchi M, Tadanaga K
J. Ceram. Soc. Jpn., 126, 7, 568, 572, 2018年07月, ［査読有り］ - Synthesis, crystal structure and optical absorption of NaInS2-xSex
Takahashi N, Ito H, Miura A, Rosero-Navarro N.C, Goto Y, Mizuguchi Y, Moriyoshi C, Kuroiwa Y, Nagao M, Watauchi S, Tanaka I, Tadanaga K
J. Alloy. Compounds, 750, 409, 423, 2018年06月, ［査読有り］ - Float zone growth and spectroscopic properties of Yb:CaYAlO4 single crystal for ultra-short pulse lasers
Moe Narita, Mikio Higuchi, Takayo Ogawa, Satoshi Wada, Akira Miura, Kiyoharu Tadanaga
Optical Materials, 80, 57, 61, Elsevier B.V., 2018年06月01日, ［査読有り］
英語, 研究論文（学術雑誌）, Yb:CaYAlO4 single crystals were grown by the floating zone method and their spectral properties were investigated. Void formation was effectively suppressed by using a feed rod of Y-rich composition with the aid of a double zone-pass technique. For the oxygen excess composition of Yb:Ca0.9925Y1.0075AlO4.00375, a void-free crystal was obtained by performing only the double zone-pass. On the other hand, for cation-deficient type of Yb:Ca0.9925Y1.005AlO4, void-free crystal could not be obtained by performing the double zone-pass. The void formation is attributable to the constitutional supercooling caused by segregation of main constituents of Y and Ca, and the congruent composition may exist in the Y-rich region with existence of interstitial excess oxide ions. The absorption cross section for σ-polarization was slightly larger than that for π-polarization, which is reasonable on the basis of the crystal structure of CaYAlO4. - Crystal Structure and Superconductivity of Tetragonal and Monoclinic Ce1- xPrxOBiS2
Akira Miura, Masanori Nagao, Yosuke Goto, Yoshikazu Mizuguchi, Tatsuma D. Matsuda, Yuji Aoki, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yoshihiko Takano, Satoshi Watauchi, Isao Tanaka, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga
Inorganic Chemistry, 57, 9, 5364, 5370, American Chemical Society, 2018年05月07日, ［査読有り］
英語, 研究論文（学術雑誌）, Ce1-xPrxOBiS2 powders and Ce0.5Pr0.5OBiS2 single crystals were synthesized and their structure and superconductive properties were examined by X-ray diffraction, X-ray absorption, electronic resistivity, and magnetization. While PrOBiS2 was found to be in a monoclinic phase with one-dimensional Bi-S zigzag chains showing no superconductive transition above 0.1 K, CeOBiS2 was in a tetragonal phase with two-dimensional Bi-S planes showing zero resistivity below 1.3 K. In the range x = 0.3-0.9 in Ce1-xPrxOBiS2, both monoclinic and tetragonal phases were formed together with zero resistivity up to a maximum temperature of 2.2 K. A Ce0.5Pr0.5OBiS2 single crystal, which showed both zero resistivity and a decrease in magnetization at ∼2.4 K, presented a tetragonal structure. Short Bi-S bonding in flat two-dimensional Bi-S planes and mixed Ce3+/Ce4+ were characteristic features of the Ce0.5Pr0.5OBiS2 single crystal, which presumably triggered its superconductivity. - Structural and Electrochemical Evaluation of Three- and Two-Dimensional Organohalide Perovskites and Their Influence on the Reversibility of Lithium Intercalation
Daniel Ramirez, Yusaku Suto, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga, Franklin Jaramillo
Inorganic Chemistry, 57, 7, 4181, 4188, American Chemical Society, 2018年04月02日, ［査読有り］, ［国際共著］
英語, 研究論文（学術雑誌）, Organic-inorganic hybrid perovskite materials have recently been investigated in a variety of applications, including solar cells, light emitting devices (LEDs), and lasers because of their impressive semiconductor properties. Nevertheless, the perovskite structure has the ability to host extrinsic elements, making its application in the battery field possible. During the present study, we fabricated and investigated the electrochemical properties of three-dimensional (3D) methylammonium lead mixed-halide CH3NH3PbI3-xBrx and two-dimensional (2D) propylammonium-methlylammonium lead bromide (CH3NH3)2(CH3(CH2)2NH3)2Pb3Br10 hybrid perovskite thin films as electrode materials for Li-ion batteries. These electrodes were obtained by solution processing at 100 °C. CH3NH3PbBr3 achieved high discharge/charge capacities of ∼500 mA h g-1 /160 mA h g-1 that could account also for other processes taking place during the Li intercalation. It was also found that bromine plays an important role for lithium intercalation, while the new 2D (CH3NH3)2(CH3(CH2)2NH3)2Pb3Br10 with a layered structure allowed reversibility of the lithium insertion-extraction of 100% with capacities of ∼375 mA h g-1 in the form of a thin film. Results suggest that tuning the composition of these materials can be used to improve intercalation capacities, while modification from 3D to 2D layered structures contributes to improving lithium extraction. The mechanism of the lithium insertion-extraction may consist of an intercalation mechanism in the hybrid material accompanying the alloying-dealloying process of the LixPb intermetallic compounds. This work contributes to revealing the relevance of both composition and structure of potential hybrid perovskite materials as future thin film electrode materials with high capacity and compositional versatility. - Preparation of sulfide solid electrolytes in the Li2S–P2S5 system by a liquid phase process
Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
Inorganic Chemistry Frontiers, 5, 2, 501, 508, Royal Society of Chemistry ({RSC}), 2018年02月01日, ［査読有り］, ［最終著者］
英語, 研究論文（学術雑誌）, Sulfide solid electrolytes in the Li2S-P2S5 system were synthesized by a liquid phase process under ultrasonic irradiation, and heat treatments at low temperatures. Crystal phase, structure, morphology and ionic conductivity of the sulfide electrolytes were examined after solvent removal at 180 °C and two different heat treatment temperatures, 220 °C and 250 °C. The study revealed that the ionic conductivities of the xLi2S·(100 - x)P2S5 sulfide electrolytes, in compositions with 70 ≤ x ≤ 75 mol%, are largely influenced by the local structure. The heat treatment at 220 °C was found to be an adequate temperature to promote crystallization of the high ionic conductive Li7P3S11 phase. Higher temperatures for heat treatment such as 250 °C lead to the formation of P2S6 4- (hypo-thiodiphosphate) units in the local structure of the sulfide electrolytes leading to a reduction of ionic conductivity. The formation and distribution of PS4 3- (ortho-thiophosphate), P2S7 4- (pyro-thiophosphate) and P2S6 4- units in the local structure were found to be key factors in achieving higher ionic conductivity (up to 10-3-10-4 S cm-1 at room temperature). - Explosive Reaction for Barium Niobium Perovskite Oxynitride
Jin Odahara, Akira Miura, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga
Inorganic Chemistry, 57, 1, 24, 27, American Chemical Society, 2018年01月02日, ［査読有り］
英語, 研究論文（学術雑誌）, An intense exothermic and explosive reaction between Ba(OH)2, NbCl5, and NaNH2 produced barium niobium perovskite oxynitride in seconds. The addition of hexane reduced the risk of explosion during mixing of the starting materials, and subsequent heat treatment at 498 K in hexane allowed control of this exothermic reaction, leading to formation of the perovskite oxynitride with fewer impurities. The synthesis of barium tantalum perovskite oxynitride under similar reaction conditions was successful. - Liquid-phase synthesis of Li6PS5Br using ultrasonication and application to cathode composite electrodes in all-solid-state batteries
Shunjiro Chida, Akira Miura, Nataly Carolina Rosero-Navarro, Mikio Higuchi, Nguyen H. H. Phuc, Hiroyuki Muto, Atsunori Matsuda, Kiyoharu Tadanaga
CERAMICS INTERNATIONAL, 44, 1, 742, 746, ELSEVIER SCI LTD, 2018年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Lithium-ion conductive Li6PS5Br is prepared using ultrasonication of Li2S, P2S5 and LiBr in ethyl propionate-ethanol solution and subsequent heating at 453 K. The main phase of the synthesized product is Li6PS5Br and its lithium ion conductivity is 3.4 x 10(-5) S cm(-1) at room temperature. The cathode composite of LiCo1/3Ni1/3Mn1/3O2, Li6PS5Br and vapor grown carbon fiber (VGCF) is prepared via ultrasonication of the Li6PS5Br precursor solution containing LiCo1/3Ni1/3Mn1/3O2 and VGCF, and the all-solid-state lithium battery using this cathode composite is fabricated. The cell exhibits the discharge capacity of 109 mAh g(-1) for the first cycle and its capacity of 87 mAh g(-1) after 10 cycles. - Evolution of anisotropic displacement parameters and superconductivity with chemical pressure in BiS2-Based REO0.5F0.5BiS2 (RE = La, Ce, Pr, and Nd)
Yoshikazu Mizuguchi, Kazuhisa Hoshi, Yosuke Goto, Akira Miura, Kiyoharu Tadanaga, Chikako Moriyoshi, Yoshihiro Kuroiwa
Journal of the Physical Society of Japan, 87, 2, 023704, Physical Society of Japan, 2018年, ［査読有り］
英語, 研究論文（学術雑誌）, In order to understand the mechanisms behind the emergence of superconductivity by the chemical pressure effect in REO0.5F0.5BiS2 (RE = La, Ce, Pr, and Nd), where bulk superconductivity is induced by the substitutions with a smaller-radius RE, we performed synchrotron powder X-ray diffraction, and analyzed the crystal structure and anisotropic displacement parameters. With the decrease of the RE3+ ionic radius, the in-plane disorder of the S1 sites significantly decreased, very similar to the trend observed in the Se-substituted systems: LaO0.5F0.5BiS2−xSex and Eu0.5La0.5FBiS2−xSex. Therefore, the emergence of bulk superconductivity upon the suppression of the in-plane disorder at the chalcogen sites is a universal scenario for the BiCh2-based superconductors. In addition, we indicated that the amplitude of vibration along the c-axis of the in-plane chalcogen sites may be related to the Tc in the BiCh2-based superconductors. - Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La2O2Bi3AgS6
Yudai Hijikata, Tomohiro Abe, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yosuke Goto, Akira Miura, Kiyoharu Tadanaga, Yongming Wang, Osuke Miura, Yoshikazu Mizuguchi
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 86, 12, 124802, PHYSICAL SOC JAPAN, 2017年12月, ［査読有り］
英語, 研究論文（学術雑誌）, We have synthesized a new layered oxychalcogenide La2O2Bi3AgS6. From synchrotron X-ray diffraction and Rietveld refinement, the crystal structure of La2O2Bi3AgS6 was refined using a model of the P4/nmm space group with a = 4.0644(1) angstrom' and c = 19.412(1) angstrom, which is similar to the related compound LaOBiPbS3, while the interlayer bonds (M2-S1 bonds) are apparently shorter in La2O2Bi3AgS6. The tunneling electron microscopy (TEM) image confirmed the lattice constant derived from Rietveld refinement (c similar to 20 angstrom). The electrical resistivity and Seebeck coefficient suggested that the electronic states of La2O2Bi3AgS6 are more metallic than those of LaOBiS2 and LaOBiPbS3. The insertion of a rock-salt-type chalcogenide into the van der Waals gap of BiS2-based layered compounds, such as LaOBiS2, will be a useful strategy for designing new layered functional materials in the layered chalcogenide family. - Thermal stability and cutting performance of Al-rich cubic AlxTi1-xN coating prepared by low-pressure chemical vapour deposition
Anongsack Paseuth, Yasuki Kido, Shinya Imamura, Kazuo Yamagata, Akira Miura, Kiyoharu Tadanaga
Journal of the Ceramic Society of Japan, 125, 12, 913, 918, Ceramic Society of Japan, 2017年12月01日, ［査読有り］
英語, 研究論文（学術雑誌）, Al-rich cubic (c-) AlxTi1-xN (x μ 0.8) coating comprising self-organised c-Al(Ti)N/c-Ti(Al)N nanolamellae was prepared in a previous study by low-pressure chemical vapour deposition (LP-CVD) using an AlCl3-TiCl4-NH3-Ar-H2 precursor system. In the present study, we investigated the effects of isothermal annealing at 800 to 1200°C for 1 to 10 h on the crystal structure, microstructure, and hardness of the coating, and compared them to those of a monolithic c-AlxTi1-xN (x μ 0.6) coatings prepared by arc-evaporated physical vapour deposition (PVD). The X-ray diffraction patterns indicated high phase stability of the former coating up to 1200°C after 1 h. High-resolution transmission electron microscopy revealed that the nanolamellae in c-AlxTi1-xN (x μ 0.8) coating remained stable after post-annealing at 900°C for 5 h. The spontaneously formed coherent nanostructure suppressed diffusion in this coating, and the spinodal decomposition and hexagonal phase formation were thus shifted to higher temperatures. Consequently, age hardening in LP-CVD c-AlxTi1-xN (x μ 0.8) helped to maintain its hardness at up to 1100°C after 10 h. The improved thermal stability and hardness at elevated temperature of the Al-rich c-AlxTi1-xN coating by LP-CVD led to a significant improvement in the cutting tool life, by factors of 2 and 10 compared to state-of-the-art CVD-and PVD-coated inserts, respectively. These improvements in thermal stability and elevated hardness in c-AlxTi1-xN (x μ 0.8) coating prepared via LP-CVD process could remarkably enhance tool life for dry and high-speed cutting applications. - Prediction of Ternary Liquidus Temperatures by Statistical Modeling of Binary and Ternary Ag-Al-Sn-Zn Systems.
Akira Miura, Tsukasa Hokimoto, Masanori Nagao, Takashi Yanase, Toshihiro Shimada, Kiyoharu Tadanaga
ACS omega, 2, 8, 5271, 5282, 2017年08月31日, ［査読有り］, ［国際誌］
英語, The relationship of liquidus temperatures among six binary and four ternary phases in a Ag-Al-Sn-Zn system was analyzed by means of statistical modeling. Four statistical models to predict changes in the liquidus temperatures in Ag-Al-Sn-Zn were proposed on the basis of different hypotheses derived from macroscopic and microscopic standpoints. The results of interpolation tests to evaluate the prediction accuracies of the ternary liquidus temperatures suggested that the multivariate regression model based on binary liquidus temperatures, interactive binary liquidus temperatures, and products of atomic ratios was found to be the most effective among the four models. It was numerically shown that the prediction accuracies of the liquidus temperatures in local ternary systems of Ag-Al-Sn-Zn can be improved further by using the models identified in their neighboring systems. Finally, the possibility to extract the general trend and the abnormal combination of elements for the prediction of liquidus temperatures was discussed on the basis of the statistical framework we considered. - Preparation and scintillation properties of translucent LiCaBO3:Ce polycrystalline plates
Saki Toyoda, Mikio Higuchi, Youichi Tsubota, Junichi H. Kaneko, Kiyoharu Tadanaga
OPTICAL MATERIALS, 70, 180, 183, ELSEVIER SCIENCE BV, 2017年08月, ［査読有り］
英語, 研究論文（学術雑誌）, Translucent LiCaBO3:Ce thin plates were prepared by liquid phase sintering using LiBO2 as a sintering aid, and their fluorescent and scintillation properties were investigated to examine the possibility to use as neutron scintillator. Since the initial part of the directionally solidified specimen contained a second phase of Ca3B2O6, LiCaBO3 may melt incongruently, and simple melt growth of LiCaBO3:Ce is consequently difficult. Translucent thin plates 300 mu m in thickness were successfully fabricated from LiCaBO3:Ce sintered compacts. Although strong fluorescence with the peak wavelength of 390 nm was observed in photoluminescence measurement, scintillation light yield and detection efficiency by alpha-particle irradiation were rather poor. The diffuse reflectance spectrum of LiCaBO3:Ce revealed existence of an absorption band other than Ce3+ bands in the ultraviolet region. The band may corresponds to defect levels, which interrupt the energy transfer from the conduction band of the host to the 5d level of Ce3+ resulting in the degradation of the scintillation performance. (C) 2017 Elsevier B.V. All rights reserved. - Synthesis, structure and photocatalytic activity of layered LaOInS2
Akira Miura, Takayoshi Oshima, Kazuhiko Maeda, Yoshikazu Mizuguchi, Chikako Moriyoshi, Yoshihiro Kuroiwa, Yu Meng, Xiao-Dong Wen, Masanori Nagao, Mikio Higuchia, Kiyoharu Tadanaga
JOURNAL OF MATERIALS CHEMISTRY A, 5, 27, 14270, 14277, ROYAL SOC CHEMISTRY, 2017年07月, ［査読有り］
英語, 研究論文（学術雑誌）, Indium oxychalcogenides would be attractive semiconductors considering the practical use of indium oxides and sulfides such as indium-tin oxides (ITO) and copper-indium-gallium diselenides (CIGS). In this work, a novel layered indium oxysulfide, LaOInS2, was synthesized by a metathesis reaction between LaOCl and NaInS2. Synchrotron X-ray diffraction showed that LaOInS2 consisted of alternately stacked rocksalt-type In-S and PbO-type La-O layers. The InS6 octahedron had split In sites with abnormally large anisotropic atomic displacement factors. LaOInS2 was found to be a direct semiconductor. Density functional theory calculations exhibited well-dispersed bands composed of In 5s/5p and S 3p/O 2p orbitals with a band gap of similar to 2.4 eV, which was close to the experimental value estimated by optical absorption (2.64 eV). Under visible light irradiation this visible-light absorption, LaOInS2 exhibited photocatalytic activity for H-2 and O-2 evolution from water with the aid of Pt and IrO2 cocatalysts, respectively. - FePS3 electrodes in all-solid-state lithium secondary batteries using sulfide-based solid electrolytes
Yuta Fujii, Akira Miura, Nataly Carolina Rosero-Navarro, Mikio Higuchi, Kiyoharu Tadanaga
ELECTROCHIMICA ACTA, 241, 370, 374, PERGAMON-ELSEVIER SCIENCE LTD, 2017年07月, ［査読有り］
英語, 研究論文（学術雑誌）, In bulk-type all-solid-state lithium batteries with sulfide-based solid electrolytes, composite electrodes, in which an active material, a solid electrolyte, and a conductive additive are mixed, have been used to enhance lithium-ion diffusion and electronic conductivity. However, the addition of electrolytes and electron-conductive additives to the composite electrodes decreases the amount of active materials in the batteries. In the present study, FePS3 was employed as the electrode in an all-solid-state lithium secondary battery, without mixing the solid electrolytes and conductive additives. The all-solid-state cell using the FePS3 electrode exhibited reversible charge-discharge behavior for more than 30 cycles under a constant current density of 0.13 mA cm (2) at room temperature. The discharge capacity of the cell was 107 mAh g (1) at the 30th cycle. This behavior was comparable to that of a cell with an electrode including a solid electrolyte and/or a conductive additive, indicating that the FePS3 electrode had sufficient paths of lithium ions and of electron conduction. These results suggest that FePS3 is an attractive iron-based electrode for an all-solid-state battery using a sulfide-based solid electrolyte. (C) 2017 Elsevier Ltd. All rights reserved. - Synthesis of LaO0.5F0.5BiS2 nanosheets by ultrasonification
Akira Miura, Satoshi Ishii, Masanori Nagao, Ryo Matsumoto, Yoshihiko Takano, Satoshi Watauchi, Isao Tanaka, Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga
Journal of Asian Ceramic Societies, 5, 2, 183, 185, Elsevier B.V., 2017年06月01日, ［査読有り］
英語, 研究論文（学術雑誌）, LaO0.5F0.5BiS2 nanosheets were produced by ultrasonification. A slightly reddish colloidal suspension was obtained by ultrasonification of LaO0.5F0.5BiS2 powder in ethanol. Transmission electron microscope (TEM) images of the dried suspension indicated the nanosheet morphology of LaO0.5F0.5BiS2, and the electron diffraction spots indicated 4-fold symmetry. The thickness of the sheets was 2–6 nm, which corresponded to 2–4 unit cells of the c-axis of LaO0.5F0.5BiS2. - Effect of the binder content on the electrochemical performance of composite cathode using Li6PS5Cl precursor solution in an all-solid-state lithium battery
Nataly Carolina Rosero-Navarro, Taiki Kinoshita, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga
IONICS, 23, 6, 1619, 1624, SPRINGER HEIDELBERG, 2017年06月, ［査読有り］
英語, 研究論文（学術雑誌）, All-solid-state batteries with cathode composites containing high concentration of active materials are required to achieve higher energy densities. Here, a composite cathode containing up to 89 wt% of high-voltage cathode active material (LiNi1/3Mn1/3Co1/3O2) was prepared by covering this with a solution-derived solid electrolyte (argyrodite, Li6PS5Cl) and the incorporation of different content binder (ethyl cellulose). All-solid-state batteries were fabricated using 80Li(2)Sa (TM) 20P(2)S(5) (mol%) glass and indium metal as a solid electrolyte and anode, respectively. The all-solid-state battery with a composite cathode containing 0.5 wt% of ethyl cellulose showed an initial discharge capacity of 45 mAhg(-1) at 25 A degrees C and maintained 91.7% of the discharge capacity after ten cycles, around 30% higher than that obtained for the battery with the composite cathode without a binder. - Hydrothermal Synthesis, Structure, and Superconductivity of Simple Cubic Perovskite (Ba0.62K0.38)(Bi0.92Mg0.08)O-3 with T-c similar to 30 K
Mirza H. K. Rubel, Takahiro Takei, Nobuhiro Kumada, M. Mozahar Ali, Akira Miura, Kiyoharu Tadanaga, Kengo Oka, Masaki Azuma, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa
INORGANIC CHEMISTRY, 56, 6, 3174, 3181, AMER CHEMICAL SOC, 2017年03月, ［査読有り］
英語, 研究論文（学術雑誌）, We have synthesized a new superconducting perovskite bismuth oxide by a facile hydrothermal route at 220 degrees C. The choice of starting materials, their mixing ratios, and the hydrothermal reaction temperature was crucial for obtaining products with superior superconducting properties. The structure of the powder sample was investigated using laboratory X-ray diffraction, high -resolution synchrotron X-ray diffraction (SXRD) data, and electron diffraction (ED) patterns [transmission electron microscopy (TEM) analysis]. The refinement of SXRD data confirmed a simple perovskitetype structure with a cubic cell of a = 4.27864(2) angstrom [space group Pm3m (No. 221)]. Elemental analysis detected magnesium in the final products, and a refinement based on SXRD and inductively coupled plasma data yielded an ideal undistorted simple cubic perovskite-type structure, with the chemical composition (Ba0.62K0.38)(Bi0.92Mg0.08)O-3. ED patterns also confirmed the simple cubic perovskite structure; the cube -shaped microstructures and compositional homogeneity on the nanoscale were verified by scanning electron microscopy and TEM analyses, respectively. The fabricated compound exhibited a large shielding volume fraction of about 98% with a maximum T-c(mag) of similar to 30 K, which was supported by the measured bismuth valence as well. Its electrical resistivity dropped at similar to 21 K, and zero resistivity was observed below 7 K The compound underwent thermal decomposition above 400 degrees C. Finally, the calculated band structure showed a metallic behavior for this hydrothermally synthesized bismuth oxide. - Electrical and mechanical properties of glass and glass-ceramic electrolytes in the system Li3BO3-Li2SO4
Masahiro Tatsumisago, Ryohei Takano, Masashi Nose, Kenji Nagao, Atsutaka Kato, Atsushi Sakuda, Kiyoharu Tadanaga, Akitoshi Hayashi
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 125, 6, 433, 437, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2017年, ［査読有り］
英語, 研究論文（学術雑誌）, Low-melting oxide glasses are promising as electrolytes for all-solid-state lithium rechargeable batteries. Glasses in the pseudobinary system Li3BO3-Li2SO4 were prepared by a mechanochemical technique. Raman spectra revealed that the glasses contained no macroanions which form networks but consisted only of Li+ ions and two discrete ortho-oxoanions, BO33+ and SO42-. The density and molar volume increased and elastic moduli decreased with an increase in the Li2SO4 content in the glasses. The heat treatment of the Li3BO3-Li2SO4 glasses at around 300 degrees C brought about the crystallization to form ion conducting glass-ceramics. Electrical conductivities of the glasses and glass-ceramics in this system were maximized with the mixing of Li3BO3 and Li2SO4. The conductivities were higher in the glass-ceramics of the compositions with small amounts of Li2SO4, ranging from 3 x 10(-6) to 1 x 10(-5) S cm(-1) at room temperature, compared to the corresponding glasses. This conductivity enhancement by the heat treatment is probably due to the precipitation of solid solutions with a high temperature Li3BO3 phase. (C) 2017 The Ceramic Society of Japan. All rights reserved. - Optimization of Al2O3 and Li3BO3 Content as Sintering Additives of Li7-xLa2.95Ca0.05ZrTaO12 at Low Temperature
Nataly Carolina Rosero-Navarro, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga
JOURNAL OF ELECTRONIC MATERIALS, 46, 1, 497, 501, SPRINGER, 2017年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Simultaneous effect of Al2O3 and Li3BO3 additions on sintering behavior and Li-ion conductivity of Li7-xLa2.95Ca0.05ZrTaO12 (LLCZT) garnet electrolyte sintered at 900 degrees C (10 h) is evaluated. The crystal phase and microstructure of the different composites were evaluated by x-ray diffraction and scanning electron microscopy (SEM), respectively. Electrical properties of the composites with high relative densities (95%) were examined by impedance spectroscopy. The cubic phase was formed for LLCZT sintered with 0-0.21 mol of Al2O3 and 0.70 mol-0.80 mol of Li3BO3. The excess of Al2O3 (0.22 mol) led to the formation of secondary phases. SEM observation revealed the good interconnection between LLCZT grains and the distribution of the glassy phase formed by Li3BO3 and Al2O3. Effective combination of 0.21 mol of Al2O3 and 0.80 mol of Li3BO3 produced denser material with high relative density of 95% and high Li-ion conduction of 1 x 10(-4) S/cm at 32 degrees C. - Instantaneous preparation of high lithium-ion conducting sulfide solid electrolyte Li7P3S11 by a liquid phase process
Marcela Calpa, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga
RSC ADVANCES, 7, 73, 46499, 46504, ROYAL SOC CHEMISTRY, 2017年, ［査読有り］
英語, 研究論文（学術雑誌）, A solid electrolyte with a small particle size, good mechanical properties and high ionic conductivity is required to achieve high energy and power density in the all-solid-state battery. Here, we report an instantaneous preparation of high lithium-ion conducting sulfide solid electrolyte Li7P3S11 by a simple procedure involving a liquid phase process under ultrasonic irradiation and low thermal treatment at 220 degrees C. A short reaction time of 30 min was enough to produce the formation of PS43- units. Subsequent drying and heating processes led to the precipitation of the Li7P3S11 phase with a particle size below 500 nm, achieving high ionic conductivity of 1.0 x 10(-3) S cm(-1) at 22 degrees C and a low activation energy of 12.8 kJ mol(-1). - Effect of Sintering Additives on Relative Density and Li-ion Conductivity of Nb-Doped Li7La3ZrO12 Solid Electrolyte
Nataly Carolina Rosero-Navarro, Taira Yamashita, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 100, 1, 276, 285, WILEY, 2017年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Lithium ion conductors with garnet-type structure are promising candidates for applications in all solid-state lithium ion batteries, because these materials present a high chemical stability against Li metal and a rather high Li+ conductivity (10(-3)-10(-4)S/cm). Producing densified Li-ion conductors by lowering sintering temperature is an important issue, which can achieve high Li conductivity in garnet oxide by preventing the evaporation of lithium and a good Li-ion conduction in grain boundary between garnet oxides. In this study, we concentrate on the use of sintering additives to enhance densification and microstructure of Li7La3ZrNbO12 at sintering temperature of 900 degrees C. Glasses in the LiO2-B2O3-SiO2-CaO-Al2O3 (LBSCA) and BaO-B2O3-SiO2-CaO-Al2O3 (BBSCA) system with low softening temperature (<700 degrees C) were used to modify the grain-boundary resistance during sintering process. Lithium compounds with low melting point (<850 degrees C) such as LiF, Li2CO3, and LiOH were also studied to improve the rearrangement of grains during the initial and middle stages of sintering. Among these sintering additives, LBSCA and BBSCA were proved to be better sintering additives at reducing the porosity of the pellets and improving connectivity between the grains. Glass additives produced relative densities of 85-92%, whereas those of lithium compounds were 62-77%. Li7La3ZrNbO12 sintered with 4 wt% of LBSCA at 900 degrees C for 10h achieved a rather high relative density of 85% and total Li-ion conductivity of 0.8x10(-4)S/cm at room temperature (30 degrees C). - Deposition and Analysis of Al-Rich c-AlxTi1-xN Coating with Preferred Orientation
Anongsack Paseuth, Kazuo Yamagata, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 100, 1, 343, 353, WILEY, 2017年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Metastable c-AlxT1-xN is an important and well-established hard coating in the tool industry. To improve the mechanical and thermal properties, Al-rich c-AlxTi1-xN coatings with controllable preferred crystal orientations were fabricated via low-pressure chemical vapor deposition (LP-CVD) in an industrial plant, using an AlCl3-TiCl4-NH3-Ar-H-2 precursor system. The c-AlxTi1-xN coatings with (100)- and (111)-preferred orientations and average x values of 0.82 and 0.73, respectively, comprised c-Al(Ti)N/c-Ti(Al)N nanolamellae with average compositions of c-Al0.9Ti0.1N/c-Al0.6Ti0.4N and c-Al0.80Ti0.20N/c-Al0.50Ti0.50N; the average lamellar periods were 7.7 and 4.5 nm, respectively. High-resolution transmission electron microscopy indicated that the c-Al(Ti)N/c-Ti(Al)N nanolamellae were modulated along the < 100 > direction, implying coherent spinodal decomposition of c-AlxTi1-xN in the as-deposited state. The hardness of the c-AlxTi1-xN coatings varied from 33 to 36 GPa, depending on the (100)- or (111)-preferred orientation. Residual stress measurements in the as-deposited state showed tensile stress values of 1.8 and 4.6 GPa for the (100)- and (111)-oriented c-AlxT1-xN coatings, respectively. This stress may be generated by the difference in the thermal expansion coefficient of the c-AlxT1-xN coating and the carbide substrate and by coherency stress in the c-Al(Ti)N/c-Ti(Al)N nanolamellae. In situ high-temperature X-Ray diffraction results revealed high thermal stability up to 1000 degrees C. - Preparation of Zn-Al layered double hydroxide thin films intercalated with Eosin Y by hot water treatment of sol-gel derived precursor films
Kiyoharu Tadanaga, Jun-ichiro Oi, Mikio Higuchi
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 79, 2, 303, 307, SPRINGER, 2016年08月, ［査読有り］
英語, 研究論文（学術雑誌）, Zn-Al layered double hydroxide (LDH) thin films intercalated with Eosin Y were prepared by the sol-gel method with hot water treatment. Sol-gel derived amorphous Al2O3-ZnO thin films were immersed in hot water containing Eosin Y. Extended interlayer spacing, in comparison with the Zn-Al LDH with carbonate anions, was observed after immersion in distilled water containing 5 mM Eosin Y at 100 A degrees C for 30 min, indicating that crystals of Zn-Al LDH intercalated with Eosin Y were precipitated on the precursor film. Intercalated Eosin Y was confirmed to have high thermal durability compared with Eosin Y adsorbed on the LDH surface. A cell consisting of the heat-treated thin film of Zn-Al LDH intercalated with Eosin Y on fluorine-doped tin oxide (FTO)-coated glass, triiodide/iodide electrolyte, and Pt-loaded FTO glass was confirmed to work as a solar cell under visible light irradiation.
Zn-Al layered double hydroxide thin films intercalated with Eosin Y were prepared by the sol-gel method with hot water treatment. Intercalated Eosin Y is confirmed to have high thermal durability.
[GRAPHICS] - Nitrogen-Rich Manganese Oxynitrides with Enhanced Catalytic Activity in the Oxygen Reduction Reaction
Akira Miura, Carolina Rosero-Navarro, Yuji Masubuchi, Mikio Higuchi, Shinichi Kikkawa, Kiyoharu Tadanaga
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 55, 28, 7963, 7967, WILEY-V C H VERLAG GMBH, 2016年07月, ［査読有り］
英語, 研究論文（学術雑誌）, The catalytic activity of manganese oxynitrides in the oxygen reduction reaction (ORR) was investigated in alkaline solutions to clarify the effect of the incorporated nitrogen atoms on the ORR activity. These oxynitrides, with rock-saltlike structures with different nitrogen contents, were synthesized by reacting MnO, Mn2O3, or MnO2 with molten NaNH2 at 240-280 degrees C. The anion contents and the Mn valence states were determined by combustion analysis, powder X-ray diffraction, and X-ray absorption near-edge structure analysis. An increase in the nitrogen content of rock-salt-based manganese oxynitrides increases the valence of the manganese ions and reinforces the catalytic activity for the ORR in 1m KOH solution. Nearly single-electron occupancy of the antibonding e(g) states and highly covalent Mn-N bonding thus enhance the ORR activity of nitrogen-rich manganese oxynitrides. - Development of All-solid-state Lithium Secondary Batteries Using NiPS3 Electrode and Li2S-P2S5 Solid Electrolyte
Yuta Fujii, Yusaku Suto, Akira Miura, Mikio Higuchi, Kiyoharu Tadanaga
CHEMISTRY LETTERS, 45, 6, 652, 654, CHEMICAL SOC JAPAN, 2016年06月, ［査読有り］
英語, 研究論文（学術雑誌）, An all-solid-state lithium secondary battery using a NiPS3 electrode and a 80Li(2)S center dot 20P(2)S(5) glass solid electrolyte was fabricated, and the charge-discharge cycle performance of the corresponding all-solid-state cell was investigated. This all solid-state cell exhibited a stable reversible capacity of about 80 mAh g(-1) after 30 cycles with a current density of 64 mu A cm(-2) at room temperature. This suggests that NiPS3 has a potential as an electrode active material in all-solid-state lithium secondary batteries using Li2S-P2S5 solid electrolytes. - Compositional and temperature evolution of crystal structure of new thermoelectric compound LaOBiS2-xSex
Y. Mizuguchi, A. Miura, A. Nishida, O. Miura, K. Tadanaga, N. Kumada, C. H. Lee, E. Magome, C. Moriyoshi, Y. Kuroiwa
JOURNAL OF APPLIED PHYSICS, 119, 15, 155103, AMER INST PHYSICS, 2016年04月, ［査読有り］
英語, 研究論文（学術雑誌）, We examined the crystal structure of the new thermoelectric material LaOBiS2-xSex, whose thermoelectric performance is enhanced by Se substitution, by using powder synchrotron X-ray diffraction and Rietveld refinement. The emergence of metallic conductivity and enhancement of the thermoelectric power factor of LaOBiS2-xSex can be explained with the higher in-plane chemical pressure caused by the increase of Se concentration at the in-plane Ch1 site (Ch = S, Se). High-temperature X-ray diffraction measurements for optimally substituted LaOBiSSe revealed anomalously large atomic displacement parameters (U-iso) for Bi and Ch atoms in the BiCh(2) conduction layers. The anisotropic analysis of the atomic displacement parameters (U-11 and U-33) for the in-plane Bi and Ch1 sites suggested that Bi atoms exhibit large atomic displacement along the c-axis direction above 300 K, which could be the origin of the low thermal conductivity in LaOBiSSe. The large Bi vibration along the c-axis direction could be related to in-plane rattling, which is a new strategy for attaining low thermal conductivity and phonon-glass-electron-crystal states. Published by AIP Publishing. - Fabrication of all-solid-state lithium secondary batteries with amorphous TiS4 positive electrodes and Li7La3Zr2O12 solid electrolytes
Takuya Matsuyama, Ryohei Takano, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
SOLID STATE IONICS, 285, 122, 125, ELSEVIER SCIENCE BV, 2016年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Amorphous TiS4 (a-TiS4) thin film electrode was deposited on the garnet-type Li7La3Zr2O12 (LLZ) solid electrolyte pellet sintered at 1230 degrees C by the pulsed laser deposition method. The a-TiS4 electrode was dense and its thickness was ca. 400 nm and good contacts between the electrode and the electrolyte were obtained. All-solid-state cells of Li/LLZ/a-TiS4 operated as a lithium secondary battery at 25 degrees C, and showed reversible capacity of about 500 mAh per gram of a-TiS4 at 0.010 mA cm(-2) and good cycle performance for 15 cycles. Interfacial resistance between a-TiS4 electrode and LIZ electrolyte was almost constant during charge-discharge cycling. A pelletized LLZ was prepared with Li3BO3 at a lower sintering temperature of 900 degrees C, and the obtained LLZ-Li3BO3 pellet with the conductivity of 1.0 x 10(-4) S cm(-1) at 25 degrees C was applied to all-solid-state cells. The cells with LLZ-Li3BO3 and a-TiS4 also operated as a lithium secondary battery. The reversible capacity of the cells using LLZ-Li3BO3 was about 480 mAh per gram of a-TiS4 at a current density of 0.020 mA cm(-2). (C) 2015 Elsevier B.V. All rights reserved. - Preparation of Li7La3(Zr2-x,Nb-x)O-12 (x=0-1.5) and Li3BO3/LiBO2 composites at low temperatures using a sol-gel process
N. C. Rosero-Navarro, T. Yamashita, A. Miura, M. Higuchi, K. Tadanaga
SOLID STATE IONICS, 285, 6, 12, ELSEVIER SCIENCE BV, 2016年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Li7La3(Zr-2 (-) Nb-x(x))O-12 (LLZNbO, x = 0-1.5) was prepared using sol-gel process at low temperatures. Additives (LiBO2 and Li3BO3) were used to improve the sintering of the ceramic electrolyte at low temperatures. XRD patterns of the calcined powder displayed the formation of cubic garnet phase between 600 and 700 degrees C in composition with higher Nb content (LLZNbO, x >= 0.5). The density of composites with additives sintered at 900 degrees C achieves 90%. In composites sintered with LiBO2, the presence of La2Zr2O7 was detected, whereas single cubic phase was obtained for the composites sintered with Li3BO3. The ion conductivity attained was 7 x 10(-5) S/cm at 30 degrees C using 6.5 wt% Li3BO3 (900 degrees C), representing enhancement by more than two orders of magnitude compared to the material without additives. Improvements of Li ion conductivity can be interpreted by the enhanced relative density as the result of the rearrangement of particles produced by adequate concentration of the additive. (C) 2015 Elsevier B.V. All rights reserved. - Structures and optical absorption of Bi2OS2 and LaOBiS2
Akira Miura, Yoshikazu Mizuguchi, Takahiro Takei, Nobuhiro Kumada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, Kiyoharu Tadanaga
SOLID STATE COMMUNICATIONS, 227, 19, 22, PERGAMON-ELSEVIER SCIENCE LTD, 2016年01月, ［査読有り］
英語, 研究論文（学術雑誌）, The band gaps of isostructural Bi2OS2 and LaOBiS2 were examined using optical absorption and discussed with the band structures calculated based on the crystal structures determined, using synchrotron X-ray diffraction. The Bi 6p and S 3p orbitals in the Bi-S plane were computationally predicted to constitute the bands near the Fermi level. The optical reflectance spectra of Bi2OS2 and LaOBiS2 showed optical band gaps of similar to 1.0 eV, which were close to the computationally calculated direct band gaps of similar to 0.8 eV. Our results show that Bi2OS2 and LaOBiS2 are semiconductors containing direct band gaps of 0.8-1.0 eV, and they are suggested to be candidates for optoelectronic materials in the near-infrared region without highly toxic elements. (C) 2015 Elsevier Ltd. All rights reserved. - Hydrothermal Synthesis, Crystal Structure, and Superconductivity of a Double-Perovskite Bi Oxide
Mirza H. K. Rubel, Takahiro Takei, Nobuhiro Kumada, M. Mozahar Ali, Akira Miura, Kiyoharu Tadanaga, Kengo Oka, Masaki Azuma, Masatomo Yashima, Kotaro Fujii, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, James R. Hester, Maxim Aydeev
CHEMISTRY OF MATERIALS, 28, 2, 459, 465, AMER CHEMICAL SOC, 2016年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Double-perovskite Bi oxides are a new series of superconducting materials, and their crystal structure and superconducting properties are under investigation. In this paper, we describe the synthesis and characterization of a new double-perovskite material that has an increased superconductive transition temperature of 31.5 K. The structure of the material was examined using powder neutron diffraction (ND), synchrotron X-ray diffraction (SXRD), and transmission electron microscopy (TEM). Rietveld refinement of the sample based on ND and SXRD data confirmed an A-site-ordered (K-1.00)(Ba-1.00)(3)(Bi0.89Na0.11)(4)O-12 double-perovskite-type structure with the space group Im (3) over barm (No. 229). This structural analysis revealed the incorporation of Na with Bi in the structure and a bent bond between (Na, Bi)-O-(Na, Bi). TEM analyses also confirmed a cubic double-perovskite structure. This hydrothermally synthesized compound exhibited a large shielding volume fraction, exceeding 100%, with onset of superconductivity at similar to 31.5 K. Its electrical resistivity dropped near onset at similar to 28 K, and zero resistivity was confirmed below 13 K. The calculated band structure revealed that the metallicity of the compound and the flatness of the conduction bands near the Fermi level (E-F) are important for the appearance of superconductivity. - Structural Difference in Superconductive and Nonsuperconductive Bi-S Planes within Bi4O4Bi2S4 Blocks
Akira Miura, Yoshikazu Mizuguchi, Tsuyoshi Sugawara, Yongming Wang, Takahiro Takei, Nobuhiro Kumada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, Osuke Miura, Kiyoharu Tadanaga
INORGANIC CHEMISTRY, 54, 21, 10462, 10467, AMER CHEMICAL SOC, 2015年11月, ［査読有り］
英語, 研究論文（学術雑誌）, The relationship between the structure and superconductivity of Bi4O4S3 powders synthesized by heating under ambient and high pressures was investigated using synchrotron X-ray diffraction, Raman spectroscopy, and transmission electron microscopy (TEM) observation. The Bi4O4S3 powders synthesized under ambient pressure exhibited a strong superconductivity (diamagnetic) signal and zero resistivity below similar to 4.5 K, while the Bi4O4S3 powder synthesized by the high-pressure method exhibited a low-intensity signal down to 2 K. Further annealing of the latter Bi4O4S3 powder under ambient pressure led to the development of a strong signal and zero resistivity. The crystal structures of all Bi4O4S3 phases consisted of Bi4O4Bi2S4 blocks including a Bi-S layer and anion(s) sandwiched between Bi4O4Bi2S4 blocks, but minor structural differences were detected. A comparison of the structures of the superconductive and nonsuperconductive Bi4O4S3 samples suggested that the superconductive Bi4O4S3 phases had slightly smaller lattice parameters. The average structures of the superconductive Bi4O4S3 phases were characterized by a slightly shorter and less bent BiS plane. Raman spectroscopy detected vibration of the S-O bonds, which can be attributed to sandwiched anion(s) such as SO42-. TEM observation showed stacking faults in the superconductive Bi4O4S3 phases, which indicated local fluctuation of the average structures. The observed superconductivity of Bi4O4S3 was discussed based on impurity phases, enhanced hybridization of the px and py orbitals of the Bi-S plane within Bi4O4Bi2S4 blocks, local fluctuation of the average structures, compositional deviation related to suspicious anion(s) sandwiched between Bi4O4Bi2S4 blocks, and the possibility of suppression of the charge-density-wave state by enriched carrier concentrations. - In-plane chemical pressure essential for superconductivity in BiCh(2)-based (Ch: S, Se) layered structure
Yoshikazu Mizuguchi, Akira Miura, Joe Kajitani, Takafumi Hiroi, Osuke Miura, Kiyoharu Tadanaga, Nobuhiro Kumada, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa
SCIENTIFIC REPORTS, 5, 14968, NATURE PUBLISHING GROUP, 2015年10月, ［査読有り］
英語, 研究論文（学術雑誌）, BiCh(2)-based compounds (Ch: S, Se) are a new series of layered superconductors, and the mechanisms for the emergence of superconductivity in these materials have not yet been elucidated. In this study, we investigate the relationship between crystal structure and superconducting properties of the BiCh(2)-based superconductor family, specifically, optimally doped Ce1-xNdxO0.5F0.5BiS2 and LaO0.5F0.5Bi(S1-ySey)(2). We use powder synchrotron X-ray diffraction to determine the crystal structures. We show that the structure parameter essential for the emergence of bulk superconductivity in both systems is the in-plane chemical pressure, rather than Bi-Ch bond lengths or in-plane Ch-Bi-Ch bond angle. Furthermore, we show that the superconducting transition temperature for all REO(0.5)F(0.5)BiCh(2) superconductors can be determined from the in-plane chemical pressure. - Preparation of high lithium-ion conducting Li6PS5Cl solid electrolyte from ethanol solution for all-solid-state lithium batteries
So Yubuchi, Shingo Teragawa, Keigo Aso, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF POWER SOURCES, 293, 941, 945, ELSEVIER, 2015年10月, ［査読有り］
英語, 研究論文（学術雑誌）, A Li6PS5Cl solid electrolyte was successfully prepared by dissolution-reprecipitation process via ethanol solution. An ionic conductivity of the Li6PS5Cl solid electrolyte from the homogeneous ethanol solution was 1.4 x 10(-5) S cm(-1) at room temperature. LiCoO2 particles were coated with the Li6PS5Cl electrolyte via ethanol solution to form favorable electrode-electrolyte interface with a large contact areas. An all-solid-state cell using the electrolyte-coated LiCoO2 operated as a rechargeable battery and showed the initial discharge capacity of 45 rnAh g(-1) at 25 degrees C. (C) 2015 Elsevier B.V. All rights reserved. - Effect of the addition of hydrated titanium oxide on proton conductivity for aromatic polymer electrolyte membrane
Atsuhiko Onuma, Jun Kawaji, Shuichi Suzuki, Makoto Morishima, Yoshiyuki Takamori, Naoki Asano, Kiyoharu Tadanaga
SOLID STATE IONICS, 277, 72, 76, ELSEVIER SCIENCE BV, 2015年09月, ［査読有り］
英語, 研究論文（学術雑誌）, To improve the proton conductivities of a polymer electrolyte membrane which is composed of multi-block copolymers, in low humidity conditions, the effect of adding hydrated titanium oxide into a membrane was investigated. Membranes containing hydrated titanium oxide were prepared by using tetraethoxy titanium. Membranes containing hydrated titanium oxide showed higher proton conductivity than the membrane not containing the additives regardless of humidity. This result showed that adding hydrated titanium oxide improved proton conductivity. By contrast, all the polymer electrolyte membranes showed almost the same water content rate. The content rates of hydrated titanium oxide in membranes were lower than 3 wt%. Thus, adding hydrated titanium oxide was not considered to affect the water content rate of membranes. This result showed that proton conductivity was improved by adding hydrated titanium oxide without increasing water content rate. From the scanning transmission electron microscope observation, micro-phase-separated structures were observed clearly in membranes containing hydrated titanium oxide. It seemed that hydrated titanium oxide enhanced the hydrophilic sengments aggregation during the film-forming process. Probably, the well-defined hydrophilic domains functioned as proton paths and enhanced the proton conductivity of the membrane. (C) 2015 Elsevier B.V. All rights reserved. - Octahedral and trigonal-prismatic coordination preferences in Nb-, Mo-, Ta-, and W-based ABX(2) layered oxides, oxynitrides, and nitrides
Akira Miura, Kiyoharu Tadanaga, Eisuke Magome, Chikako Moriyoshi, Yoshihiro Kuroiwa, Takei Takahiro, Nobuhiro Kumada
JOURNAL OF SOLID STATE CHEMISTRY, 229, 272, 277, ACADEMIC PRESS INC ELSEVIER SCIENCE, 2015年09月, ［査読有り］
英語, 研究論文（学術雑誌）, Crystallographic and electronic structures of Nb-, Mo-, Ta-, and W-based layered oxides, oxynitrides, and nitrides were analyzed to elucidate the structural relationship between layered oxides and nitrides consisting of octahedral and trigonal-prismatic layers. The electron density, as derived by synchrotron X-ray analysis of LiNbO2 and Ta5-x(O,N)(6), showed orbital overlaps between Nb-Nb and Ta-Ta metals in the trigonal layers. Computational calculations based on DFT exhibited that these overlaps stabilized these structures by lowering the hybridization states composed of the d(xy), d(x2-y2), and d(z2) orbitals below the Fermi level. Crystal structures and formation energies suggest that tuning the Fermi level through the substitutions and vacancies of the cation/anion sites determines the structural preferences of the coordination. The properties and syntheses of these compounds are briefly described. This study enhances the understanding of layered oxides, oxynitrides, and nitrides to further the development of new synthetic approaches, compounds, and applications. (C) 2015 Elsevier Inc. All rights reserved. - Hydrothermal synthesis of a new Bi-based (Ba0.82K0.18)(Bi0.53Pb0.47)O-3 superconductor
Mirza H. K. Rubel, Takahiro Takei, Nobuhiro Kumada, M. M. Ali, Akira Miura, Kiyoharu Tadanaga, K. Oka, M. Azuma, E. Magomae, C. Moriyoshi, Y. Kuroiwa
JOURNAL OF ALLOYS AND COMPOUNDS, 634, 208, 214, ELSEVIER SCIENCE SA, 2015年06月, ［査読有り］
英語, 研究論文（学術雑誌）, A new type of bismuth-oxide-based superconductor was prepared by a hydrothermal reaction at 240 degrees C. The synchrotron X-ray powder diffraction pattern reveals a simple perovskite-type structure with a cubic cell of a = 4.28877(1) angstrom with space group Pm-(3) over barm. The chemical composition of this cubic perovskite oxide was formulated as (Ba0.82K0.18)(Bi0.53Pb0.47)O-3 after structural refinement using synchrotron X-ray powder diffraction and chemical analysis data. The cubic microstructure and compositional homogeneity were confirmed by scanning electron microscopy analysis. This compound exhibited a diamagnetic signal with a shielding volume fraction of similar to 64% with an onset of approximately 22.8 K. Its resistivity started to drop at similar to 15 K, and zero resistivity was observed below 4 K. The thermal decomposition of this simple perovskite structure started above 600 degrees C. Finally, the calculated band structure also exhibited metallic behavior at ambient conditions. (C) 2015 Elsevier B.V. All rights reserved. - Preparation of Li4Ti5O12 electrode thin films by a mist CVD process with aqueous precursor solution
Kiyoharu Tadanaga, Akihiro Yamaguchi, Akitoshi Hayashi, Masahiro Tatsumisago, Jadra Mosa, Mario Aparicio
Journal of Asian Ceramic Societies, 3, 1, 88, 91, Elsevier B.V., 2015年03月01日, ［査読有り］
英語, 研究論文（学術雑誌）, Spinel Li4Ti5O12 thin films were prepared by a mist CVD process, using an aqueous solution of lithium nitrate and a water-soluble titanium lactate complex as the source of Li and Ti, respectively. In this process, mist particles ultrasonically atomized from a source aqueous solution were transferred by nitrogen gas to a heating substrate to prepare thin films. Scanning electron microscopy observation showed that thin films obtained by this process were dense and smooth, and thin films with a thickness of about 500nm were obtained. In the X-ray diffraction analysis, formation of Li4Ti5O12 spinel phase was confirmed in the obtained thin film sintered at 700°C for 4h. The cell with the thin films as an electrode exhibited a capacity of about 110mAhg-1, and the cell showed good cycling performance during 10 cycles. - Photocatalytic O-2 evolution from water over Zn-Cr layered double hydroxides intercalated with inorganic anions
Naoya Hirata, Kiyoharu Tadanaga, Masahiro Tatsumisago
MATERIALS RESEARCH BULLETIN, 62, 1, 4, PERGAMON-ELSEVIER SCIENCE LTD, 2015年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Zn-Cr layered double hydroxides (LDHs) intercalated with inorganic anions (CO32-, Cl-, SO42- and NO3-) were synthesized by the co-precipitation method and the anion exchange process. The photocatalytic activity of the LDHs was studied by O-2 evolution from aqueous solution of AgNO3 as a sacrificial agent. All the prepared LDHs showed photocatalytic activity under either UV and/or visible light irradiation. Besides, the interlayer anions affected the photocatalytic activity of the LDHs. After irradiation, Ag particles were formed on the LDHs by accepting the electrons generated during the photocatalytic reaction. (C) 2014 Elsevier Ltd. All rights reserved. - Development of alkaline fuel cells using hydroxide-ion conductive layered double hydroxides
Kiyoharu Tadanaga, Kohei Igarashi, Takashi Kubota, Akira Miura, Mikio Higuchi
ECS Transactions, 69, 17, 385, 389, Electrochemical Society Inc., 2015年, ［査読有り］
英語, 研究論文（国際会議プロシーディングス）, Layered double hydroxides (LDHs) intercalated with CO3 2- show high hydroxide ion conductivity of the order of 10-3 S cm-1 under 80% relative humidity. In the present study, (Ni, Mn)-Al LDHs and (Ni, Mn)-Fe LDHs intercalated with CO32- were prepared. The conductivity of (Ni, Mn)-Al LDH and (Ni, Mn)-Fe LDH was higher than that of Ni-Al LDH or Ni-Fe LDH. These LDHs were applied to the catalyst layer in an alkaline fuel cell for the improvement of the oxygen reduction reaction (ORR) at the triple phase boundary (TPB) in the catalyst layer. The addition of LDHs to the catalyst layer increased the current for ORR, indicating that hydroxide ion conducting LDHs introduced OH- conducting paths and increased TPB region within the catalyst layer. Above all, the addition of (Ni, Mn)-Fe LDH to the catalyst layer more effectively increased the reduction current for ORR than the addition of (Ni, Mn)-Al LDHs or Ni-Fe LDH. H2-O2 fuel cells with Ni-Al or Mg-Al LDHs as an electrolyte and MnO2 as the cathode catalyst were fabricated. The H2-O2 fuel cells were confirmed to be operated. - Liquid-phase step-by-step growth of an iron cyanide coordination framework on LiCoO2 particle surfaces
Rie Makiura, Shingo Teragawa, Kohei Tsuchiyama, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
DALTON TRANSACTIONS, 44, 34, 15279, 15285, ROYAL SOC CHEMISTRY, 2015年, ［査読有り］
英語, 研究論文（学術雑誌）, Surface modification of inorganic objects with metal-organic frameworks (MOFs) - organic-inorganic hybrid framework materials with infinite networks - opens wide windows for potential applications. In order to derive a target property, the key is the ability to fine tune the degree of modification. Solution-based step-by-step growth techniques provide excellent control of layer thickness which can be varied with the number of deposition cycles. Such techniques with MOFs have been mainly applied to flat substrates, but not to particle surfaces before. Here, we present the facile surface modification of inorganic particles with a framework compound under operationally simple ambient conditions. A solution-based sequential technique involving the alternate immersion of LiCoO2 (LCO) - a positive electrode material for a lithium ion battery - into FeCl2 center dot 4H(2)O and K-3[Fe(CN)(6)] solutions results in the formation of Prussian blue (PB) nanolayers on the surface of the LCO particles (PBNL@LCO). The PB growth is finely controlled by the number of immersion cycles. An electrochemical cell with PBNL@LCO as a positive electrode material exhibits a discharge capacity close to the specific capacity of LCO. The results open a new direction for creating suitable interfacial conditions between electrode materials and electrolytes in secondary battery materials. - Preparation of lithium ion conductive Al-doped Li7La3Zr2O12 thin films by a sol-gel process
Kiyoharu Tadanaga, Hiromi Egawa, Akitoshi Hayashi, Masahiro Tatsumisago, Jadra Mosa, Mario Aparicio, Alicia Duran
JOURNAL OF POWER SOURCES, 273, 844, 847, ELSEVIER SCIENCE BV, 2015年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Thin films of garnet-type Al-doped Li7La3Zr2O12 (LLZ) are prepared by the sol-gel process. Thin films are prepared on MgO substrates by a dip-coating process using a precursor sol from Zr-alkoxide and Li, La and Al nitrates. After the dip-coating, the dried films are calcined at 450 degrees C to get precursor films. When the precursor films are heat-treated at 900 degrees C in an alumina crucible, La2Zr2O7 is mainly obtained. With coexistence of Li2CO3 powders in the crucible during the heat-treatment at 900 degrees C, thin film of polycrystalline cubic LLZ is obtained. Addition of an ionic surfactant, lithium dodecylsulfate, improves the quality of the thin films, and the thin film heat-treated at 900 degrees C with coexistence of Li2CO3 powders in the crucible shows the ionic conductivity of 2.4 x 10(-6) S cm(-1) at 25 degrees C. (C) 2014 Elsevier B.V. All rights reserved. - Li4Ti5O12 thin-film electrodes by in-situ synthesis of lithium alkoxide for Li-ion microbatteries
J. Mosa, M. Aparicio, K. Tadanaga, A. Hayashi, M. Tatsumisago
ELECTROCHIMICA ACTA, 149, 293, 299, PERGAMON-ELSEVIER SCIENCE LTD, 2014年12月, ［査読有り］
英語, 研究論文（学術雑誌）, Rechargeable thin-film batteries have recently become the topic of widespread research for use as efficient energy storage devices. Spinel Li4Ti5O12 has been considered as one of the most prospective anode materials for Li-ion batteries because of its excellent reversibility and long cycle life. We report here the sol-gel synthesis and coating preparation of spinel thin-film Li4Ti5O12 electrodes for Li-ion microbatteries using lithium ethoxide produced in situ that reacts with titanium alkoxide to produce the precursor solution without particle precipitation. This synthesis procedure reduces the thermal treatment to obtain a pure phase at only 700 degrees C and 15 minutes. The physical and structural characterization of the 300 nm Li4Ti5O12 coatings shows a very homogeneous distribution of elements and a pure spinel phase. Galvanostatic discharge-charge tests indicate maximum discharge capacities of 152 mA h g(-1) when the material is treated at 700 degrees C for 15 minutes. (C) 2014 Elsevier Ltd. All rights reserved. - Preparation of Li3BO3-Li2SO4 glass-ceramic electrolytes for all-oxide lithium batteries
Masahiro Tatsumisago, Ryohei Takano, Kiyoharu Tadanaga, Akitoshi Hayashi
JOURNAL OF POWER SOURCES, 270, 603, 607, ELSEVIER SCIENCE BV, 2014年12月, ［査読有り］
英語, 研究論文（学術雑誌）, Newly designed oxide glass ceramic electrolyte of Li2.9B0.9S0.1O3.1 with high Li+ ion conductivity and low melting property was prepared by mechanical milling and subsequent heat treatment at 290 degrees C. This material showed 1.4 x 10(-5) S cm(-1) at room temperature and excellent deformation properties to obtain powder-compressed pellets with low interfacial resistance like in the case of sulfide solid electrolytes. The glass-ceramic exhibited favorable mechanical properties to form favorable solid-solid contacts in solid-state batteries by pressing without high temperature heat treatments. All-solid-state In/LiCoO2 cells using these oxide glass-ceramic electrolytes operated as secondary batteries at room temperature. (C) 2014 Elsevier B.V. All rights reserved. - Float zone growth and spectral properties of Cr,Nd:CaYAlO4 single crystals
Aki Ueda, Mikio Higuchi, Daiki Yamada, Sho Namiki, Takayo Ogawa, Satoshi Wada, Kiyoharu Tadanaga
JOURNAL OF CRYSTAL GROWTH, 404, 152, 156, ELSEVIER SCIENCE BV, 2014年10月, ［査読有り］
英語, 研究論文（学術雑誌）, Cr,Nd:CaYAlO4 single crystals were grown by the floating zone method and their spectroscopic properties were investigated. Many voids were observed in the crystals grown with a stoichiometric feed rod even at a relatively low growth rate of 2.5 mm/h, while a void-free crystal was grown at the same growth rate using a feed rod the composition of which was Y-rich to Ca. These results indicate that voids were attributable to constitutional supercooling due to the segregation of main constituents caused by the difference in congruent and stoichiometric compositions. The as-grown crystals were deep red and showed strong absorption in the wavelength region of 320-600 nm. The absorption cross section for sigma-polarization at 430 nm, where Cr,Nd:YAG has the maximum absorption, is about 1160 x 10(-20) cm(2), which is 165 times as large as that of Cr,Nd:YAG. By pumping at 400 nm, which is a pad of the absorption band of Cr3+ Cr,Nd:CaYAlO4 showed fluorescence bands around 900 am and 1080 nm by Nd3+ indicating energy transfer from Cr3+ to Nd3+ in the crystal. Cr,Nd:CaYAlO4 single crystals are therefore one of the promising gain media for solar-pumped solid state laser systems. (C) 2014 Elsevier B.V. All rights reserved. - Electrochemical oxygen separation using hydroxide ion conductive layered double hydroxides
Yuji Arishige, Daiju Kubo, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
SOLID STATE IONICS, 262, 238, 240, ELSEVIER SCIENCE BV, 2014年09月, ［査読有り］
英語, 研究論文（学術雑誌）, This paper reports a novel electrochemical oxygen separation process using a hydroxide ion conductor as an electrolyte. In this study, we used Ni-Fe layered double hydroxide (LDH) intercalated with CO32- (Ni-Fe CO32- LDH) as a hydroxide ion conductive material. Ni-Fe CO32- LDH was prepared using the co-precipitation method. Electrodes using Pt/C as a catalyst and Ni-Fe CO32- LDH as an ionomer were prepared and a membrane reactor for oxygen separation using Ni-Fe CO32- LDH as an electrolyte was fabricated. The electrochemical oxygen product flow was confirmed to be proportional to the external current density, and thus the membrane functioned at 50 degrees C under 70% of relative humidity and an electrical potential gradient. (C) 2013 Elsevier B.V. All rights reserved. - Preparation of LiMn2O4 cathode thin films for thin film lithium secondary batteries by a mist CVD process
Kiyoharu Tadanaga, Akihiro Yamaguchi, Atsushi Sakuda, Akitoshi Hayashi, Masahiro Tatsumisago, Alicia Duran, Mario Aparacio
MATERIALS RESEARCH BULLETIN, 53, 196, 198, PERGAMON-ELSEVIER SCIENCE LTD, 2014年05月, ［査読有り］
英語, 研究論文（学術雑誌）, LiMn2O4 cathode thin films for thin film lithium secondary batteries were prepared by using so-called the "mist CVD process", employing an aqueous solution of lithium acetate and manganese acetate, as the source of Li and Mn, respectively. The aqueous solution of starting materials was ultrasonically atomized to form mist particles, and mists were transferred by nitrogen gas to silica glass substrate to form thin films. FE-SEM observation revealed that thin films obtained by this process were dense and smooth, and thin films with a thickness of about 750 nm were obtained. The electrochemical cell with the thin films obtained by sintering at 700 degrees C exhibited a capacity of about 80 mAh/g, and the cell showed good cycling performance during 10 cycles. (C) 2014 Elsevier Ltd. All rights reserved. - Low temperature synthesis of Al-doped Li7La3Zr2O12 solid electrolyte by a sol-gel process
Ryohei Takano, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
SOLID STATE IONICS, 255, 104, 107, ELSEVIER SCIENCE BV, 2014年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Al-doped Li2La3Zr2O12 (LLZ) was prepared by a sol-gel process using lithium nitrate, lanthanum nitrate hexahydrate, zirconium propoxide and aluminum tri-sec-butoxide as starting materials. Single phase of cubic LLZ was obtained by a heat treatment at 700 degrees C, which is lower than that in the solid state reaction process. The LLZ powders were sintered at 900 degrees C using LiBO2 or Li3BO3 to form composite solid electrolyte. In the composite sintered with LiBO2, La2Zr2O7 was formed as an impurity phase. On the other hand, in the composite sintered with Li3BO3, single phase of cubic LLZ was obtained. The composite of Al-doped LLZ and Li3BO3 sintered at 900 degrees C showed the total electrical conductivity of 1.9 x 10(-5) S cm(-1), while Al-doped LLZ pellet without additives showed 1.6 x 10(-6) S cm(-1). (C) 2013 Elsevier B.V. All rights reserved. - Preparation of Li2S-P2S5 solid electrolyte from N-methylformamide solution and application for all-solid-state lithium battery
Shingo Teragawa, Keigo Aso, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF POWER SOURCES, 248, 939, 942, ELSEVIER SCIENCE BV, 2014年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Electrode solid electrolyte composite materials for all-solid-state lithium batteries were prepared by coating of the Li2S-P2S5 solid electrolyte onto LiCoO2 particles using a N-methylformamide (NMF) solution of 80Li(2)S-20P(2)S(5) (mol%) solid electrolyte. SEM and EDX analysis showed that the Li2S P2S5 solid electrolyte was uniformly coated on LiCoO2 particles. The all-solid-state cell using the LiCoO2 particles coated with the solid electrolyte showed higher charge discharge capacity than the cells using uncoated LiCoO2 particles. (C) 2013 Elsevier B.V. All rights reserved. - All-solid-state electrochemical capacitors using MnO2 electrode/SiO2-Nafion electrolyte composite prepared by the sol-gel process
Kazushi Shimamoto, Kiyoharu Tadanaga, Masahiro Tatsumisago
JOURNAL OF POWER SOURCES, 248, 396, 399, ELSEVIER SCIENCE BV, 2014年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Electrode electrolyte composites of MnO2 active material, acetylene black (AB), and SiO2 Nafion solid electrolyte were prepared using the sot gel process to form good solid solid interfaces. The composites were obtained by the addition of MnO2 and AB into a sol of hydrolyzed tetraethoxysilane with Nafion, and successive solidification of the precursor sol. Scanning electron microscope and energy dispersive X-ray spectroscopy measurements show that good solid solid interface is formed between electrodes and solid electrolytes in the composites. All-solid-state hybrid capacitors were fabricated using the composites or the hand-grinding mixture of MnO2, AB and SiO2 Nafion powder as positive electrodes, activated carbon powder as a negative electrode, and phosphosilicate gel as a solid electrolyte. The allsolid-state hybrid capacitors using the composites exhibit larger capacitances and better rate performance than the capacitors using the electrode prepared by hand-mixing of powders. Specific discharge capacitances of the capacitor with the composite are 85 F g(-1) for the one with the composite electrode and 48 F g(-1) for the one with the hand-mixed electrode, at 1 mA cm-2. Moreover, the all-solid-state capacitors using the composite electrode can be operated at temperatures between -30 degrees C and 60 degrees C. (C) 2013 Elsevier B.V. All rights reserved. - Liquid-phase synthesis of a Li3PS4 solid electrolyte using N-methylformamide for all-solid-state lithium batteries
Shingo Teragawa, Keigo Aso, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF MATERIALS CHEMISTRY A, 2, 14, 5095, 5099, ROYAL SOC CHEMISTRY, 2014年, ［査読有り］
英語, 研究論文（学術雑誌）, A Li3PS4 solid electrolyte was directly synthesized from Li2S and P2S5 by a liquid-phase reaction using N-methylformamide (NMF) and n-hexane as reaction media. After the reaction of Li2S and P2S5, a yellow NMF solution was obtained. The NMF solution was dried at 180 degrees C for 3 hours under vacuum to remove NMF and to obtain a powder. A crystalline phase of the obtained powder from the NMF solution was attributed to Li3PS4 crystals, and the ionic conductivity of the obtained powder was 2.3 x 10(-6) S cm(-1) at 25 degrees C. Electrode-electrolyte composite materials for all-solid-state lithium batteries were prepared by coating the Li3PS4 solid electrolyte onto LiCoO2 particles using the NMF solution. SEM and EDX analysis showed that LiCoO2 particles were uniformly coated with the Li3PS4 solid electrolyte. An all-solid-state cell using the LiCoO2 particles coated with the Li3PS4 solid electrolyte as a positive electrode operated as a secondary battery. - Li4Ti5O12 thin-film electrodes by sol-gel for lithium-ion microbatteries
J. Mosa, J. F. Velez, J. J. Reinosa, M. Aparicio, A. Yamaguchi, K. Tadanaga, M. Tatsumisago
JOURNAL OF POWER SOURCES, 244, 482, 487, ELSEVIER SCIENCE BV, 2013年12月, ［査読有り］
英語, 研究論文（学術雑誌）, Spinel Li4Ti5O12 has been considered as one of the most prospective anode materials for Li-ion microbatteries. Homogeneous, transparent and crack-free Li4Ti5O12 coatings with thickness around 110 nm have been prepared by dipping gold-coated quartz substrates in sols prepared using titanium isopropoxide and lithium acetate. The influence of the thermal treatment on the phase composition, structure and electrochemical behavior was studied. Rutile TiO2 (considered as an impurity in this study) is only detected in the coatings treated at 700 degrees C. XPS and TOF-SIMS depth profiles show a homogeneous distribution, with a Li increase and Ti reduction at the surface. Electrochemical characterization of samples treated at 600 degrees C presents a redox reaction around 1.55 V indicating that the film is simple phase of Li4Ti5O12. The shift to slightly lower voltage in samples treated at 700 degrees C is a consequence of Rutile impurities. Larger capacity and good reversibility in the sample heat-treated at 600 degrees C can be attributed to high crystallinity of Li4Ti5O12 and phase purity. RBS analysis specifies a composition close to Li4Ti5O12 in the case of the pristine and charged samples, and Li7Ti5O12 for the discharged sample. Surface XPS study confirms the presence of an outermost layer containing LiF and Li2CO3. (C) 2012 Elsevier B.V. All rights reserved. - Formation of Li2S-P2S5 Solid Electrolyte from N-Methylformamide Solution
Shingo Teragawa, Keigo Aso, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
CHEMISTRY LETTERS, 42, 11, 1435, 1437, CHEMICAL SOC JAPAN, 2013年11月, ［査読有り］
英語, 研究論文（学術雑誌）, Li2S-P2S5 solid electrolyte (SE) powders were successfully reprecipitated from a liquid phase. Powders of 80Li(2)S center dot 20P(2)S(5) (mol %) SE originally prepared by mechanical milling were dissolved in N-methylformamide (NMF) and a homogeneous solution was obtained. The NMF solution was dried at 150 degrees C for 3 h under vacuum to obtain precipitates. The main structural unit in the obtained powder was PS43-. The crystalline phase of the powders was confirmed to be Li3PS4, and ionic conductivity was 2.6 x 10(-6) cm(-1). - Synthesis of monodispersed silica nanoparticles with high concentration by the Stober process
Kiyoharu Tadanaga, Koji Morita, Keisuke Mori, Masahiro Tatsumisago
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 68, 2, 341, 345, SPRINGER, 2013年11月, ［査読有り］
英語, 研究論文（学術雑誌）, Silica nanoparticles with high concentration were prepared by the sol-gel process based on the Stober method using tetraethoxysilane as a starting material. It was found that silica sol with about 4 wt% in concentration and with a diameter of about 10 nm was obtained by controlling the reaction conditions in the Stober process. By removing the solvent under a reduced pressure, the particle concentration was increased up to 15 wt% without aggregation. - Surface morphology control of thin films prepared by solution processes and its application
Kiyoharu Tadanaga
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 121, 1417, 819, 824, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2013年09月, ［査読有り］
英語, 研究論文（学術雑誌）, Surface morphology of materials brings various new properties to the surface, and thus, the control of the surface morphology is very important. In this paper, surface morphology control of sol-gel derived films using several processes has been reviewed. Hot water treatment (bottom up process), combination of UV-irradiation and chemical etching (top down process), and micropattern formation using a hydrophobic-hydrophilic patterned surface were reported. (C)2013 The Ceramic Society of Japan. All rights reserved. - Low temperature synthesis of highly ion conductive Li7La3Zr2O12-Li3BO3 composites
Kiyoharu Tadanaga, Ryohei Takano, Takahiro Ichinose, Shigeo Mori, Akitoshi Hayashi, Masahiro Tatsumisago
ELECTROCHEMISTRY COMMUNICATIONS, 33, 51, 54, ELSEVIER SCIENCE INC, 2013年08月, ［査読有り］
英語, 研究論文（学術雑誌）, Highly lithium ion conductive composites with Al-doped Li7La3Zr2O12 (LLZ) and amorphous Li3BO3 were prepared from sol-gel derived precursor powders of LLZ and Li3BO3. Precursor LLZ powders with cubic phase were obtained by a heat treatment of the precursor dried gel at 600 degrees C. Pellets of the mixture of the obtained LLZ and Li3BO3 were first held at 700 degrees C, and then successively sintered at 900 degrees C. Density of the sintered pellet with Li3BO3 was larger than that of the pellet without Li3BO3. From the TEM observation, the pellets were found to consist of cubic LLZ and amorphous Li3BO3. Total electrical conductivity of the obtained LLZ-Li3BO3 composite was 1 x 10(-4) Scm(-1) at 30 degrees C. (c) 2013 Elsevier B.V. All rights reserved. - Multifunctional inorganic electrode materials for high-performance rechargeable metal-air batteries
Daiju Kubo, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
Journal of Materials Chemistry A, 1, 23, 6804, 6809, 2013年06月21日, ［査読有り］
英語, 研究論文（学術雑誌）, This paper reports the application of Ni-Fe layered double hydroxides (LDHs) intercalated with CO32- (Ni-Fe CO3 2- LDH) to a catalyst layer of a rechargeable metal-air battery using an alkaline electrolyte. Ni-Fe CO32- LDH is found to play multifunctional roles in the catalyst layer as a mixed conductor with hydroxide ions and electrons, and also as an electrocatalyst. The air electrode with Ni-Fe CO32- LDH shows superior performance to all electrodes with other LDHs, indicating that Ni-Fe CO32- LDH forms more favorable triple-phase boundary regions in the catalyst layer of the air electrode. The Ni-Fe CO32- LDH addition to the catalyst layer of the reversible air electrode using α-MnO2 also improves the performance of a rechargeable zinc-air battery. The reversible air electrode with α-MnO2 shows good cycle stability during 40 cycles, indicating that Ni-Fe LDH as an ionomer remains stable in the reversible air electrode after cycles. There must be a limited influence of CO2 on Ni-Fe CO32- LDH which can exist stably in air. Consequently, these results demonstrate that Ni-Fe CO3 2- LDHs are promising materials for use as multifunctional ionomers with high durability. They are widely applicable to rechargeable metal-air batteries using alkaline electrolytes. © 2013 The Royal Society of Chemistry. - Synthetic Control of Cage/Network Ratio of Poly(methylsilsesquioxane)s for Storage Stability, Hardness, and Weather Resistance of Coating Films
Satoshi Urano, Rie Tomita, Kiyoharu Tadanaga
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY, 51, 3, 653, 663, WILEY-BLACKWELL, 2013年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Poly(methylsilsesquioxane) (PMSQ) was synthesized using a two-step process consisting of hydrolysis of methyl trimethoxysilane (MTMS) with aluminum chelate catalyst and successive condensation reactions conducted at elevated temperatures. Results of nuclear magnetic resonance and Fourier transform infrared measurements show that all terminal functional groups were Si-OH in PMSQ. Results show further that PMSQ has both a cage structure and a network structure, and a cage/network ratio is represented by a height ratio of -64.5/-66.6 ppm. PMSQ of different molecular weight but the same Si-OH concentration is obtainable by varying the condensation reaction conditions such as the concentration, temperature, amount of aluminum chelate catalyst, and the solvent solubility parameter. A difference of the cage/network ratio occurs. A different cage/network ratio is dependent on the different reactivities of the intramolecular and intermolecular reactions. The relations of molecular structure of the obtained PMSQ molecular structure were characterized along with functions of storage stability, film hardness, and weather resistance. PMSQ designed with a larger cage/network ratio is necessary to obtain PMSQ with good storage stability and a coating film having good weather resistance. PMSQ designed with a smaller cage/network ratio should be prepared to obtain a coating film with high hardness. (C) 2012 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 653-663 - All-solid-state electrochemical capacitors using MnO2/ carbonnanotube composite electrode
Kazushi Shimamoto, Kiyoharu Tadanaga, Masahiro Tatsumisago
Electrochimica Acta, 109, 651, 655, Elsevier Ltd, 2013年, ［査読有り］
英語, 研究論文（学術雑誌）, MnO2/carbon nanotube (CNT) composite was prepared by a solution process. In the obtained MnO2-CNTcomposite, MnO2particles were well-dispersed on CNTs. The specific capacitance of the MnO2-CNT com-posite in an aqueous electrolyte was higher than that of MnO2and CNT. All-solid-state electrochemicalcapacitors (ECs) were fabricated using the MnO2-CNT composite as a positive electrode, activated carbonpowder as a negative electrode, and phosphosilicate gel as an electrolyte. The obtained all-solid-state ECsoperated at the temperature range between -30°C and 100°C. The specific discharge capacitance andthe rate ability of the capacitors were improved by elevating temperature. In addition, the fabricatedall-solid-state ECs exhibited excellent cycle performance at the temperature range between -30°C and100°C for 20,000 cycles. These results indicate that all-solid-state ECs using MnO2are promising energystorage devices with excellent stability and high reliability at the wide range of temperatures. © 2013 Elsevier Ltd. All rights reserved. - Improvement of electrochemical performance in alkaline fuel cell by hydroxide ion conducting Ni-Al layered double hydroxide
Daiju Kubo, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF POWER SOURCES, 222, 493, 497, ELSEVIER SCIENCE BV, 2013年01月, ［査読有り］
英語, 研究論文（学術雑誌）, This paper reports on the application of hydroxide ion conducting layered double hydroxides (LDHs) to the catalyst layer in an alkaline fuel cell for the improvement of the oxygen reduction reaction (ORR) at the triple phase boundary (TPB) in the catalyst layer. Ni-Al LDH intercalated with CO32- (Ni-Al CO32- LDH) and Mg-Al CO32- LDH were used in this study. Ni-Al CO32- LDH showed higher ionic conductivity than Mg-Al CO32- LDH under R.H. of 80%. The catalyst layers with and without hydroxide ion conducting LDHs was prepared, and a half-cell using the prepared catalyst layers was fabricated. The addition of LDHs to the catalyst layer increased the reduction current for ORR, indicating that hydroxide ion conducting LDHs introduced OH- conducting paths and increased TPB region within the catalyst layer. Above all, the addition of Ni-Al CO32- LDH to the catalyst layer more effectively increased the reduction current for ORR than the addition of Mg-Al CO32- LDH. The performance of the alkaline-type direct ethanol fuel cell was also improved. These experimental results indicate that high hydroxide ion conducting Ni-Al CO32- LDH effectively increased TPB region within the catalyst layer. (C) 2012 Elsevier B.V. All rights reserved. - Synthesis of monodispersed lithium silicate particles using the sol-gel method
Hiroaki Ishida, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
Journal of Sol-Gel Science and Technology, 65, 1, 41, 45, 2013年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Lithium silicate particles were prepared by the sol-gel process based on the Stöber method using tetraethoxysilane and lithium ethoxide as starting materials
lithium dodecyl sulfate (LDS) was used as a surfactant. Lithium ion concentration of the obtained particles increased with an increase of Li/Si ratios from 1 to 4. Scanning electron microscope images showed that the obtained particles were rather monodispersed with diameter of 100-300 nm, and the particle size was not influenced by the amount of added LDS but the Li/Si ratios. Fourier-transform infrared spectra of the particles showed that the intensity of the peaks due to CO3 2- increased with an increase of the Li/Si ratios. X-ray diffraction patterns and 29Si magic-angle spinning-nuclear magnetic resonance spectra of the particles indicated that Q3 and Q2 units were present as amorphous state in the particles prepared with Li/Si ratios of 1 and 2, respectively. In the case of Li/Si ratios of more than 3, lithium metasilicate crystals formed, and Q1 and Q2 units were dominant. © 2012 Springer Science+Business Media, LLC. - All-solid-state lithium secondary batteries with metal-sulfide-coated LiCoO<inf>2</inf> prepared by thermal decomposition of dithiocarbamato complexes
Atsushi Sakuda, Naoyuki Nakamoto, Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of Materials Chemistry, 22, 30, 15247, 15254, Royal Society of Chemistry, 2012年08月14日, ［査読有り］
英語, 研究論文（学術雑誌）, LiCoO<
inf>
2<
/inf>
particles were coated with cobalt and nickel sulfides by thermal decomposition of their respective diethyldithiocarbamato complexes. All-solid-state lithium secondary batteries were fabricated using the coated LiCoO<
inf>
2<
/inf>
positive electrode and a Li<
inf>
2<
/inf>
S-P<
inf>
2<
/inf>
S <
inf>
5<
/inf>
solid electrolyte. The coatings reduced the interfacial resistance between LiCoO<
inf>
2<
/inf>
and the Li<
inf>
2<
/inf>
S-P<
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2<
/inf>
S<
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5<
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solid electrolyte of the all-solid-state batteries after the first charge, resulting in an improved cell performance. The all-solid-state cell with NiS-coated LiCoO<
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2<
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was charged and discharged at a high rate of 10 C. The coatings reduced deterioration of the interface between LiCoO<
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2<
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and the Li<
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2<
/inf>
S-P<
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2<
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S<
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5<
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solid electrolyte, indicating that they function as an effective buffer layer at the interface. © The Royal Society of Chemistry 2012. - Mechanochemical synthesis of BaO-B2O3 glass and glass-ceramic phosphor powders containing europium ions
Atsuko Shinomiya, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
PHYSICS AND CHEMISTRY OF GLASSES-EUROPEAN JOURNAL OF GLASS SCIENCE AND TECHNOLOGY PART B, 53, 3, 128, 131, SOC GLASS TECHNOLOGY, 2012年06月, ［査読有り］
英語, 研究論文（学術雑誌）, Glasses in the system Eu2O3-BaO-B2O3 were prepared by a mechanochemical process using B2O3, BaO, and Eu2O3 as starting materials. X-ray diffraction patterns indicate that amorphous 99.5(0.2BaO.0.8B2O3).0.5Eu(2)O(3) (mol%) powder was obtained using a planetary ball mill. From infrared and Raman spectra, the structural units observed in the milled glass with milling times longer than 5 h were the same as ones in the melt quenched glass. In photoluminescence measurements, the milled 99.5(0.2BaO.0.8B2O3).0.5Eu(2)O(3) glasses showed red emission due to Eu3+ ions. By heating the milled glass in air at temperatures higher than the crystallization temperature, 99.5(0.2BaO.0.8B2O3).0.5Eu(2)O(3) glass-ceramic was also prepared. The glass-ceramic showed broad emission in the range 380-450 nm from Eu2+ ions. Crystallization of the milled glass induced reduction of Eu3+ to Eu2+ in air. - Mechanochemical synthesis of BaO-B 2O 3 glass and glass-ceramic phosphor powders containing europium ions
Atsuko Shinomiya, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Physics and Chemistry of Glasses: European Journal of Glass Science and Technology Part B, 53, 3, 128, 131, 2012年06月
英語, 研究論文（学術雑誌）, Glasses in the system Eu 2O 3-BaO-B 2O 3 were prepared by a mechanochemical process using B 2O 3, BaO, and Eu 2O 3 as starting materials. X-ray diffraction patterns indicate that amorphous 99 · 5(0 · 2BaO.0 · 8B 2O 3).0 · 5Eu 2O 3 (mol%) powder was obtained using a planetary ball mill. From infrared and Raman spectra, the structural units observed in the milled glass with milling times longer than 5 h were the same as ones in the melt quenched glass. In photoluminescence measurements, the milled 99 · 5(0 · 2BaO.0 · 8B 2O 3).0 · 5Eu 2O 3 glasses showed red emission due to Eu 3+ ions. By heating the milled glass in air at temperatures higher than the crystallization temperature, 99 · 5(0 · 2BaO.0 · 8B 2O 3).0 · 5Eu 2O 3 glass-ceramic was also prepared. The glass-ceramic showed broad emission in the range 380-450 nm from Eu 2+ ions. Crystallization of the milled glass induced reduction of Eu 3+ to Eu 2+ in air. © 2012 Publishing Technology. - Hydroxide ion conduction in Ni-Al layered double hydroxide
Daiju Kubo, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 671, 102, 105, ELSEVIER SCIENCE SA, 2012年04月, ［査読有り］
英語, 研究論文（学術雑誌）, Ionic conductivities of Ni/Al layered double hydroxides (Ni-Al LDHs) intercalated with CO32-, Cl- and OH- were evaluated in the temperature range of 25-80 degrees C under 65-95% relative humidity. X-ray diffraction and Fourier transform infrared measurements confirmed the formation of Ni-Al LDHs intercalated with CO32-, Cl- and OH-. In the AC conductivity measurements, Ni-Al LDH intercalated with CO32- (Ni-Al CO32- LDH) showed the highest ionic conductivity among them. The ionic conductivity of Ni-Al CO32- LDH was 1.3 x 10(-2) S cm(-1) at 80 degrees C under 80% relative humidity. The electromotive force for the water vapor concentration cell using Ni-Al CO32- LDH showed similar behavior with that using anion exchange membrane, indicating that Ni-Al CO32- LDH is a hydroxide ion conductor. Pelletized Ni-Al CO32- LDH was confirmed to work as the electrolyte of alkaline-type direct ethanol fuel cell. (C) 2012 Elsevier B.V. All rights reserved. - Preparation of Co-Al and Ni-Al layered double hydroxide thin films by a sol-gel process with hot water treatment
Kiyoharu Tadanaga, Akira Miyata, Daisuke Ando, Naoko Yamaguchi, Masahiro Tatsumisago
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 62, 1, 111, 116, SPRINGER, 2012年04月, ［査読有り］
英語, 研究論文（学術雑誌）, Using hot water treatment of sol-gel derived precursor gel films, Co-Al and Ni-Al layered double hydroxide (LDH) thin films were prepared. The precursor gel films of Al2O3-CoO or Al2O3-NiO were prepared from cobalt or nickel nitrates and aluminum tri-sec-butoxide using the sol-gel method. Then, the precursor gel films were immersed in a NaOH aqueous solution of 100 A degrees C. Nanocrystallites of Co-Al and Ni-Al LDH were precipitated with the hot water treatment with NaOH solution. The largest amounts of nanocrystals were obtained with a solution of pH = 10 for Co-Al LDH, and with that of pH = 9 for Ni-Al LDH. X-ray diffraction measurements confirmed that this process formed CO3 (2-) intercalated LDHs. Both Co-Al and Ni-Al LDH thin films were confirmed to work as electrodes for electrochemical devices by cyclic voltammogram measurements. - Effect of Mg/Al Ratio on Hydroxide Ion Conductivity for Mg-Al Layered Double Hydroxide and Application to Direct Ethanol Fuel Cells
Kiyoharu Tadanaga, Yoshihiro Furukawa, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 159, 4, B368, B370, ELECTROCHEMICAL SOC INC, 2012年, ［査読有り］
英語, 研究論文（学術雑誌）, Mg-Al layered double hydroxides (LDHs) intercalated with carbonate anions were prepared by the co-precipitation process with Mg/Al = 2, 3 and 4, and the effect of Mg/Al ratio on the ionic conductivity was examined. It is shown that the Mg/Al ratio influences ionic conductivities of Mg-Al CO32- LDH. The conductivity of Mg-Al CO32- LDH with Mg/Al = 2 and 3 exhibited almost the same ionic conductivity of about 1 x 10(-3) S cm(-1) at room temperature under 80% relative humidity, while that of LDH with Mg/Al = 4 was lower by one order of magnitude. Thermal analyses showed that Mg-Al CO32- LDH with Mg/Al = 2 or 3 keeps interlayer water molecules at higher temperatures compared with Mg/Al = 4, suggesting that the interlayer water molecules are strongly held in the interlayer. The strongly held interlayer water molecules are assumed to contribute the high ionic conductivity in Mg-Al CO32- LDH with Mg/Al = 2 and 3. The alkaline type direct ethanol fuel cells using Mg/Al CO32- LDHs as hydroxide conducting electrolyte were confirmed to operate, and larger power was obtained in Mg-Al CO32- LDH with smaller Mg/Al ratio. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.007204jes] All rights reserved. - Novel Inorganic Materials for Polymer Electrolyte and Alkaline Fuel Cells
Kiyoharu Tadanaga
2ND ASEAN - APCTP WORKSHOP ON ADVANCED MATERIALS SCIENCE AND NANOTECHNOLOGY (AMSN 2010), 1455, 29, 32, AMER INST PHYSICS, 2012年, ［査読有り］
英語, 研究論文（国際会議プロシーディングス）, Inorganic materials with high ionic conductivity must have big advantages for the thermal and long term stability when the materials are used as the electrolyte of fuel cells. In the present paper, novel ionic conductive inorganic materials for polymer electrolyte fuel cells (PEFCs) and all solid state alkaline fuel cells (AFCs) that have been developed by our group have been reviewed. PEFCs which can operate in temperature range from 100 to 200 degrees C are intensively studied because of some advantages such as reduction of CO poisoning of Pt catalyst and acceleration of electrode reactions. We showed that the fuel cells using the composite membranes prepared from phosphosilicate gel powder and polyimide precursor can operate in the temperature range from 30 to 180 degrees C. We also found that the inorganic-organic hybrid membranes with acid-base pairs from 3-aminopropyltriethoxysilane and H2SO4 or H3PO4 show high proton conductivity under dry atmosphere, and the membranes are thermally stable at intermediate temperatures. On the other hand, because the use of noble platinum is the serious problem for the commercialization of PEFCs and because oxidation reactions are usually faster than those of acid-type fuel cells, alkaline type fuel cells, in which a non-platinum catalyst can be used, are attractive. Recently, we have proposed an alkaline-type direct ethanol fuel cell (DEFC) using a natural clay electrolyte with non-platinum catalysts. So-called hydrotalcite clay, Mg-Al layered double hydroxide intercalated with CO32-(Mg-Al CO32- LDH), has been proved to be a hydroxide ion conductor. An alkaline-type DEFC using Mg-Al CO32-LDH as the electrolyte and aqueous solution of ethanol and potassium hydroxide as a source of fuel exhibited excellent electrochemical performance. - 水酸化物イオン伝導性無機固体材料の創製
忠永 清治, 辰巳砂 昌弘
電気化学および工業物理化学 : denki kagaku, 79, 8, 630, 633, The Electrochemical Society of Japan, 2011年08月05日
日本語 - Characterization of solid electrolytes prepared from ionic glass and ionic liquid for all-solid-state lithium batteries
Akitoshi Hayashi, Hideki Morishima, Kiyoharu Tadanaga, Masahiro Tatsumisago
Solid State Ionics, 192, 1, 126, 129, 2011年06月16日, ［査読有り］
英語, 研究論文（国際会議プロシーディングス）, Glassy solid electrolytes were prepared by combining the 50Li 2SO4•50Li3BO3 (mol%) ionic glass and the 1-ethyl-3-methyl-imidazolium tetrafluoroborate ([EMI]BF 4) ionic liquid. High-energy ball milling was carried out for the mixture of the inorganic ionic glass and the organic ionic liquid. The ambient temperature conductivity of the glass electrolyte with 10 mol% [EMI]BF 4 was 10-4 S cm-1, which was three orders of magnitude higher than that of the 50Li2SO4•50Li 3BO3 glass. The addition of [EMI]BF4 to the ionic glass decreased glass transition temperature (Tg) of the glass and the decrease of Tg is closely related to the enhancement of conductivity of the glass. Morphology and local structure of the glass electrolyte was characterized. The dissolution of an ionic liquid in an ionic glass with Li+ ion conductivity is a novel way to developing glass electrolytes for all-solid-state lithium secondary batteries. © 2010 Elsevier B.V. All rights reserved. - Improvement of electrochemical performance of all-solid-state lithium secondary batteries by surface modification of LiMn2O4 positive electrode
Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Solid State Ionics, 192, 1, 304, 307, 2011年06月16日, ［査読有り］
英語, 研究論文（国際会議プロシーディングス）, To improve the electrochemical performance of an all-solid-state In/80Li2S2·0P2S5 (electrolyte)/LiMn 2O4 cell, a lithium-titanate thin film was used to coat LiMn2O4. The interfacial resistance between LiMn 2O4 and the electrolyte (measured after initial charging) decreased when the LiMn2O4 particles were coated with lithium-titanate. A cell with lithium-titanate-coated LiMn2O 4 had a higher capacity than a cell with noncoated LiMn 2O4 for current densities in the range 0.064 to 2.6 mA cm- 2. Additionally, a cell with coated LiMn2O4 retained 96% of the 10th-cycle reversible capacity at a current density of 0.064 mA cm- 2 after 50 cycles. © 2010 Elsevier B.V. All rights reserved. - Evaluation of ionic conductivity for Mg-Al layered double hydroxide intercalated with inorganic anions
Yoshihiro Furukawa, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
SOLID STATE IONICS, 192, 1, 185, 187, ELSEVIER SCIENCE BV, 2011年06月, ［査読有り］
英語, 研究論文（学術雑誌）, This study demonstrates that humidity, temperature, and the interlayer anions influence ionic conductivities of Mg-Al layered double hydroxides (LDHs) intercalated with inorganic anions. Results show that Mg-Al LDH intercalated with Br(-) exhibited the highest ionic conductivity among Mg-Al LDHs intercalated with CO(3)(2-), Cl(-), Br(-), NO(3)(-) and SO(4)(2-). Its ionic conductivity was 1.1 x 10(-2) S cm(-1) at 80 degrees C under 80% relative humidity. The electromotive force for the hydroxide ion concentration cell using Mg-Al CO(3)(2-) LDH showed the same behavior with that using an anion exchange membrane, indicating that Mg-Al CO(3)(2-) LDH can be a hydroxide ion conductor. (C) 2010 Elsevier B.V. All rights reserved. - Substituent effects on the glass transition phenomena of polyorganosilsesquioxane particles prepared by two-step acid-base catalyzed sol-gel process
Kenji Takahashi, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 119, 1387, 173, 179, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2011年03月, ［査読有り］
英語, 研究論文（学術雑誌）, Polyorganosilsesquioxanes (RSiO3/2) (R: organic group) particles with different organic groups such as alkyl and aryl groups were prepared using a two-step acid-base catalyzed sol-gel process. Spherical particles were formed at room temperature using the two-step acid-base catalyzed sol-gel process in which trifunctional organoalkoxysilanes with R = methyl, n-propyl, n-butyl, phenyl, and benzyl were used as starting materials. Polyorganosilsesquioxanes with longer alkyl groups or phenethyl group prepared by the two-step acid-base catalyzed sol-gel process were oily material at room temperature. Polyorganosilsesquioxanes with shorter alkyl or aryl groups exhibited the glass transition. In contrast, polyorganosilsesquioxanes with longer alkyl groups showed no glass transition behavior. The occurrence of glass transition phenomena of polyorganosilsesquioxanes was concluded to be strongly dependent on the chain length of organic substituents. (C) 2011 The Ceramic Society of Japan. All rights reserved. - Monolithic electrode for electric double-layer capacitors based on macro/meso/microporous S-Containing activated carbon with high surface area
George Hasegawa, Mami Aoki, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada, Kiyoharu Tadanaga
JOURNAL OF MATERIALS CHEMISTRY, 21, 7, 2060, 2063, ROYAL SOC CHEMISTRY, 2011年, ［査読有り］
英語, 研究論文（学術雑誌）, Macro/meso/microporous carbon monoliths doped with sulfur have been prepared from sulfonated poly(divinylbenzene) networks followed by the activation with CO2 resulted in the activated carbon monoliths with high surface area of 2400 m(2) g(-1). The monolithic electrode of the activated carbon shows remarkably high specific capacitance (175 F g(-1) at 5 mV s(-1) and 206 F g(-1) at 0.5 A g(-1)). - Softening of Octyl-modified phenylsilsesquioxanes
Jelena MacAn, Kiyoharu Tadanaga, Masahiro Tatsumisago
Polimeri, 32, 3-4, 112, 118, 2011年
英語, 研究論文（学術雑誌）, Octyl-modified phenylsilsesquioxanes were prepared from phenyltriethoxysilane and octyltriethoxysilane by two-step acid-base catalysed sol-gel process. Resulting silsesquioxanes were characterized by scanning electron microscopy, X-ray diffraction analysis, gel permeation chromatography and Fourier-transform infrared spectroscopy, while the thermal properties were investigated by differential scanning calorimetry and thermogravimetric analysis. Morphology of polysilsesquioxanes was found to greatly depend on ratio of alkoxides, presumably because of poor miscibility of long alkyl chains which results in a less homogeneous initial mixture. Long alkyl chains also present steric hindrance to condensation of phenyltriethoxysilane eventually preventing the formation of particles. Incomplete condensation caused the decrease of softening temperature from 160°C to ∼50°C and overall poorer thermal stability of polysilsesquioxanes. Decrease in initial temperature of degradation by at least 150°C is probably caused by alkyl chains exposed on the surface of the particles. Increased solvent content improves incorporation of octyl chains due to better solubility and yields polysilsesquioxanes with a more regular structure and a more homogeneous particle size distribution. On the other hand it adversely influences the level of condensation and the softening temperature. - Macroporous carbon monoliths with large surface area for electric double-layer capacitor
George Hasegawa, Mami Aoki, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada, Kiyoharu Tadanaga
Materials Research Society Symposium Proceedings, 1304, 38, 43, 2011年
英語, 研究論文（国際会議プロシーディングス）, Macro/meso/microporous carbon monoliths doped with sulfur have been prepared from sulfonated polydivinylbenzene networks followed by the activation with CO 2 resulted in the activated carbon monoliths with high surface area of 2400 m 2 g -1. The monolithic electrode of the activated carbon shows remarkably high specific capacitance (175 F g -1 at 5 mV s -1 and 206 F g -1 at 0.5 A g -1). © 2011 Materials Research Society. - Electrochemical performance of all-solid-state lithium secondary batteries with Li-Ni-Co-Mn oxide positive electrodes
Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Electrochimica Acta, 55, 28, 8821, 8828, 2010年12月01日, ［査読有り］
英語, 研究論文（学術雑誌）, LiNi1/3Co1/3Mn1/3O2 was applied as a promising material to the all-solid-state lithium cells using the 80Li2S·19P2S5·1P 2O5 (mol%) solid electrolyte. The cell showed the first discharge capacity of 115 mAh g-1 at the current density of 0.064 mA cm-2 and retained the reversible capacity of 110 mAh g-1 after 10 cycles. The interfacial resistance was observed in the impedance spectrum of the all-solid-state cell charged to 4.4 V (vs. Li) and the transition metal elements were detected on the solid electrolyte in the vicinity of LiNi1/3Co1/3Mn1/3O2 by the TEM observations with EDX analyses. The electrochemical performance was improved by the coating of LiNi1/3Co1/3Mn1/3O2 particles with Li4Ti5O12 film. The interfacial resistance was decreased and the discharge capacity was increased from 63 to 83 mAh g-1 at 1.3 mA cm-2 by the coating. The electrochemical performance of LiNi1/3Co1/3Mn1/3O2 was compared with that of LiCoO2, LiMn2O4 and LiNiO2 in the all-solid-state cells. The rate capability of LiNi 1/3Co1/3Mn1/3O2 was lower than that of LiCoO2. However, the reversible capacity of LiNi 1/3Co1/3Mn1/3O2 at 0.064 mA cm -2 was larger than that of LiCoO2, LiMn2O 4 and LiNiO2. © 2010 Elsevier Ltd All rights reserved. - Preparation and Characterization of Methylsilsesquioxane Thin Film Containing Tris(ethylenediamine)cobalt(III) Chloride as a Photobase Generator
Yusuke Uraoka, Kiyoharu Tadanaga, Masahiro Tatsumisago
CHEMISTRY OF MATERIALS, 22, 22, 6125, 6129, AMER CHEMICAL SOC, 2010年11月, ［査読有り］
英語, 研究論文（学術雑誌）, Porous methylsilsesquioxane thin films were prepared using the sol gel process, with tris(ethylenediamine)cobalt(III) chloride (Co(en)(3)Cl(3)) as a photobase generator and polypropylene glycol (PPG) as a template. The generation of amines was confirmed for more than 2 min of ultraviolet (UV) irradiation. The prepared film with the UV irradiation and subsequent heat treatment showed a low refractive index of n = 1.35. Subsequent field-emission scanning electron microscopy (FE-SEM) observations confirmed that shrinkage of the film with the heat treatment was suppressed in the film with UV irradiation. The photogenerated amines from Co(en)(3)Cl(3) worked as a catalyst for the condensation reaction in the gel films during the initial stage of heat treatment. A porous structure was obtained using the thermal decomposition of PPG without collapse of the gel network. - Direct Ethanol Fuel Cell Using Hydrotalcite Clay as a Hydroxide Ion Conductive Electrolyte
Kiyoharu Tadanaga, Yoshihiro Furukawa, Akitoshi Hayashi, Masahiro Tatsumisago
ADVANCED MATERIALS, 22, 39, 4401, +, WILEY-V C H VERLAG GMBH, 2010年10月, ［査読有り］
英語, 研究論文（学術雑誌）, An alkaline-type direct ethanol fuel cell (DEFC) using a natural clay electrolyte with nonplatinum catalysts is proposed. So-called hydrotalcite clay, Mg-Al layered double hydroxide intercalated with CO(3)(2-), is shown to be a hydroxide ion conductor. An alkaline-type DEFC using this natural clay as the electrolyte and aqueous solution of ethanol and potassium hydroxide as a source of fuel exhibits excellent electrochemical performance from room temperature to 80 degrees C. - Electrochemical performance of all-solid-state lithium secondary batteries using Li4Ti5O12 electrode and Li 2S-P2S5 solid electrolytes
Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of Materials Research, 25, 8, 1548, 1553, 2010年08月, ［査読有り］
英語, 研究論文（学術雑誌）, All-solid-state Li-In/Li4Ti5O12 cells using Li2S-P2S5 solid electrolytes were assembled to investigate their electrochemical properties in the wide voltage range of 0-3 V (versus Li). The Li/Li4Ti5O12 cells using 1 M LiPF6 in ethylene carbonate and diethyl carbonate were fabricated for comparison with the all-solid-state cells. The capacity of the all-solid-state cell using the 70Li2S·27P 2S5·3P2O5 (mol%) solid electrolyte decreased with an increase in the current density as well as the cell using the liquid electrolyte. However, the allsolid-state cell was charged and discharged even at a high current density of 10 m A/cm2. The all-solid-state cell was cycled at 1.3 mA/cm2 and retained 90% of the first reversible capacity of about 120 mAh/g after 500 cycles. The all-solid-state cell cycling at 100 °C showed the small overpotential and reversible capacity of about 120 mAh/g at 13 mA/cm2. © 2010 Materials Research Society. - Characterization of proton conducting CsHSO4-CsH2PO4 ionic glasses prepared by the melt-quenching method
T. Sugahara, A. Hayashi, K. Tadanaga, M. Tatsumisago
SOLID STATE IONICS, 181, 3-4, 190, 192, ELSEVIER SCIENCE BV, 2010年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Proton conducting ionic glasses which consist of only isolated ions were successfully prepared from only CsHSO4 and the mixture of CsHSO4 and CsH2PO4 by melt-quenching technique. The 50CsHSO(4)center dot 50CsH(2)PO(4) glass showed the conductivity of 4.2 x 10(-6)S cm(-1) at room temperature. The 50CsHSO(4)center dot 50CsH(2)PO(4) glass exhibited much higher ionic conductivity than CsHSO4 and Cs-2(HSO4)(H2PO4) crystals in a relatively wide temperature range of ambient to 90 degrees C under dry Ar atmosphere, indicating that vitrification of CsHSO4-based solid acids is effective in enhancing their conductivity. (C) 2009 Elsevier B.V. All rights reserved. - Preparation of proton conducting ionic glasses in the systems CsHSO4-MHSO4 (M = Na, K, Rb)
Kiyoharu Tadanaga, Yoshinobu Yamashita, Akitoshi Hayashi, Masahiro Tatsumisago
SOLID STATE IONICS, 181, 3-4, 187, 189, ELSEVIER SCIENCE BV, 2010年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Glass formation in the systems CsHSO4-MHSO4 (M = Na, K, and Rb) was examined by the melt quenching technique using a twin roller, and thermal and ionic conducting properties of the glasses were investigated. To avoid the dehydration reaction, the melts were quenched immediately after the confirmation of complete melting. In the CsHSO4-NaHSO4 system, glasses were obtained at the composition of x = 50, 60 and 70 in xCsHSO(4) (100 - x)NaHSO4 (mol%). However, vitrification was not observed in the CsHSO4-KHSO4 and CsHSO4-RbHSO4 systems. The FT-IR spectra of the glasses obtained by the quenching of molten CsHSO4 and NaHSO4 showed that these glasses consist of isolated HSO4- units, and the glasses were confirmed to be "ionic glass" which consist of only isolated ionic species. From the DSC measurements, the 70CsHSO(4)center dot 30NaHSO(4) ionic glass was found to have the glass transition temperature of 17 degrees C, and crystallization temperature of 58 degrees C. The ionic conductivity of the 70CsHSO(4)center dot 30NaHSO(4) glass is in the order of 10(-5) S cm(-1) at room temperature, which is higher than that of CsHSO4 low-temperature phase. After heating above the crystallization temperature, the ionic conductivity rapidly decreased. These results suggest that vitrified solid acids have advantages in proton conduction compared with the low-temperature phase of solid acids. (C) 2009 Elsevier B.V. All rights reserved. - Influence of copolymerization with alkyltrialkoxysilanes on condensation and thermal behaviour of poly(phenylsilsesquioxane) particles
J. Macan, K. Tadanaga, M. Tatsumisago
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 53, 1, 31, 37, SPRINGER, 2010年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Alkyl-modified phenylsilsesquioxane (PhSSQ) particles were prepared from phenyltriethoxysilane by two-step acid-base catalysed sol-gel process, using alkyltriethoxysilanes of varying chain length (methyl, ethyl, pentyl and octyl), in order to control the softening temperature and thermal stability of the resulting particles. Resulting particles were characterized by scanning electron microscopy, X-ray diffraction analysis, gel permeation chromatography and Fourier-transform infrared spectroscopy, while the thermal properties were investigated by differential scanning calorimetry and thermogravimetric analysis. Increased chain length presents steric hindrance to condensation of phenyltriethoxysilane, leading to decreased softening temperature and thermal stability, while copolymerization with methyltrialkoxysilane leads to increase of softening temperature without influencing the thermal stability. Copolymerization with alkyltrialkoxysilanes is therefore a feasible method to control the softening temperature of PhSSQ particles. By their properties the modified PhSSQ could be grouped in short-chain modified (methyl and ethyl) and long-chain modified (pentyl and octyl) ones. - All-Solid-State Electric Double-Layer Capacitor Using Ion Conductive Inorganic-Organic Hybrid Membrane Based on 3-Glycidoxypropyltrimethoxysilane
M. Aoki, K. Tadanaga, M. Tatsumisago
ELECTROCHEMICAL AND SOLID STATE LETTERS, 13, 4, A52, A54, ELECTROCHEMICAL SOC INC, 2010年, ［査読有り］
英語, 研究論文（学術雑誌）, An all-solid-state electric double-layer capacitor was fabricated with an inorganic-organic hybrid membrane from 3-glycidoxypropyltrimethoxysilane, tetraethoxysilane, and orthophosphoric acid as an electrolyte, and activated carbon fiber cloth as polarized electrodes. The electrochemical properties of the capacitor were studied in a temperature range from room temperature to 100 degrees C. The specific capacitance of the capacitor was 41 F/g at 100 degrees C with 12% relative humidity, and the capacitor showed good cycle performance. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3305323] All rights reserved. - Preparation of needle-like α-Fe2O3 particles and influences of their morphology on the electrochemical behavior in all-solid-state lithium batteries
Hirokazu Kitaura, Kenji Takahashi, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of the Ceramic Society of Japan, 118, 1376, 326, 328, Ceramic Society of Japan, 2010年, ［査読有り］
英語, 研究論文（学術雑誌）, Needle-like α-Fe2O3 particles with the length of 2 μm and the width of 250nm were prepared by thermal decomposition of β-FeOOH and the electrochemical performances in the all-solid-state cells were examined. The cell using needle-like particles with acetylene black as a conductive additive showed the first discharge capacity of about 700 mAhg -1 at the current density of 0.064mA cm-2. The lithium ion and electron conduction path of the electrode was improved by using vapor grown carbon fiber as a conductive additive. The needle-like α-Fe 2O3 particles were compared with α-Fe 2O3 spherical particles
the suitability for the active material of all-solid-state batteries was investigated. ©2010 The Ceramic Society of Japan. All rights reserved. - All-solid-state lithium secondary batteries using LiMn2 O 4 electrode and Li2 S- P2 S5 solid electrolyte
Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of the Electrochemical Society, 157, 4, A407, A411, 2010年, ［査読有り］
英語, 研究論文（学術雑誌）, All-solid-state In/ LiMn2 O4 cells with the 80 Li2 S20 P2 S5 (mol %) solid electrolyte were assembled. Cycle and rate performances were evaluated. The cell showed the first discharge capacity of 55 mAh g-1 at a current density of 0.064 mA cm-2 and retained the reversible capacity of 47 mAh g-1 after 100 cycles. The capacity decreased with increase in the current density, and the overpotential at the beginning of discharge was observed. The discharge capacity was about 23 mAh g-1 at a current density of 2.6 mA cm -2. To identify the cause of the overpotential, impedance measurements were carried out, and resistance components were analyzed by changing the state of charge and by evaluating an all-solid-state Li 1-x Mn2 O4 symmetric cell. The interfacial resistance between the LiMn2 O4 electrode and the solid electrolyte was identified after the charge process. The transmission electron microscopy observation and energy-dispersive X-ray analysis, showed that Mn slightly diffused from LiMn2 O4 to the solid electrolyte at the interface. © 2010 The Electrochemical Society. - Formation of Zn-Al layered double hydroxide thin films intercalated with sulfonated spiropyran
Kiyoharu Tadanaga, Naoko Yamaguchi, Masahiro Tatsumisago
RESEARCH ON CHEMICAL INTERMEDIATES, 35, 8-9, 949, 956, SPRINGER, 2009年11月, ［査読有り］
英語, We prepared Zn-Al layered double hydroxide (LDH) thin films intercalated with sulfonated 1,3',3'-trimethyl-6-nitrospiro[2H-chromene-2,2'-indoline] anions (SP-SO(3) (-)) by immersion of sol-gel derived amorphous Al(2)O(3)-ZnO thin films in hot water containing SP-SO(3)H. Extended interlayer spacing, in comparison to the Zn-Al LDH with carbonate anions, was observed after immersion in distilled water containing SP-SO(3)H at 60 A degrees C for 30 min, indicating that we formed Zn-Al LDH films with SP-SO(3) (-) directly on glass substrates. The merocyanine form of SP-SO(3) (-) was shown by UV spectra to have stabilized in the hydroxide layers of LDH. - Electrochemical performance of SnO-B2O3-V 2O5 glasses as negative electrodes for lithium secondary batteries
Akuoshi Hayashi, Hideyuki Morimoto, Miyuki Nakai, Kiyoharu Tadanaga, Masahiro Tatsumisago
Glass Technology: European Journal of Glass Science and Technology Part A, 50, 5, 273, 276, 2009年10月
英語, 研究論文（学術雑誌）, Glasses in the system SnO-B2O3-V2O 5 were prepared using a planetary ball mill apparatus. Amorphous 45SnO.45B2O3.10V2O5 (mol%) powder was obtained by ball milling for 50 h at a rotation speed of 370 rpm. The glass transition was observed at about 440°C by differential thermal analysis. Electrochemical cells using a conventional liquid electrolyte (1 M LiPF 6 in EC-DEC) were assembled. The cell with the 45 SnO.45B 2O3.10V2O5glass as a working electrode exhibited an initial capacity of 610 mAhg-1, which was smaller than the capacity of the cell using a 50SnO.50B2O3 electrode (710 mAh g-1). On the other hand, the glass with V 2O5 retained a larger capacity of 330 mAh g-1 than the glass without V2O5(180 mAh g-1) after 20 cycles. The addition Of V2O5played an important role in enhancing the cycle performance of cells using SnO-based glass electrodes. - Electrochemical performance of SnO-B2O3-V2O5 glasses as negative electrodes for lithium secondary batteries
Akitoshi Hayashi, Hideyuki Morimoto, Miyuki Nakai, Kiyoharu Tadanaga, Masahiro Tatsumisago
GLASS TECHNOLOGY-EUROPEAN JOURNAL OF GLASS SCIENCE AND TECHNOLOGY PART A, 50, 5, 273, 276, SOC GLASS TECHNOLOGY, 2009年10月, ［査読有り］
英語, 研究論文（学術雑誌）, Glasses in the system SnO-B2O3-V2O5 were prepared using a planetary ball mill apparatus. Amorphous 45SnO(center dot)45B(2)O(3 center dot)10V(2)O(5) (mol%) powder was obtained by ball milling 50 h at a rotation speed of 370 rpm. The glass transition was observed at about 440 degrees C by differential thermal analysis. Electrochemical cells using a conventional liquid electrolyte (1 M LiPF6 in EC-DEC) were assembled. The cell With the 45SnO(center dot)45B(2)O(3 center dot)10V(2)O(5) glass as a working electrode exhibited an initial capacity of 610 mAh g(-1), which was smaller than the capacity of the cell using a 50SnO(center dot)50B(2)O(3) electrode (710 mAh g(-1)). Oil the other hand, the glass With V2O5 retained a larger capacity of 330 mAh g(-1) than the glass without V2O5 (180 mAh g(-1)) after 20 cycles. The addition Of V2O5 played an important role in enhancing the cycle performance of cells using SnO-based glass electrodes. - Template-assisted synthesis of PbTiO3 nanotubes
Per Martin Rorvik, Kiyoharu Tadanaga, Masahiro Tatsumisago, Tor Grande, Mari-Ann Einarsrud
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 29, 12, 2575, 2579, ELSEVIER SCI LTD, 2009年09月, ［査読有り］
英語, 研究論文（学術雑誌）, Nanotubes of ferroelectric lead titanate (PbTiO3) have been made by a template-assisted method. An equimolar Pb-Ti sol was dropped onto porous alumina membranes and penetrated into the channels of the template. Single-phase PbTiO3 perovskite nanotubes were obtained by annealing at 700 degrees C for 6 h. The nanotubes had diameters of 200-400 nm with a wall thickness of approximately 20 nm. Excess PbO or annealing in a Pb-containing atmosphere was not necessary in order to achieve single-phase PbTiO3 nanotubes. The influence of the heating procedure and the sol concentration is discussed. (C) 2009 Elsevier Ltd. All rights reserved. - Mechanochemical synthesis of amorphous solid electrolytes in the system Li2O-B2O3-[EMI]BF4
Akitoshi Hayashi, Daisuke Furusawa, Keiichi Minami, Kiyoharu Tadanaga, Masahiro Tatsumisago
GLASS TECHNOLOGY-EUROPEAN JOURNAL OF GLASS SCIENCE AND TECHNOLOGY PART A, 50, 4, 217, 220, SOC GLASS TECHNOLOGY, 2009年08月, ［査読有り］
英語, 研究論文（学術雑誌）, A new type of solid electrolyte was mechanochemically prepared from lithium pyroborate glass as a Li+ ion conductor, and 1-ethyl-3-methyl-imidazolium tetrafluoroborate ([EMI]BF4) as an ionic liquid. It was revealed from FT-IR and B-11 MAS-NMR measurements that [EMI](+) cations and BF4- anions were not decomposed by high energy ball milling, and were still present in the prepared (100-x)(0.67Li(2)O center dot 0.33B(2)O(3))center dot x[EMI]BF4 (mol%) glasses. DSC analysis suggests that glass transition temperatures were decreased by the addition of [EMI]BF4 to the lithium borate glass. The ambient temperature conductivity of the glass containing 10 mol%, [EMI]BF4 was 10(-4) S cm(-1), Which isoform orders of magnitude higher than that of 67Li(2)O.33B(2)O(3) (mol%) glass, The activation energy for conduction was decreased by the addition of [EMI]BF4. The dissolution of ail ionic liquid in glass is a novel Way to enhance the conductivity of glass electrolytes. - Mechanochemical synthesis of amorphous solid electrolytes in the system Li2O-B2O3-[EMI]BF4
Akitoshi Hayashi, Daisuke Furusawa, Keiichi Minami, Kiyoharu Tadanaga, Masahiro Tatsumisago
Glass Technology: European Journal of Glass Science and Technology Part A, 50, 217, 220, 2009年08月01日
A new type of solid electrolyte was mechanochemically prepared from lithium pyroborate glass as a Li+ ion conductor, and l-ethyl-3-methyl- imidazolium tetrafluoroborate ([EMI]BF4) as an ionic liquid. It was revealed from FT-IR and 11B MAS-NMR measurements that [EMI] + cations and BF4- anions were not decomposed by high energy ball milling, and were still present in the prepared (100-x)(0-67Li2O.0-33B2O3).\[EMI]BF4, (mol%) glasses. DSC analysis suggests that glass transition temperatures were decreased by the addition Of [EMI]BF4 to the lithium borate glass. The ambient temperature conductivity of the glass containing 10 mol% [EMI]BF4 was 10-4 S cm'1, which is four orders of magnitude higher than that of 67Li2O.33B2O3 (mol%) glass. The activation energy for conduction was decreased by the addition Of [EMI]BF4. The dissolution of an ionic liquid in glass is a novel way to enhance the conductivity of glass electrolytes. - High-rate performance of all-solid-state lithium secondary batteries using Li4Ti5O12 electrode
Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of Power Sources, 189, 1, 145, 148, 2009年04月01日, ［査読有り］
英語, 研究論文（学術雑誌）, The all-solid-state Li-In/Li4Ti5O12 cell using the 80Li2S·20P2S5 (mol%) solid electrolyte was assembled to investigate rate performances. It was difficult to obtain the stable performance at the charge current density of 3.8 mA cm-2 in the all-solid-state cell. In order to improve the rate performance, the pulverized Li4Ti5O12 particles were applied to the all-solid-state cell, which retained the reversible capacity of about 90 mAh g-1 at 3.8 mA cm-2. The 70Li2S·27P2S5·3P2O5 glass-ceramic, which exhibits the higher lithium ion conductivity than the 80Li2S·20P2S5 solid electrolyte, was also used. The Li-In/70Li2S·27P2S5·3P2O5 glass-ceramic/pulverized Li4Ti5O12 cell was charged at a current density higher than 3.8 mA cm-2 and showed the reversible capacity of about 30 mAh g-1 even at 10 mA cm-2 at room temperature. © 2008 Elsevier B.V. All rights reserved. - All-solid-state lithium secondary batteries with oxide-coated LiCoO2 electrode and Li2S-P2S5 electrolyte
Atsushi Sakuda, Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of Power Sources, 189, 1, 527, 530, 2009年04月01日, ［査読有り］
英語, 研究論文（学術雑誌）, All-solid-state lithium secondary batteries using LiCoO2 active materials coated with Li2SiO3 and SiO2 oxide films and Li2S-P2S5 solid electrolytes were fabricated and their electrochemical performance was investigated. The electrochemical performace of the all-solid-state cells at a high voltage region was highly improved by using oxide-coated LiCoO2. The oxide coatings are effective in suppressing the formation of an interfacial resistance between LiCoO2 and the solid electrolyte at a high cutoff voltage of 4.6 V (vs. Li). As a result, charge-discharge capacities and cycle performance at the cutoff voltage were improved. The cell with Li2SiO3-coated LiCoO2 showed a large initial discharge capacity of 130 mAh g-1 and a good capacity retention of 110 mAh g-1 after 50th cycles at the cutoff voltage of 4.6 V (vs. Li). © 2008 Elsevier B.V. All rights reserved. - Proton-Conductive Inorganic-Organic Hybrid Membrane Prepared from 3-(2-Aminoethylaminopropyl)triethoxysilane and Sulfuric Acid by the Sol-Gel Method
Teruaki Tezuka, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 156, 1, B174, B177, ELECTROCHEMICAL SOC INC, 2009年, ［査読有り］
英語, 研究論文（学術雑誌）, Proton conductive inorganic-organic hybrid membranes were prepared from 3-(2-aminoethylaminopropyl)triethoxysilane (AEAPTES) and H(2)SO(4) by the sol-gel method. Differential thermal analysis-thermogravimetry measurements revealed that the resulting membranes were thermally stable up to 300 degrees C. From the IR spectra, formation of acid-base pairs by protonation of the amino groups with H(2)SO(4) was confirmed. X-ray diffraction patterns of the membranes showed diffraction peaks corresponding to d-spacings of hexagonal structure, probably indicating that stacking of rodlike polysiloxanes with the acid-base pairs extruded outside. The conductivity of the membrane with the molar ratio of H(2)SO(4)/AEAPTES=2.0 was 1x10(-3) S cm(-1) at 150 degrees C under dry Ar atmosphere. - Modification of interface between LiCoO2 electrode and Li 2S- P2S5 solid electrolyte using Li 2O-SiO2 glassy layers
Atsushi Sakuda, Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of the Electrochemical Society, 156, 1, A27, A32, 2009年, ［査読有り］
英語, 研究論文（学術雑誌）, Effects of modification of the electrode/electrolyte interface with Li 2O-SiO2 thin films on impedance profiles and rate capabilities of all-solid-state In80 Li2S20 P2S 5 glass ceramic/ LiCoO2 cells were investigated. Large resistance was observed at the LiCoO2 -electrode/sulfide-electrolyte interface in all-solid-state cells. The interfacial resistance was decreased by 0.06 wt % oxide coatings on LiCo O2
the effective coatings were a lithium-ion conductive Li2Si O3 glassy film and an insulative SiO 2 film. The Li2Si O3 coating film decreased the interfacial resistance more effectively when the coating amounts increased from 0.06 to 0.6 wt % (film thickness was ca. 10 nm). However, 0.6 wt % of SiO 2 coating exhibited higher interfacial resistance than noncoating because the thick SiO2 coating film acted as a high-resistance layer. Temperature dependence of the interfacial resistance suggests that the resistance decrease was achieved mainly by an increase of pre-exponential factor rather than by a decrease of activation energy for ion conduction at the interface. At room temperature, all-solid-state cells with Li2Si O3 -coated LiCoO2 were discharged even under the high current density, 6.4 mA cm-2. © 2008 The Electrochemical Society. - Electrochemical analysis of Li4 Ti5 O12 electrode in all-solid-state lithium secondary batteries
Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of the Electrochemical Society, 156, 2, A114, A119, 2009年, ［査読有り］
英語, 研究論文（学術雑誌）, All-solid-state Li-In Li4 Ti5 O12 cells using the 80 Li2 S20 P2 S5 solid electrolyte were assembled to investigate their rate performances and impedance behaviors. Furthermore, Li Li4 Ti5 O12 cells using 1 mol dm-3 LiP F6 dissolved in ethylene carbonate and diethyl carbonate were fabricated for comparison to the all-solid-state cells. In the all-solid-state cells, resistance attributable to the lithium-ion transfer from the solid electrolyte to Li4 Ti5 O12 spinel phase was observed during the lithium insertion into Li4 Ti5 O12 spinel phase during the discharge process. Results clarified that the cells using the solid electrolyte showed higher resistance and larger activation energy for this lithium-ion transfer than the cells using the liquid electrolyte. Resistance was not observed in the charge process. The all-solid-state cell showed the average charge voltage of 1.9 V (vs Li) and reversible capacity of ∼80 mAh g-1 at the charge current density of 1.3 mA cm-2 and the discharge current density of 0.064 mA cm-2. © 2008 The Electrochemical Society. - Structural change and proton conductivity of phosphosilicate gel-polyimide composite membrane for a fuel cell operated at 180 degrees C
Kiyoharu Tadanaga, Yoshiki Michiwaki, Teruaki Tezuka, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF MEMBRANE SCIENCE, 324, 1-2, 188, 191, ELSEVIER SCIENCE BV, 2008年10月
英語, 研究論文（学術雑誌）, Proton-conductive composite membranes were prepared from phosphosilicate gel powders and a commercially available polyimide precursor. The conductivity of a composite membrane containing 75 wt.% of gel powder was about 2.5 x 10(-3) S cm(-1) at 180 degrees C under more than 0.4%RH. However, under dry N(2) atmosphere at 180 degrees C, the conductivity decreased with time because of the formation of Si(5)O(PO(4))(6) crystals. The open circuit voltage (OCV) of a fuel cell in which the phosphosilicate gel-polyimide composite sheet was used as electrolyte and Pt-loaded carbon paper sheets were used as electrodes in the membrane electrode assembly. was about 0.85 V at 80 degrees C with a flow of hydrogen and air, and the OCV decreased to about 0.70 V at temperatures higher than 100 degrees C. At 180 degrees C under 2%RH, the cell OCV was 0.67 V; power density of about 14 mW cm(-2) was obtained with current density of 40 mA cm(-2). Consequently, the fuel cell using the composite sheet as an electrolyte was verified to operate at temperatures from room temperature to 180 degrees C. (C) 2008 Elsevier B.V. All rights reserved. - Proton conductive inorganic-organic hybrid membranes prepared from 3-aminopropyltriethoxysilane and phosphoric acid by the sol-gel method
Teruaki Tezuka, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
SOLID STATE IONICS, 179, 21-26, 1151, 1154, ELSEVIER SCIENCE BV, 2008年09月
英語, 研究論文（学術雑誌）, Proton conductive inorganic-organic hybrid membranes with acid-base pairs have been prepared from 3-aminopropyltriethoxysilane and phosphoric acid by the sol-gel method. The self-standing membranes obtained are represented as poly(3-aminopropylsilsesquioxane)-H(3)PO(4) (PAPS-H(3)PO(4)) membranes. Infrared absorption spectra of the PAPS-H(3)PO(4) films showed that amino groups of PAPS were protonated by phosphoric acid, indicating the formation of acid-base pairs. X-ray diffraction patterns of the PAPS-H(3)PO(4) membranes showed diffraction peaks attributed to hexagonal structure, which is probably formed by stacking of rodlike polysiloxane with the acid-base pairs extruded outside. The conductivities of the PAPS-H(3)PO(4) membranes with a molar ratio Of H(3)PO(4)/APTES = 1.0 was 4 x 10(-4) S cm(-1) at 150 degrees C under dry condition. (c) 2008 Elsevier B.V. All rights reserved. - Mechanochemical Synthesis of α-Fe2O3 Nanoparticles and Their Application to All-Solid-State Lithium Batteries
H. Kitaura, K. Takahashi, F. Mizuno, A. Hayashi, K. Tadanaga, M. Tatsumisago
J. Power Sources, 183, 1, 418, 421, ELSEVIER SCIENCE BV, 2008年08月
英語, 研究論文（学術雑誌）, alpha-Fe2O3 fine particles have been prepared by a mechanochemical process and a solution process. alpha-Fe2O3 nanoparticles with aggregates composed of the several tens nm primary particles were produced by the mechanochemical process. The nanoparticles were applied to the electrode as an active material for all-solid-state lithium batteries and the electrochemical properties of the cell were investigated. Typical charge-discharge curves, as seen in the liquid type cell using the alpha-Fe2O3 nanoparticles as an electrode were observed in the all-solid-state cell. The first discharge capacity of the cell of about 780 mAh g(-1) was, however, smaller than the capacity of a cell using alpha-Fe2O3 particles prepared by the solution process, which were monodispersed particles of 250 nm without aggregates. In order to develop electrochemical performance of all-solid-state batteries, it is important to use the electrode particles without aggregation which lead to the formation of good solid-solid interface between active material and solid electrolyte particles. (C) 2008 Elsevier B.V. All rights reserved. - Coatings made by sol-gel and chemical nanotechnology
M. A. Aegerter, R. Almeida, A. Soutar, K. Tadanaga, H. Yang, T. Watanabe
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 47, 2, 203, 205, SPRINGER, 2008年08月
英語 - Anti-reflective properties of nano-structured alumina thin films on poly(methyl methacrylate) substrates by the sol-gel process with hot water treatment
Kiyoharu Tadanaga, Naoko Yamaguchi, Yusuke Uraoka, Atsunori Matsuda, Tsutomu Minami, Masahiro Tatsumisago
THIN SOLID FILMS, 516, 14, 4526, 4529, ELSEVIER SCIENCE SA, 2008年05月
英語, 研究論文（学術雑誌）, Alumina gel films were coated on poly(methyl methacrylate) (PMMA) substrates using the sol-gel process, and pseudo-boehmite nanocrystals of several tens of nanometers were precipitated on the surface of the alumina gel films through immersion in hot water. It was found that the PMMA substrates, which were coated with the pseudo-boehmite nanocrystals precipitated alumina, exhibited very slight incident-angle dependence in transmittance up to 60 degrees. The reflectance of PMMA substrates coated with the nanocrystal-precipitated alumina was less than 0.8% in the visible light region. (C) 2007 Elsevier B.V. All rights reserved. - Characterization of ramiform precipitates formed on SiO2-TiO2 gel coatings by electric field hot water treatment
Atsunori Matsuda, Kumpei Kobayashi, Toshihiro Kogure, Mototsugu Sakai, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
JOURNAL OF NON-CRYSTALLINE SOLIDS, 354, 12-13, 1263, 1266, ELSEVIER SCIENCE BV, 2008年02月
英語, 研究論文（学術雑誌）, The shape of the precipitates on sol-gel derived SiO2-TiO2 coatings at the negative electrode changed from granular to ramiform, by applying an electric field to the substrates during a hot water treatment, whereas such changes in the shape of titania nanocrystals with the electric field were not observed at the positive electrode. The granular and ramiform. precipitates were identified as anatase (TiO2) and hydrated titania (n(TiO2) center dot mH(2)O), respectively. The ramiform shape of the titania, precipitates became significant with increasing the applied voltage, while the coatings gradually became dark-colored due to the reduction of Ti4+ to Ti3+. The coatings with ramiform precipitates showed an excellent wettability for water. (c) 2007 Published by Elsevier B.V. - Improvement of high-rate performance of all-solid-state lithium secondary batteries using LiCoO2 coated with Li2O-SiO2 glasses
Atsushi Sakuda, Hirokazu Kitaura, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
ELECTROCHEMICAL AND SOLID STATE LETTERS, 11, 1, A1, A3, ELECTROCHEMICAL SOC INC, 2008年
英語, 研究論文（学術雑誌）, Development of rate capability is one of the most important issues to be solved in all-solid-state lithium secondary batteries. The electrochemical performance of these batteries has been highly improved by coating LiCoO2 particles with Li2O-SiO2 thin film. The interfacial resistance between LiCoO2 and the glass-ceramic electrolyte was decreased by those coatings. The rate capabilities of the cells using the coated LiCoO2 particles were superior to that of the cell using noncoated LiCoO2. The Li2SiO3 coating was more effective than the SiO2 coating in enhancing rate performance, suggesting that lithium-ion conductivity of the coating materials is important for high-rate performance. (C) 2007 The Electrochemical Society. - Electrochemical performance and structural change during charge-discharge reaction of SnO-P2O5 glassy electrodes in rechargeable lithium batteries
Takanori Konishi, Akitoshi Hayashi, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
JOURNAL OF NON-CRYSTALLINE SOLIDS, 354, 2-9, 380, 385, ELSEVIER SCIENCE BV, 2008年01月
英語, 研究論文（学術雑誌）, Using melt quenching, SnO-P2O5 glasses were synthesized, and then characterized as negative electrode materials for lithium secondary batteries. The electrochemical cell Li/the 67SnO center dot 33P(2)O(5) (mol%) glass maintained reversible capacity of about 400 mAh g(-1) for 20 cycles. The cell's cycle performance was better than those of cells using Sn-based crystals such as Sn, SnO, and SnO2 as working electrodes. The local structure of the 67SnO center dot 33P(2)O(5) glass after lithium insertion and extraction was analyzed. Li-7 MAS-NMR measurements revealed that the Li-Sn alloy was formed during the first lithium insertion to the glass and that alloying-dealloying of the Li-Sn domain occurred during charge-discharge cycling. The glassy matrix surrounding the alloy was investigated using P-31 MAS-NMR. The P2O74- group might be changed to PO43- and P2O64- groups by the first lithium insertion to the glass. The formed phosphate groups remained after the consecutive lithium extraction process. An all-solid-state cell with the 67SnO center dot 33P(2)O(5) glass exhibited the discharge capacity of 750 mAh g(-1) at the first cycle, which is greater than that of a cell with the 50SnO center dot 50B(2)O(3) glass. (C) 2007 Published by Elsevier B.V. - Glass transition and thermal softening of poly(phenylsilsesquioxane) particles prepared using two-step acid-base catalyzed sol-gel process
Kenji Takahashi, Kiyoharu Tadanaga, Akitoshi Hayashi, Atsunori Matsuda, Masahiro Tatsumisago
JOURNAL OF NON-CRYSTALLINE SOLIDS, 354, 2-9, 700, 704, ELSEVIER SCIENCE BV, 2008年01月
英語, 研究論文（学術雑誌）, Spherical poly(phenylsilsesquioxane) (PhSiO(3)/2) particles prepared using a two-step acid-base catalyzed sol-gel process had a 'core-shell' structure: their inside and outside parts were composed respectively of PhSiO(3/2) species with low and high molecular weights. The PhSiO(3/2) particles prepared using the two-step acid-base catalyzed sol-gel process exhibited two glass transition temperatures (T,). The PhSiO(3/2) species in the inside of the particles showed glass transition behavior at a lower temperature than those in the outside of the particles, indicating that T(g) is mainly dependent on the materials' respective molecular weights. (C) 2007 Elsevier B.V. All rights reserved. - Effects of various additives during hot water treatment on the formation of alumina thin films for superhydrophobic surfaces
Kiyoharu Tadanaga, Naoko Yamaguchi, Atsunori Matsuda, Tsutomu Minami, Masahiro Tatsumisago
JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY, 22, 3-4, 387, 394, BRILL ACADEMIC PUBLISHERS, 2008年
英語, 研究論文（学術雑誌）, Alumina thin films, with roughness of 20-50 nm and pseudoboehmite nanocrystals precipitated on the surface, were formed through immersion of porous alumina gel films in hot water. By coating hydrolyzed fluoroalkylsilane on such a thin film with slight roughness, a superhydrophobic surface with high transparency was obtained. Additives such as hydrochloric acid, sodium hydroxide, sodium chloride, manganese chloride, ethanol and ethylene glycol were dissolved in the hot water, and the effects of these additives on pseudobochmite nanocrystal formation during hot water treatment were examined. Pseudoboehmite nanocrystals were formed at pH = 5.5-8.0 when an acid or a base was added to water. The addition of inorganic salts and alcohol diminished the boehmite nanocrystal formation. These results suggest that the boehmite nanocrystals were formed through a dissolution and re-precipitation process. (c) Koninklijke Brill NV, Leiden, 2008 - Structure of polyphenylsilsesquioxane particles prepared by two-step acid-base catalyzed sol-gel process and formation of hollow particles
Kenji Takahashi, Kiyoharu Tadanaga, Akitoshi Hayashi, Atsunori Matsuda, Kiyofumi Katagiri, Masahiro Tatsurnisago
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, 7, 9, 3307, 3312, AMER SCIENTIFIC PUBLISHERS, 2007年09月
英語, 研究論文（学術雑誌）, Spherical polyphenylsilsesquioxane (PhSiO(3/2)) particles, one of the inorganic-organic hybrid materials, were synthesized by a two-step acid-base catalyzed sol-gel process, and hollow particles were successfully prepared by washing the as-prepared particles with organic solvents. It was found that the inside and outside parts of the as-prepared particles were composed of PhSiO(3/2) species with relatively low and high molecular weight, respectively, i.e., the PhSiO(3/2) particles had a kind of "core-shell" structure. Because the core portion in the as-prepared particles was soluble in ethanol and tetrahydrofuran, hollow particles were obtained through washing the as-prepared PhSiO(3/2) particles with ethanol or tetrahydrofuran. Furthermore, the molecular weight of the as-prepared particles was varied by the concentration of phenyltriethoxysilane used as a starting alkoxide. As a result of the variation of the molecular weight, the hollow PhSiO(3/2) particles with different stabilities against organic solvents were formed. - Fabrication of convex-shaped polybenzylsilsesquioxane micropatterns by the electrophoretic sol-gel deposition process using indium tin oxide substrates with a hydrophobic-hydrophilic-patterned surface
Kenji Takahashi, Kiyoharu Tadanaga, Atsunori Matsuda, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 43, 1, 85, 91, SPRINGER, 2007年07月
英語, 研究論文（学術雑誌）, Polybenzylsilsesquioxane (BnSiO3/2) particles become a supercooled liquid through a heat treatment above the glass transition temperature (T (g)) of the particles. Micropatterns of BnSiO3/2 thick films with high transparency were obtained by the electrophoretic deposition of the BnSiO3/2 particles on indium tin oxide (ITO)-coated substrates with a hydrophobic-hydrophilic-patterned surface and subsequent heating above T (g) of the particles. It was found that the control of electrophoretic deposition conditions, in which the amounts of the particles deposited on the substrates were changed, led to two types of micropatterning processes of the BnSiO3/2 thick films. In the first process, the particles were selectively deposited on the hydrophilic areas after the electrophoretic deposition. In the second process, the particles were deposited on the whole area of the ITO-coated substrate with hydrophobic-hydrophilic patterns after the electrophoretic deposition. Due to the difference in wettability of BnSiO3/2 molten liquids between hydrophobic and hydrophilic surfaces, the molten liquids on the hydrophobic areas, which were obtained by heating above T (g) of the particles, migrated toward the hydrophilic areas. In both the processes, convex-shaped BnSiO3/2 micropatterns with high transparency were fabricated only on the hydrophilic areas after a heat treatment above T (g) of the particles. - Direct formation of Mg-Al-layered double-hydroxide films on glass substrate by the sol-gel method with hot water treatment
Naoko Yamaguchi, Daisuke Ando, Kiyoharu Tadanaga, Masahiro Tatsumisago
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 90, 6, 1940, 1942, WILEY-BLACKWELL PUBLISHING, INC, 2007年06月
英語, 研究論文（学術雑誌）, Amorphous Al(2)O(3)-MgO thin films with an Mg/Al ratio of unity were prepared on glass substrates by the sol-gel method with a heat treatment at 300 degrees C for 30 min. By immersing the films in water containing sodium hydroxide (pH 10-13) at 100 degrees C, nano-crystals of Mg-Al-layered double hydroxide (LDH) with a hexagonal structure, which is called hydrotalcite and the most basic composition of LDH, were precipitated on the amorphous Al(2)O(3)-MgO films. The maximum amount of Mg-Al nanocrystals was obtained when the film was immersed in basic solution of pH 12. - Inorganic-organic hybrid membranes prepared from 3-aminopropyltriethoxysilane and sulfuric acid as anhydrous proton conductors
Teruaki Tezuka, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
SOLID STATE IONICS, 178, 7-10, 705, 708, ELSEVIER SCIENCE BV, 2007年04月
英語, 研究論文（学術雑誌）, W, have prepared novel proton conducting inorganic-organic hybrid membranes from 3-aminopropyltriethoxysilane (APTES) and H(2)SO(4) by the sol-gel method. The resulting poly(3-aminopropylsitsesquioxane sulfate or hydrogensulfate) (PAPS-SO(4)/-HSO(4)) membranes were thermally stable up to 300 degrees C. From the results of IR spectra, it was confirmed that sulfuric acids in the membranes react with amino groups of PAPS to form ion complexes. XRD patterns of the PAPS-SO(4)/-HSO(4) membranes showed diffraction peaks assigned to hexagonal structure, which is probably formed by stacking of rodlike polysiloxanes with the ion complexes extruded outside. The PAPS-SO(4)/-HSO(4) membranes with a molar ratio of H(2)SO(4)/APTES = 1.0 showed high proton conductivities of 2 x 10(-3) S cm(-1) at 200 degrees C under dry condition. (c) 2007 Elsevier B.V All rights reserved. - Characterization of proton-conductive SiO2-H3PW12O40 composites prepared by mechanochemical treatment
Atsunori Matsuda, Yusuke Daiko, Tomohiko Ishida, Kiyoharu Tadanaga, Masahiro Tatsumisago
Solid State Ionics, 178, 7-10, 709, 712, 2007年04月, ［査読有り］
英語, 研究論文（学術雑誌）, Dodecatungstophosphoric acid (H3PW12O40·nH2O) and SiO2 were mechanically milled, and a new class of proton-conductive composites was prepared. The conductivity of WPA-SiO2 composite with P/Si = 0.1 was 3 × 10- 3 S cm- 1 at 30 °C and 60% relative humidity (RH), which was higher than that (6 × 10- 4 S cm- 1) of the corresponding mixture before milling. In the medium temperature range, the WPA-SiO2 composite retained relatively high conductivity of 1 × 10- 4 S cm- 1 at 100 °C and 2% RH, which was higher by one order of magnitude than that of the mixture without milling. These higher values of conductivity for the milled composite can be ascribed to the presence of mechanochemically formed surface defects such as Si-OH and P-OH groups. © 2007 Elsevier B.V. All rights reserved. - Thermoplastic and thermosetting properties of polyphenylsilsesquioxane particles prepared by two-step acid-base catalyzed sol-gel process
Kenji Takahashi, Kiyoharu Tadanaga, Atsunori Matsuda, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 41, 3, 217, 222, SPRINGER, 2007年03月
英語, 研究論文（学術雑誌）, Polyphenylsilsesquioxane (PhSiO(3/2)) particles were synthesized by a two-step acid-base catalyzed sol-gel process, in which phenyltriethoxysilane used as a starting alkoxide was hydrolyzed and condensed in the first step under two different acid-catalyzed conditions. The PhSiO(3/2) particles prepared under an acid-catalyzed process without using a solvent were thermally hardened after the first heating up to 200 degrees C. In contrast, the PhSiO(3/2) particles prepared under an acid-catalyzed process with ethanol as a solvent were thermally softened with the repeated heating processes up to 200 degrees C. From the gel permeation chromatography measurements, it was found that the average molecular weight of the particles prepared with the use of ethanol was decreased in comparison with that of the particles prepared without using ethanol. The addition of ethanol in the sols during hydrolysis and condensation reaction under the acid-catalyzed process caused the decrease in the average molecular weight, which should result in the changes of thermal property of PhSiO(3/2) particles from thermosetting to thermoplastic. - Preparation and characterization of polyaminophenylsilsesquioxane particles by two-step acid-base-catalyzed sol-gel process
Kenji Takahashi, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
CHEMISTRY LETTERS, 36, 2, 324, 325, CHEMICAL SOC JAPAN, 2007年02月
英語, 研究論文（学術雑誌）, Spherical polyaminophenylsilsesquioxane (H2NC6H4SiO3/2) particles were prepared by a two-step acid-base-catalyzed sol-gel process, and we found that the particles showed the glass transition behavior. Amino groups in the H2NC6H4SiO3/2 particles were partially changed to amido ones by acetylation using acetic anhydride. - Antireflective properties of flowerlike alumina thin films on soda-lime silica glass substrates prepared by the sol-gel method with hot water treatment
Naoko Yamaguchi, Kiyoharu Tadanaga, Atsunori Matsuda, Tsutomu Minami, Masahiro Tatsumisago
THIN SOLID FILMS, 515, 7-8, 3914, 3917, ELSEVIER SCIENCE SA, 2007年02月
英語, 研究論文（学術雑誌）, The antireflective (AR) properties of Al(2)O(3) thin films with small roughness on soda-lime silica glass substrates were investigated. By immersing porous Al(2)O(3) thin films in hot water, nanocrystals of pseudoboehmite were formed on the film surface. The reflectance of the Al(2)O(3) films treated with hot water for 30 min was less than 0.5% in the wavelength region of 360-620 nm. The Al(2)O(3) films with small roughness resulting from the hot water treatment become denser from their surface to the interface with the substrate, and the refractive index gradient brought by the structure results in excellent AR properties. (c) 2006 Elsevier B.V. All rights reserved. - 酸-塩基触媒ゾルーゲル法を用いたポリフェニルシルセスキオキサン微粒子作製におけるフェニルトリエトキシシランの濃度の効果
高橋 賢司, 忠永 清治, 松田 厚範, 林 晃敏, 辰巳砂 昌弘
日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi, 115, 1338, 131, 135, 公益社団法人日本セラミックス協会, 2007年02月01日
英語, Spherical polyphenylsilsesquioxane particles were prepared by a two-step acid-base catalyzed sol-gel process, in which various amounts of ethanol were used as a solvent to vary the concentration of phenyltriethoxysilane (PhSi(OEt)_3) used as a starting alkoxide. The decrease in the PhSi (OEt)_3 concentration led to the decrease in the average molecular weight and glass transition temperature of the polyphenylsilsesquioxanes. Thus, the change of the PhSi (OEt)_3 concentration in the preparation of polyphenylsilsesquioxane particles by the two-step acid-base catalyzed sol-gel process is an effective means to control the glass transition temperature of the particles. - Effects of phenyltriethoxysilane concentration in starting solutions on thermal properties of polyphenylsilsesquioxane particles prepared by a two-step acid-base catalyzed sol-gel process
Kenji Takahashi, Kiyoharu Tadanaga, Atsunori Matsuda, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 115, 1338, 131, 135, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2007年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Spherical polyphenylsilsesquioxane particles were prepared by a two-step acid-base catalyzed sol-gel process, in which various amounts of ethanol were used as a solvent to vary the concentration of phenyltriethoxysilane (PhSi (OEt)(3)) used as a starting alkoxide. The decrease in the PhSi (OEt) 3 concentration led to the decrease in the average molecular weight and glass transition temperature of the polyphenylsilsesquioxanes. Thus, the change of the PhSi (OEt)(3) concentration in the preparation of polyphenylsilsesquioxane particles by the two-step acid-base catalyzed sol-gel process is an effective means to control the glass transition temperature of the particles. - Preparation of Proton Conductive Composites with CsHSO4/CsH2PO4 and Phosphosilicate Gel
T. Tezuka, K. Tadanaga, A. Hayashi, M. Tatsumisago
Solid State Ionics, 177, 2463, 2466, 2007年 - Effects of phenyltriethoxysilane concentration in starting solutions on thermal properties of polyphenylsilsesquioxane particles prepared by a two-step acid-base catalyzed sol-gel process
Kenji Takahashi, Kiyoharu Tadanaga, Atsunori Matsuda, Akitoshi Hayashi, Masahiro Tatsumisago
Journal of the Ceramic Society of Japan, 115, 1338, 131, 135, Ceramic Society of Japan, 2007年
英語, 研究論文（学術雑誌）, Spherical polyphenylsilsesquioxane particles were prepared by a two-step acid-base catalyzed sol-gel process, in which various amounts of ethanol were used as a solvent to vary the concentration of phenyltriethoxysilane (PhSi(OEt)3) used as a starting alkoxide. The decrease in the PhSi(OEt)3 concentration led to the decrease in the average molecular weight and glass transition temperature of the polyphenylsilsesquioxanes. Thus, the change of the PhSi(OEt)3 concentration in the preparation of polyphenylsilsesquioxane particles by the two-step acid-base catalyzed sol-gel process is an effective means to control the glass transition temperature of the particles. - Direct formation of Zn-Al layered double hydroxide thin films intercalated with various organic anions through the sol-gel method with hot water treatment
Naoko Yamaguchi, Kiyoharu Tadanaga, Masahiro Tatsumisago
ADVANCES IN NANOMATERIALS AND PROCESSING, PTS 1 AND 2, 124-126, 635, +, TRANS TECH PUBLICATIONS LTD, 2007年
英語, 研究論文（国際会議プロシーディングス）, Zn-Al layered double hydroxide (LDH) thin films intercalated with various organic anions were prepared by immersion of sol-gel derived amorphous Al2O3-ZnO thin films in hot water containing organic salts like sodium dodecyl sulfate (SDS), sodium p-toluenesulfonate, and benzenecarboxylates. In all the systems, extended interlayer spacing of the Zn-Al LDH was observed after immersion in distilled water with the organic salts in comparison to the LDH with carbonate anions, indicating that we have succeeded in direct formation of Zn-Al LDH films with various organic anions on the substrates. It is suggested that divalent anions such as terephthalate ion have higher selectivity than monovalent anions. - Micropatterning for vinylsilsesquioxane-titania hybrid gel films with ultraviolet light irradiation
Atsunori Matsuda, Ryohei Ogawa, Yusuke Daiko, Kiyoharu Tadanaga, Masahiro Tatsumisago
JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY, 20, 1, 101, 105, TECHNICAL ASSOC PHOTOPOLYMERS,JAPAN, 2007年
英語, 研究論文（学術雑誌）, Transparent vinylsilsesquioxane-titania (ViSiO(3/2)-TiO(2)) hybrid gel films were prepared from vinyltriethoxysilane and titanium tetrabutoxide by the sol-gel method. UV light irradiation partly cleaved Si-C bonds and addition-polymerized C = C bonds to form Si-O-Si and Si(CH(2))(n)Si linkage in the hybrid films due to the photosensitizing effect of TiO(2) component. The refractive index and dynamic hardness of the hybrid films increased, and the thickness and contact angle for water decreased by the structural changes induced by the UV light irradiation. in comparison with several kinds of organosilsesquioxane-titania (RSiO(3/2)-TiO(2), R=methyl, ethyl, phenyl and benzyl) hybrid gel films, ViSiO(3/2)-TiO(2) was found to show the largest increase in hardness due to the formation Of Si(CH2)nSi linkage. Micropatterning was successfully performed on the ViSiO(3/2)-TiO(2) hybrid films by UV light irradiation through a photomask. The patterned film can be applied as a printing plate with the surface energy differences as well as a micro-optical component with the surface profiles and refractive index differences. - Mechanochemical Synthesis of Proton Conductive M3H(SO4)2 (M=Na,K, Rb) Crystatls
T. Tezuka, Y. Yamashita, A. Hayashi, K, Tadanaga, M. Tatsumisago
Chem. Sustainable Development, 15, 237, 241, 2007年 - Preparation of α-Fe2O3 Electrode Materials Via Solution Process and Their Electrochemical Properties in All-Solid-State Lithium Batteries
H. Kitaura, K. Takahashi, F. Mizuno, A. Hayashi, K. Tadanaga, M. Tatsumisago
J. Electrochem. Soc., 154, 7, A725, A729, ELECTROCHEMICAL SOC INC, 2007年
英語, 研究論文（学術雑誌）, alpha-Fe2O3 particles of various sizes were prepared by a solution process and were applied to the electrodes for all-solid-state lithium rechargeable batteries. The prepared alpha-Fe2O3 was monodispersed particles with sizes controlled from about 250 nm to 3.7 mu m. Their electrochemical properties were examined for the all-solid-state cells with highly conductive Li2S-P2S5 solid electrolytes and the influences of the particle size of alpha-Fe2O3 on the electrochemical performance of the cells were investigated. The first discharge capacities increased with decreasing the particle size of alpha-Fe2O3 and the cell using the smallest alpha-Fe2O3 particles of 250 nm showed the highest capacity of 1050 mAh g(-1). The charge-discharge reaction mechanism in the all-solid-state cells was investigated by means of X-ray diffraction and was revealed to be similar to that in conventional cells with a liquid electrolyte. The lithium intercalation to alpha-Fe2O3 occurred in the initial stage of the first discharge only in the cases using alpha-Fe2O3 particles with small crystallite size, large specific surface area and large pore volume. By controlling the cutoff voltage, the all-solid-state cell retained the constant capacity of about 130 mAh g(-1) for 15 cycles at the current density of 0.064 mA cm(-2). The rate capability at 25 degrees C and temperature dependence of the first discharge capacity in the all-solid-state cells were also investigated. The cell at 60 degrees C showed the larger first-discharge capacity of 940 mAh g(-1) at the current density of 1.27 mA cm(-2). (C) 2007 The Electrochemical Society. - Formation of anti-reflective alumina films on polymer substrates by the sol-gel process with hot water treatment
Naoko Yamaguchi, Kiyoharu Tadanaga, Atsunori Matsuda, Tsutomu Minami, Masahiro Tatsumisago
SURFACE & COATINGS TECHNOLOGY, 201, 6, 3653, 3657, ELSEVIER SCIENCE SA, 2006年12月
英語, 研究論文（学術雑誌）, Al(2)O(3) films with a small roughness of less than 100 nm prepared through the sol-gel method have been found to show anti-reflective (AR) property in a wide wavelength region on polymer substrates such as poly(ethylene terephtalate) (PET), poly carbonate (PC), and poly(methyl methacrylate) (PMMA). The highest AR effects were obtained on PMMA substrates, the refractive index of which is similar to that of porous Al(2)O(3) gel films. The reflectance of PET, PC, and PMMA substrates coated with flowerlike Al(2)O(3) was less than 1.5, 1.0, and 0.8% in the visible light region, respectively. (c) 2006 Elsevier B.V. All rights reserved. - Hot-water treatment of sol-gel derived SiO2-TiO2 microparticles and application to electrophoretic deposition for thick films
Atsunori Matsuda, Yugo Higashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
JOURNAL OF MATERIALS SCIENCE, 41, 24, 8101, 8108, SPRINGER, 2006年12月
英語, 研究論文（学術雑誌）, SiO2-TiO2 spherical microparticles of about 0.7 mu m in diameter were prepared by the sol-gel method. Anatase nanocrystals were formed in the microparticles and their specific surface area was increased after a hot-water treatment at 90 degrees C. From the changes in the concentration of I-2 photocatalytically generated from KI aqueous solution, the activity of the SiO2-TiO2 microparticles was found to increase with increasing the hot-water treatment time. Particulate, thick films were electrophoretically deposited on indium tin oxide (ITO)-coated glass substrates using the anatase nanocrystal-precipitated SiO2-TiO2 microparticles. The thickness of the electrophoretically deposited particulate film increased to be approximately 10 mu m with an increase in applied voltage. The resultant thick film showed a high photocatalytic activity. - Inorganic-organic hybrid membranes with anhydrous proton conduction prepared from 3-aminopropyltriethoxysilane and sulfuric acid by the sol-gel method
Teruaki Tezuka, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 128, 51, 16470, 16471, AMER CHEMICAL SOC, 2006年12月
英語, 研究論文（学術雑誌） - Preparation and application of alumina- and titania- nanocrystals-dispersed thin films via sol-gel process with hot water treatment
Kiyoharu Tadanaga
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 40, 2-3, 281, 285, SPRINGER, 2006年12月
英語, 研究論文（学術雑誌）, A process to prepare nanocrystals-dispersed thin films at low temperatures using a hot water treatment of the gel films, and application of these nanocomposite thin films were demonstrated. When amorphous Al2O3 gel films were immersed in a hot water, we found that boehmite nanocrystals were formed on the surface of the films. In the hot water treatment of Al2O3-ZnO amorphous films, Zn-Al layered double hydroxide (LDH) was found to be formed on the films. When the SiO2-TiO2 gel films containing poly(ethylene glycol) were treated in a hot water, anatase nanocrystals were formed on the surface and inside of the films, and for the gel films without an organic polymer, the anatase nanocrystals were formed only on the surface of the films. In the hot water treatment of SiO2-TiO2 gel films under a vibration, titania nanosheets were found to be precipitated, instead of anatase nanocrysltals. Since formation of nanocrystals on the substrates using a hot water treatment is very mild conditions as the precipitation of crystals, we believe this process will open new application fields of nanocystals-dispersed thin films. - Micropatterning of transparent poly(benzylsilesquioxane) thick films prepared by the electrophoretic sol-gel deposition process using a hydrophobic-hydrophilic-patterned surface
Kenji Takahashi, Kiyoharu Tadanaga, Akitoshi Hayashi, Masahiro Tatsumisago, Atsunori Matsuda
Journal of the American Ceramic Society, 89, 12, 3832, 3835, 2006年12月, ［査読有り］
英語, 研究論文（学術雑誌）, Poly(benzylsilsesquioxane) (BnSiO3/2) particles show glass transition behavior, and the particles become a supercooled liquid when they are heated at temperatures above the glass transition temperature. Contact angles of BnSiO3/2 molten liquid on the hydrophobic surface with fluoroalkylsilane and hydrophilic surface with silica were found to be around 77° and 12°, respectively. Using the difference in wettability for BnSiO3/2 molten liquid between the hydrophobic and hydrophilic surfaces, micro-patterns of transparent BnSiO3/2-thick films were formed by the electrophoretic deposition of BnSiO3/2 particles on indium tin oxide substrates with hydrophobic-hydrophilic patterns and subsequent heating above the glass transition temperature. © 2006 The American Ceramic Society. - Operation of PEFC using composite sheets composed of phosphosilicate gels and thermally stable organic polymers
Atsunori Matsuda, Naoki Nakamoto, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
SOLID STATE IONICS, 177, 26-32, 2437, 2441, ELSEVIER SCIENCE BV, 2006年10月
英語, 研究論文（学術雑誌）, Thermally stable, flexible, and proton conductive composite sheets have been prepared from phosphosilicate (P(2)O(5)-SiO(2), P/Si = 1 in mole ratio) gel powder and several kinds of organic polymers. The organic polymers examined were polyimide (PI), polyamideimide (PAI), polyvinylidene fluoride (PVdF) and styrene-ethylene-butylenes-styrene elastomer (SEBS). PI and PAI effectively improved the chemical durability of the composite sheets by depressing the leaching of phosphoric acid from the gel. PVdF and SEBS provided the composite sheets with an excellent flexibility. Fuel cells using the membrane electrode assembly (MEA) composed of the composite sheet as an electrolyte and Pt-loaded carbon paper sheets as electrodes operated at temperatures in the range from room temperature to medium temperatures (similar to 150 degrees C) . (c) 2006 Elsevier B.V. All rights reserved. - High lithium ion conducting glass-ceramics in the system Li2S-P2S5
Fuminori Mizuno, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
SOLID STATE IONICS, 177, 26-32, 2721, 2725, ELSEVIER SCIENCE BV, 2006年10月
英語, 研究論文（学術雑誌）, Highly ion-conductive Li2S-P2S5 glass-ceramic electrolytes were prepared by controlling the compositions and heat treatment temperatures of the glasses. The 70Li(2)S.30P(2)S(5) (mol%) glass-ceramic heated at 360 degrees C showed the highest conductivity of 3.2 x 10(-3) S cm(-1) at room temperature and the lowest activation energy of 12 kJ mol(-1) for conduction in the binary system Li2S-P2S5. The outstanding property was attributed to both the precipitation of the new crystal as a metastable phase and the increase in crystallinity of the phase. With increasing heat treatment temperatures, the metastable phase changed into thermodynamically stable phases such as the Li4P2S6 crystal by heat treatment up to 550 degrees C, resulting in low conductivities of the glass-ceramics. It was, thus, found that the formation of superionic metastable phases by heating the Li2S-P2S5 glasses is responsible for the marked enhancement on the conducting properties of the glass-ceramics. (c) 2006 Elsevier B.V. All rights reserved. - High rate performances of all-solid-state In/LiCoO2 cells with the Li2S-P2S5 glass-ceramic electrolytes
Fuminori Mizuno, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
SOLID STATE IONICS, 177, 26-32, 2731, 2735, ELSEVIER SCIENCE BV, 2006年10月
英語, 研究論文（学術雑誌）, Composite positive electrodes for all-solid-state In/LiCoO2 cells with Li2S-P2S5 glass-ceramic electrolytes were designed in order to improve rate performances of the cells. In the composite positive electrodes with LiCoO2 in 40 wt.% and the glass-ceramic electrolyte in 60 wt.%, suitable lithium ion conducting paths were formed, and the addition of vapor grown carbon fiber (VGCF) made it easier to form electron-conducting paths. The solid-state cell kept high capacities of about 90 mAh g(-1) even under high current densities of over 1 mA cm(-2) after charged and discharged under low current densities for 100 cycles. It was, thus, suggested that high rate performances of all-solid-state cells were achieved by controlling the mixed state of composite electrodes and the operating condition during charge-discharge cycles. (c) 2006 Elsevier B.V. All rights reserved. - Formation of electrode-electrolyte interface by lithium insertion to SnS-P2S5 negative electrode materials in all-solid-state cells
Akitoshi Hayashi, Takanori Konishi, Kiyoharu Tadanaga, Masahiro Tatsumisago
SOLID STATE IONICS, 177, 26-32, 2737, 2740, ELSEVIER SCIENCE BV, 2006年10月
英語, 研究論文（学術雑誌）, All-solid-state cells with the SnX-P2X5 (X = S and 0) glassy electrodes and the ce:inf > S/ce:inf > S-P2S5 glass-ceramic electrolytes were fabricated, and their electrochemical performance was examined. The 67SnS.33P(2)S(5) (mol%) glassy electrode exhibited higher capacity of about 400 mAhg(-1) than the 67SnO.33P(2)O(5) glass and the SnS crystal. In the case of using the 67SnS.33P(2)S(5) glass as an active material, the cell using the composite electrode consisting of active material and conductive additive (acetylene-black) powders showed almost the same charge-discharge behaviors as the cell using the conventional composite electrode consisting of active material, conductive additive, and the solid electrolyte powders. The similarity of cell performance suggests that the highly Li+ ion conductive ce:inf > S/ce:inf > S-P2S5 solid electrolytes were formed by electrochemical Li insertion to the SnS-P2S5 electrode; the self-formed electrolyte supplied a Li+ ion conduction path in the composite electrode. A close electrode-electrolyte interface, which is important to develop all-solid-state batteries, would be established by utilizing the self-formation process of solid electrolyte. (c) 2006 Elsevier B.V. All rights reserved. - Lithium ion conducting solid electrolytes prepared from Li2S, elemental P and S
Fuminori Mizuno, Takamasa Ohtomo, Akitoshi Hayashi, Kiyoharu Tadanaga, Masahiro Tatsumisago
SOLID STATE IONICS, 177, 26-32, 2753, 2757, ELSEVIER SCIENCE BV, 2006年10月
英語, 研究論文（学術雑誌）, Glassy electrolyte of 80Li(2)S.20P(2)S(5) (mol%) was prepared by mechanical milling of Li2S and the mixture of elemental phosphorus and sulfur, which was mechanically milled in advance (two-step process). The glass showed relatively low conductivity of 3.9 x 10(-5) S cm(-1) at room temperature, while the glass-ceramic obtained by crystallization exhibited higher conductivity of 4.3 x 10(-4) S cm(-1) than the pristine glass. Raman spectroscopy revealed that the glass was mainly composed of the PS43- ions and slightly contained homo bonds such as P-P and S-S bonds. The mechanochemical synthesis using the two-step process was effective in reducing the homo bonds in the glassy electrolytes. The glass-ceramic, in which a highly ion-conductive thio-LISICON analog was precipitated, was mainly composed of the PS43- ions and very small amounts of S-S bonds. Cyclic voltammmetry demonstrated that the Li2S-P-S glass-ceramic had wide electrochemical window of 5 V. (c) 2006 Elsevier B.V. All rights reserved. - Characterization and electrophoretic deposition of poly(phenylsilsesquioxane)-titania hybrid particles prepared by the sol-gel method
Kenji Takahashi, Kiyoharu Tadanaga, Masahiro Tatsumisago, Atsunori Matsuda
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 89, 10, 3107, 3111, WILEY-BLACKWELL, 2006年10月
英語, 研究論文（学術雑誌）, Poly(phenylsilsesquioxane)-titania (PhSiO3/2-TiO2) hybrid particles were prepared from phenyltriethoxysilane and titanium tetra-n-butoxide by the sol-gel method. Fourier transform infrared spectra showed that PhSiO3/2 and the TiO2 components were hybridized through Si-O-Ti bonds. The refractive index of the particles was monotonically increased from 1.57 to 1.62 with an increase in the TiO2 content. The PhSiO3/2-TiO2 particles were electrophoretically deposited on indium tin oxide (ITO)-coated glass substrates to form opaque, thick films about 3 mu m in thickness. When the mole ratio x in (1-x)PhSiO3/2.xTiO(2) was equal to or less than 0.05, the deposited PhSiO3/2-TiO2 films became transparent with a heat treatment at 400 degrees C because of the thermal sintering of the particles. - Direct formation of Zn-Al layered double hydroxide films with high transparency on glass substrate by the sol-gel process with hot water treatment
Naoko Yamaguchi, Tomohiko Nakamura, Kiyoharu Tadanaga, Atsunori Matsuda, Tsutomu Minami, Masahiro Tatsumisago
CRYSTAL GROWTH & DESIGN, 6, 7, 1726, 1729, AMER CHEMICAL SOC, 2006年07月
英語, 研究論文（学術雑誌）, Amorphous Al(2)O(3)-ZnO thin films with various Zn/Al ratios were prepared on glass substrates by the sol-gel method with a heat treatment at 400 degrees C for 30 min followed by immersion of the films in distilled water at 100 degrees C to form nanocrystalline Zn-Al layered double hydroxide (LDH) with hexagonal structure. Zn-Al LDH nanocrystals were precipitated on the amorphous Al(2)O(3)-ZnO films with various Zn/Al ratios, and the maximum amount of nanocrystals was formed on the film of the Zn/Al atomic ratio of unity. Zn-Al LDH crystals with the size of 200-500 nm have been precipitated on glass substrates through hot water treatment at temperatures lower than 100 degrees C. - Formation of convex shaped-poly(phenylsilsesquioxane) micropatterns on indium tin oxide substrates with hydrophobic-hydrophilic patterns using the electrophoretic sol-gel deposition method
Kenji Takahashi, Kiyoharu Tadanaga, Atsunori Matsuda, Akitoshi Hayashi, Masahiro Tatsumisago
JOURNAL OF MATERIALS RESEARCH, 21, 5, 1255, 1260, CAMBRIDGE UNIV PRESS, 2006年05月
英語, 研究論文（学術雑誌）, Hydrophobic-hydrophilic patterns were formed on indium tin oxide substrates, and thick films of poly(phenylsilsesquioxane) (PhSiO3/2) particles, prepared by the sol-gel process, were selectively deposited onto hydrophilic areas of the substrates by electrophoresis. The films composed of PhSiO3/2 particles became transparent with morphological changes from aggregates of particles to a continuous phase after a heat treatment. After heat treatment at 200 degrees C, convex-shaped PhSiO3/2 micropatterns were formed on the hydrophilic region of the pattern. Moreover, the height of micropatterns was controlled by the deposition time. This patterning technique has a wide variety of applications such as fabrication of micro-optical components. - Platelike crystal growth of Zn-Al layered double hydroxide by hot water treatment of sol-gel derived Al2O3-ZnO films on glass substrate
N Yamaguchi, T Nakamura, K Tadanaga, A Matsuda, T Minami, M Tatsumisago
CHEMISTRY LETTERS, 35, 2, 174, 175, CHEMICAL SOC JAPAN, 2006年02月
英語, 研究論文（学術雑誌）, We have successfully immobilized Zn-Al layered double hydroxide (LDH) directly on glass substrates through the sol-gel method with hot water treatment. Al2O3-ZnO thin films were originally prepared on glass substrates by the sol-gel method with a heat treatment at 400 degrees C for 30 min, and then the films were immersed in distilled water at 100 degrees C for 15 min to form nanocrystalline Zn-Al LDH with hexagonal structure. - Micropatterning of inorganic-organic hybrid thick films from vinyltriethoxysilane
Kiyoharu Tadanaga, Toshitsugu Sueki, Atsunori Matsuda, Tsutomu Minami, Masahiro Tatsumisago
Journal of the Ceramic Society of Japan, 114, 1325, 125, 127, Ceramic Society of Japan, 2006年, ［招待有り］
英語, 研究論文（学術雑誌）, Inorganic-organic hybrid films with a maximum thickness of about 40 μm were prepared from vinyltriethoxysilane (VTES) through a sol-gel process. UV light from a high-pressure mercury lamp was irradiated through a photomask on the hybrid films from VTES. IR and 29Si NMR spectra of the coating films showed that C = C bonds in VTES were polymerized by UV irradiation. Micropatterns with a maximum height of about 40 μm were formed by the etching of unirradiated area of the films. - Micropatterning of phenylsilsesquioxane thick films by the electrophoretic sol-gel deposition process using ITO substrates with a hydrophobic-hydrophilic patterned surface
Kiyoharu Tadanaga, Kenji Takahashi, Masahiro Tatsumisago, Atsunori Matsuda
Key Engineering Materials, 314, 159, 164, 2006年
英語, 研究論文（国際会議プロシーディングス）, Micropatterns of phenylsilsesquioxane thick films have been prepared by electrophoretic sol-gel deposition using ITO-coated substrates with a hydrophobic-hydrophilic patterned surface. After the electrophoretic deposition, phenylsilsesquioxane thick films were formed only on hydrophilic areas on the pattern. These thick films obtained immediately after the electrophoretic deposition were opaque due to light scattering. However, phenylsilsesquioxane particles in the films were morphologically changed from aggregates of the spherical particles to continuous phase by a heat treatment process, and finally convex shaped phenylsilsesquioxane micropatterns were formed only on the hydrophilic areas. - External-field hot-water treatments of sol-gel derived SiO 2-TiO2 coatings for surface nanostructure control
Atsunori Matsuda, Mototsugu Sakai, Toshihiro Kogure, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of the Ceramic Society of Japan, 114, 1325, 26, 35, Ceramic Society of Japan, 2006年
英語, This review paper is focused on the area of titania nanocoatings prepared from sol-gel derived films by hot-water treatment under external reaction fields to design their functionality through the control of their surface morphology and crystallinity at low processing temperatures. First, the formation of titania nanocrystalline coatings at low temperatures by wet chemical procedures is briefly reviewed. Second, a concept of material design based on an external-field hot-water treatment for sol-gel derived films and the effects of the external fields on the formation of titania nanocrystals from the sol-gel derived films are discussed. Finally, promising characteristics of the resultant titania nanocrystal-dispersed coatings with unique morphology are described. External fileds of vibrations and electric voltages affect the nanostructure of titania crystallites formed on SiO 2-TiO2 gel coatings during hot-water treatment. Without the external fields granular anatase nanocrystals of 30-50 nm in size are formed on the coatings during the hot-water treatment, whereas the shape of the precipitates becomes sheetlike by applying a vibration to the substrate during hot-water treatment. Similar changes in shape of the precipitates on the coatings are also observed, and ramiform (branchlike) crystallites are formed at the negative electrode by applying an electric field between the substrates. The sheetlike and ramiform crystallites are mainly composed of a hydrated titania, m(TiO2)· nH2O, with the lepidocrocite-like layered structure with a rf-spacing of 0.6-0.8 nm. Titania nanosheets are characterized by a large surface-to-volume ratio, which gives rise to the excellent wettability for water and antifogging properties. Processing temperatures for the preparation of the coatings are lower than 100°C under atmospheric pressure, so that the coatings have a great potential for applications to various substrates including organic polymers with poor heat resistance. - All-Solid-State Rechargeable Lithium Batteries Using SnX-P2X5（X=S and O）Amorphous Negative Electrodes
A. Hayashi, T. Konishi, K. Tadanaga, T. Minami, M. Tatsumisago
Research on Chemical Intermediates, 32, 5-6, 497, 506, 2006年 - Electrophoretic Deposition of Sol-Gel Derived V2O5 Microparticles and Its Application for Cathodes for Li-Secondary Batteries
A. Matsuda, Y. Higashi, K. Tadanaga, T. Minami, M. Tatsumisago
Key Engineering Materials, 314, 107, 111, 2006年 - Titania Nanocrystals-Dispersed Coatings from SiO2-TiO2 Gel Films through Hydrolysis and Dissolution
A. Matsuda, T. Kogure, H. Muto, M. Sakai, K. Tadanaga, T. Minami, M. Tatsumisago
Key Engineering Materials, 317-318, 565, 568, 2006年 - Electrophoretic deposition of sol-gel derived V2O5 microparticles and its application for cathodes for Li-secondary batteries
A. Matsuda, Y. Higashi, K. Tadanaga, T. Minami, M. Tatsumisago
ELECTROPHORETIC DEPOSITION: FUNDAMENTALS AND APPLICATIONS II, 314, 107, 111, TRANS TECH PUBLICATIONS LTD, 2006年, ［査読有り］
英語, 研究論文（学術雑誌）, V2O5 microparticles of 0.3-0.6 mu m in diameter were prepared from VO(O-C3H7i)(3) in an ethanol solution by the sol-gel method. The addition of poly(ethylene glycol) and acetyl acetone into the sols was effective to control the size and spherical shape Of V2O5 particles. The particles thus obtained were amorphous having a layered structure with hydrated water, and transformed into an orthorhombic phase at 500 degrees C through a glassy state. The microparticles were positively charged in I-2-containing acetone, so that they were electrophoretically deposited on the cathode with applied DC voltage. The prepared particles were used as a cathode in an electrochemical cell with a lithium metal as an anode. Discharge capacity of a rechargeable cell of Li/LiPF6 (ethylene carbonate + diethylene carbonate) / V2O5-based composite was 110-180 mAh g(-1) when the potential range and current density were 2-4 V and 0.1 m-Acm(-2), respectively. - Titania nanocrystals-dispersed coatings from SiO(2)-TiO(2) gel films through hydrolysis and dissolution
A. Matsuda, T. Kogure, H. Muto, M. Sakai, K. Tadanaga, T. Minami, M. Tatsumisago
SCIENCE OF ENGINEERING CERAMICS III, 317-318, 565, 568, TRANS TECH PUBLICATIONS LTD, 2006年, ［査読有り］
英語, 研究論文（学術雑誌）, Anatase nanocrystals were formed on sol-gel derived SiO(2)-TiO(2) coatings with water vapor or hot water treatments. The anatase nanocrystals were precipitated through hydrolysis of Si-O-Ti bonds, dissolution Of SiO(2) component, migration of hydrolyzed titania species, and nucleation and growth. The process temperatures can be lowered below 60 degrees C, which should open new applications. It was found that the crystal habit of titania was changes from roundish anatase to sheet-like titania by applying vibration during the hot water treatment. The nanosheets were identified as hydrated titania, TiO(2) mH(2)O, with layerd structure. The coatings of hydrated titania showed high photocatalytic activities and excellent antifogging properties due to their unique morphology. - External-field hot-water treatments of sol-gel derived SiO2-TiO2 coatings for surface nanostructure control - A review
A Matsuda, M Sakai, T Kogure, K Tadanaga, M Tatsumisago
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 114, 1325, 26, 35, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2006年01月, ［査読有り］
英語, 研究論文（学術雑誌）, This review paper is focused on the area of titania nanocoatings prepared from sol-gel derived films by hot-water treatment under external reaction fields to design their functionality through the control of their surface morphology and crystallinity at low processing temperatures. First, the formation of titania nanocrystalline coatings at low temperatures by wet chemical procedures is briefly reviewed. Second, a concept of material design based on an external-field hot-water treatment for sol-gel derived films and the effects of the external fields on the formation of titania nanocrystals from the sol-gel derived films are discussed. Finally, promising characteristics of the resultant titania nanocrystal-dispersed coatings with unique morphology are described. External fileds of vibrations and electric voltages affect the nanostructure of titania crystallites formed on SiO2-TiO2 gel coatings during hot-water treatment. Without the external fields granular anatase nanocrystals of 30-50 nm in size are formed on the coatings during the hot-water treatment, whereas the shape of the precipitates becomes sheet-like by applying a vibration to the substrate during hot-water treatment. Similar changes in shape of the precipitates on the coatings are also observed, and ramiform (branchlike) crystallites are formed at the negative electrode by applying an electric field between the substrates. The sheetlike and ramiform crystallites are mainly composed of a hydrated titania, m (TiO2) center dot nH(2)O, with the lepidocrocite-like layered structure with a d-spacing of 0.6-0.8 urn. Titania nanosheets are characterized by a large surf ace-to-volume ratio, which gives rise to the excellent wettability for water and antifogging properties. Processing temperatures for the preparation of the coatings are lower than 100 degrees C under atmospheric pressure, so that the coatings have a great potential for applications to various substrates including organic polymers with poor heat resistance. - Micropatterning of inorganic-organic hybrid thick films from vinyltriethoxysilane
K Tadanaga, T Sueki, A Matsuda, T Minami, M Tatsumisago
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 114, 1325, 125, 127, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2006年01月, ［査読有り］
英語, 研究論文（学術雑誌）, Inorganic-organic hybrid films with a maximum thickness of about 40 mu m were prepared from vinyltriethoxysilane (VTES) through a sol-gel process. UV light from a high-pressure mercury lamp was irradiated through a photomask on the hybrid films from VTES. IR and Si-29 NMR spectra of the coating films showed that C=C bonds in VTES were polymerized by UV irradiation. Micropatterns with a maximum height of about 40 mu m were formed by the etching of unirradiated area of the films. - Preparation of proton conducting composites by mechanical milling for phosphorus-containing solid acids
A Matsuda, T Tezuka, Y Nono, K Tadanaga, T Minami, M Tatsumisago
SOLID STATE IONICS, 176, 39-40, 2899, 2904, ELSEVIER SCIENCE BV, 2005年12月
英語, 研究論文（学術雑誌）, Solid acids such as A1H(2)P(3)O(10)(.)2H(2)O, Zr(HPO(4))(2)(.)H(2)O, arnorphous-AIPO(4), and A1H(3)(PO(4))(2)(.)3H(2)O showed low conductivities of 10(-8)- 10(-7) S cm(-1) at 130 degrees C, whereas mechanical milling for these solid acids was found to improve the conductivities by 2 to 4 orders of magnitude. On the other hand, a large amount of phosphorus was leached out during a durability test after milling. XRD showed the solid acids were transformed to amorphous or crystal-amorphous composites by mechanical milling. (31)P MAS NMR spectra indicated that the intensities of the bands due to Q(3) and Q 4 units decreased and that of the peak due to Q(0) units increased. The increase in conductivity and the decrease of chemical durability of the mechanically milled solid acids are probably caused by the fort-nation Q0 units, i.e., orthophosphoric acid, in the resultant composites due to the disruption of inorganic structures. (c) 2005 Elsevier B.V. All rights reserved. - Preparation of proton conductive composites with cesium hydrogen sulfate and phosphosilicate gel
M Tatsumisago, T Tezuka, A Hayashi, K Tadanaga
SOLID STATE IONICS, 176, 39-40, 2909, 2912, ELSEVIER SCIENCE BV, 2005年12月
英語, 研究論文（学術雑誌）, We prepared a new composite material composed of cesium hydrosulfate (CSHSO(4)) and phosphosilicate gel (P(2)O(5)-SiO(2) gel); a high temperature form of the former exhibits exceptionally high proton conductivity at above 144 degrees C without humidification and the latter is one of the high proton conductors working under low humidity in a temperature range tip to around 150 degrees C. High electric conductivities of 10(-5) to 10(-2) Scm(-1) of the composite were observed under dry N(2) atmosphere in a wide temperature range from ambient to 160 degrees C and no steep change in conductivity at around 144 degrees C was observed. In X-ray diffraction patient of CsHSO(4)-(P(2)O(5)-SiO(2) gel) composites, new diffraction peaks were observed and original peaks of CsHSO(4) disappeared. A reaction of CsHSO(4) and orthophosphoric acid (H(3)PO(4)), which is probably formed by the hydrolysis Of P(2)O(5)-SiO(2) gel, would occur to produce a new crystalline phase with high proton conductivity at lower temperatures. (c) 2005 Elsevier B.V. All rights reserved. - Utilization of glass papers as a support for proton conducting inorganic-organic hybrid membranes from 3-glycidoxypropyltrimethoxysilane, tetraalkoxysilane and orthophosphoric acid
T Tezuka, K Tadanaga, A Matsuda, A Hayashi, M Tatsumisago
SOLID STATE IONICS, 176, 39-40, 3001, 3004, ELSEVIER SCIENCE BV, 2005年12月
英語, 研究論文（学術雑誌）, Proton conductive inorganic -organic membranes supported by glass paper were prepared from 3-glycidoxypropyltrimethoxysilane, tetraalkoxysilane and orthophosphoric acid. Hybrid membranes with a thickness of 70-80 mu m were obtained by using two types of glass papers. The open circuit voltage of the test cell using the membrane supported by class paper was 0.75 V. A power density of about 80 mW cm(-2) was obtained with a current density of 300 mA cm(-2) at a cell temperature of 130 degrees C under 7% relative humidity. (c) 2005 Elsevier B.V. All rigths reserved. - Inorganic-organic hybrid films using epoxycyclohexylethyltrimethoxysilane and orthophosphoric acid for PEFC operated at medium temperatures
K Tadanaga, H Yoshida, A Matsuda, T Minami, M Tatsumisago
SOLID STATE IONICS, 176, 39-40, 2997, 2999, ELSEVIER SCIENCE BV, 2005年12月
英語, 研究論文（学術雑誌）, Proton conductive inorganic -organic hybrid films, which show high proton conductivity at temperatures higher than 100 degrees C with low humidification, have been prepared from epoxycyclohexylethyltiimethoxysilane (EHTMS), 3-glycidoxypropyltrimethoxysilane (GPTMS) and H(3)PO(4) by the sol-gel method. Self-supporting, flexible films with a thickness of about 150 to 300 pm were obtained. The ionic conductivity of the films increased with an increase in the relative humidity and was about 1 X 10(-2) S cm(-1) under 25% relative humidity at 130 degrees C. For a fuel cell with the hybrid film (P/Si= 1.5) as an electrolyte under H(2) and air at 130 degrees C, 17% relative humidity, the open circuit voltage of the cell was about 2 2 0.9 V and a power of about 40 mW cm(-2) was obtained with current density of 110 mA cm(-2). It was also confirmed that the test cell can operate 2 more than 10 h with a current density of 100 mA cm(-2). (c) 2005 Elsevier B.V. All rights reserved. - Mechanochemical synthesis of lithium ion conducting glasses and glass-ceramics in the system Li2S-P-S
T Ohtomo, F Mizuno, A Hayashi, K Tadanaga, M Tatsumisago
SOLID STATE IONICS, 176, 31-34, 2349, 2353, ELSEVIER SCIENCE BV, 2005年10月
英語, 研究論文（学術雑誌）, The Li2S-P-S glasses were prepared by mechanical milling from the mixture of Li2S and elemental phosphorus and sulfur. The conductivity of the glasses was 2.0 x 10(-5) S cm(-1) at room temperature. Raman spectroscopy revealed that the glasses mainly consisted of PS43- and Li+ ions, and partially contained homo bonds such as P-P and S-S bonds. Heat treatment of the glasses above the crystallization temperature produced glass-ceramics in which the crystal analogous to thio-LISICON with high conductivity was precipitated. The precipitation of the thio-LISICON analog enhanced the conductivity of the glasses, and the conductivity of the glass-ceramics was 3.9 x 10(-4) S cm(-1) at room temperature. The Li2S-P-S glass-ceramics contained mainly 4 ions with a small amount of S-S bonds, and the amounts of the P-P and S-S homo bonds in the glass-ceramics were diminished by heat treatment than those in the glasses. The local structure of the Li2S-P-S glass-ceramics was similar to that of the Li2S-P2S5 glass-ceramics prepared from Li2S and P2S5 using as raw materials. (c) 2005 Elsevier B.V. All rights reserved. - All-solid-state lithium secondary batteries with SnS-P2S5 negative electrodes and Li2S-P2S5 solid electrolytes
A Hayashi, T Konishi, K Tadanaga, T Minami, M Tatsumisago
JOURNAL OF POWER SOURCES, 146, 1-2, 496, 500, ELSEVIER SCIENCE BV, 2005年08月
英語, 研究論文（学術雑誌）, The 80SnS(center dot)20P(2)S(5) (mol%) amorphous material was prepared by a mechanical milling technique. The obtained material was fine powders with a few micrometers in size. All-solid-state cells with the SnS center dot P2S5 amorphous electrode and the Li2S center dot P2S5 glass-ceramic electrolyte, where a continuous P2S5 sulfide network between both the materials was formed, were fabricated. The cells exhibited high reversible capacity of over 400 mAh g(-1) for 50 cycles at room temperature. The addition of P2S5 as a glass former to SnS improved cell capacity and cyclability, suggesting that P2S5 network played an important role in enhancing the availability of SnS as an electrode material. (c) 2005 Elsevier B.V. All rights reserved. - Design of composite positive electrode in all-solid-state secondary batteries with Li2S-P2S5 glass-ceramic electrolytes
F Mizuno, A Hayashi, K Tadanaga, M Tatsumisago
JOURNAL OF POWER SOURCES, 146, 1-2, 711, 714, ELSEVIER SCIENCE BV, 2005年08月
英語, 研究論文（学術雑誌）, Composite positive electrodes for all-solid-state ][n/LiCoO2 cells with Li2S-P2S5 glass-ceramic electrolytes were designed in order to improve the high rate performances of the cells. The composite electrodes consisted of the active material, the solid electrolyte and carbon conductive additive powders. The cell with vapor grown carbon fiber (VGCF) as a conductive additive was charged and discharged at current densities of over I mA cm(-2), while the cell with acetylene black (AB) did not work as a rechargeable battery. The difference in the cell performances was explained from viewpoints of the morphology of the carbon additives. VGCF formed a more continuous electron conducting path in the composite positive electrode than AB. The cells without conductive additives were charged and discharged by increasing LiCoO2 content in the composite positive electrode. Using a suitable morphology and amount of component powders for composite electrodes is a key to improve rate performances of all-solid-state secondary batteries. (c) 2005 Elsevier B.V All rights reserved. - Electrical and electrochemical properties of Li2S-P2S5-P2O5 glass-ceramic electrolytes
T Ohtomo, F Mizuno, A Hayashi, K Tadanaga, M Tatsumisago
JOURNAL OF POWER SOURCES, 146, 1-2, 715, 718, ELSEVIER SCIENCE BV, 2005年08月
英語, 研究論文（学術雑誌）, The electrical and electrochemical properties of the Li2S-P2S5-P2O5 glass-ceramic electrolytes were investigated. The 80Li(2)S. (20-X)P(2)S(5)(.)xP(2)O(5) (mol%) glass-ceramics were prepared by a mechanical milling and a subsequent heat treatment. The 80Li(2)S(.)19P(2)S(5) (.) 1P(2)O(5) glass-ceramic showed the high lithium ion conductivity of 7.4 x 10(-4) S cm(-1) at room temperature and the low activation energy of 34 U mol(-1) for conduction. The addition of a small amount of P2O5 to the Li2S-P2S5 sulfide system lowered the electronic conductivity and enhanced the electrochemical stability of the glass-ceramic electrolytes. All-solid-state In/LiCoO2 cells with the 80Li(2)S (.) 19P(2)S(5) (.) 1P(2)O(5) glass-ceramic as a solid electrolyte worked as lithium secondary batteries at room temperature. The cells maintained high discharge capacity of about 100 mAh g(-1) for 10 cycles. (c) 2005 Elsevier B.V All rights reserved. - Structural changes in RSiO3/2-TiO2 hybrid films with UV irradiation and their photocatalytic micropatterning
T Sasaki, A Matsuda, K Tadanaga, M Tatsumisago
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 113, 1320, 519, 524, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2005年08月, ［査読有り］
英語, 研究論文（学術雑誌）, UV light irradiation induced structural changes of the cleavage of silicon-carbon bonds and elimination of organic groups in organosilsesquioxane-titania (RSiO3/2-TiO2,R=methyl, ethyl, phenyl and benzyl) hybridfilms due to the photocatalytic effect of TiO2 component. Phenyl and benzyl groups tended to remain in the films after the cleavage of Si-C bonds presumably due to their higher stability of aromatic rings and lager steric effect. The refractive index and dynamic hardness of all the hybrid films increased, and the thickness and contact angle for water decreased by the structural changes induced by the UV light irradiation. On the basis of these changes in film properties, micropatterning was successfully performed on the RSiO3/2-TiO2 hybrid films by UV light irradiation through a photomask. The micropatterns thus obtained should be applicable to a printing plate using the surface energy differences as well as a micro-optical component using the surface profiles and refractive index changes. - Lowering of preparation temperatures of anatase nanocrystals-dispersed coatings via sol-gel process with hot water treatment
A Matsuda, T Matoda, K Tadanaga, T Minami, M Tatsumisago, T Kogure
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 88, 6, 1421, 1426, WILEY-BLACKWELL, 2005年06月
英語, 研究論文（学術雑誌）, A longer period of time was necessary to form anatase nanocrystals on silica-titania gel coatings at lower hot water treatment temperature, whereas considerable amounts of anatase nanocrystals were observed even at 38 degrees C after a treatment of 65 h. The coatings pre-heated at 60 degrees C for 1 h and treated with hot water at 55 degrees C for 15 h showed higher photocatalytic activity for methylene blue bleaching than the coatings prepared under the conditions with higher processing temperature close to 100 degrees C. Such a high photocatalytic activity of the coatings obtained through low processing temperatures can be ascribed to a large specific surface area of the coatings and a smaller crystal size of the precipitated anatase. - New, highly ion-conductive crystals precipitated from Li2S-P2S5 glasses
F Mizuno, A Hayashi, K Tadanaga, M Tatsumisago
ADVANCED MATERIALS, 17, 7, 918, +, WILEY-BLACKWELL, 2005年04月
英語, 研究論文（学術雑誌）, Novel sulfide lithium-ion conducting.. materials are synthesized by crystallization of mechanically milled Li2S-P2S5 glasses. High ambient-temperature conductivities (a) compared with other electrolytes (see Figure) and a low conduction activation energy are achieved by the formation of a highly conductive new crystalline phase. - Effects of electric field on the formation of titania nanocrystals on SiO2-TiO2 gel coatings during hot water treatment
A Matsuda, K Kobayashi, T Kogure, M Sakai, K Tadanaga, T Minami, M Tatsumisago
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 113, 1316, 333, 335, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2005年04月, ［査読有り］
英語, 研究論文（学術雑誌）, Sol-gel derived SiO2-TiO2 coatings on indium tin oxide (ITO)-coated glass substrates were treated with hot water at 90 degrees C under electric field aiming at the control of morphology and crystalline phase of the titania precipitates. The shape of the precipitates on 75SiO(2) center dot 25TiO(2) (mol %) coating at the negative electrode changed from granular to ramiform by applying an electric field to the substrates during the treatment, whereas such changes in the shape of titania nanocrystals with the electric field were not observed at the positive electrode. The granular and ramiform precipitates were identified as anatase (TiO2) and hydrated titania (n(TiO2) center dot mH(2)O), respectively. The ramiform shape of the titania precipitates became significant with increasing the applied voltage, while the coatings gradually dark-colored due to the reduction of Ti4+ to Ti3+. - Utilization of glass paper as a support of proton conductive inorganic-organic hybrid membranes based on 3-glycidoxypropyltrimethoxysilane
T Tezuka, K Tadanaga, A Matsuda, A Hayashi, M Tatsumisago
ELECTROCHEMISTRY COMMUNICATIONS, 7, 3, 245, 248, ELSEVIER SCIENCE INC, 2005年03月
英語, 研究論文（学術雑誌）, Proton conductive inorganic-organic membranes supported by glass paper were prepared from 3-glycidoxypropyltrimethoxysilane, tetraethoxysilane and orthophosphoric acid. Hybrid membranes with a thickness of 80 mum were obtained by using 40 mum-thick glass papers. Support of the hybrid membrane by the glass paper enables the formation of the membrane with small thickness and high mechanical strength. The open circuit voltage of the test cell using the membrane supported by the glass paper was 0.75 V and a power density of about 85 mW cm(-2) was obtained with current density of 300 mA cm(-2) at cell temperature of 130 degreesC and 7% relative humidity. (C) 2005 Elsevier B.V. All rights reserved. - Formation and characterization of titania nanosheet-precipitated coatings via sol-gel process with hot water treatment under vibration
A Matsuda, T Matoda, T Kogure, K Tadanaga, T Minami, M Tatsumisago
CHEMISTRY OF MATERIALS, 17, 4, 749, 757, AMER CHEMICAL SOC, 2005年02月
英語, 研究論文（学術雑誌）, Vibrations were found to affect the nanostructure of titania crystallites formed on SiO(2)-TiO(2) gel coatings during hot water treatment. Granular anatase nanocrystals of 30-50 nm in size ere formed on the coatings during hot water treatment without vibration, whereas the shape of the precipitates elongated to be sheetlike by applying a vibration to the substrate during hot water treatment. The sheetlike crystals mainly consisted of nanosheets with a spacing of about 0.6 inn, and were identified as a hydrated titania, m(TiO(2))(.)nH(2)O, with the lepidocrocite-like layered Structure. Titania nanosheets were characterized by a large surface-to-volume ratio, allowing the high photocatalytic reactivity comparable to that of anatase crystals. In addition, the coatings were highly transparent even after the formation of the nanosheets and thermally stable at around 500 degreesC. The hydrated titania nanosheet-precipitated coatings maintained an excellent wettability for water and antifogging properties even after being kept in dark for 2000 It due to their unique physicochemical properties. Processing temperatures for the coatings preparation are lower than 100 degreesC under atmospheric pressure, so that the coatings have a great potential for applications to various substrates including organic polymers with poor heat resistance. - Anti-reflective coatings of flowerlike alumina on various glass substrates by the sol-gel process with the hot water treatment
N Yamaguchi, K Tadanaga, A Matsuda, T Minami, M Tatsumisago
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 33, 1, 117, 120, SPRINGER, 2005年01月
英語, 研究論文（学術雑誌）, Anti-reflective (AR) properties of flowerlike alumina thin films with a small roughness of less than 100 nm have been studied on substrates such as soda-lime silica glass, non-alkali glass, and quartz glass. The highest AR effects were obtained on quartz glass substrate, which has the lowest refractive index of the three substrates. The reflectance of quartz glass substrates coated with flowerlike Al(2)O(3) was less than 0.5% in the wavelength region from 300 to 720 nm. - Characterization of Anatase Nanocrystal-Precipitated Coatings from (100-x) SiO2・xTiO2 Gel Films Via the Sol-Gel Process with Boiling Hot Water Treatment
A. Matsuda, T. Matoda, T. Kogure, K. Tadanaga, T. Minami, M. Tatsumisago
J. Mater. Res., 20, 1, 256, 263, CAMBRIDGE UNIV PRESS, 2005年01月
英語, 研究論文（学術雑誌）, Considerable amounts of anatase nanocrystals were formed on the (100-x)SiO(2)(.)xTiO(2) coatings with x of 16.5 and 25 mol% with boiling water treatment, whereas the formation of anatase nanocrystals was not clearly observed for the coatings with x of 50 and 75 mol%. Despite the lower TiO2 content, the coatings with x of 16.5 and 25 mol% showed higher concentration of Si-O-Ti bonds among the coatings. Thus, the hydrolysis of Si-O-Ti bonds and resultant sites should facilitate the nucleation and Growth of anatase nanocrystals. High transparency, high photocatalytic activity, and superhydrophilicity were demonstrated for the anatase nanocrystals-precipitated coatings. - Effects of electric field on the formation of titania nanocrystals on SiO2-TiO2 gel coatings during hot water treatment
Atsunori Matsuda, Kumpei Kobayashi, Toshihiro Kogure, Mototsugu Sakai, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
Journal of the Ceramic Society of Japan, 113, 1316, 333, 335, Ceramic Society of Japan, 2005年
英語, 研究論文（学術雑誌）, Sol-gel derived SiO2-TiO2 coatings on indium tin oxide (ITO)-coated glass substrates were treated with hot water at 90°C under electric field aiming at the control of morphology and crystalline phase of the titania precipitates. The shape of the precipitates on 75SiO 2· 25TiO2 (mol%) coating at the negative electrode changed from granular to ramiform by applying an electric field to the substrates during the treatment, whereas such changes in the shape of titania nanocrystals with the electric field were not observed at the positive electrode. The granular and ramiform precipitates were identified as anatase (TiO2) and hydrated titania (n(TiO2) ·mH 2O), respectively. The ramiform shape of the titania precipitates became significant with increasing the applied voltage, while the coatings gradually dark-colored due to the reduction of Ti4+ to Ti 3+. - Structural changes in RSiO3/2-TiO2 hybrid films with UV irradiation and their photocatalytic micropatterning
Teruyuki Sasaki, Atsunori Matsuda, Kiyoharu Tadanaga, Masahiro Tatsumisago
Journal of the Ceramic Society of Japan, 113, 1320, 519, 524, Ceramic Society of Japan, 2005年
英語, 研究論文（学術雑誌）, UV light irradiation induced structural changes of the cleavage of silicon-carbon bonds and elimination of organic groups in organosilsesquioxane- titania (RSiO3/2-TiO2, R = methyl, ethyl, phenyl and benzyl) hybrid films due to the photocatalytic effect of TiO2 component. Phenyl and benzyl groups tended to remain in the films after the cleavage of Si-C bonds presumably due to their higher stability of aromatic rings and lager steric effect. The refractive index and dynamic hardness of all the hybrid films increased, and the thickness and contact angle for water decreased by the structural changes induced by the UV light irradiation. On the basis of these changes in film properties, micropatterning was successfully performed on the RSiO3/2-TiO2 hybrid films by UV light irradiation through a photomask. The micropatterns thus obtained should be applicable to a printing plate using the surface energy differences as well as a micro-optical component using the surface profiles and refractive index changes. - Effects of conductive additives in composite positive electrodes on charge-discharge behaviors of all-solid-state lithium secondary batteries
F Mizuno, A Hayashi, K Tadanaga, M Tatsumisago
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 152, 8, A1499, A1503, ELECTROCHEMICAL SOC INC, 2005年
英語, 研究論文（学術雑誌）, The effects of conductive additives in composite positive electrodes on charge-discharge behaviors of all-solid-state In/LiCoO2 cells with (LiS)-S-2-P2S5 glass-ceramic electrolytes were investigated. Acetylene black (AB), vapor grown carbon fiber (VGCF), titanium nitride (TiN), and nickel metal (Ni) were used as conductive additives. Carbon materials were more effective to decrease the resistivities of composite positive electrodes compared to TiN and Ni. Under a current density of 64 mu A cm(-2), discharge capacities of about 100 mAh g(-1) were maintained over 50 cycles in the cell with VGCF, while gradual decreases in discharge capacities were observed in the cells with AB, TiN, and Ni. Furthermore, even under a current density over 1 mA cm-2, the cell with VGCF kept larger discharge capacities during 50 cycles than the cell with AB. Since VGCF is composed of submicrometer-ordered fibers, close solid-solid contacts among electrode, electrolyte, and VGCF were achieved. The design of continuous electron conducting paths from a point of view of morphology for conductive additives is important to improve cell performances of all-solid-state lithium secondary batteries. (c) 2005 The Electrochemical Society. [DOI: 10.1149/1.1939633] All rights reserved. - New lithium-ion conducting crystal obtained by crystallization of the Li2S-P2S5 glasses
F Mizuno, A Hayashi, K Tadanaga, M Tatsumisago
ELECTROCHEMICAL AND SOLID STATE LETTERS, 8, 11, A603, A606, ELECTROCHEMICAL SOC INC, 2005年
英語, 研究論文（学術雑誌）, A lithium-ion highly conductive new crystal was first precipitated in the Li2S-P2S5 glass-ceramics obtained by crystallization of the glasses. The 70Li(2)S center dot 30P(2)S(5) (mol %) glass-ceramic heated at 360 degrees C showed the highest conductivity of 3.2 X 10(-3) S cm(-1) at room temperature and the lowest activation energy of 12 kJ mol(-1) for conduction. The new crystal was formed by heat-treatment from 240 to 360 degrees C, and the Li4P2S6 crystal was present at 550 degrees C, indicating that the new crystal was precipitated as a metastable phase. The superionic metastable phase is responsible for the high conductivity and low activation energy of the glass-ceramics. (c) 2005 The Electrochemical Society. - Rechargeable lithium batteries, using sulfur-based cathode materials and Li2S-P2S5 glass-ceramic electrolytes
Akitoshi Hayashi, Takamasa Ohtomo, Fuminori Mizuno, Kiyoharu Tadanaga, Masahiro Tatsumisago
Electrochimica Acta, 50, 2-3, 893, 897, 2004年11月30日
英語, 研究論文（国際会議プロシーディングス）, All-solid-state cells, using sulfur-based cathode materials and Li 2S-P2S5 glass-ceramic electrolytes exhibited excellent cycling performance at room temperature. The cathode materials consisting of sulfur and CuS were synthesized by mechanical milling, using a mixture of sulfur and copper crystals with several different molar ratios. The cell performance was influenced by the composition of S/Cu for the cathode materials and the cell with the cathode material of S/Cu = 3 prepared by milling for 15min retained large discharge capacities over 650mA h g-1 for 20 cycles. Sulfur as well as CuS in the cathode materials proved to be utilized as active materials on charge-discharge processes in the all-solid-state batteries. © 2004 Elsevier Ltd. All rights reserved. - All-solid-state lithium secondary batteries using Li2S-SiS 2-Li4SiO4 glasses and Li2S-P 2S5 glass ceramics as solid electrolytes
Fuminori Mizuno, Akitoshi Hayashi, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
Solid State Ionics, 175, 1-4, 699, 702, 2004年11月30日
英語, 研究論文（国際会議プロシーディングス）, Highly lithium ion conducting Li2S-SiS2-Li 4SiO4 glasses and Li2S-P2S 5 glass ceramics were prepared by using the melt-quenching method and the mechanical milling method, respectively. All-solid-state In/LiCoO 2 cells using the glass and glass ceramic as solid electrolytes were assembled and their cell performances were evaluated at room temperature. Although the cells worked as lithium secondary batteries, they had large irreversible capacities at the 1st cycle. Cyclic voltammetry (CV) suggested that an irreversible anodic reaction occurred only at the 1st cycle in both cells. By using charge-discharge conditions optimized, the solid-state cells with Li2S-SiS2-Li4SiO4 glasses and Li2S-P2S5 glass ceramics respectively kept high discharge capacity around 60 and 100 mA h g-1 over 100 cycles with charge-discharge efficiencies around 100%. © 2004 Elsevier B.V. All rights reserved. - Characterization of Li2S-P2S5 glass-ceramics as a solid electrolyte for lithium secondary batteries
Akitoshi Hayashi, Shigenori Kama, Fuminori Mizuno, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
Solid State Ionics, 175, 1-4, 683, 686, 2004年11月30日
英語, 研究論文（国際会議プロシーディングス）, Glass-ceramic solid electrolytes were prepared by crystallization of the mechanically milled 80Li2S ·20P2S5 glass and their electrical and electrochemical properties were examined. The glass-ceramics exhibited favorable features as a solid electrolyte for lithium secondary batteries such as high ambient temperature conductivity of 7.2×10-4 S cm-1, unity of lithium transport number, wide electrochemical window, and high stability against lithium metal. All-solid-state cells In/80Li2S ·20P2S5 glass-ceramic/LiCoO2 worked as lithium secondary batteries at room temperature and maintained large discharge capacity of about 100 mA h g -1 up to the 200th cycle with the charge-discharge efficiency of 100%. © 2004 Elsevier B.V. All rights reserved. - Medium temperature operation of fuel cells using thermally stable proton-conducting composite sheets composed of phosphosilicate gel and polyimide
Naoki Nakamoto, Atsunori Matsuda, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
Journal of Power Sources, 138, 1-2, 51, 55, 2004年11月15日, ［査読有り］
英語, 研究論文（学術雑誌）, Fuel cells using a composite sheet composed of phosphosilicate (P 2O5-SiO2, P/Si = 1 in mole ratio) gel powder and polyimide operated up to 150°C under a relatively low water vapor pressure. Maximum power density of the fuel cell increased with increasing operation temperature up to 150°C and increasing humidity. No degradation was observed even after the continuous operation for 10 h at 150°C and 4% relative humidity (RH) under 50mA cm-2. Sieving of the mechanically milled phosphosilicate gel powders to be less than 5μm in size was found to improve the homogeneity and thus the proton conductivity of the resultant composite sheets. The conductivity of the composite sheet containing 75wt.% of the sieved gel powder was 4 × 10-3 S cm-1 at 150°C and 18% RH. Good contact between the composite sheet as an electrolyte and Pt-loaded carbon paper sheets as electrodes in the membrane electrode assembly (MEA) was very important to attain high performance of the fuel cells, which was achieved by the painting of phosphosilicate sol on the surface of the carbon paper and the hot-pressing of the MEA in vacuo. © 2004 Elsevier B.V. All rights reserved. - Medium temperature operation of fuel cells using inorganic-organic hybrid films from 3-glycidoxypropyltrimethoxysilane and orthophosphoric acid
K Tadanaga, H Yoshida, A Matsuda, T Minami, M Tatsumisago
ELECTROCHIMICA ACTA, 50, 2-3, 705, 708, PERGAMON-ELSEVIER SCIENCE LTD, 2004年11月
英語, 研究論文（学術雑誌）, Proton conductive inorganic-organic hybrid films, which show high proton conductivity at temperatures higher than 100 degreesC with low relative humidity, were prepared from 3-glycidoxypropyltrimethoxysilane (GPTMS), tetramethoxysilane (TMOS) and orthophosphoric acid by the sol-gel method. The relative humidity dependence of the conductivity measurements showed that the ionic conductivity of the films, which increased with an increase in the relative humidity, was about 5 x 10(-2) S cm(-1) under 20% relative humidity (RH) at 130 degreesC. The polarization performances measured for test cells at 130 degreesC showed that the maximum power density increased with an increase in the relative humidity. For a cell with the hybrid film (molar ratio P/Si = 1.5) as an electrolyte under H(2) and air at 130 degreesC, 17% RH, the open circuit voltage of the cell was about 0.88 V and a power of about 50 MW cm(-2) was obtained with current density of 150 mA cm(-2) (C) 2004 Elsevier Ltd. All rights reserved. - Preparation and characterization of SnO-P2O5 glasses as anode materials for lithium secondary batteries
Akitoshi Hayashi, Takanori Konishi, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
Journal of Non-Crystalline Solids, 345-346, 478, 483, 2004年10月15日
英語, 研究論文（国際会議プロシーディングス）, The glass structure, thermal and electrochemical properties of the SnO-P2O5 glasses, prepared by melt-quenching technique, were examined. The glasses showed relatively low glass transition temperatures of about 250°C and these values were lower than those of the SnO-B 2O3 and SnO-BPO4 glasses. Local structure of the glasses was investigated by Raman and 31P MAS-NMR measurements, suggesting that the number of bridging oxygens decreased whereas the non-bridging oxygen concentration increased with increasing SnO content in the glasses. The electrochemical properties of the glasses as anode materials for lithium secondary batteries were examined using the cells with conventional liquid electrolytes. The cell using the 67SnO · 33P2O 5 (mol%) glass as a working electrode exhibited an excellent cycling performance and retained high charge-discharge capacities over 400mAhg -1 for 20 cycles under a cut-off voltage of 0-0.8 V. © 2004 Published by Elsevier B.V. - Preparation of proton conductive inorganic-organic hybrid films using epoxycyclohexylethyltrimethoxysilane and orthophosphoric acid
K Tadanaga, H Yoshida, A Matsuda, T Minami, M Tatsumisago
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 31, 1-3, 365, 368, SPRINGER, 2004年08月
英語, 研究論文（学術雑誌）, Proton conductive inorganic- organic hybrid films, which show high proton conductivity at temperatures higher than 100degrees C with low humidification, have been prepared from epoxycyclohexylethyltrimethoxysilane ( EHTMS), 3- glycidoxypropyltrimethoxysilane, and orthophosphoric acid by the sol- gel method. Self- supporting, flexible, and brownish transparent films with a thickness ranging from 150 to 300 mum were obtained. Differential thermal analyses and thermogravimetric measurements revealed that the films were stable up to about 200degrees C. Ionic conductivity of the films increased with an increase in the content of phosphoric acid in the films. The films with a molar ratio of P/ Si = 1.75 retained a high conductivity of about 6 x 10(-4) S cm(-1) even after holding for 150 h under 0.7% relative humidity at 130degrees C. The conductivity of the films increased with an increase in the relative humidity and was about 1 x 10(-2) S cm(-1) under 20% relative humidity at 130degrees C. - Micropatterning of sol-gel derived thin films using hydrophobic-hydrophilic patterned surface
Kiyoharu Tadanaga, Takayuki Fujii, Atsunori Matsuda, Tsutomu Minami, Masahiro Tatsumisago
Journal of Sol-Gel Science and Technology, 31, 1-3, 299, 302, 2004年08月
英語, 研究論文（学術雑誌）, Formation process of convexly shaped oxide micropatterns using hydrophobic-hydrophilic patterned surface has been examined, and this technique was applied to several oxide thin films such as SnO2, ZrO 2, TiO2 and A12O3. Hydrophobic-hydrophilic patterned surfaces were prepared on glass substrates by selective UV irradiation through a photomask on double-layered films of a very thin TiO2 gel film as the underlayer and a hydrolyzed fluoroalkyltrimethoxysilane layer as the top layer. Precursor solutions were then spin-coated on the hydrophobichydrophilic patterns, and the coated substrates were dried at room temperature. The micropatterns of oxides were very difficult to be formed on the hydrophobic-hydrophilic patterned surfaces from metal-alkoxides as a precursor solution, but convexly shaped micropatterns were formed on the hydrophilic regions of the pattern when metal chlorides or oxychlorides were used as starting materials. This patterning technique potentially has a wide variety of applications such as fabrication of micro-optical components and finely patterned transparent electrodes. - Preparation of titania nanosheet-precipitated coatings on glass substrates by treating SiO2-TiO2 gel films with hot water under vibrations
Atsunori Matsuda, Tatsuo Matoda, Toshihiro Kogure, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
Journal of Sol-Gel Science and Technology, 31, 1-3, 229, 233, 2004年08月, ［査読有り］
英語, 研究論文（学術雑誌）, Titania nanosheet-precipitated coatings have been prepared by treating SiO2-TiO2 gel films on glass substrates with hot water at 90°C under vibration. Longitudinal vibrations at about 6 Hz during the treatment enhanced the formation of titania nanosheet. The titania nanosheet consisted of several layers with a spacing of about 0.6 nm and was identified as hydrated titania with a lepidocrocite-type structure. The morphology of the titania nanosheet-precipitated coatings is probably achieved by lowering of the concentration of hydrolyzed titania species at the surface due to rapid water flow driven by the vibrations. The coatings were transparent in the visible range and showed high photocatalytic activity and antifogging property. - Preparation and characterization of copolymerized methylsilsesquioxane-benzylsilsesquioxane microparticles for electrophoretic sol-gel deposition
A. Matsuda, T. Tanaka, K. Tadanaga, T. Minami, M. Tatsumisago
Journal of Materials Science, 39, 3, 903, 909, 2004年02月01日, ［査読有り］
英語, 研究論文（国際会議プロシーディングス）, Copolymerized methylsilsesquioxane-benzylsilsesquioxane, (100 - x)MeSiO3/2·xBnSiO3/2 (mol%), microparticles of 0.3-0.4 μm in average diameter have been prepared by the sol-gel method and applied to the formation of thick films on indium tin oxide (ITO)-coated glass substrates by the electrophoretic deposition. The microparticles obtained were considered to be hybrid containing both methyl and benzyl groups from thermal analyses and structural investigations. The microparticles became fusible at x ≥ 80 by a heat treatment. Thick film, ca. 5 μm thick, consisting of electrophoretically deposited pure BnO3/2 microparticles became transparent upon thermal sintering of the particles during heat treatment at temperatures higher than 100°C. On the other hand, the increase in optical transmittance during the heat treatment of the films consisting of 20MeSiO 3/2·80BnSiO3/2 microparticles was as small as about 20% in visible range even after the heat treatment. The smaller increase in transmittance is probably due to the relatively high viscosity of the 20MeSiO3/2·80BnSiO3/2 upon sintering in comparison with pure BnO3/2 for elimination of the voids in the films. © 2004 Kluwer Academic Publishers. - Micropatterning of SnO2 thin films using hydrophobic-hydrophilic patterned surface
K Tadanaga, T Fujii, A Matsuda, T Minami, M Tatsumisago
CERAMICS INTERNATIONAL, 30, 7, 1815, 1817, ELSEVIER SCI LTD, 2004年
英語, 研究論文（学術雑誌）, SnO2 micropatterns were prepared by using hydrophobic-hydrophilic patterned surfaces. Hydrophobic-hydrophilic patterned surfaces were prepared by selective UV-irradiation through a photomask on multilayered films of a very thin TiO2 gel layer and a hydrolyzed fluoroalkyltrimethoxysilane layer. SnO2 precursor solution prepared from SnCl2 and ethanol was coated on the hydrophobic-hydrophilic patterned surfaces. Convexly shaped SnO2 patterns were formed on hydrophilic area of the patterned surfaces. Thickness of these patterns was more than 1 mum. This patterning technique must have a wide variety of applications such as fabrication of micro-optical components and micropatterned oxide thin films. (C) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved. - Hydrophobic and Photocatalytically Active Surface Using Micropatterns of Anatase Nanocrystals-Dispersed Film
K. Kobayashi, A. Matsuda, T. Kogure, K. Tadanaga, T. Minami, M. Tatsumisago
J. Ceram. Soc. Jpn., 112, 5, S1425-S1429, 2004年 - Characterization of SnO-MxOy (M=B and P) Glassy Anode Materials for Lithium Secondary Batteries Prepared by Melt-Quenching and Mechanical Milling
A. Hayashi, T. Konishi, M. Nakai, H. Morimoto, K. Tadanaga, T. Minami, M. Tatsumisago
J. Ceram. Soc. Jpn., 112, 5, S713-S716, 2004年 - Structure and Ionic Conductivity of Li2S-P2S5-P2O5 Glasses and Glass-Ceramics Prepared by Mechanical Milling
F. Mizuno, T. Ohtomo, A. Hayashi, K. Tadanaga, T. Minami, M. Tatsumisago
J. Ceram. Soc. Jpn., 112, 5, S709-S712, 2004年 - All-solid-state lithium secondary batteries using a layer-structured LiNi0.5Mn0.5O2 cathode material
F Mizuno, A Hayashi, K Tadanaga, T Minami, M Tatsumisago
JOURNAL OF POWER SOURCES, 124, 1, 170, 173, ELSEVIER SCIENCE BV, 2003年10月
英語, 研究論文（学術雑誌）, All-solid-state cells of In/LiNi0.5Mn0.5O2 Using a superionic oxysulfide glass with high conductivity at room temperature of 10(-3) S cm(-1) as a solid electrolyte were fabricated and the cell performance was investigated. Although a large irreversible capacity was observed at the 1st cycle, the solid-state cells worked as lithium secondary batteries and exhibited excellent cycling performance after the 2nd cycle; the cells kept charge-discharge capacities around 70 mAh g(-1) and its efficiency was almost 100%. This is the first case to confirm that all-solid-state cells using manganese-based layer-structured cathode materials work as lithium secondary batteries. (C) 2003 Elsevier B.V. All rights reserved. - Inorganic-organic hybrid films from 3-glycidoxypropyltrimethoxysilane and orthophosphoric acid for medium temperature fuel cells
K Tadanaga, H Yoshida, A Matsuda, T Minami, M Tatsumisago
ELECTROCHEMISTRY COMMUNICATIONS, 5, 8, 644, 646, ELSEVIER SCIENCE INC, 2003年08月
英語, 研究論文（学術雑誌）, Proton conductive in organic-organic hybrid films were prepared from 3-glycidoxypropyltrimethoxysilane, tetramethoxysilane and orthophosphoric acid by the sol-gel method, and the polarization performances were measured at 130 degreesC for test cells using the hybrid film and the composite electrode with precursor sol of the hybrid film and Pt-loaded carbon sheet. For a cell with the hybrid film (P/Si = 1.5) as an electrolyte under H-2 and air at 130 degreesC, 17% relative humidity, the open circuit voltage of the cell was about 0.88 V and a power of about 50 mW cm(-2) was obtained with current density of 150 mA cm(-2). (C) 2003 Elsevier Science B.V. All rights reserved. - All-solid-state Li/S batteries with highly conductive glass-ceramic electrolytes
A Hayashi, T Ohtomo, F Mizuno, K Tadanaga, M Tatsumisago
ELECTROCHEMISTRY COMMUNICATIONS, 5, 8, 701, 705, ELSEVIER SCIENCE INC, 2003年08月
英語, 研究論文（学術雑誌）, All-solid-state cells using sulfur-based cathode materials and Li2S-P2S5 glass-ceramic electrolytes were successfully prepared and exhibited excellent cycling performance at room temperature. The cathode materials consisting of sulfur and CuS were synthesized by mechanical milling using sulfur and copper crystals as starting materials. The cell performance was influenced by the milling time for the cathode materials and the cell with cathode materials obtained by milling for 15 min retained large capacities over 650 mA h g(-1) for 20 cycles. Sulfur as well as CuS in cathode materials proved to be utilized as active materials on charge-discharge processes in the all-solid-state Li/S cells. (C) 2003 Published by Elsevier B.V. - Formation of anatase nanocrystals-precipitated silica coatings on plastic substrates by the sol-gel process with hot water treatment
A Matsuda, T Matoda, T Kogure, K Tadanaga, T Minami, M Tatsumisago
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 27, 1, 61, 69, SPRINGER, 2003年05月
英語, 研究論文（学術雑誌）, Anatase nanocrystals-precipitated silica coatings were formed on plastic substrates such as poly(ethylene terephtalate) (PET), acrylic resin (AC) and polycarbonate (PC) from silica-titania gel coatings with and without addition of poly(ethylene glycol) (PEG) by hot water treatment. The maximum thickness of the coatings which can be formed without cracking or peeling-off was 100 to 200 nm for PET and PC substrates, whereas it was less than 50 nm for AC substrates. After a hot water treatment at 90degreesC for 120 min, the size of the anatase nanocrystals increased to be 30 and 50 nm for the coatings obtained with and without PEG, respectively. Anatase nanocrystals were formed throughout the whole of the coatings obtained with PEG and were formed only on the surface of the coatings obtained without PEG. Both coatings obtained with and without PEG were highly transparent. The plastic substrates with coatings obtained without PEG showed good weathering resistance owing to the protective effects of the residual silica under-layer. The coatings obtained with PEG showed higher photocatalytic activities than those obtained without PEG due to smaller size and higher dispersion of anatase nanocrystals in the coatings. - Preparation of proton-conductive inorganic-organic hybrid films from 3-glycidoxypropyltrimethoxysilane and orthophosphoric acid
K Tadanaga, H Yoshida, A Matsuda, T Minami, M Tatsumisago
CHEMISTRY OF MATERIALS, 15, 9, 1910, 1912, AMER CHEMICAL SOC, 2003年05月
英語, 研究論文（学術雑誌）, Proton-conductive inorganic-organic hybrid films, which can be used as an electrolyte for polymer electrolyte-type fuel cells at temperatures higher than 100 degreesC with low humidification, have been prepared from 3-glycidoxypropyltrimethoxysilane, tetramethoxysilane, and orthophosphoric acid by the sol-gel method. Self-supporting, flexible, and brownish transparent films with a thickness of about 200 to 300 mum were obtained. Differential thermal analysis and thermogravimetric measurements revealed that the films were stable up to about 200 degreesC. The ionic conductivity of the films increased with an increase in the content of phosphoric acid in the films. The films with a molar ratio of P/Si = 1.5 kept a high conductivity of about 7 x 10(-4) S cm(-1\) even after holding for 6 h under 0.7% relative humidity at 130 degreesC. - Formation of superhydrophobic alumina coating films with high transparency on polymer substrates by the sol-gel method
K Tadanaga, K Kitamuro, A Matsuda, T Minami
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 26, 1-3, 705, 708, KLUWER ACADEMIC PUBL, 2003年01月
英語, 研究論文（学術雑誌）, Transparent, superhydrophobic coating films have been prepared on polymer substrates at low temperatures through the sol-gel method. Al2O3 gel films were prepared on poly( ethylene terephthalate) substrates from Al(O-sec-C4H9)(3) chemically modified with ethyl acetoacetate. A small roughness of about 20-50 nm was found to form on the surface of the Al2O3 gel films dried at room temperature and then immersed in hot water at 60degreesC. The electron diffraction measurements have shown that this roughened surface consists of pseudoboehmite nanocrystals. The coating of hydrolyzed fluoroalkyltrimethoxysilane on the Al2O3 gel films with the small roughness produced transparent, superhydrophobic films with contact angle for water larger than 150degrees. - Micropatterning of inorganic-organic hybrid coating films from various tri-functional silicon alkoxides with a double bond in their organic components
K Tadanaga, K Ueyama, T Sueki, A Matsuda, T Minami
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 26, 1-3, 431, 434, SPRINGER, 2003年01月
英語, 研究論文（学術雑誌）, Inorganic-organic hybrid coating films were prepared from various trifunctional silicon alkoxides with a C=C double bond in their organic components, such as vinyltriethoxysilane (VTES), allyltriethoxysilane (ATES) or trimethoxysilylpropylmethacrylate (TMSPM), and zirconium n-tetrapropoxide modified with methacrylic acid. UV light from a high-pressure mercury lamp was irradiated through a photomask on the hybrid films, and this irradiation increased refractive index and microhardness of the films and decreased solubility of the films in alcohol or alkaline solution. IR spectra of the coating films have shown that C=C bonds in these trifunctional silicon alkoxides were polymerized with the UV irradiation. Patterns with a width of about 10 mum and thickness of about 5-15 mum were formed by the etching of unirradiated region of the films. Since VTES and ATES have a shorter organic chain than TMSPM, the hybrid films prepared from VTES or ATES are expected to show small optical loss in the near-infrared region due to C-H bonds in their use as waveguides. - Preparation of LiCoPO4 for Lithium Battery Cathodes through Solution Process
Kiyoharu TADANAGA, Fuminori MIZUNO, Akitoshi HAYASHI, Tsutomu MINAMI, Masahiro TATSUMISAGO
Electrochemistry, 71 [12], 1192-1195, 12, 1192, 1195, 2003年, ［査読有り］
英語 - Proton conductivity at medium temperature range and chemical durability of phosphosilicate gels added with a third component
A Matsuda, Y Nono, K Tadanaga, T Minami, M Tatsumisago
SOLID STATE IONICS, 162, 253, 259, ELSEVIER SCIENCE BV, 2003年
英語, 研究論文（学術雑誌）, Phosphosilicate (P2O5-SiO2) gels with an addition of Al2O3 or B2O3 as a third component have been prepared by the sol-gel method aiming at the improvement in chemical durability of the gels. The presence of strongly interacted water with gel matrices was confirmed for all the gels from an endothermic peak with weight loss at around 230 degreesC in thermal analyses. The addition of Al2O3 or B2O3 suppressed the formation of Si5O(PO4)(6) in phosphosilicate gels during heat treatment and Al2O3 remarkably improved the chemical durability of the resultant gels after a heat treatment at 300 degreesC. Al2O3-added gels (P/Si/ Al = 1:0.9:0.1 molar ratio) showed conductivities of about 10(-4) Scm(-1) at 130 degreesC and 0.7% R.H. after a pre-treatment at 30 degreesC and 60% R.H. for 3 h, whereas pure phosphosilicate gels (P/Si = 1: 1) and B2O3-added gels (P/Si/B = 1:0.9:0.1 molar ratio) showed higher conductivities of about 10(-2) Scm(-1) under the same conditions. The lower conductivity of the Al2O3-added gel was ascribed to the smaller amounts of H3PO4 formed by hydrolysis Of Si5O(PO4)(6) in the gels during the pre-treatment. (C) 2003 Elsevier B.V. All rights reserved. - Preparation and characterization of thermally stable proton-conducting composite sheets composed of phosphosilicate gel and polyimide
A Matsuda, N Nakamoto, K Tadanaga, T Minami, M Tatsumisago
SOLID STATE IONICS, 162, 247, 252, ELSEVIER SCIENCE BV, 2003年
英語, 研究論文（学術雑誌）, Thermally stable proton-conducting composite sheets of 50-100 mum thick have been prepared from phosphosilicate gel (P/ Si = 1 molar ratio) powders and polyimide precursor. The proton conductivity of the composite sheet increased with an increase in the phosphosilicate gel content. The composite sheet containing 70 wt.% of the gel showed a tensile strength of about 170 N cm(-2) at 150 degreesC and a conductivity of 2 x 10(-4) S cm(-1) at 150 degreesC and 0.4% relative humidity (RH). The open circuit potential of the test cell using the composite sheet as an electrolyte was about 0.9 V at 30 degreesC and 60% RH, and the power density was maximized to be about 30 mW cm(-2) at around 90 mA cm(-2). (C) 2003 Elsevier B.V All rights reserved. - All solid-state lithium secondary batteries using high lithium ion conducting Li2S-P2S5 glass-ceramics
Fuminori Mizuno, Shigenori Hama, Akitoshi Hayashi, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago
Chemistry Letters, 12, 1244, 1245, Chemical Society of Japan, 2002年12月05日
英語, 研究論文（学術雑誌）, All solid-state cells of In/LiCoO2 using the 80Li2S·20P2S5 (mol%) glass-ceramics with high ambient temperature conductivity of about 10-3 S cm-1 as a solid electrolyte were fabricated, and the cell performance was investigated. Although an irreversible capacity was observed at the 1st cycle, the solid-state cell exhibited excellent cycling performances with the reversible charge-discharge capacities of about 100 mAh g-1 even after 200 cycles. - Sol-gel derived porous silica gels impregnated with sulfuric acid. Pore structure and proton conductivities at medium temperatures
Atsunori Matsuda, Takao Kanzaki, Kiyoharu Tadanaga, Toshiro Kogure, Masahiro Tatsumisago, Tsutomu Minami
Journal of the Electrochemical Society, 149, 8, E292, E297, 2002年08月
英語, 研究論文（学術雑誌）, Pore structure and proton conductivities of several types of porous silica gels impregnated with H2SO4 have been studied. The amounts of impregnated H2SO4 increased with an increase in the pore volume of the silica gels, and with an increase in the concentration of H2SO4 used for the impregnation. The surfactant-templated mesoporous silica gels, which were impregnated with 5 M H2SO4, showed high conductivities in the order of 10-1 S cm-1 in a range from 40 to 80°C and 6 RH. Regularly ordered cylindrical pores with smaller pore diameter in the mesoporous silica gel were found to permit the retention of physisorbed water at high temperatures and thus high conductivities at temperatures around 100°C. - Photocatalytic micropatterning of transparent ethylsilsesquioxane-titania hybrid films
A Matsuda, T Sasaki, K Tadanaga, M Tatsumisago, T Minami
CHEMISTRY OF MATERIALS, 14, 6, 2693, 2700, AMER CHEMICAL SOC, 2002年06月
英語, 研究論文（学術雑誌）, Refractive index of ethylsilsesquioxane-titania hybrid films increased from 1.50 to 1.55 accompanied by a decrease in film thickness by about 30% after UV light irradiation. The contact angle for water of the films decreased from 95degrees to about 45degrees and the dynamic hardness increased with UV irradiation. These changes in physical and chemical properties of the films with UV irradiation were caused by the cleavage of silicon-carbon bonds and elimination of ethyl groups in the films due to the photocatalytic effect of the titania component. Micropatterning was successfully performed on the films coated on the substrates by UV irradiation through a photomask. - Conductivity enhancement and thermal properties of AgI-MO2 (M = Zr, Si) composites using sol-gel derived aerogels
K Tadanaga, K Imai, M Tatsumisago, T Minami
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 149, 6, A773, A777, ELECTROCHEMICAL SOC INC, 2002年06月
英語, 研究論文（学術雑誌）, AgI-ZrO2 and AgI-SiO2 composites were prepared using sol-gel derived aerogels. The conductivity at room temperature showed a maximum for the composition of 0.4AgI.0.6ZrO(2) or 0.4AgI.0.6SiO(2) and was 3.3 x 10(23) S cm(-1) for the composite using ZrO2 aerogels and 1.2 x 10(24) S cm(-1) for the composite using SiO2 aerogels. The diffusion of AgI into the micropores of the aerogel was observed for the ZrO2 system, suggesting that the diffusion caused a decrease of the crystallinity of AgI and the formation of a high conductive phase of AgI at the AgI-ZrO2 interface. In the SiO2-containing system, however, the diffusion was not observed and, hence, the conductivity was an order of magnitude lower than that of the ZrO2-based system. (C) 2002 The Electrochemical Society. - Phosphosilicate gels as a solid state proton conductor at medium temperature and low humidity
A Matsuda, T Kanzaki, K Tadanaga, M Tatsumisago, T Minami
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 110, 2, 131, 134, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2002年02月, ［査読有り］
英語, 研究論文（学術雑誌）, Phosphosilicate (P2O5-SiO2) gels with a P/Si molar ratio of 1.0 heat-treated at 150degreesC were found to retain a high conductivity of 1.5 x 10(-2) S . cm(-1) even after holding at a temperature of 130degreesC at a relative humidity of 0.7% for about 400 min. On the other hand, the conductivity of the porous silica gels impregnated with 5 M H3PO4 largely decreased from 1 x 10(-2) to 6 x 10(-6) S . cm(-1) during holding under the same conditions for about 400 min. The difference in the changes of conductivities between phosphosilicate gels and H3PO4-impregnated porous silica gels with holding time indicates that the former can retain larger amounts of adsorbed water at MOT than the latter. Condensed structural units with Si-O-P-OH groups in the phosphosilicate gels are expected to enhance the retention of the adsorbed water in the gels and improve the proton conductivity even at relatively high temperatures and low humidity conditions. - Phosphosilicate gels as a solid state proton conductor at medium temperature and low humidity
Atsunori Matsuda, Takao Kanzaki, Kiyoharu Tadanaga, Masahiro Tatsumisago, Tsutomu Minami
Journal of the Ceramic Society of Japan, 110, 1278, 131, 134, Ceramic Society of Japan, 2002年
英語, 研究論文（学術雑誌）, Phosphosilicate (P2O5-SiO2) gels with a P/Si molar ratio of 1.0 heat-treated at 150°C were found to retain a high conductivity of 1.5 × 10-2 S·cm-1 even after holding at a temperature of 130°C at a relative humidity of 0.7% for about 400 min. On the other hand, the conductivity of the porous silica gels impregnated with 5 M H3PO4 largely decreased from 1 × 10-2 to 6 × 10-6 S·cm-1 during holding under the same conditions for about 400 min. The difference in the changes of conductivities between phosphosilicate gels and H 3PO4-impregnated porous silica gels with holding time indicates that the former can retain larger amounts of adsorbed water at 130°C than the latter. Condensed structural units with Si-O-P-OH groups in the phosphosilicate gels are expected to enhance the retention of the adsorbed water in the gels and improve the proton conductivity even at relatively high temperatures and low humidity conditions. - Proton Conductivities of Sol-Gel Derived Phosphosilicate Gels in Medium Temperature Range with Low Humidity
A. Matsuda, T. Kanzaki, K. Tadanaga, M. Tatsumisago, T. Minami
Solid State Ionics, 154-155, 687, 692, 2002年, ［査読有り］ - Proton Conductive Inorganic-Organic Hybrid Membranes as an Electrolyte for Fuel Cells Prepared from 3-Glycidoxypropyltrimethoxysilane and Orthophosphoric Acid
K. Tadanaga, H. Yoshida, A. Matsuda, T. Minami, M. Tatsumisago
Electrochemistry, 70, 12, 998, 1000, 電気化学会, 2002年
英語 - Formation of Convexly Shaped Silica Micropatterns on Sol-Gel Derived Films Using a Difference in Surface Free Energy
K. Tadanaga, J. Morinaga, T. Fujii, A. Matsuda, T. Minami
Glass Technol., 43C, 275, 277, 2002年, ［査読有り］ - Transparent, inorganic-organic thick films by electrophoretic sol-gel deposition using polysilsesquioxane particles
A Matsuda, K Tadanaga, T Minami, M Tatsumisago
ELECTROPHORETIC DEPOSITION: FUNDAMENTALS AND APPLICATIONS, PROCEEDINGS, 2002, 21, 287, 294, ELECTROCHEMICAL SOCIETY INC, 2002年, ［査読有り］
英語, 研究論文（国際会議プロシーディングス）, Transparent, inorganic-organic thick films of a few micrometers in thickness have been prepared on glass substrates coated with indium tin oxide (ITO) by constant-voltage electrophoretic sol-gel deposition method using polysilsesquioxane particles such as polyphenylsilsesquioxane (PhSiO3/2) and polybenzylsilsesquioxane (BnSiO3/2). The films composed of aggregates of PhSiO3/2 and BnSiO3/2 particles became transparent with morphological changes from aggregates of particles to a monolithic, continuous layer with high refractive indices after heat treatment. The increase in optical transmittance was caused by thermal sintering of the particles in the films. Thermal sintering of PhSiO3/2 particles at 140 degreesC and that of BnSiO3/2 particles at 50 degreesC reduced the interfaces and openings among the particles and decreased light scattering of the films to form transparent films. The thermal sintering of the PhSiO3/2 and BnSiO3/2 particles was caused by the decrease of viscosity at temperatures higher than the glass transition temperatures. - Proton conductivity of acid-impregnated mesoporous silica gels prepared using surfactants as a template
A Matsuda, Y Nono, T Kanzaki, K Tadanaga, M Tatsumisago, T Minami
SOLID STATE IONICS, 145, 1-4, 135, 140, ELSEVIER SCIENCE BV, 2001年12月
英語, 研究論文（学術雑誌）, Highly proton-conductive acid-impregnated mesoporous silica gels have been prepared using alkyltrimethylammonium. chlorides with different alkyl chain length as a template and several kinds of protonic acids such as HClO4, H2SO4 and H3PO4 as a proton donor. The specific surface area and pore volume of the mesoporous silica gels increased with an increase in the number of carbon atoms in the alkyl chain. The electric conductivities of all the acid-impregnated mesoporous silica gels also tended to increase with increasing the number of carbon atoms in the alkyl chain in the surfactant. This phenomenon can be ascribed to an increase in the amounts of impregnated acid due to the enlarged pore volume in the mesoporous silica gels. It was found that HClO4 and H2SO4 more effectively enhanced the proton conductivity of the resultant acid-impregnated silica gels than H3PO4. The conductivities of the HClO4- and H2SO4-impregnated mesoporous silica gels obtained were higher than 10(-1) S cm(-1) under 60% relative humidity at 85 degreesC. (C) 2001 Elsevier Science B.V. All rights reserved. - Medium temperature range characterization as a proton conductor for phosphosilicate dry gels containing large amounts of phosphorus
A Matsuda, T Kanzaki, K Tadanaga, M Tatsumisago, T Minami
ELECTROCHIMICA ACTA, 47, 6, 939, 944, PERGAMON-ELSEVIER SCIENCE LTD, 2001年12月
英語, 研究論文（学術雑誌）, Proton conductivities of phosphosilicate dry gets derived from tetraethoxysilane (TEOS) and H3PO4 increased with an increase in the P/Si mole ratio from 0.5 to 1.0 and tended to level off at 1.0-1.5. The dry gel powder pellets with a P/Si mole ratio of 1.0 showed a high conductivity of 1 x 10(-2) S cm(-1) even after keeping under the atmosphere at 150 degreesC and 0.4% relative humidity (R.H.) for 400 min, Si5O(PO4)(6) crystals and highly condensed phosphates, both of which were formed in the gels during the heat treatment process at 150 degreesC, were readily hydrolyzed. The hydrolyzed species like isolated phosphoric acid and a structural unit with Si O-P OH groups permits the gels to retain high proton conductivity even at temperatures in the medium range with low humidity owing to the good affinity with adsorbed water. (C) 2001 Elsevier Science Ltd. All rights reserved. - Formation of Superhydrophobic-Superhydrophilic Pattern on Flowerlike Alumina Thin Film by the Sol-Gel Method(共著)
TADANAGA K, MORINAGA J, MINAMI T
J. Sol-Gel Sci. Tech., 19, 1-3, 211, 214, Kluwer Academic Publishers, 2000年12月, ［招待有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）, We have prepared superhydrophobic surfaces which become superhydrophilic by heat-treatment at 500°C or irradiation of UV-light. When hydrolyzed fluoroalkyltrimethoxysilane (FAS) was coated on Al2O3 gel film with a roughness of 20 to 50 nm, the films showed superhydrophobicity and high transparency
the contact angle for water of the film was 165° and the transmittance for the visible light was higher than 92%. When the FAS-coated thin films were heat-treated at temperatures higher than 500°C, the films became superhydrophilic
the contact angle for water on the films was smaller than 5°. Thin films of amorphous TiO2 or anatase TiO2 were coated between Al2O3 gel and FAS layer, and the contact angle for water was also about 160°. UV irradiation using high-pressure mercury lamp on these films resulted in the contact angle to be smaller than 5°. When UV light was irradiated through a photomask, superhydrophobic-superhydrophilic micropatterns applicable as a stamper for printing or a substrate of micro-optical components were successfully obtained on the films. - Preparation and Ferroelectric Properties of YMnO3 Thin Films with c-Axis Preferred Orientation by the Sol-Gel Method(共著)
KITAHATA H, TADANAGA K, MINAMI T, FUJIMURA N, ITO T
J. Sol-Gel Sci. Tech., 19, 1-3, 589, 593, KLUWER ACADEMIC PUBL, 2000年12月
英語, 研究論文（学術雑誌）, Hexagonal YMnO3 has a ferroelectric property with an optimal remanent polarization along the c-axis. The c-axis oriented YMnO3 thin films with a small leakage current were prepared by the sol-gel dipping method. The c-axis orientation of the films was promoted by the addition of diethanolamine to the Mn precursor solution. A heat treatment with multiple steps led to a dense film structure with fine grains. The dense structure resulted in the decrease of the leakage current. Furthermore, when the films were heat-treated in a vacuum, the leakage current became considerably small and the ferroelectricity of the YMnO3 thin films was observed even at room temperature. - Near-and Mid-Infrared Spectroscopy of Sol-Gel Derived Ormosil Films for Photonics from Tetramethoxysilane and Trimethoxysilylpropylmethacrylate(共著)
TADANAGA K, ELLIS B, SEDDON A B
J. Sol-Gel Sci. Tech., 19, 1-3, 687, 690, KLUWER ACADEMIC PUBL, 2000年12月
英語, 研究論文（学術雑誌）, Ormosil dipped thin films and cast films were prepared using tetramethoxysilane and trimethoxysilylpropylmethacrylate (TMSPM). Structural changes during thermally induced polymerisation of the organic groups were investigated using near- and mid-infrared (IR) spectroscopy. IR spectra of the ormosil dipped thin films, dried at 60 degreesC, have shown that further heat-treatment of the films at 160 degreesC leads to the free radical polymerisation of C=C bonds in TMSPM. In the mid-infrared spectra, the intensity of the band at around 3500 cm(-1), due to O-H bonds, increased with the progress of polymerisation of vinyl groups. Near-infrared spectra of the cast films showed that this increase in intensity of the O-H band is due to the increase of monomeric water molecules hydrogen bonded to silanols. We suggest that optical loss measurements must be made in a dry atmosphere or, with a cover coating to protect the ormosil from adsorption of water, to reduce this source of optical loss for waveguides based on TMSPM. - Fine Patterning of Transparent, Conductive SnO2 Thin Films by UV-Irradiation(共著)
TADANAGA K, OWAN T, MORINAGA J, URBANEK S, MINAMI T
J. Sol-Gel Sci. Tech., 19, 1-3, 791, 794, SPRINGER, 2000年12月
英語, 研究論文（学術雑誌）, Finely patterned transparent, conductive SnO2 thin films have been prepared. UV-light from a high-pressure mercury lamp was irradiated through a mask on the precursor films prepared from SnCl2 with acetyl acetone in the ambient atmosphere, and this irradiation led to the change of solubility of the films in alkaline solution. Patterns with a width of about 3 to 50 mum and thickness of about 0.1 mum were formed with a pitch of about 2 to 20 mum. The resistivity of the films heat-treated at 500 degreesC after UV irradiation was about 1 x 10(-2) Omega cm, which was almost the same resisitivity for the films heat-treated at 500 degreesC without UV irradiation. - Preparation of AgI-Al2O3 Composites with High Ionic Conductivity Using Al2O3 Aerogel and Xerogel(共著)
TADANAGA K, IMAI K, TATSUMISAGO M, MINAMI T
J. Electrochem. Soc., 147, 11, 4061, 4064, ELECTROCHEMICAL SOC INC, 2000年11月
英語, 研究論文（学術雑誌）, AgI-Al2O3 composites were prepared using sol-gel-derived Al2O3 aerogels and xerogels. The addition of Al2O3 aerogel or xerogel to AgI enhanced the ionic conductivity. The conductivity at room temperature showed a maximum at the composition 0.4AgI .0.6Al(2)O(3) in both aerogel-containing and xerogel-containing composites and was 2.8 X 10(-3) S cm(-1) for the aerogel composite. The conductivity of aerogel-containing composites was larger than that of xerogel-containing composites for all compositions, suggesting that the pore size distribution of aerogels was more effective than that of xerogels for enhancing the ionic conductivity. (C) 2000 The Electrochemical Society. S0013-4651(00)04-072-6. All rights reserved. - Preparation of Super-Water-Repellent Alumina Coating Film with High Transparency on Poly(ethylene terephthalate)by the Sol-Gel Method(共著)
TADANAGA K, KITAMURO K, MORINAGA J, KOTANI Y, MATSUDA A, MINAMI T
Chem. Lett., 8, 864, 865, CHEMICAL SOC JAPAN, 2000年08月
英語, 研究論文（学術雑誌）, Al2O3 gel films were prepared on poly(ethylene terephthalate) substrates from Al(O-sec-C4H9)(3) chemically modified with ethyl acetoacetate. A small roughness of about 20-50 nm was found to form on the Al2O3 gel films dried at room temperature and then immersed in hot water at 60 degrees C. When hydrolyzed fluoroalkyltrimethoxysilane was coated on the Al2O3 films, transparent thin films with contact angle for water to be more than 150 degrees were obtained. - Precursor structure of chemically modified aluminum-tri-sec-butoxide in diethylene glycol and ethylene glycol monoethyl ether
K Tadanaga, T Minami
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 108, 4, 420, 423, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 2000年04月, ［査読有り］
英語, 研究論文（学術雑誌）, Precursor structure of chemically modified Al(O-sec-Bu)(3) with ethyl acetoacetate or diethanolamine, dissolved in diethylene glycol (DEG), ethylene glycol monoethyl ether (EGE), and sec-butyl alcohol (sec-BuOH), was investigated using Al-27 NMR. Al-27 NMR spectra revealed that the reaction of DEG or EGE with Al(O-sec-Bu)(3) led to the formation of six-coordinated structural units, The precursor structure of Al(O-sec-Bu)(3) modified with ethyl acetoacetate in EGE, which consisted of six- and five-coordinated structural units, was almost the same as that in DEG, but different from that in sec-BuOH, where four-coordinated structural units were also observed, In Al(O-sec-Bu)(3) modified with diethanolamine, five- and six-coordinated structural units were present in all the solvents used in this study and the effect of solvents on the coordination state was very small. - Superhydrophobic-superhydrophilic micropatterning on flowerlike alumina coating film by the sol-gel method
K Tadanaga, J Morinaga, A Matsuda, T Minami
CHEMISTRY OF MATERIALS, 12, 3, 590, +, AMER CHEMICAL SOC, 2000年03月
英語, 研究論文（学術雑誌）, A never route to form superhydrophobic-superhydrophilic micropatterned coating film has been developed. UV light was irradiated on the superhyrdrophobic coating film which consists of three layers, a flowerlike Al2O3 gel film, a very thin TiO2 gel layer, and a FAS layer, to cleave the fluoroalkyl chain in FAS selectively, and well-defined superhydrophobic and superhydrophilic regions were formed. - Structural changes during thermally induced polymerisation of ormosil films from trimethoxysilylpropylmethacrylate and zirconium-n-propoxide modified with methacrylic acid
K Tadanaga, B Ellis, AB Seddon
SOL-GEL OPTICS V, 3943, 228, 235, SPIE-INT SOC OPTICAL ENGINEERING, 2000年
英語, 研究論文（国際会議プロシーディングス）, Structural changes during thermally induced polymerisation of the dipped thin films prepared from TMSPM, zirconium n-tetrapropoxide and methacrylic acid were investigated using near- and mid-infrared (IR) spectroscopy. In the mid-infrared spectra, the intensity of the band due to C=C was decreased by the heat-treatment at 160 degrees C. The intensity of the band due to C=O at around 1720 cm(-1) was also decreased, and that of a band at around 1740 cm(-1) which is assigned to an ester carbonyl C=O in the polymerised methacrylate, was increased. In the near-infrared spectra, the intensities of a band due to the first overtone of fundamental nu(as)(CH2=) and a combination band of nu(as)(CH2=) and nu(C=C) were largely decreased with the heat-treatment at 160 degrees C. These spectral changes show that heat-treatment of the films at 160 degrees C leads to depletion of C=C bonds, indicating that polymerisation has occurred of TMSPM and methacrylic acid. However, in the mid-infrared spectra, the intensity of the band at around 3500 cm(-1) due to O-H bonds, increased with the progress of polymerisation of vinyl groups. Near-infrared spectra of the dipped thin films showed that this increase in intensity of the O-H band is due to the increase of monomeric water molecules hydrogen bonded to silanols. This indicates that polymerised samples are more hydrophilic than unpolymerised ones. The refractive index of the dipped films, measured with a prism coupling method, increased from 1.508 to 1.516 with the polymerisation for composition Zr/(Zr + Si) of 0.2. - Precursor Structure of Chemically Modified Aluminum-tri-sec-Butoxide in Diethylene Glycol and Ethylene Glycol Monoethyl Ether(共著)
忠永 清治, 南 努
J. Ceram. Soc. Jpn., 108, 1256, 420, 423, 2000年 - Origin of Leakage Current of YMnO3 Thin Films Prepared by the Sol-Gel Method(共著)
H Kitahata, K Tadanaga, T Minami, N Fujimura, T Ito
Mat. Res. Soc. Symp. Proc., 596, 481, 486, MATERIALS RESEARCH SOC, 2000年
英語, 研究論文（国際会議プロシーディングス）, The preparation conditions of YMnO3 thin films by the sol-gel method using yttrium alkoxide were optimized to decrease the leakage current of the films. The leakage current of the films was decreased due to the dense microstructure of the films. Moreover, the heat treatment in hydrogen atmosphere and the zirconium doping resulted in a further decrease of the leakage current The heat treatment in hydrogen atmosphere and the zirconium doping were effective in the decrease of carriers originating in the valence fluctuation of the Mn ions in YMnO3. - Preparation and Proton Conductivity of Surfactant-Templated Mesoporous Silica Gels Impregnated with Protonic Acids(共著)
Shogo Nishiwaki, Kiyoharu Tadanaga, Masahiro Tatsumisago, Tsutomu Minami
J. Am. Ceram. Soc., 83, 12, 3004, 3008, American Ceramic Soc, 2000年, ［査読有り］
英語, 研究論文（学術雑誌）, Surfactant-templated mesoporous silica gel that was impregnated with various protonic acids has been prepared, and we propose this material as a new type of proton conductor. The conductivity of the mesoporous silica gel that was impregnated with 5.0M H2SO4 was approx. 1 × 10-4 S/cm at room temperature in a dry nitrogen-gas atmosphere after drying in vacuo at room temperature
this value was four orders of magnitude greater than that of silica gel that was prepared via the conventional sol-gel method and impregnated with H2SO4. The amount of impregnated H2SO4 in the mesoporous silica gel was approx. 2.5 times larger than that of impregnated H2SO4 in the conventional silica gel. The H2O molecules in the mesoporous silica gel that was impregnated with H2SO4 remained in the pores of the gel, even after drying in vacuo at room temperature. - Lowering the Crystallization Temperature of YMnO3 Thin Films by the Sol-Gel Method Using an Yttrium Alkoxide(共著)
KITAHATA H, TADANAGA K, MINAMI T, FUJIMURA N, ITO T
Jpn. J. Appl. Phys., 38, 9B, 5448, 5451, JAPAN J APPLIED PHYSICS, 1999年09月
英語, 研究論文（学術雑誌）, We have succeeded in lowering the crystallization temperature of sol-gel derived YMnO3 thin films to 500 degrees C by using yttrium alkoxide as a starting material. The X-ray diffraction measurements indicated that the films heat treated at temperatures above 500 degrees C had a single phase of hexagonal YMnO3. The crystallization temperature of the YMnO3 thin film prepared from yttrium alkoxide was lower by at least 300 degrees C than that of film prepared from yttrium acetate. The film prepared from the alkoxide and heal treated at 700 degrees C for 3 min had a high crystallinity with c-axis preferred orientation, and ferroelectricity was observed in the film. The formation temperature of the ferroelectric YMnO3 thin film prepared from yttrium alkoxide was lower by at least 100 degrees C than that of film prepared from yttrium acetate. - Ferroelectricity of YMnO3 Thin Films Prepared via Solution(共著)
KITAHATA H, TADANAGA K, MINAMI T, FUJIMURA N, ITO T
Appl. Phys. Lett., 75, 5, 719, 721, AMER INST PHYSICS, 1999年08月
英語, 研究論文（学術雑誌）, We have observed the ferroelectricity at room temperature in YMnO3 thin films prepared via solution. Precursor films of YMnO3 on Pt/sapphire or Y2O3/Si substrates were heat treated in vacuum or in air for controlling the crystallinity. X-ray diffraction measurements indicated that each film was a single phase of hexagonal YMnO3. While the film heat treated in air indicated an insufficient crystallinity, the film heat treated in vacuum showed a high crystallinity with a c-axis preferred orientation. The leakage current of the film heat treated in vacuum was at least three orders of magnitude lower than that heat treated in air. The ferroelectricity of the film heat treated in vacuum was confirmed in the capacitance-voltage measurement at room temperature due to its high crystallinity with the c-axis preferred orientation and the small leakage current. (C) 1999 American Institute of Physics. [S0003-6951(99)04131-5]. - High-Resolution Solid-State NMR Studies of Ionically Conductive Li2S-SiS2-Li2O-P2O5 Oxysulphide Glasses(共著)
A Hayashi, R Araki, K Tadanaga, M Tatsumisago, T Minami
Phys. Chem. Glasses, 40, 3, 140, 145, SOC GLASS TECHNOLOGY, 1999年06月
英語, 研究論文（学術雑誌）, Glass structure of oxysulphide glasses of composition (1-y) [xLi(2)S. (100-x)SiS2].y[xLi(2)O.(100-x)P2O5] (50 less than or equal to x less than or equal to 65; y=0.05, 0.20) was systematically investigated using Si-29 and P-31 MAS-NMR measurements by changing x, the total lithium ion concentration, and also by changing y, the amount of oxide Li2O-P2O5 added to the sulphide Li2S-SiS2. fn the case of changing x with a constant y=0.05 the amounts of SiOnS4-n (n=1,2,3) tetrahedral units were maximised and those of SiS4 tetrahedral units were minimised in the glass with x=55. PS4 and POS3 tetrahedral units were mainly present in the range 50 less than or equal to x less than or equal to 58. However; the amounts of PO2S2, PO3S and PO4 tetrahedral units increased with an increase of x in the range 60 less than or equal to x less than or equal to 65. In the case of changing y with a constant x=60 the fraction of SiS4, PS4 and POS3 units decreased with an increase of y from 0.05 to 0.20. - Structural change accompanying crystallization in the lithium ion conductive Li2S-SiS2-Li3PO4 oxysulfide glasses
A Hayashi, K Tadanaga, M Tatsumisago, T Minami, Y Miura
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 107, 6, 510, 516, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 1999年06月, ［査読有り］
英語, 研究論文（学術雑誌）, The structural change of the (100 - x) (0.6Li(2)S . 0.4SiS(2)). xLi(3)PO(4) oxysulfide glasses during crystallization was analyzed by means of solid-state nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). The unique tetrahedral units of SiOnS4-n (n = 1, 2, 3) and POnS4-n (n = 1, 2, 3) present in the glass samples vanished and the SiS4, SiO4, PS4 and PO4 units increased with proceeding of the crystallization process. Nonbridging sulfur and oxygen atoms decreased while bridging oxygens and S2- increased with proceeding of the crystallization process. Large structural difference between the glass and the corresponding crystallized sample explained the high stability against crystallization found in the oxysulfide glass with the composition of x = 5. - Water and oxygen permeability of silica thin films containing organic polymers coated on poly (ethylene terephtalate) substrate by the sol-gel method
K Azuta, K Tadanaga, T Minami
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 107, 3, 293, 296, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 1999年03月, ［査読有り］
英語, 研究論文（学術雑誌）, Silica thin films containing organic polymers, such as poly(vinyl alcohol), poly(vinylpyrrolidone) or poly(vinyl acetate), were prepared on PET substrates by the sol-gel method. Poly(vinyl alcohol) was found to be most effective to suppress the water permeability of PET substrates coated with the organic-inorganic composite films among the three. Under the optimal condition, the water permeability coefficient was about 40% of that of PET substrates. The oxygen permeability coefficient was decreased with an increase in the poly(vinyl alcohol) content in the composites and was about 10% of that of PET substrates when a large amount of poly(vinyl alcohol) was included in the composites. - Water and Oxygen Permeability of Silica Thin Films Containing Organic Polymers Coated on Poly (Ethylene Terephthalate) Substrate by the Sol-Gel Method (共著)
AZUTA K, TADANAGA K, MINAMI T
J. Ceram. Soc. Jpn., 107, 1243, 293, 296, 1999年 - Structural Change Accompanying Crystallization in the Lithium Ion Conductive Li2S-SiS2-Li3PO4 Oxysulfide Glasses(共著)
HAYASHI A, TADANAGA K, TATSUMISAGO M, MINAMI T, MIURA Y
J. Ceram. Soc. Jpn., 107, 1246, 510, 516, 1999年 - Preparation and Characterization of Super-Water-Repellent Coating Films by the Sol-Gel Method(共著)
Topical Issues in Glasses: Photons, Glasses and Coatings, 3, 99, 103, 1999年 - Color Coating for Recyclable Glass Bottles by the Sol-Gel Method Using Organic Colorants(共著)
H Nakazumi, K Ishii, Y Sakashita, T Ikai, K Tadanaga, T Minami, M Ueda, M Funato, H Kanazawa, K Natsukawa, Y Sakurai
Proc. 2nd Inter. Conf. on Coating on Glass, 114, 119, ELSEVIER SCIENCE BV, 1999年
英語, 研究論文（国際会議プロシーディングス）, The sol-gel colored coating of glass bottles which enabled recycling of the bottles in production process was investigated. The stability of the sol, characteristics and practical resistance of the colored gel films for glass bottles are examined by the gel permeation chromatography, spectroscopic analyses using a fluorescent dye, and mechanical strength analysis, respectively. We found that the inorganic-organic gel films prepared from the mixed alkoxysilanes of phenyltrimethoxysilane and methoxysilane oligomer exhibit good feasibility for this process, especially for the high resistance against boiling water required for sterilization and goad homogeneous dispersion of organic colorants in the gel films. Thermal analyses of organic pigments used in color coating were also performed by a GC-mass spectrometer. - Preparation and Dielectric Properties of YMnO3 Ferroelectric Thin Films by the Sol-Gel Method
Kiyoharu Tadanaga, Hiroya Kitahata, Tsutomu Minami, Norifumi Fujimura, Taichiro Ito
Journal of Sol-Gel Science and Technology, 13, 1-3, 903, 907, 1999年
英語, 研究論文（学術雑誌）, Thin films of YMnO3 are proposed as a new candidate for non-volatile ferroelectric memory devices. They were prepared via solutions through two different processes: thermal decomposition and reflux using yttrium acetate tetrahydrate and manganese acetate tetrahydrate as starting materials. For coatings prepared by thermal decomposition process, the starting materials were dissolved in ethanol containing diethanolamine, and single phase YMnO3 was obtained with heat-treatment at 900°C. When the starting materials were refluxed using 2-ethoxyethanol as a solvent, single phase YMnO3 was obtained with heat-treatment at 800°C. Scanning electron microscopy showed that the 300 nm thick films with a stoichiometric Y/Mn ratio had many pinholes, and a very large dielectric loss, 0.83 at 100 kHz. Inclusion of 5-10% excess of Y in the coating solution produced dense structures with improved dielectric properties. The dielectric constant and loss tangent of the thin films with Y/Mn ratio of 1.00/0.90 were about 20 and 0.05 at 100 kHz, respectively. - Thermal and Electrical Properties of Rapidly Quenched Li2S-SiS2-Li2O-P2O5 Oxysulfide Glasses(共著)
HAYASHI A, ARAKI R, KOMIYA R, TADANAGA K, TATSUMISAGO M, MINAMI T
Solid State Ionics, 113, 733, 738, ELSEVIER SCIENCE BV, 1998年12月
英語, 研究論文（学術雑誌）, We have systematically investigated the thermal and electrical properties of (1 - y)[xLi(2)S .(100 - x)SiS2]. y[xLi(2)O .(100 - x)P2O5] (45 less than or equal to x less than or equal to 67; y = 0, 0.05, 0.20) oxysulfide glasses in the wide range of lithium ion concentration. These oxysulfide glasses with y = 0.05 exhibited high Tc-Tg values, which is a measure of the glass stability against crystallization, and high ion conductivities at room temperature in the middle range of lithium ion concentration around x = 55 mol%. In the same composition range, large amounts of silicon atoms coordinated with both sulfur and oxygen atoms, i.e. SiOnS4-n (n = 1, 2, 3) tetrahedral units, were observed by Si-29 MAS-NMR measurements. The presence of such unique structural units brought about the high glass stability and high ion conductivity of the glasses with y = 0.05. (C) 1998 Published by Elsevier Science B.V. All rights reserved. - Microstructure and Dielectric Properties of YMnO3 Thin Films Prepared by Dip-Coating(共著)
H Kitahata, K Tadanaga, T Minami, N Fujimura, T Ito
J. Am. Ceram. Soc., 81, 5, 1357, 1360, AMER CERAMIC SOC, 1998年05月
英語, 研究論文（学術雑誌）, YMnO3 thin films with Y/Mn ratios from 1.00/1.05 to 1.00/0.90 were prepared by dip-coating from solution, in which starting materials were refluxed, and the effects of the Y/Mn ratio on the structure and dielectric properties of YMnO3 thin films were investigated. XRD measurements indicated that the films with the Y/Mn ratios in this study were a single phase of polycrystalline YMnO3. The lattice constants along the a-axis and c-axis lengthened with an increase in the Y/Mn ratio. FE-SEM micrographs of the films showed that the surface of the films became smoother and denser with an increase in the Y/Mn ratio. YMnO3 thin films with good dielectric properties were obtained with an Y/Mn ratio of 1.00/0.90, which gave the smoothest and densest microstructure and the smallest leakage current. - Sintering and Crystallization of La2O3-Doped Al2O3 Aerogels from Chemically Modified Aluminum Alkoxide(共著)
TADANAGA K, KOBAYASHI H, MINAMI T
J. Non-Cryst. Solids., 225, 1-3, 230, 233, Elsevier, 1998年
英語, 研究論文（学術雑誌）, Sintering and crystallization of low-density La2O3-doped Al2O3 aerogels prepared from Al-alkoxide chemically modified with ethyl acetoacetate were investigated. Isothermal sintering experiments showed that the sintering mechanism of Al2O3 aerogels is surface diffusion. The specific surface areas (SSA) of Al2O3 aerogels heat-treated at 1000 to 1200°C were greatly increased by the addition of 1-2 mol% La2O3. The crystalline phase of Al2O3 aerogels with 1 mol% La2O3 is θ-Al2O3 with heat-treatment at 1200°C, while that of non-doped Al2O3 aerogels is α-Al2O3 with small surface area. Addition of more than 5 mol% La2O3 caused crystallization of La-containing crystalline phases, and the SSA of these aerogels was smaller than that of Al2O3 aerogels with 1-2 mol% La2O3. Addition of small amount of La2O3 prevented aerogels from sintering through surface diffusion, while the addition of more La2O3 caused nucleation of La-containing crystals. © 1998 Elsevier Science B.V. All rights reserved. - Preparation and Thermal Stability of La2O3-Al2O3 Aerogels from Chemically Modified Al-Alkoxide(共著)
KOBAYASHI H, TADANAGA K, MINAMI T
J. Mater. Chem., 8, 5, 1241, 1244, 1998年 - New Production Process for Colored Glass Bottles Enabling Recycling by the Sol-Gel Method Using Organic Colorants(共著)
Proc. (]G0010[)(]G0008[) Inter. Cong. on Glass, A5, 112, 117, 1998年 - Preparation and Dielectric Properties of YMnO3 Ferroelectric Thin Films by the Sol-Gel Method(共著)
TADANAGA K, KITAHATA H, MINAMI T, FUJIMURA N, ITO T
J. Sol-Gel Sci. Tech., 13, 1/3, 903, 907, 1998年 - Formation Process of Super-Water-Repellent Al2O3 Coating Films with High Transparency by the Sol-Gel Method(共著)
TADANAGA K, KATATA N, MINAMI T
J. Am. Ceram. Soc., 80, 12, 3213, 3216, AMER CERAMIC SOC, 1997年12月
英語, 研究論文（学術雑誌）, Alumina thin films with a roughness of 20 to 50 nm were formed by immersing porous alumina gel films prepared by the sol-gel method in boiling water. When hydrolyzed fluoroalkyltrimethoxysilane was coated on the alumina films, the contact angle for water was increased with an increase of immersion time, and immersion for 30 s was long enough to give super-water-repellency and high transparency; the contact angle for water of the film was 165 degrees and the transmittance for the visible light was higher than 92%. It was found that the surface of the alumina gel films immersed in boiling water consisted of boehmite crystals. It was shown that the existence of air in the hydrophobic pores on the surface caused the super-water-repellency. - YMnO3 thin films prepared from solutions for non volatile memory devices
N Fujimura, H Tanaka, H Kitahata, K Tadanaga, T Yoshimura, T Ito, T Minami
JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 36, 12A, L1601, L1603, JAPAN SOC APPLIED PHYSICS, 1997年12月, ［査読有り］
英語, 研究論文（学術雑誌）, We demonstrated for the first time that hexagonal YMnO3 films were fabricated from solutions which were effective for lowering the formation temperature. Two different processes, a thermal decomposition method and a reflux method, were studied. In the thermal decomposition method, the solution containing Y(OAc)3 . 4H(2)O and Mn(OAc)(2) . 4H(2)O dissolved in ethanol containing diethanolamine was used for coating. Firing temperatures over 900 degrees C were needed to obtain the YMnO3 single phase film using the thermal decomposition process. In the reflux method, the precursor solution prepared from 2-ethoxyethanol as a solvent was refluxed at 125 degrees C and the solution obtained was used for coating. The reflux process drastically lowered the firing temperatures to 700 degrees C, and this process also improved the microstructure. Effects of reflux on the crystallization process and dielectric properties have been demonstrated. - Preparation of Organic-Inorganic Hybrid Coating Films from Vinyltriethoxysilane-Tetraethoxysilane by the Sol-Gel Method(共著)
K Tadanaga, K Azuta, T Minami
J. Ceram. Soc. Jpn., 105, 7, 555, 558, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 1997年07月
英語, 研究論文（学術雑誌）, Organic-inorganic hybrid coating films were prepared using vinyltriethoxysilane and tetraethoxysilane by the sol-gel method on polyimide substrates. Tetraethoxysilane (TEOS) and vinyltriethoxysilane (VTES) or polyvinyltriethoxysilane (PVTES), which was obtained by the radical polymerization of VTES, were used as starting materials. In the TEOS-PVTES system, the organic-inorganic hybrid films with both carbon-carbon and siloxane bonds were obtained, and PVTES gave crack-free and flexible films over a wide composition range. It was found that the Si-O-Si bonds in the organic-inorganic hybrid films contributed to the increase in the dynamic hardness, while the smoothness of the coating films prepared using PVTES contributed to the increase in the pencil hardness. - Water Permeation of SiO2-CH3SiO3/2 Thin Films Modified with Trimethylsilyl Groups on Nylon-6 Substrates(共著)
IWASHITA K, TADANAGA K, MINAMI T
J. Sol-Gel Sci. Tech., 10, 3, 301, 307, KLUWER ACADEMIC PUBL, 1997年
英語, 研究論文（学術雑誌）, SiO2-CH3SiO3/2 thin films coated on nylon-6 substrates by the sol-gel method were modified with trimethylsilyl (TMS) groups and their water permeability was evaluated. The water permeability coefficient of the nylon-6 substrates coated with TMS-modified SiO2-CH3SiO3/2 thin films was smaller than that of unmodified ones. The wettability for water of SiO2-CH3SiO3/2 thin films modified with TMS was smaller than that of unmodified ones. The decrease in the wettability by the modification with TMS resulted in the decrease in water permeability. The measurements of pore size distribution and the water permeability coefficient of coating films with different pressures of upstream side suggested that the mechanism of permeation was governed by the capillary condensation flow. This mechanism was also supported by the result that the water permeability coefficient was decreased with a decrease in wettability. - YMnO3 Thin Films Prepared from Solutions for Non Volatile Memory Deviced(共著)
FUJIMURA N, TANAKA H, KITAHATA H, TADANAGA K, YOSHIMURA T, ITO T, MINAMI T
Jpn. J. Appl. Phys., 36, 12A, L1601, L1603, 1997年 - Super-Water-Repellent Al2O3 Coating Films with High Transparency(共著)
K. Tadanaga, N. Katata, T. Minami
J. Am. Ceram. Soc., 80, 4, 1040, 1042, 1997年 - Water Permeation Properties of SiO2-RS-O┣D73(/)2┫D7(R=Methyl, Viryl. Pheryl) Thin Films Prepared by the Sol-Gel Method on Nylon-6 Substrates
IWASHITA K, TADANAGA K, MINAMI T
J. Appl. Polymer Sci., 61, 12, 2173, 2177, John Wiley and Sons Inc., 1996年09月19日
英語, 研究論文（学術雑誌）, Nylon-6 substrates were coated with SiO2-RSiO3/2 (R = methyl, vinyl, phenyl) thin films by the sol-gel method, and their water permeability was evaluated. Tetraethoxysilane (TEOS) and trifunctional alkoxides such as methyltriethoxysilane (MTES), vinyltriethoxysilane (VTES), and phenyltriethoxysilane (PhTES) were used as starting materials. Water permeability coefficients of the nylon-6 substrates coated with these SiO2-RSiO3/2 thin films were increased with an increase in the content of these trialkoxysilanes in the films. The water permeability coefficients of these coated nylon-6 substrates were smaller in the order of the systems TEOS-PhTES <
TEOS-VTES <
TEOS-MTES in the relatively low content of the trialkoxysilanes. © 1996 John Wiley &
Sons, Inc. - Formation of SiO2-based coatings by the sol-gel method and their effects on water vapour permeability of polyimide films
N Tohge, K Tadanaga, H Sakatani, T Minami
JOURNAL OF MATERIALS SCIENCE LETTERS, 15, 17, 1517, 1519, CHAPMAN HALL LTD, 1996年09月
英語, 研究論文（学術雑誌） - Precursor structure and microstructure of Al2O3 xerogels prepared from aluminum-tri-sec-butoxide chemically modified with mono-, di-, tri-ethanolamines
K Tadanaga, S Ito, T Minami, N Tohge
JOURNAL OF NON-CRYSTALLINE SOLIDS, 201, 3, 231, 236, ELSEVIER SCIENCE BV, 1996年06月
英語, 研究論文（学術雑誌）, The precursor structures of aluminum-tri-sec-butoxide (Al(O-sec-Bu)(3)) chemically modified with alkanolamines, such as mono-, di-, and tri-ethanolamines, were investigated using Al-27 NMR. Those spectra revealed that the addition of these alkanolamines led to the structural change around Al atoms and peak half-width decreased with an increase in the number of OH groups in the alkanolamine molecules. The specific surface area of the gels prepared using triethanolamine, which has the strongest stabilizing ability among these alkanolamines, was smaller than the gels using monoethanolamine or diethanolamine. The specific surface area and pore size distribution of Al2O3 gels were thus controllable with varying the kind of alkanolamines. - Coating and water permeation properties of SiO2 thin films prepared by the sol-gel method on nylon-6 substrates
K Tadanaga, K Iwashita, T Minami, N Tohge
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 6, 1, 107, 111, KLUWER ACADEMIC PUBL, 1996年
英語, 研究論文（学術雑誌）, Nylon-6 substrates were coated with SiO2 thin films by the sol-gel method and their water permeability coefficient was evaluated. Methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS) were used as starting materials. The addition of MTES to TEOS has enabled the formation of-crack-free thin films on the substrates. The thin films strongly adhered to the substrates. The water permeability coefficients of nylon-6 substrates coated with these thin films decreased with the increase in the ratio of TEOS to the total alkoxides. The pretreatment of the nylon-6 substrates with gamma-aminopropyltriethoxysilane was found to be effective to suppress the water permeability. The water permeability was suppressed by about 40% under the optimal condition. - EFFECT OF ALKANOLAMINES ON THE MICROSTRUCTURE AND DIELECTRIC-PROPERTIES OF LEAD ZIRCONIUM TITANIUM TRIOXIDE THIN-FILMS PREPARED FROM MODIFIED METAL ALKOXIDES
H TANAKA, K TADANAGA, N TOHGE, T MINAMI
JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 34, 9A, L1155, L1157, JAPAN SOC APPLIED PHYSICS, 1995年09月
英語, 研究論文（学術雑誌）, Lead zirconium titanium trioxide (PZT) thin films were prepared by the sol-gel method using Ti and Zr alkoxides chemically modified with acetylacetone and trihydrated lead acetate dissolved in ethanol containing alkanolamines, such as monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA), as starting materials. In FE-SEM micrographs of PZT thin films with each alkanolamine, the perovskite phases of 400-600 nm in diameter and the Pb-deficient pyrochlore grains of 20-50 nm in diameter, which could not be detected by Xray diffraction (XRD), were observed, although the XRD patterns of the films showed a single perovskite phase. The fraction and size of perovskite phases in the films using MEA are larger than those in the films using DEA or TEA. An overcoating of PbO on these films can lead to the formation of the perovskite single phase. The PZT thin films using MEA showed better dielectric properties than the films using DEA or TEA. - MICROSTRUCTURE OF AL2O3 XEROGELS AND AEROGELS FROM ALUMINUM-TRI-SEC-BUTOXIDE MODIFIED WITH ETHYLACETOACETATE
K TADANAGA, T IWAMI, T MINAMI, N TOHGE
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 103, 6, 582, 585, CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI, 1995年06月
英語, 研究論文（学術雑誌）, Microstrucutre of Al2O3 xerogels and aerogels prepared from aluminum-tri-sec-butoxide (Al(O-seo-Bu)(3)) modified with ethylacetoacetate (EAcAc) was investigated for controlling the microstructure of Al2O3. The specific surface area and the pore volume of heat-treated xerogels decreased with an increase in the EAcAc/Al(O-sec-Bu)(3) molar ratio, whereas the size of pores was not affected by the ratio. The specific surface area of aerogels decreased monotonously with an increase in the heat-treatment temperature up to 1000 degrees C and was larger than that of xerogels in the whole temperature range of heat treatment, while that of xerogels decreased with increasing temperature due to sintering and drastically decreased at 1000 degrees C. - PREPARATION OF CDS-DOPED GLASSES FROM GELS CONTAINING DIETHYLDITHIOCARBAMATOCADMIUM
T IWAMI, K TADANAGA, M TATSUMISAGO, T MINAMI, N TOHGE
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 78, 6, 1668, 1672, AMER CERAMIC SOC 735 CERAMIC PLACE, 1995年06月
英語, 研究論文（学術雑誌）, CdS-doped SiO2 glasses were prepared via silica gels containing diethyldithiocarbamatocadmium Cd(S2CN(C2H5)(2))(2). Heat treatment of the gels gave transparent yellow SiO2 glasses doped with hexagonal CdS crystals. In optical absorption and fluorescence spectra, the optical absorption edge and the emission peak clearly exhibited a blue shift, which was attributed to the quantum size effect of the carrier confinement, as the CdS content was decreased. In the fluorescence spectra of the CdS-doped silica glasses, the emission peak was observed only near 500 nm and not observed at longer wavelengths which were known to be present if there were sulfur vacancies. - アセト酢酸エチルによって化学修飾されたアルミニウムトリセカンダリーブトキシドから作製したAl_2O_3キセロゲル及びエアロゲルの細孔構造
忠永 清治, 岩見 知明, 南 努, 峠 登
日本セラミックス協会学術論文誌 : Nippon Seramikkusu Kyokai gakujutsu ronbunshi, 103, 1198, 582, 585, 公益社団法人日本セラミックス協会, 1995年06月01日
日本語, Microstrucutre of Al_2O_3 xerogels and aerogels prepared from aluminum-tri-sec-butoxide (Al(O-sec-Bu)_3) modified with ethylacetoacetate (EAcAc) was investigated for controlling the microstructure of Al_2O_3. The specific surface area and the pore volume of heat-treated xerogels decreased with an increase in the EAcAc/Al(O-sec-Bu)_3 molar ratio, whereas the size of pores was not affected by the ratio. The specific surface area of aerogels decreased monotonously with an increase in the heat-treatment temperature up to 1000℃ and was larger than that of xerogels in the whole temperature range of heat treatment, while that of xerogels decreased with increasing temperature due to sintering and drastically decreased at 1000℃. - SOFT-X-RAY XAFS - LOCAL-STRUCTURE OF MULLITE GELS PREPARED FROM MODIFIED ALUMINUM ALKOXIDES
N KAMIJO, N UMESAKI, K FUKUI, C GUY, K TADANAGA, M TATSUMISAGO, T MINAMI
JOURNAL OF NON-CRYSTALLINE SOLIDS, 177, 187, 192, ELSEVIER SCIENCE BV, 1994年11月
英語, 研究論文（学術雑誌）, Using a laboratory X-ray absorption fine structure facility, the local structure of mullite gels prepared from chemically modified aluminium alkoxides has been determined. The gels were dried and heat treated at several temperatures between 60 and 1200 degrees C and the bond lengths and coordination numbers around the aluminium and silicon in each gel were obtained. It is found that the coordination number of oxygen around aluminium is reduced from 6 (in gels dried at 60 degrees C) to similar to 4 (in gels heat-treated at 200, 400 and 800 degrees C). Above 800 degrees C, the coordination number then returns to approximately 5. Double shell models are found to provide better fits for both Al-O and Si-O bonds in all measured gels during curve-fitting analyses. The results indicate that more than two types of coordination coexist for both the Al-O and Si-O sites. Local structure models of the gels are discussed. - Preparation and optical properties of CdS microcrystallite-doped glasses from silica gels containing dithiocarbamatocadmium complex
Tsutomu Minami, Tomoaki Iwami, Kiyoharu Tadanaga, Masahiro Tatsumisago
Proceedings of SPIE, Sol-Gel Optics III, 2288, 183, 192, SPIE, 1994年10月13日
研究論文（国際会議プロシーディングス） - 27Al NMR Study of Coordination States of Aluminum-tri-sec-butoxide Dissolved in Diacetone Alcohol
Kiyoharu Tadanaga, Tsutomu Minami, Noboru Tohge
Chemistry Letters, 23, 8, 1507, 1510, The Chemical Society of Japan, 1994年08月, ［査読有り］
英語, 研究論文（学術雑誌）, 27Al NMR spectra of aluminum-tri-sec-butoxide (Al(O-sec-Bu)3) dissolved in several molar ratios of diacetone alcohol were measured. The spectrum of Al(O-sec-Bu)3 dissolved in diacetone alcohol showed the formation of five-coordinated structural units from original four-coordinated ones. This structural change revealed that diacetone alcohol chemically modified the Al-alkoxide and reduced the reactivity of the alkoxide. - Precursor Structure and Hydrolysis-Gelation Process of Al(O-sec-Bu)(3) Modified with Ethylacetoacetate
Kiyoharu Tadanaga, Tomoaki Iwami, Noboru Tohge, Tsutomu Minami
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 3, 1, 5, 10, SPRINGER, 1994年01月
英語, 研究論文（学術雑誌）, The precursor structure and hydrolysis-gelation process of aluminum-sec-butoxide, Al(O-sec-Bu)(3), modified with ethylacetoacetate (EAcAc) were investigated using IR, UV and high magnetic field (11.7 T) Al-27 NMR spectra. Al-27 NMR showed that the reaction of EAcAc with Al(O-sec-Bu)(3) led to the formation of six-coordinated structural units and most of the precursors were assumed to be present as linear trimer containing a four-and two six-coordinated Al atoms. It was found that EAcAc formed the strong chelating bonds with Al(O-sec-Bu)(3), which were hardly hydrolyzed by the attack of water molecules in the gelation process. - Optimization of Melt-Solidification Process for Bi1.6 Pb0.4 Ca2 Sr2 Cu3 Ox High-Tc Superconductor Thick Films(共著)
TATSUMISAGO M, CHIGUSA H, TADANAGA K, TOHGE N, MINAMI T
Materials Chemistry and Physics, 34, 2, 162, 165, ELSEVIER SCIENCE SA LAUSANNE, 1993年05月
英語, 研究論文（学術雑誌）, The preparation process in the melt-solidification method for obtaining high-T(c) superconductor thick films consists of four steps: (I) melting, (II) solidification, (III) heat treatment and (IV) cooling. The preparation conditions for each step were optimized to obtain higher-T(c) superconductor films of Bi1.6Pb0.4Ca2Sr2Cu3Ox. The resulting optimum conditions were found to be very limited; melting at 1000-degrees-C for 15 min (I), solidification at a cooling rate of about 400-degrees-C min-1 (II), heat treatment at 855-degrees-C for more than 12 h (III) and cooling as quickly as possible (IV) brought about the best results. The thick films prepared under these optimum conditions exhibited a T(c)(zero) of 104 K. - A 207Pb MAS-NMR Study of Pb-containing Glasses(共著)
T YOKO, K TADANAGA, F MIYAJI, S SAKKA
Journal of Non-Crystalline Solids, 150, 1-3, 192, 196, ELSEVIER SCIENCE BV, 1992年11月
英語, 研究論文（学術雑誌）, Pb-207 magic angle spinning (MAS)-NMR spectra have been obtained for various Pb-containing crystalline compounds and high lead glasses. The isotropic chemical shifts were determined for the crystalline samples. The more ionic lead atoms with a coordination number larger than six had relatively small chemical shifts between 0 and 2382 ppm with respect to crystalline Pb(NO3)2. On the other hand, the covalent lead atoms with PbO3 trigonal and PbO4 square pyramidal configurations gave a multiplet line profile with shifts ranging from about 3000 to 6000 ppm. The lead atoms with different local environments in PbSiO3 (alamosite) and H-Pb2SiO4, for instance, could be clearly distinguished from each other on the basis of the isotropic chemical shift. The NMR spectra for the high lead glasses of composition 67PbO.33SiO2, 80PbO.20B2O3 and 70PbO.30GaO1.5 were found to exhibit an extremely broad peak with a shift ranging from about 3000 to 6000 ppm. This shift indicates that, in these glasses, neither such highly ionic lead atoms as found in symmetrical PbO6 octahedra nor such highly covalent ones as found in PbO4 square pyramids in the PbO crystal are predominant, but instead PbO3 trigonal or PbO4 square pyramids, with two or three other neighboring oxygens at larger distances as found in H-Pb2SiO4 or PbSiO3, are the major lead-oxygen configuration. - 3RD HARMONIC-GENERATION FROM MOX-PBO-GAO1.5 TERNARY GLASSES
F MIYAJI, K TADANAGA, S SAKKA
APPLIED PHYSICS LETTERS, 60, 17, 2060, 2061, AMER INST PHYSICS, 1992年04月
英語, 研究論文（学術雑誌）, Third harmonic generation from nonconventional MO(x)-PbO-GaO1.5 (M = Ti,Nb,W) glasses have been measured. The nonlinear susceptibility, chi(3), of these glasses at 0.635-mu-m are about 30 times higher than that of SiO2 glass at the same wavelength. It has been found that TiO2 is most effective in increasing refractive index and chi(3). - COORDINATION OF GA3+ IONS IN PBO-GA2O3 GLASSES AS DETERMINED BY GA-71 NMR
F MIYAJI, K TADANAGA, T YOKO, S SAKKA
JOURNAL OF NON-CRYSTALLINE SOLIDS, 139, 3, 268, 270, ELSEVIER SCIENCE BV, 1992年03月
英語, Ga-71 NMR spectra of GaAs and beta-LiGaO2 crystals consisting of four-coordinated Ga3+ ions, GaNbO4 and alpha-Ga2O3 crystals consisting of six-coordinated Ga3+ ions, and PbO-Ga2O3 glasses were measured. About 240 ppm difference in chemical shift was observed between the spectra of beta-LiGaO2 crystal and GaNbO4 crystal. It has been found that Ga3+ ions are mainly tetrahedrally coordinated by four oxygen ions in the glasses by comparison of spectra of the glasses with those of the crystals. - Properties and Structure of Binary PbO-GaO1.5 Glasses as the Base of Nonlinear Optical Multicomponent Glasses
Miyaji, Fumiaki, Tadanaga, Kiyoharu, Sakka, Sumio
Bulletin of the Institute for Chemical Research, Kyoto University, 69, 5-6, 495, 510, Institute for Chemical Research, Kyoto University, 1992年
英語 - FORMATION PROCESS OF HIGH-TC SUPERCONDUCTING BI-PB-CA-SR-CU-O THICK-FILMS VIA MELT SOLIDIFICATION
M TATSUMISAGO, K TADANAGA, S TSUBOI, N TOHGE, T MINAMI
APPLIED PHYSICS LETTERS, 57, 24, 2597, 2599, AMER INST PHYSICS, 1990年12月
英語, 研究論文（学術雑誌）
その他活動・業績
- LiF-SnO-P2O5系低融性ガラスの作製と評価
柴田姫芽, 藤井雄太, 三浦章, 鱒渕友治, 忠永清治, ガラスおよびフォトニクス材料討論会講演要旨集, 64th, 2023年 - CO2還元電極触媒として用いるZn-Al系層状複水酸化物に対して摩砕が及ぼす影響
中里亮介, 松本慶江子, 山口登, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, CAVALLO Margherita, CROCELLA Valentina, BONINO Francesca, HADERMANN Joke, QUINTELIER Matthias, 日本セラミックス協会年会講演予稿集(Web), 2023, 2023年 - Zn含有層状複水酸化物による電気化学的CO2還元
中里亮介, 松本慶江子, 山口登, ROSERO-NAVARRO Nataly Carolina, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, 日本セラミックス協会秋季シンポジウム講演予稿集(Web), 36th, 2023年 - 焼結助剤を用いたガーネット型Li-La-Zr-O系固体電解質の低温焼結
忠永 清治, Nataly Carolina, ROSERO-NAVARRO, 粉体および粉末冶金, 69, 12, 481, 483, 2022年12月15日, ［招待有り］, ［筆頭著者, 責任著者］
Japan Society of Powder and Powder Metallurgy - 遷移金属を含む層状複水酸化物のCO2電気化学還元触媒への応用
忠永清治, 山口登, 松本慶江子, ROSERO-NAVARRO Nataly Carolina, 中里亮介, 三浦章, 日本セラミックス協会秋季シンポジウム講演予稿集(Web), 35th, 2022年 - 電気化学デバイス用材料としての層状複水酸化物
忠永清治, Journal of the Society of Inorganic Materials, Japan, 27, 108, 2020年05月, ［招待有り］
記事・総説・解説・論説等（学術雑誌） - 層状複水酸化物の水酸化物イオン伝導性と電気化学素子への応用
忠永清治, セラミックス, 53, 5, 335, 338, 2018年05月, ［招待有り］
記事・総説・解説・論説等（学術雑誌） - ゾル－ゲル法による微細な凹凸構造をもつ低反射コーティング膜の形成（解説）
忠永 清治, NEW GLASS, 30, 2, 31, 33, 2015年07月
ニューガラスフォーラム, 日本語, 記事・総説・解説・論説等（商業誌、新聞、ウェブメディア） - 水酸化物イオン伝導性固体材料の開発と燃料電池への応用 (特集 21世紀,期待される新型電池と新しいイオン伝導性固体たち)
忠永 清治, 辰巳砂 昌弘, マテリアルインテグレ-ション, 24, 1, 17, 21, 2011年01月
ティー・アイ・シィー, 日本語 - Thin film electrode materials Li4Ti5O12 and LiCoO2 prepared by spray pyrolysis method
M. Takahashi, J. Tani, H. Kido, A. Hayashi, K. Tadanaga, M. Tatsumisago, IOP Conference Series: Materials Science and Engineering, 18, SYMPOSIUM 9A, 2011年
The Li4Ti5O12 and the LiCoO2 have been considered as promising candidates of electrode materials for all-solid-state lithium secondary batteries. The spray pyrolysis method is a useful economical technique to prepare various thicknesses of oxide films though have not been intensively studied for fabrication of thin film lithium batteries. Thin films of Li4Ti5O12 and LiCoO2 electrode materials about 100-400 nm were prepared on quartz and gold substrates by the spray pyrolysis method by using Liacac and, TiO(acac)4 or Co(acac)3 with DMF solvent as starting materials. Electric properties as electrode materials for lithium batteries were estimated by using 3 probe liquid cells with liquid electrolyte LiPF 6 in EC-DMC and Li metal as reference and counter electrodes. Structure and morphology of the films were investigated by XRD and SEM. Crystalline Li4Ti5O12 and LiCoO2 thin films were found to be prepared over 700 °C of substrate temperature. Cyclic voltammograms of the Li4Ti5O12 electrode thin films showed sharp oxidation and reduction peaks around 1.6 and 1.5 V, respectively. Charge-discharge curves for both Li4Ti 5O12 and LiCoO2 electrode thin films showed discharge plateaus around 1.4 and 3.8 V with about 80 mAhg-1 of capacity. These results showed that these electrode thin films prepared by the spray pyrolysis method are electrochemically active and spray pyrolysis method is a promising technique to prepare thin film electrode materials. © 2011 Ceramic Society of Japan., 英語 - エアロゲルの作製と特性
忠永清治, 成形加工, 19, 12, 738, 741, 2007年 - 水溶液プロセスにより合成した鉄系酸化物微粒子を用いた全固体型リチウム二次電池
北浦 弘和, 高橋 賢司, 水野 史教, 林 晃敏, 忠永 清治, 辰巳砂 昌弘, 日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2006, 0, 94, 94, 2006年
本研究では、FeCl<SUB>3</SUB>水溶液に蒸留水または水酸化ナトリウム水溶液を加え、100℃で数日間エージングすることでβ-FeOOHとα-Fe<SUB>2</SUB>O<SUB>3</SUB>をそれぞれ作製した。α-Fe<SUB>2</SUB>O<SUB>3</SUB>は加える水酸化ナトリウム水溶液の量を変えることで粒子径を制御した。得られた粒子を全固体型電池の電極へと応用した。その結果、β-FeOOHが全固体型電池の電極活物質として機能することがわかった。また、全固体型電池においてα-Fe<SUB>2</SUB>O<SUB>3</SUB>の粒子サイズが電気化学的特性に影響を及ぼすことがわかった。また、α-Fe<SUB>2</SUB>O<SUB>3</SUB>の様々な充放電状態のXRD測定から全固体型電池における充放電メカニズムを明らかにした。, 公益社団法人 日本セラミックス協会, 日本語 - All-solid-state rechargeable lithium batteries using SnX-P2X5 (X = S and O) amorphous negative electrodes
Akitoshi Hayashi, Takanori Konishi, Kiyoharu Tadanaga, Tsutomu Minami, Masahiro Tatsumisago, RESEARCH ON CHEMICAL INTERMEDIATES, 32, 5-6, 497, 506, 2006年
SnS-P2S5 and SnO-P2O5 amorphous materials were prepared by a mechanical milling technique. The SnO-P2O5 milled materials worked as a reversible electrode with higher capacity than SnO crystal in rechargeable lithium cells with conventional liquid electrolytes. All-solid-state cells with a SnX-P2X5 (X = S and 0) amorphous electrode and the Li2S-P2S5 glass-ceramic electrolyte were charged and discharged at room temperature. The sulfide electrodes exhibited better charge-discharge performance than the oxide electrodes, suggesting that SnS-P2S5 electrodes are more compatible with Li2S-P2S5 sulfide solid electrolytes. All-solid state batteries 80SnS center dot 20P(2)S(5)/LiCoO2 showed a charge-discharge plateau of about 3.4 V and high reversible capacity of over 400 mAh/g, even after 50 cycles. The SnX (X = S and O)-based amorphous materials are promising negative electrode materials with high capacity for rechargeable lithium batteries using not only liquid electrolytes but solid electrolytes., SPRINGER, 英語, 書評論文,書評,文献紹介等 - ゾル－ゲル電気泳動電着法による厚膜の作製（解説）
忠永清治, 化学工業, 57, 12, 55, 59, 2006年 - 中温作動形燃料電池用電解質 1.中温作動プロトン伝導性非晶質電解質（解説）
忠永清治, 辰巳砂昌弘, Electrochemistry, 73, 9, 833, 836, 2005年 - 3-グリシドキシプロピルトリメトキシシランと4官能アルコキシシランをベースとするプロトン伝導性無機‐有機ハイブリッドとガラスペーパーの複合化
手塚 照明, 忠永 清治, 松田 厚範, 林 晃敏, 辰巳砂 昌弘, 日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2004, 0, 16, 16, 2004年
3-グリシドキシプロピルトリメトキシシラン、4官能アルコキシシラン、オルトリン酸からなるプロトン伝導性無機‐有機ハイブリッドの薄膜化、機械的強度の付与を目的として、ガラスペーパーとの複合体膜を作製した。厚さ約40μmのガラスペーパーを用いて、約50-100μmの複合体膜を作製することができた。複合体の導電率は130℃、相対湿度7％の条件下で1.0×10<sup>-3</sup> S cm<sup>-1</sup>と高い値を示した。これらを電解質膜として用いた燃料電池は、130℃、相対湿度７％の条件下で最大出力密度120ｍWcm<sup>-2</sup>を示した。また、50時間までの連続発電を確認した。, 公益社団法人 日本セラミックス協会 - 無機ベース複合系電解質膜の研究開発（解説）
忠永清治, 辰巳砂昌弘, 燃料電池, 4, 1, 24, 2004年 - 無機－有機複合体膜の燃料電池への応用（解説）
忠永清治, 辰巳砂昌弘, ケミカルエンジニアリング, 49, 12, 903, 2004年 - Li2S-P2S5系ガラスセラミックスを固体電解質として用いた全固体リチウム二次電池のサイクル特性
水野 史教, 林 晃敏, 忠永 清治, 電気化学および工業物理化学, 71, 12, 1196, 1200, 2003年12月
電気化学会, 英語 - 中温作動燃料電池用プロトン伝導性無機－有機複合体電解質膜（解説）
工業材料, 51 [4] 35-38, 2003年 - 電解質膜 ホスホシリケートゲルおよび無機-有機ハイブリッド (特集 燃料電池実用化のカギを握る材料開発) -- (材料事例)
松田 厚範, 忠永 清治, 辰巳砂 昌弘, 工業材料, 50, 3, 39, 42, 2002年03月
日刊工業新聞社, 日本語 - O2およびH2Oハイバリア性有機－無機ハイブリッドコーティング膜（総説）
忠永清治, セラミックス, 37, 3, 165, 168, 2002年 - ゾル-ゲル法による超はっ水コーティング薄膜の形成と応用 (特集 超はっ水・超親水表面)
忠永 清治, 南 努, マテリアルインテグレ-ション, 14, 10, 9, 13, 2001年10月
ティ-・アイ・シ-, 日本語 - 新イメージング材料“光触媒”（解説）忠永清治
日本印刷学会誌, 38 〔5〕 331-335, 2001年 - Structural changes during thermally induced polymerisation of ormosil films from trimethoxysilylpropylmethacrylate and zirconium-n-propoxide modified with methacrylic acid
K Tadanaga, B Ellis, AB Seddon, SOL-GEL OPTICS V, 3943, 228, 235, 2000年
Structural changes during thermally induced polymerisation of the dipped thin films prepared from TMSPM, zirconium n-tetrapropoxide and methacrylic acid were investigated using near- and mid-infrared (IR) spectroscopy. In the mid-infrared spectra, the intensity of the band due to C=C was decreased by the heat-treatment at 160 degrees C. The intensity of the band due to C=O at around 1720 cm(-1) was also decreased, and that of a band at around 1740 cm(-1) which is assigned to an ester carbonyl C=O in the polymerised methacrylate, was increased. In the near-infrared spectra, the intensities of a band due to the first overtone of fundamental nu(as)(CH2=) and a combination band of nu(as)(CH2=) and nu(C=C) were largely decreased with the heat-treatment at 160 degrees C. These spectral changes show that heat-treatment of the films at 160 degrees C leads to depletion of C=C bonds, indicating that polymerisation has occurred of TMSPM and methacrylic acid. However, in the mid-infrared spectra, the intensity of the band at around 3500 cm(-1) due to O-H bonds, increased with the progress of polymerisation of vinyl groups. Near-infrared spectra of the dipped thin films showed that this increase in intensity of the O-H band is due to the increase of monomeric water molecules hydrogen bonded to silanols. This indicates that polymerised samples are more hydrophilic than unpolymerised ones. The refractive index of the dipped films, measured with a prism coupling method, increased from 1.508 to 1.516 with the polymerisation for composition Zr/(Zr + Si) of 0.2., SPIE-INT SOC OPTICAL ENGINEERING, 英語 - Color coating for recyclable glass bottles by the sol-gel method using organic colorants
H Nakazumi, K Ishii, Y Sakashita, T Ikai, K Tadanaga, T Minami, M Ueda, M Funato, H Kanazawa, K Natsukawa, Y Sakurai, 2ND INTERNATIONAL CONFERENCE ON COATINGS ON GLASS, ICCG, 114, 119, 1999年
The sol-gel colored coating of glass bottles which enabled recycling of the bottles in production process was investigated. The stability of the sol, characteristics and practical resistance of the colored gel films for glass bottles are examined by the gel permeation chromatography, spectroscopic analyses using a fluorescent dye, and mechanical strength analysis, respectively. We found that the inorganic-organic gel films prepared from the mixed alkoxysilanes of phenyltrimethoxysilane and methoxysilane oligomer exhibit good feasibility for this process, especially for the high resistance against boiling water required for sterilization and goad homogeneous dispersion of organic colorants in the gel films. Thermal analyses of organic pigments used in color coating were also performed by a GC-mass spectrometer., ELSEVIER SCIENCE BV, 英語 - Preparation and Characterization of Super-Water-Repellent Coating Films by the Sol-Gel Method(共著)
Topical Issues in Glasses: Photons, Glasses and Coatings, 3, 99, 103, 1999年 - New Production Process for Colored Glass Bottles Enabling Recycling by the Sol-Gel Method Using Organic Colorants(共著)
Proc. (]G0010[)(]G0008[) Inter. Cong. on Glass, A5, 112, 117, 1998年 - ゾル-ゲル法による機能性コーティング薄膜の作製(共著)
表面技術, 48, 3, 298, 303, 1997年 - Preparation and Characterization of Super-Water-Repellent Al2O3 Coating Films with High Transparency(共著)
Tsutomu Minami, Noriko Katata, Kiyoharu Tadanaga, SPIE Proc., 3136, 168, 175, 1997年
Alumina thin films with a roughness of 20 to 50 nm were formed by immersing the porous alumina gel films prepared by the sol-gel method in boiling water. When hydrolyzed fluoroalkyltrimethoxysilane was coated on the alumina films, the films showed super-water-repellency and high transparency
the contact angle for water of the film was 165° and the transmittance for visible light was higher than 92 %. When the fluoroalkyltrimethoxysilane-coated thin films were heat-treated at temperatures higher than 500°C, the films became super-hydrophilic
the contact angle for water on the films was less than 5°. It was shown the existence of air in the pores on the surface caused the super-water-repellency and that of water in the pores caused the super-hydrophilic property. The transparent, super water-repellent and super-hydrophilic coating films formed on glasses, metals, and ceramics have practical applications such as optical lenses, eye-glasses, cover glasses for solar cells, windshields of automobiles, and so on., 英語 - エアロゲルの作製と特性(共著)
忠永清治, 南 努, 化学, 48, 5, 360, 1993年 - ゾル-ゲル法による超撥水コーティング膜の作製(共著)
ニューガラス, 12, 2, 42, 45
書籍等出版物
- Next Generation Batterie
Tadanaga K, Rosero-Navarro N.C, Miura A, Wet Chemical Processes for the Preparation f Composite Electrodes in All-Solid-State Lithium Battery
Springer, Singapore, 2021年03月, ［分担執筆］ - Solid Electrolytes for Advanced Applications: Garnets and Competitors
N.C. Rosero Navarro, K. Tadanaga, Sintering Additives for Garnet-type Electrolytes
Springer Nature, Switzerland,, 2019年, ［分担執筆］ - 全固体電池のイオン伝導性向上技術と材料、製造プロセスの開発
忠永清治, 液相法による硫化物固体電解質の作製と電極活物質への固体電解質のコーティング
技術情報協会, 2017年, ［分担執筆］ - Handbook of Sol-Gel Science and Technology
Nataly Carolina Rosero-Navarro, Kiyoharu Tadanaga, Sol-Gel Processing of Solid Electrolytes for Li-ion Batteries
Springer International Publishing, 2016年08月, ［分担執筆］ - ゲルテクノロジーハンドブック
忠永清治, 辰巳砂昌弘, ゾル- ゲル法による薄膜形成
エヌ・ティー・エス, 2014年10月, 461-466, 日本語, ［分担執筆］ - ゾル－ゲル法の最新応用と展望
忠永 清治, ゾル－ゲル反応の化学
シーエムシー出版, 2014年02月, ［分担執筆］ - プラスチックハードコート材料の最新技術（分担執筆） 執筆項目「防曇、防汚」
シーエムシー出版, 2008年 - ナノイオニクス ―最新技術とその展望―（分担執筆） 執筆項目「ゾルーゲル法による電極－電解質ナノ固体界面形成」
シーエムシー出版, 2008年 - ゾル－ゲル法および有機－無機ハイブリッド材料 ―構造制御・高性能化とその応用― 辰巳砂昌弘・忠永清治（分担執筆） 「無機－有機ハイブリッドおよびコンポジット電解質の作製」
技術情報協会, 2007年 - ゾル－ゲル法および有機－無機ハイブリッド材料 ―構造制御・高性能化とその応用― 忠永清治・辰巳砂昌弘（分担執筆） 「電気泳動電着法による透明厚膜の作製」
技術情報協会, 2007年 - ねれと(超)撥水、(超)親水技術、そのコントロール ―実用化および表面処理・試験評価・商品展開― 忠永清治（分担執筆） 「ゾル－ゲル法による撥水－親水パターンの形成と応用」
技術情報協会, 2007年 - 現代無機材料科学（編著：足立吟也、南 努） 忠永清治（分担執筆） 「燃料電池」
化学同人, 2007年 - エコマテリアルハンドブック 忠永清治（分担執筆） 「有機－無機ハイブリッドガラス」
丸善, 2006年 - 撥水・親水・防汚剤の開発とコーティングおよびぬれ性の制御 忠永清治（分担執筆） 「ゾル－ゲル法によるアルミナ透明超撥水膜の作製」
情報機構, 2006年 - Solid State Ionics for Batteries 忠永清治（分担執筆） 「Proton-Conducting Hybrid Materials」
Springer-Verlag Tokyo, 2005年 - ゾル－ゲル法のナノテクノロジーへの応用 忠永清治（分担執筆） 「ガスバリアコーティング膜」
シーエムシー出版, 2005年 - ナノマテリアル工学大系 第１巻ニューセラミックス・ガラス（監修：平尾一之） 忠永清治（分担執筆） 「超撥水ナノコーティング膜」
フジ・テクノシステム, 2005年 - ナノハイブリッド材料の最新技術 忠永清治・辰巳砂昌弘（分担執筆） 「プロトン伝導性無機－有機ハイブリッド電解質膜」
シーエムシー出版, 2005年 - Handbook of Sol-Gel Science and Technology, Vol.2 Characterization of Sol-Gel Materials and Products K. Tadanaga and T. Minami Measurements of Gas Adsorption and Permeability of Sol–Gel Materials
Kluwer Academic Publisher, 2005年 - [ディスプレイ、包装材料用]ハイバリア材料の開発―成膜技術とバリア性の測定・評価方法― （著書、分担執筆） 執筆項目「ゾル－ゲル法による高分子フィルムへの有機－無機ハイブリッド膜のコーティング」
技術情報協会出版, 2004年 - 目的を達成するための ゾル－ゲル法における構造制御ノウハウ集（著書、分担執筆） 執筆項目「ガスバリアコーティング膜－実用化に向けて－」
技術情報協会, 2003年 - 目的を達成するための ゾル－ゲル法における構造制御ノウハウ集（著書、分担執筆） 執筆項目「超撥水、超親水コーティング膜」
技術情報協会, 2003年 - Recent Research Developments in Materials Science (著書, 分担執筆) A. Matsuda, K. Tadanaga, and T. Minami "Prepareation and Application of Nanocomposite Films via Sol-Gel Process with Hot Water Treatment"
Research Signpost, 2001年 - 執筆題目「ゾルーゲル技術による新機能」松田厚載・忠永清治・南努
ナノマテリアルの最新技術（著書、分担執筆）小泉光恵他編, 2001年 - Recent Research Developments in Materials Science (著書, 分担執筆) A. Matsuda, K. Tadanaga, and T. Minami "Prepareation and Application of Nanocomposite Films via Sol-Gel Process with Hot Water Treatment"
Research Signpost, 2001年
講演・口頭発表等
- ゾル-ゲル法による微細構造を有するZrO2-Al2O3二層系膜の作製とその撥水膜への応用
清藤太郎, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治
日本セラミックス協会年会講演予稿集(CD-ROM), 2020年
2020年 - 2020年 - MgCr2S4の選択的メタセシス合成
三浦章, 井藤浩明, BARTEL Christopher J., SUN Wenhao, ROSERO-NAVARRO Nataly Carolina, 忠永清治, 中田博子, 前田和彦, CEDER Gerbrand, CEDER Gerbrand
日本セラミックス協会年会講演予稿集(CD-ROM), 2020年
2020年 - 2020年 - 固体窒素源を用いたSr-Ta系酸化物前駆体薄膜の窒化
樋口亜門, ROSERO-NAVARRO Nataly Calorina, 三浦章, 鱒渕友治, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2020年
2020年 - 2020年 - マイクロ波加熱を用いたLi2S-P2S5系固体電解質の液相合成
三浦章, 馬庭陸, ROSERO-NAVARRO Nataly Carolina, 忠永清治
電池討論会PDF要旨集(CD-ROM), 2019年
2019年 - 2019年 - ゾル-ゲル法によるシリカを添加したメチル-フェニルシルセスキオキサン厚膜の作製
井上雄太, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, 笠作衛, 幸塚広光, 米田裕和, 新開誠司
日本セラミックス協会年会講演予稿集(CD-ROM), 2019年
2019年 - 2019年 - 自己燃焼反応による新規マンガンモリブデン窒化物の合成
三浦章, 小田原仁, ROSERO-NAVARRO Nataly Carolina, 忠永清治, 長尾雅則, 田中功
日本セラミックス協会年会講演予稿集(CD-ROM), 2019年
2019年 - 2019年 - シリカフィラーを添加したメチル-フェニルシルセスキオキサン透明厚膜の作製
井上雄太, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, 笠作衛, 幸塚広光, 米田裕和, 新開誠司
日本ゾル-ゲル学会討論会講演予稿集, 2019年
2019年 - 2019年 - リチウムイオン伝導性無機-有機ハイブリッドの合成および正極-ガーネット型酸化物固体電解質界面への応用
梶浦龍之介, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治
電気化学会大会講演要旨集(CD-ROM), 2019年
2019年 - 2019年 - ペロブスカイト型有機-無機ハロゲン化鉛を電極材料として用いた全固体リチウム二次電池の構築
藤井雄太, RAMIREZ Daniel, ROSERO-NAVARRO Nataly Carolina, JULIAN Domingo, 三浦章, JARAMILLO Franklin, 忠永清治
電気化学会大会講演要旨集(CD-ROM), 2019年
2019年 - 2019年 - 大面積(Gd,La)2Si2O7:Ce多結晶薄板の作製とその対アルファ線シンチレーション特性
福島光, 樋口幹雄, 金子純一, 三浦章, 忠永清治
セラミックス基礎科学討論会講演要旨集, 2018年
2018年 - 2018年 - LiZnBO3:Mnの合成と中性子イメージングへの応用
川又俊介, 樋口幹雄, 金子純一, 竹谷篤, 小林知洋, 若林泰生, 大竹淑恵, 三浦章, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - 浮遊帯溶融法によるYbドープK2NiF4型およびメリライト型酸化物単結晶の育成
近添慎弥, 樋口幹雄, 樋口幹雄, 小川貴代, 和田智之, 緑川克美, 鱒渕友治, 三浦章, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - アミド溶液を介した酸化インジウム薄膜への窒素ドープ
成瀬雅浩, 三浦章, ROSERO-NAVARRO Nataly Carolina, 忠永清治, 伊左治忠之, 前田真一, 藤本修
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - SiO2フィラーを添加したフェニルシルセスキオキサン透明厚膜の作製
井上雄太, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, 笠作衛, 幸塚広光, 米田裕和, 新開誠司
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - 焼結助剤を用いたLi7La3Zr2O12系リチウムイオン伝導体の低温焼結とその評価
竹當知矩, ROSERO NAVARRO Nataly Carolina, 三浦章, 忠永清治
セラミックス基礎科学討論会講演要旨集, 2018年
2018年 - 2018年 - (Ce,Pr)OBiS2の構造と超伝導
三浦章, 長尾雅則, 綿打敏司, 田中功, 後藤陽介, 水口佳一, 森吉千佳子, 黒岩芳弘, ROSERO-NAVARRO Nataly Carolina, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - 層状酸硫化物LnOInS2(Ln=La,Ce,Pr,Sm)の構造と物性
井藤浩明, 三浦章, ROSERO-NAVARRO Nataly C., 水口佳一, 後藤陽介, 森吉千佳子, 黒岩芳弘, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - 液相法で作製した酸化銅薄膜の尿素を用いた窒化
大東侑生, 三浦章, ROSERO NAVARRO Nataly Carolina, 忠永清治
セラミックス基礎科学討論会講演要旨集, 2018年
2018年 - 2018年 - 液相法による形態制御されたLi6PS5Clの合成
三浦章, ROSERO-NAVARRO Nataly Carolina, 忠永清治
電池討論会講演要旨集, 2018年
2018年 - 2018年 - Fe-P-S正極を用いた全固体リチウム二次電池の充放電特性
小林美咲, 藤井雄太, ROSERO NAVARRO N. C., 三浦章, 忠永清治
電気化学秋季大会講演要旨集(CD-ROM), 2018年
2018年 - 2018年 - Mg-Al系層状複水酸化物を固体電解質に用いたアンモニア水燃料電池の構築
石山翔, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治
電気化学秋季大会講演要旨集(CD-ROM), 2018年
2018年 - 2018年 - リチウムイオン伝導性を有するポリエチレンオキシド系無機-有機ハイブリッドの合成
梶浦龍之介, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治
日本ゾル-ゲル学会討論会講演予稿集, 2018年
2018年 - 2018年 - フェニルシルセスキオキサンゲルの熱軟化を利用した透明厚膜作製
井上雄太, ROSERO-NAVARRO Nataly Carolina, 三浦章, 忠永清治, 笠作衛, 幸塚広光, 米田裕和, 新開誠司
日本ゾル-ゲル学会討論会講演予稿集, 2018年
2018年 - 2018年 - フェニルシルセスキオキサンゲルの熱軟化挙動を利用した厚膜作製
忠永清治, 井上雄太, NAVARRO N.C. Rosero, 三浦章, 笠作衛, 幸塚広光, 米田裕和, 新開誠司
日本セラミックス協会年会講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - NaInS2-xSex(x=0.5,1,1.5)の結晶構造および光吸収
三浦章, 高橋夏海, 長尾雅則, 綿打敏司, 田中功, 後藤陽介, 水口佳一, 森吉千佳子, 黒岩芳弘, ROSERO-NAVARRO N.C., 忠永清治
日本セラミックス協会年会講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - ペロブスカイト型酸窒化物BaTaO2Nの爆発的反応合成
小田原仁, 三浦章, ROSERO-NAVARRO Nataly Carolina, 忠永清治
日本セラミックス協会年会講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - Li3SbS4の合成・結晶構造およびLi+伝導性
藤井雄太, 三浦章, ROSERO-NAVARRO N.C., 忠永清治, 後藤陽介, 水口佳一, 森吉千佳子, 黒岩芳弘
日本セラミックス協会年会講演予稿集(CD-ROM), 2018年
2018年 - 2018年 - 液相法による全固体リチウム二次電池用Li6PS5Cl固体電解質の作製における溶媒の影響
丹羽葉月, NAVARRO Nataly Carolina Rosero, 三浦章, 忠永清治
電気化学会大会講演要旨集(CD-ROM), 2018年
2018年 - 2018年 - La置換Gd2Si2O7:Ceの反応焼結とそのシンチレーション特性
福島光, 樋口幹雄, 和氣嵩暁, 金子純一, 三浦章, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2016年
2016年 - 2016年 - 透光性LiYSiO4:Ce多結晶薄板の作製とそのシンチレーション特性
豊田紗希, 樋口幹雄, 金子純一, 三浦章, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2016年
2016年 - 2016年 - NaNH2融液を用いたマンガン酸窒化物の合成とその酸素還元触媒能
三浦章, ROSERO-NAVARRO Carolina, 鱒渕友治, 樋口幹雄, 吉川信一, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2016年
2016年 - 2016年 - 液相焼結による透光性Gd2Si2O7:Ce薄板の作製とその対α線シンチレーション特性
西方真美, 樋口幹雄, 坪田陽一, 金子純一, 山本誠一, 三浦章, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2015年
2015年 - 2015年 - LiCaBO3:Ceの合成とその蛍光特性
豊田紗希, 樋口幹雄, 坪田陽一, 金子純一, 忠永清治
結晶成長国内会議予稿集(CD-ROM), 2015年
2015年 - 2015年 - Gd2Si2O7:Ce多結晶における粒成長とその対α線シンチレーション特性
西方真美, 樋口幹雄, 植田あき, 坪田陽一, 金子純一, 石橋浩之, 忠永清治
応用物理学会秋季学術講演会講演予稿集(CD-ROM), 2014年
2014年 - 2014年 - SiO2をセルフフラックスとしたGd2Si2O7:Ceの液相焼結とその対α線シンチレーション特性
西方真美, 樋口幹雄, 植田あき, 坪田陽一, 金子純一, 忠永清治, 石橋浩之
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2014年
2014年 - 2014年 - 透光性Gd2Si2O7:Ce多結晶薄板の作製とその対α線シンチレーション特性
西方真美, 植田あき, 樋口幹雄, 金子純一, 坪田陽一, 石橋浩之, 忠永清治
日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 2013年
2013年 - 2013年 - SiO2セルフフラックスを用いたGd2Si2O7:Ce焼結体における粒成長と対α線検出器への応用
西方真美, 植田あき, 樋口幹雄, 金子純一, 坪田陽一, 忠永清治, 石橋浩之
結晶成長国内会議予稿集(CD-ROM), 2013年
2013年 - 2013年 - 熱分解制御法による金属硫化物ナノ粒子の合成と全固体リチウム二次電池への応用
麻生圭吾, 林晃敏, 忠永清治, 辰巳砂昌弘, 柏木行康, 山本真理, 斉藤大志, 大野敏信, 中許昌美
日本化学会講演予稿集, 2012年03月09日, 日本語
2012年03月09日 - 2012年03月09日 - 液相法によるリチウムイオン伝導性Li7La3Zr2O12薄膜の作製
江川 洋美, 忠永 清治, 林 晃敏, 辰巳砂 昌弘, マリオ アパリシオ, アリシア デュラン
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2012年, 公益社団法人 日本セラミックス協会, 日本語
2012年 - 2012年, 【緒言】次世代のシートデバイスを実現する上で、その電源もまた薄膜として形成される必要があることから、薄膜電池は非常に重要な部材である。従来の二次電池では、有機電解液が用いられているために、液漏れや短絡による発火の可能性などの安全性に対する懸念がある。従って、液漏れの心配がなく、安全性、信頼性に優れた固体電解質を用いた薄膜リチウム電池の開発が望まれる。 固体電解質として、ガーネット型構造を有するリチウムイオン伝導性酸化物、その中でも特にLi<SUB>7</SUB>La<SUB>3</SUB>Zr<SUB>2</SUB>O<SUB>12</SUB>（LLZ）が近年注目を集めている。典型的な作製法は、1000℃以上で高温焼結する固相法であるが、低温化を目指してペチーニ法やゾルーゲル法等の溶液法の検討が進められている。しかしながら、何れもペレット成形を目的としたバルク体の報告のみである。そこで、本研究では、薄膜電池への適用を目指して、溶液法によるLLZ薄膜の作製を検討した。【実験】出発原料としてLiNO<SUB>3</SUB>、La(NO<SUB>3</SUB>)<SUB>3</SUB>・6H<SUB>2</SUB>O、Zr(OC<SUB>3</SUB>H<SUB>7</SUB>)<SUB>4</SUB>、焼結助剤としてAl(NO<SUB>3</SUB>)<SUB>3</SUB>・9H<SUB>2</SUB>O、安定化剤としてEAcAcを用いて、これらの1-プロパノール混合溶液をコーティング溶液とした。ディップコーティング法による塗布と450℃仮焼成を複数回繰り返して、MgO単結晶基板上に薄膜を形成し、最後に900℃で焼結を行い、電解質薄膜を得た。【結果】 得られた仮焼成膜を大気雰囲気下で900℃焼結すると、リチウム欠損が生じて、La<SUB>2</SUB>Zr<SUB>2</SUB>O<SUB>7</SUB>結晶が析出した。そこで、Li<SUB>2</SUB>CO<SUB>3</SUB>粉末共存下で焼結したところ、高リチウム伝導性を示す高温相である立方晶LLZを析出させることが出来た。断面SEM観察から、得られた薄膜は、膜厚約800nmの比較的緻密な膜であることがわかった。【謝辞】本研究は、JSTによる日本スペイン戦略的国際科学技術協力推進事業による援助を受けて行った。 - 支持体を用いた全固体アルカリ形燃料電池用Mg-Al系層状複水酸化物電解質膜の作製
忠永 清治, 窪 大樹, 林 晃敏, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2012年, 公益社団法人 日本セラミックス協会, 日本語
2012年 - 2012年, 全固体アルカリ形燃料電池用の電解質膜として、ガラスペーパーおよびPt触媒を担持したカーボンクロスを支持体として用いた、Mg-Al系層状複水酸化物膜を作製した。厚さ約100～150μmの電解質膜を作製した。これらの電解質膜を用いた燃料電池は、OCVが0.9V以上を示した。また、いずれを用いた場合にも、粉末のペレットを電解質として用いた場合と比べて、大きな出力を示すことがわかった。 - 電子顕微鏡を用いた全固体リチウム二次電池におけるLiCoO2電極の観察
林晃敏, 林晃敏, 長尾元寛, 作田敦, 忠永清治, 忠永清治, 辰巳砂昌弘, 辰巳砂昌弘, 戸川欣彦, 戸川欣彦, 森茂生, 森茂生
電気化学会大会講演要旨集, 2012年
2012年 - 2012年 - 溶液法による全固体薄膜リチウム電池用Li2O-P2O5系薄膜の作製
大仲 友子, 忠永 清治, 林 晃敏, 辰巳砂 昌弘, Aparicio Mario, Durá, n Alicia
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2011年, 公益社団法人 日本セラミックス協会, 日本語
2011年 - 2011年, 全固体薄膜リチウム電池への応用にむけて、溶液法によって、Li2O-P2O5系リチウムイオン伝導性薄膜を作製した。出発原料として、LiNO3とH3PO4を用い、これらの水溶液にポリビニルピロリドン（PVP）を加え、コーティング溶液とした。PVPを加えた場合、Li3PO4組成の膜において、400℃の熱処理後も膜が非晶質であることが確認された。PVPの添加は、コーティング溶液の粘度を上昇させ、得られる膜の膜厚を増加させることに有効であるだけでなく、Li3PO4結晶の結晶化の抑制にも効果のあることが確認された。 - バルク型全固体電池におけるLiCoO2正極-硫化物固体電解質界面のTEM観察
林晃敏, 林晃敏, 長尾元寛, 作田敦, 忠永清治, 忠永清治, 辰巳砂昌弘, 辰巳砂昌弘, 戸川欣彦, 戸川欣彦, 森茂生, 森茂生
電池討論会講演要旨集, 2011年
2011年 - 2011年 - ミストCVD法によるLiMn2O4正極薄膜の作製
山口晃弘, 忠永清治, 作田敦, 林晃敏, 辰巳砂昌弘, APARICIO M., DURAN A.
化学電池材料研究会ミーティング講演要旨集, 2011年
2011年 - 2011年 - オルトオキソ酸リチウムで表面修飾したLiCoO2を用いた全固体リチウム二次電池
林晃敏, 林晃敏, 櫻井友季, 作田敦, 忠永清治, 忠永清治, 辰巳砂昌弘, 辰巳砂昌弘
電気化学会大会講演要旨集, 2011年
2011年 - 2011年 - 金属硫化物によって表面修飾されたLiCoO2を用いた全固体リチウム二次電池のキャラクタリゼーション
中本尚之, 作田敦, 林晃敏, 忠永清治, 辰巳砂昌弘
セラミックス基礎科学討論会講演要旨集, 2009年
2009年 - 2009年 - 表面修飾されたLiCoO2正極を用いた全固体リチウム二次電池の作製と評価
作田 敦, 北浦 弘和, 林 晃敏, 忠永 清治, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2008年, 公益社団法人 日本セラミックス協会, 日本語
2008年 - 2008年, 酸化物によってコーティングされたLiCoO<SUB>2</SUB)粒子とLi<SUB>2</SUB>S-P<SUB>2</SUB>SS<SUB>5</SUB>S系固体電解質を用いて全固体リチウム二次電池を作製した。交流インピーダンス測定によって、コーティングが正極－電解質界面の抵抗を低減させることが分かった。界面修飾による抵抗低減により、高い電流密度での作動特性が向上した。 - 表面修飾されたLiCoO2正極を用いた全固体リチウム二次電池の作製と評価
作田敦, 北浦弘和, 林晃敏, 忠永清治, 辰巳砂昌弘
日本セラミックス協会秋季シンポジウム講演予稿集, 2008年
2008年 - 2008年 - 表面修飾LiCoO2を用いた全固体リチウム二次電池の高電位における作動特性
作田敦, 林晃敏, 忠永清治, 辰巳砂昌弘
電池討論会講演要旨集, 2008年
2008年 - 2008年 - 全固体リチウム二次電池におけるLiCoO2電極-固体電解質界面修飾
作田敦, 北浦弘和, 林晃敏, 忠永清治, 辰巳砂昌弘
電気化学会大会講演要旨集, 2008年
2008年 - 2008年 - 全固体リチウム二次電池への応用にむけた金属硫化物によるLiCoO2電極の表面修飾
中本 尚之, 作田 敦, 北浦 弘和, 林 晃敏, 忠永 清治, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2007年, 公益社団法人 日本セラミックス協会, 日本語
2007年 - 2007年, NiやCoの塩を用いてジエチルジチオカーバマト錯体を作製した。その錯体を溶解させたジクロロエタン溶液にLiCoO2粉末を混合し、乾燥・熱処理を行うことで、LiCoO2粒子表面をNiSやCoSなどの金属硫化物で修飾した。得られた試料を電極に用いて、硫化物電解質を用いた全固体電池を作製し、その特性評価を行った。その結果、金属硫化物でLiCoO2電極を表面修飾することにより、全固体電池は高電流密度下において良好な充放電性質を示すことがわかった。 - Li2SiO3ガラスで表面修飾したLiCoO2を用いた全固体リチウム二次電池
林晃敏, 作田敦, 北浦弘和, 忠永清治, 辰巳砂昌弘
電気化学秋季大会講演要旨集, 2007年
2007年 - 2007年 - ゾル-ゲル法によるLiCoO2への酸化物ガラスコーティングと全固体リチウム電池への応用
作田敦, 北浦弘和, 林晃敏, 忠永清治, 辰巳砂昌弘
電気化学会大会講演要旨集, 2007年
2007年 - 2007年 - ゾル-ゲル法によるスルホン化ポリベンジルシルセスキオキサンの作製と特性評価
奥野 真司, 高橋 賢司, 林 晃敏, 忠永 清治, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2006年, 公益社団法人 日本セラミックス協会, 日本語
2006年 - 2006年, プロトン伝導性の付与を目的としてポリベンジルシルセスキオキサンのスルホン化を試みた。スルホン化は出発原料であるフェニルトリエトキシシランをクロロスルホン酸で処理することによりスルホ基を導入し、次いでゾル-ゲル反応を進行させて試料を得る方法と、あらかじめゾル-ゲル法でポリベンジルシルセスキオキサンを作製し、ジクロロメタンに溶解させクロロスルホン酸で処理することでスルホン化した試料を得る方法の二種類を試みた。作製した試料の構造解析、熱分析、導電率の測定などの特性評価を行った。作製した試料の導電率は加湿条件下、30℃で10<sup>-4</sup>から10<sup>-3</sup> S cm<sup>-1</sup>と比較的高い値を示した。 - 水溶液プロセスにより合成した鉄系酸化物微粒子を用いた全固体型リチウム二次電池
北浦 弘和, 高橋 賢司, 水野 史教, 林 晃敏, 忠永 清治, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2006年, 公益社団法人 日本セラミックス協会, 日本語
2006年 - 2006年, 本研究では、FeCl<SUB>3</SUB>水溶液に蒸留水または水酸化ナトリウム水溶液を加え、100℃で数日間エージングすることでβ-FeOOHとα-Fe<SUB>2</SUB>O<SUB>3</SUB>をそれぞれ作製した。α-Fe<SUB>2</SUB>O<SUB>3</SUB>は加える水酸化ナトリウム水溶液の量を変えることで粒子径を制御した。得られた粒子を全固体型電池の電極へと応用した。その結果、β-FeOOHが全固体型電池の電極活物質として機能することがわかった。また、全固体型電池においてα-Fe<SUB>2</SUB>O<SUB>3</SUB>の粒子サイズが電気化学的特性に影響を及ぼすことがわかった。また、α-Fe<SUB>2</SUB>O<SUB>3</SUB>の様々な充放電状態のXRD測定から全固体型電池における充放電メカニズムを明らかにした。 - 酸_-_塩基触媒を利用したゾル_-_ゲル法によるポリフェニルシルセスキオキサン微粒子の作製と特性評価
高橋 賢司, 忠永 清治, 林 晃敏, 片桐 清文, 松田 厚範, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2006年, 公益社団法人 日本セラミックス協会
2006年 - 2006年, 我々はこれまでにゾル_-_ゲル法において、酸性条件下で加水分解・重縮合を行ってから、さらに連続して塩基性条件下で加水分解・重縮合を行うことで、無機_-_有機ハイブリッド材料の一つであるポリフェニルシルセスキオキサン微粒子の作製に成功している。しかしながら、得られた微粒子の構造や生成機構について詳しいことはまだわかっていない。そこで本研究では、熱分析測定や分子量測定などから得られた微粒子の構造やその生成プロセスについて検討を行った。また、溶媒として使用したエタノールの添加量を変えて微粒子の作製を行った結果、エタノールの添加量の増加に伴い、得られる微粒子の平均分子量は低下することがわかった。 - 高リチウムイオン伝導性Li2S-P2S5-P2O5系ガラスセラミックスの合成と全固体二次電池への応用
水野 史教, 大友 崇督, 林 晃敏, 忠永 清治, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2005年, 公益社団法人 日本セラミックス協会
2005年 - 2005年, メカニカルミリング法により作製したLi<SUB>2</SUB>S-P<SUB>2</SUB>S<SUB>5</SUB>-P<SUB>2</SUB>O<SUB>5</SUB>系ガラスを加熱結晶化することにより、高イオン伝導性結晶を有するガラスセラミックスを合成した。単体元素であるPとSを出発原料に用いたガラスセラミックスは、化合物であるP<SUB>2</SUB>S<SUB>5</SUB>を出発原料に用いたガラスセラミックスに迫る高い導電率を示した。また、少量のP<SUB>2</SUB>O<SUB>5</SUB>を添加したガラスセラミックスは、添加していないガラスセラミックスよりも高い導電率を示し、電気化学的安定性にも優れていることがわかった。これらのガラスセラミックスを固体電解質に用いて作製した全固体電池は、室温でリチウム二次電池として機能し、高容量かつ高い可逆性を保持した。 - ゾル_-_ゲル法により作製したポリフェニルシルセスキオキサン微粒子の熱的特性
高橋 賢司, 忠永 清治, 林 晃敏, 松田 厚範, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2005年, 公益社団法人 日本セラミックス協会
2005年 - 2005年, 近年、無機_-_有機ハイブリッド材料は、無機物のみでは得られない光学的性質、機械的特性、熱的性質などを有することから大変注目を集めている。我々はこれまでに、ゾル_-_ゲル法を用いて、無機_-_有機ハイブリッド材料の一つであるポリフェニルシルセスキオキサン微粒子の作製に成功しており、この微粒子においては、ガラス転移温度が観測され、その温度以上で加熱すると微粒子は熱軟化挙動を示すことが見出されている。本研究では、作製手順や使用する溶媒の添加量などを変えて、ポリフェニルシルセスキオキサン微粒子の熱軟化挙動がどのように変化するかについて検討した。 - SnO-MxOy (M=B and P)系ガラスの電気化学的ナノ構造変化
林 晃敏, 忠永 清治, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2005年, 公益社団法人 日本セラミックス協会
2005年 - 2005年, 溶融急冷法を用いて作製したSnO-B<SUB>2</SUB>O<SUB>3</SUB>系およびSnO-P<SUB>2</SUB>O<SUB>5</SUB>系ガラスについて、固体NMR測定、ラマン分光測定、メスバウア測定を用いて、局所構造解析を行った。また、ガラスを電極として用い、電気化学的にリチウムイオンの挿入脱離反応を行った。その結果、リチウムイオンの挿入により、スズイオンが還元され、Li<SUB>2</SUB>O-MxOyマトリックス中にナノサイズの金属スズ粒子が分散したナノコンポジットの得られることが推定された。さらに、ガラスマトリックスの局所構造が、リチウム挿入脱離反応に及ぼす影響についても検討を行った。 - CsHSO4または CsH2PO4とホスホシリケートゲルからなる複合体のプロトン伝導特性
手塚 照明, 忠永 清治, 林 晃敏, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2005年, 公益社団法人 日本セラミックス協会
2005年 - 2005年, 硫酸水素セシウム(CsHSO<SUB>4</SUB>)またはリン酸二水素セシウム(CsH<SUB>2</SUB>PO<SUB>4</SUB>)とホスホシリケートゲル（P<SUB>2</SUB>O<SUB>5</SUB>-SiO<SUB>2</SUB> gel）からなる複合体を作製した。これらの複合体は、その構造中でホスホシリケートゲル由来のオルトリン酸と固体酸が反応し、CsHSO<SUB>4</SUB>系ではCs<SUB>2</SUB>H<SUB>5</SUB>(SO<SUB>4</SUB>)<SUB>2</SUB>(PO<SUB>4</SUB>)、CsH<SUB>2</SUB>PO<SUB>4</SUB>系ではCsH<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>2</SUB>が生成した。これらの複合体は160℃、無加湿条件下において10<SUP>-3</SUP> Scm<SUP>-1</SUP>オーダーの高い導電率を示した。また、シリカゲルとCs<SUB>2</SUB>H<SUB>5</SUB>(SO<SUB>4</SUB>)<SUB>2</SUB>(PO<SUB>4</SUB>)およびCsH<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>2</SUB>の複合体を作製し、その特性についてホスホシリケートゲルを用いた複合体と比較検討した。 - 3-グリシドキシプロピルトリメトキシシランと4官能アルコキシシランをベースとするプロトン伝導性無機‐有機ハイブリッドとガラスペーパーの複合化
手塚 照明, 忠永 清治, 松田 厚範, 林 晃敏, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2004年, 公益社団法人 日本セラミックス協会
2004年 - 2004年, 3-グリシドキシプロピルトリメトキシシラン、4官能アルコキシシラン、オルトリン酸からなるプロトン伝導性無機‐有機ハイブリッドの薄膜化、機械的強度の付与を目的として、ガラスペーパーとの複合体膜を作製した。厚さ約40μmのガラスペーパーを用いて、約50-100μmの複合体膜を作製することができた。複合体の導電率は130℃、相対湿度7％の条件下で1.0×10<sup>-3</sup> S cm<sup>-1</sup>と高い値を示した。これらを電解質膜として用いた燃料電池は、130℃、相対湿度７％の条件下で最大出力密度120ｍWcm<sup>-2</sup>を示した。また、50時間までの連続発電を確認した。 - 全固体二次電池用固体電解質としてのLi2S-P2S5-MS2 (M=Ge,Si)系ガラスセラミックスのイオン伝導度と析出結晶相
水野 史教, 澁谷 優子, 林 晃敏, 忠永 清治, 南 努, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2004年, 公益社団法人 日本セラミックス協会
2004年 - 2004年, メカニカルミリング法により得られたLi<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>系をベースとするガラスを、加熱結晶化することによりガラスセラミックスを作製した。Li<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>-MS<sub>2</sub> (M=Ge,Si)系では、熱処理温度とともにガラスセラミックスの導電率は増大し、550℃の熱処理後では室温で10<sup>-3</sup> S•cm<sup>-1</sup>を超える高い値を示した。この高い導電率は、Li<sub>3</sub>PS<sub>4</sub>-Li<sub>4</sub>GeS<sub>4</sub>系thio-LISICONに類似の高リチウムイオン伝導性結晶の析出によりもたらされたと考えられる。これらのガラスセラミックスを固体電解質に用いた全固体電池は、室温でリチウム二次電池として機能し、300サイクル後においても100 mAh•g<sup>-1</sup>以上の充放電容量と100%の充放電効率を保持した。 - SnS-P2S5系電極とLi2S-P2S5系固体電解質から構成される全固体リチウム二次電池
林 晃敏, 小西 孝憲, 忠永 清治, 南 努, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2004年, 公益社団法人 日本セラミックス協会
2004年 - 2004年, メカノケミカル法を用いてSnS-P<sub>2</sub>S<sub>5</sub>系ガラスを作製し、熱的性質および局所構造について調べた。また、得られたガラスを電極に、高リチウムイオン伝導性Li<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>系ガラスセラミックスを固体電解質に用いることにより、電極と電解質が共通のP<sub>2</sub>S<sub>5</sub>ネットワークで繋がった新規な全固体電池を構築した。全固体型セル80SnS•20P<sub>2</sub>S<sub>5</sub> / 80Li<sub>2</sub>S•20P<sub>2</sub>S<sub>5</sub> / LiCoO<sub>2</sub>は、室温で二次電池として作動し、50サイクル後においても400 mAh/gの容量を保持することがわかった。 - メカノケミカル法によるLi2S-P-S系固体電解質の合成と評価
大友 崇督, 水野 史教, 林 晃敏, 忠永 清治, 辰巳砂 昌弘
日本セラミックス協会 年会・秋季シンポジウム 講演予稿集, 2004年, 公益社団法人 日本セラミックス協会
2004年 - 2004年, 出発原料であるLi<sub>2</sub>SとPおよびSの混合物にメカニカルミリング処理を行うことによって80Li<sub>2</sub>S・20P<sub>2</sub>S<sub>5</sub> (mol%)系ガラスを合成した。ラマン分光法によって、得られたガラスの局所構造について調べたところ、ガラスはPS<sub>4</sub><sup>3-</sup>ユニットとP<sub>2</sub>S<sub>6</sub><sup>4-</sup>ユニットから構成されていることがわかった。一方、Li<sub>2</sub>SとP<sub>2</sub>S<sub>5</sub>の混合物を用いて合成したガラスは、PS<sub>4</sub><sup>3-</sup>ユニットのみから成り、異なる出発原料を用いることによって、ガラスの局所構造に違いが見られた。これらのガラスを加熱結晶化することによって得られたガラスセラミックスは、ともにPS<sub>4</sub><sup>3-</sup>ユニットから構成されており、室温において10<sup>-4</sup> S/cm以上の高い導電率を示すことがわかった。
共同研究・競争的資金等の研究課題
- 液相法による硫化物系リチウムイオン伝導性固体電解質合成の化学
科学研究費助成事業 基盤研究(B)
2021年04月01日 - 2024年03月31日
忠永 清治, ROSERO CAROLINA
本研究では、リチウムイオン伝導性硫化物固体電解質の液相法での合成における化学を総合的に明らかにすることを目的としている。
本年度は、Li2S、P2S５およびLiClなどを出発原料、アセトニトリルおよびテトラヒドロフランを溶媒して用いたサスペンション法およびサスペンション法と溶解・再析出法を組み合わせた液相法によるLi3PS4およびLi6PS5Clなどの硫化物系固体電解質の合成について検討をおこなった。
アセトニトリルを溶媒に用いたLi2SとP2S5を出発原料とするサスペンション法の合成においては、前駆体として得られるLi3PS4とアセトニトリル分子からなる錯体の結晶構造解析を行い、その結晶構造を明らかにした。この錯体は220℃に加熱した場合に生成する結晶相の生成メカニズムを検討したところ、この前駆体錯体が、室温で安定なγ―Li3PS4よりも、高温での安定相であるβ-Li3PS4相に比較的類似した構造を有していることが、錯体の熱分解によって高温安定相であるβ-Li3PS4相が生成しやすい理由であることを明らかにした。
一方、Li2S, P2S5、LiClをアセトニトリル中でサスペンション法により前駆体錯体を含むスラリーの作製を行い、さらに、溶媒の添加による溶解―再析出法を組み合わせることにより、Li6PS5Cl結晶がられることを見出した。また、溶解再析出法において、非イオン性の界面活性剤を加えることにより、粒径を制御したLi6PS5Clを作製することができることを明らかにした。
日本学術振興会, 基盤研究(B), 北海道大学, 21H01610 - 空気中炭素の循環利用による航空用燃料合成
SICORP 日本－EU「高度バイオ燃料と代替再生可能燃料」
2021年05月 - 2024年03月
JST, 戦略的国際共同研究プログラム（SICORP), 北海道大学, 研究代表者 - 電気化学的アニオン挿入脱離可能な層状複水酸化物の創製
科学研究費助成事業 挑戦的研究(萌芽)
2021年07月09日 - 2023年03月31日
忠永 清治
安全性にすぐれた新規蓄電池システムとして、アニオン交換型の電極材料を用いた電池系が注目されている。その中で、水系電解液中で陰イオンが挿入脱離可能な材料の開発が望まれている。本研究では、インターカレーション型の塩化物イオン挿入脱離可能な電極材料として遷移金属含有層状複水酸化物（LDH）を新たに提案し、水系電解液で電気化学的挿入脱離を可能とすることを目指している。
今年度は、遷移金属含有LDHの中で、一種類のみ遷移金属を含む系の代表例としてCo-Al系LDHを選択し主に検討を行い、Co-Al系LDHの酸化還元挙動および塩化物イオンの挿入脱離について、水系電解液および非水系電解液を用いて検討した。
塩化物イオンを層間に含むCo-Al系LDHを共沈法により合成した。この塩化物含有Co-Al系LDH、金属リチウム、LiClを溶解した有機系電解液を用いて３極セルを構築し、サイクリックボルタンメトリー（CV）、定電流充放電試験を行った。CVにおいて、LDH中のCoの酸化還元を確認できた。また、このセルは充放電が可能であり、電池として動作することを確認した。充放電前後でLDH中の塩化物イオンの濃度が変化したことも確認したので、Co-Al系LDHにおいて電気化学的にCoの価数を変化させることによって塩化物イオンを挿入脱離することが確認できた。
さらに、水系電解液においては、炭酸イオンを層間に含むCo-Al系LDHにおいて、水酸化物イオンの挿入脱離を伴うCo-Al系LDHのCoの酸化・還元挙動を確認した。
日本学術振興会, 挑戦的研究(萌芽), 北海道大学, 21K19015 - 酸化物ゲル膜と溶融塩の反応による窒化物系薄膜の低温合成
科学研究費助成事業 基盤研究(B)
2017年04月01日 - 2020年03月31日
忠永 清治, 三浦 章
本研究では、ゾル－ゲル法により作製したゲル膜を、窒素を含む低温溶融塩の液相と反応させる、あるいは、様々な窒素含有化合物のと共に熱処理を行うことにより、低温プロセスで窒化物あるいは酸窒化物の薄膜を形成する新規手法を開発することを目的とした。
作製した酸化物ゲル膜を窒素気流下の電気炉で熱処理する際に、上流に尿素を置き、尿素を加熱して発生する化学種を用いてゲル膜を窒化する方法を検討したところ、あらかじめ液相法で作製した酸化銅あるいは酸化タンタルの薄膜を尿素存在下、窒素気流中熱処理を行うことにより、Cu3NまたはTaON薄膜形成できることを見出した。
日本学術振興会, 基盤研究(B), 北海道大学, 17H03382 - 液相法によるリチウムイオン伝導性酸化物の低温合成
科学研究費助成事業 特別研究員奨励費
2013年04月01日 - 2016年03月31日
忠永 清治, ROSERO-NAVARRO NATALY CAROLINA, ROSERO-NAVARRO Nataly Carolina
Lithium garnet-type oxides Li7-xLa3Zr2-xNbxO12 (LLZNbO, x=0-1) were prepared by a sol-gel process at low temperatures. Then, glass additives, LiO2-B2O3-SiO2 glass and BaO-B2O3-SiO2 glass, were used to stimulate the sintering of the ceramic electrolyte retaining the cubic phase stable at low temperatures.
The cubic garnet phase was formed by a heat-treatment of sol-gel derived precursor powders at 600 - 700 degree C. The presursor powders and glass additives, 53LiO2･31B2O3･12SiO2 (mol%) (LiO2-B2O3-SiO2 glass) or 35BaO･10CaO･5Al2O3･15B2O3･10SiO2 (mol%) (BaO-B2O3-SiO2 glass) were pressed into pellets and sintered at 900 degree C.
The relatative density of 86% was achieved by the sintering with glass additives at 900 degree C. In the composites sintered with the BaO-B2O3-SiO2 glass, the presence of La2Zr2O7 was detected at concentration higher of 4 wt%, while the single cubic phase was obtained for the composites sintered with the LiO2-B2O3-SiO2 glass.
The ionic conductivity of the obtained composite was 8x10^-5 S/cm at 30 degree C using 4 wt.% of LiO2-B2O3-SiO2 glass. The conductivity is 20% lower than the material reported by the solid state reaction process, but the heat treatment used is about 300 degree C lower than that required by the conventional solid state reaction process. This represents an important contribution to further application of the LLZNbO solid electlolyte to all-solid-state battery.
日本学術振興会, 特別研究員奨励費, 北海道大学, 13F03371 - 電子および光機能を有する水酸化物イオン伝導性層状複水酸化物の創製
科学研究費助成事業 基盤研究(B)
2013年04月01日 - 2016年03月31日
忠永 清治, 樋口 幹雄
色素増感太陽電池用色素として知られているEosin-Yを層間に含むZn-Al系層状複水酸化物（LDH）の薄膜が、色素増感太陽電池の電極として動作することおよびこの粉末が可視光照射下で光触媒活性を示すことを見出した。
層間に炭酸イオンを含む(Ni, Mn)-Al 系LDH および (Ni, Mn)-Fe 系LDHは、Mnを置換しない系よりも高いイオン伝導性を示すことがわかった。これらのLDHを触媒層に用いた空気極は、酸素還元反応において大きな還元電流を示した。Mg-Al系LDHを固体電解質として用いたアルカリ形水素－酸素燃料電池が動作することも確認した。
日本学術振興会, 基盤研究(B), 北海道大学, 25289230 - 無機水酸化物イオン伝導体を用いた酸素分離
科学研究費助成事業 挑戦的萌芽研究
2012年04月01日 - 2014年03月31日
忠永 清治
水酸化物イオン伝導体を用いた新規な電気化学的酸素分離方法を提案した。本研究では、炭酸イオンが挿入されたNi-Fe系層状複水酸化物(LDH）を水酸化物イオン伝導体膜として用い、その両面にカーボンに担持された白金を触媒として電極を作製することにより、空気中の酸素から純酸素のみを取り出す酸素分離セルを構築した。50℃、相対湿度70％において、酸素発生量は外部電源の電流値に比例したことから、Ni-Fe系LDHを電解質に用いて電気化学的酸素分離が可能であることがわかった。
日本学術振興会, 挑戦的萌芽研究, 24656391 - 硫化物系高リチウムイオン伝導材料の液相合成
科学研究費助成事業 挑戦的萌芽研究
2011年 - 2012年
辰巳砂 昌弘, 忠永 清治, 林 晃敏
本研究は、液相系からリチウムイオン伝導性硫化物を得ることを目的として行った。その中で、リチウム含量の大きいリチウムイオン伝導性硫化物ガラスがNメチルホルムアミドに溶解することを見出した。得られた溶液を150℃で真空乾燥すると結晶が析出し、約3×10-6 Scm-1の導電率を示した。また、前駆体溶液に電極活物質を分散後、乾燥させることにより、活物質表面に硫化物固体電解質をコートすることができた。この活物質を用いて全固体電池を構築したところ、良好に作動した。
日本学術振興会, 挑戦的萌芽研究, 大阪府立大学, 23656403 - 全固体電池の実用化に向けた高イオン伝導性ガラスセラミックスの創製
科学研究費助成事業
2009年 - 2012年
辰巳砂 昌弘, 忠永 清治, 林 晃敏
Li_2S-P_2S_5 系をベースとするガラスの作製方法、結晶化条件、組成を詳細に調べることによって、室温で 5×10^<-3>S cm^<-1>以上の高い導電率を示す硫化物ガラスセラミックスを作製した。またこれまでほとんど検討されていない硫化物電解質の大気安定性の評価方法を確立した。Li_2S 含量 75mol%組成の電解質が比較的大気安定性の高いことを見出し、さらに金属酸化物との複合化によって、大気安定性を向上させることができた。得られた電解質を用いた全固体リチウム電池が、サイクル性に優れた二次電池として作動することがわかった。
日本学術振興会, 基盤研究(A), 大阪府立大学, 21246098 - ゾル-ゲル法を用いた電子・イオン・光機能を有する層状複水酸化物薄膜の創製
科学研究費助成事業 基盤研究(B)
2009年 - 2011年
忠永 清治
ゾル-ゲル法により作製した酸化物薄膜を温水に浸漬することにより、様々なアニオンが層間に挿入された層状複水酸化物(LDH)微結晶が析出した薄膜を作製した。末端にスルホ基を有する有機色素や蛍光色素が容易に挿入されることがわかった。また、陰イオンの種類を選択することにより、その微結晶の配向性を制御できることがわかった。一方、Mg-Al系、Ni-Al系LDHが、高い水酸化物イオン伝導性を示すことを見出した。
日本学術振興会, 基盤研究(B), 大阪府立大学, 21350118 - イオン伝導性固体とイオン液体のハイブリッド化による新規固体電解質の創製
科学研究費助成事業
2009年 - 2010年
林 晃敏, 辰己砂 昌弘, 忠永 清治
本年度は硫化物固体電解質の導電率向上を目的として、メカノケミカル法を用いたLi_2S-P_2S_5系ガラスとイオン液体の複合化について検討した。75Li_2S・25P_2S_5(mol%)ガラスへ様々なイオン液体を添加し、遊星型ボールミル装置を用いたミリング処理を行うことによって電解質を作製した。その結果、1-ethyl-3-methylimidazolium bis(fluorosulfonyl)amide([EMII[FSA])がガラスの導電率向上に効果のあることがわかった。75Li_2S・25P_2S_5(mol%)ガラスへ10mol%の[EMI][FSA]を添加することによって、ガラスの室温導電率が3.8×10^<-4>Scm^<-1>から7.3×10^<-4>Scm^<-1>へと増加した。さらに、あらかじめリチウム塩lithium bis(trifluoromethanesulfonyl)amide Li[TFSA]を溶解しておいた[EMI][FSA]を添加して得られた電解質は、室温で10^<-3>Scm^<-1>以上の導電率を示した。またサイクリックボルタンメトリーより、この電解質は約5Vの電位窓を有することがわかった。ラマン分光測定の結果、作製した電解質中には、出発物質である硫化物ガラスおよびイオン液体の構成イオン種(PS_4^<3->や[EMI]^+、[FSI]^-)が分解せずに存在していることがわかった。一方、[EMI]BF_4を添加して得られた電解質では、母ガラスと比較して導電率が大きく減少し、これはミリング処理によるBF_4^-の分解に起因していると考えられた。以上の結果から、導電率が高く化学的に安定なイオン液体との複合化が、硫化物ガラス電解質の導電率向上に有効であると結論づけた。
日本学術振興会, 挑戦的萌芽研究, 大阪府立大学, 21656165 - 自己形成へテロ界面を有する全固体電池の構築
科学研究費助成事業
2007年 - 2008年
林 晃敏, 辰巳砂 昌弘, 忠永 清治
本年度は、電極活物質粒子へのコーティングによるヘテロ界面の構築とそのキャラクタリゼーションを行うとともに、メカノケミカル法を用いた電極-電解質ナノ複合体の合成と評価を行った。また得られた電極材料を用いた全固体電池を作製し、様々な条件での作動特性について検討した。
初期充電後のLiCoO_2正極/Li_2S-P_2S_5電解質界面の構造を調べるために、界面部分の断面TEM観察およびEDX分析を行った。ゾルーゲル法を用いてLi_2SiO_3をコートしたLiCoO_2を用いた電池では、コートなしの場合に比べて、界面付近における電解質側へのCoの拡散が抑制されており、充放電に伴う界面構造変化の小さいことがわかった。またこの電池は、繰り返し充放電による界面抵抗変化が小さく良好なサイクル特性を示し、1〜40mA cm^(-2)の大きな電流密度で二次電池として作動することが明らかになった。また、Li_2O-TiO_2系やLi_2O-Al_2O_3系薄膜についても同様に、コーティングによる界面抵抗低減効果が確認された。
メカノケミカル法により作製したNiS活物質、80Li_2S-20P_2S_5電解質、アセチレンブラックからなるナノ複合体を作用極に用いた全固体電池の充放電条件を検討した。この電池は1.3mA cm^(-2)の比較的大きな電流密度で充放電可能であり、360mAhg^<-1>の容量を50サイクルの間保持した。ナノ複合体の断面TEM観察から、充放電後においても、NiS微粒子が固体電解質と良好な界面コンタクトを保持していることが明らかになった。以上の結果から、電極/電解質ナノ複合体を用いることによって、電極活物質の利用率が増加するだけでなく、良好なサイクル特性を実現することができた。
日本学術振興会, 特定領域研究, 大阪府立大学, 19017017 - 温水処理を伴うゾルゲル法による層状複水酸化物薄膜の作製と配向制御
科学研究費助成事業 基盤研究(C)
2007年 - 2008年
忠永 清治
ゾルゲル法で作製したMO-Al_2O_3(M=Mg, Co, Ni, Zn)系前駆体薄膜を、様々な塩を含む温水に浸漬させることにより、陰イオンが層間に挿入された層状複水酸化物微結晶が表面に析出した薄膜を作製した。本手法により、有機色素などの大きな有機分子が挿入された層状複水酸化物微結晶を基板上に容易に析出させることができた。遷移金属を含む薄膜は、電気化学素子の電極として動作することを確認した
日本学術振興会, 基盤研究(C), 大阪府立大学, 19560680 - ガラスの結晶化による超イオン伝導性準安定相の創製と全固体電池への応用
科学研究費助成事業
2006年 - 2008年
辰巳砂 昌弘, 忠永 清治, 林 晃敏
Li_2S-P_2S_5系をベースとするガラス性液体からの超イオン伝導性Li_7P_3S_<11>結晶の析出条件を検討することによって、高いリチウムイオン伝導性と広い電位窓を兼ね備えた硫化物系固体電解質材料を開発した。得られた固体電解質を用いた全固体電池について、電極-電解質界面の構築と評価を行い、全固体リチウム電池が10mA cm^<-2>の大きな電流密度で二次電池として作動することを明らかにした。
日本学術振興会, 基盤研究(B), 大阪府立大学, 18360319 - 液相法によるリチウムイオン伝導性アモルファス非金属硫化物塩の合成
科学研究費助成事業
2006年 - 2007年
辰巳砂 昌弘, 忠永 清治, 林 晃敏
これまでに、硫化物系固体電解質材料が、リチウムイオン導電率が極めて高く、電極活物質との間で安定な界面を形成することを見出し、全固体リチウム二次電池用の固体電解質として応用について検討している。電極活物質微粒子をこの硫化物系固体電解質の薄膜でコーティングすることができれば、良好な界面形成によってスムーズな電気化学反応が可能となり、高電流密度の全固体二次電池にそのまま適用できるだけでなく、現在のリチウムイオン二次電池の画期的な高性能化を図ることも期待できる。そこで、本研究では、非金属硫化物リチウム塩の前駆体薄膜を溶液系から作製し、これを用いたリチウムイオン伝導性の高い硫化物固体電解質薄膜の作製条件を明らかにすることを目的として行っている。
特にガラス系で高いリチウムイオン伝導性を示すことがわかっている、Li_2S-P_2S_5系を中心に検討を行った。P_2S_5源として、ジエチルジチオカーバマトリン錯体の合成を試みた。また、Li_2S,P_2S_5,Li_3PS_4およびLi_2S-P_2S_5系ガラスを直接様々な溶媒に溶解させ、これを再析出させることによって、硫化物を得ることについても検討した。Li_3PS_4結晶やLi_2S-P_2S_5系ガラスはトルエンやジメチルスルフォキシドのような溶媒には溶解しないが、ジメチルホルムアミド(DMF)に比較的溶解しやすいことがわかった。よって、これらの硫化物が溶解したDMF溶液は、リチウムイオン伝導性アモルファス非金属硫化物の液相法のよる合成における前駆体となることが示唆された。
日本学術振興会, 萌芽研究, 大阪府立大学, 18656194 - ゾルーゲル法による電極-電解質ナノ固体界面形成
科学研究費助成事業 特定領域研究
2005年 - 2006年
忠永 清治
溶液状態から固体を作製するゾルーゲル法を用いれば、固体電解質の前駆体溶液が固体電極との間に形成する良好なナノメートルオーダーでの固-液界面を、そのまま良好な固体-固体間のナノ界面に変化させることができる。このことに着目し、本研究では、全固体電気化学素子の構築に必要な電極-固体電解質ナノ界面を形成することを目的とした。具体的には、ホスホシリケートゲル・ポリイミド複合体膜を用いた燃料電池の中温領域および無加湿条件化での発電、全固体型電気二重層キャパシタの構築、新規プロトン伝導性無機-有機ハイブリッドの合成を行った。
中温領域において無加湿条件下で高いプロトン伝導性を示す電解質膜の作製を目的として、アミノ基を有する3-アミノプロピルトリエトキシシラン(以下APTES)と硫酸あるいはリン酸を出発物質として無機-有機ハイブリッド膜を作製した。200℃付近まで安定であり、無加湿条件下、200℃で2×10^<-3>Scm^<-1>の比較的高い導電率を示すことがわかった。
次に熱軟化特性を示すことが知られているポリフェニルシルセスキオキサンに、プロトン伝導性基であるスルホ基の導入を試み、そのプロトン伝導性や熱的性質について検討した。XPS測定よりスルポ基のS_<2p>に帰属できるピークが観測されたことから、スルホ基が導入できていると考えられる。熱軟化特性については、スルホン化を行っていない試料に比べると、200℃程度での熱処理による流動は見られなかったが、粒子同士の結着が確認できた。乾燥状態では10^<-11>Scm^<-1>程度と非常に低い導電率を示したが、相対湿度の増加と共に導電率は指数関数的に大きくなり、相対湿度95%以上で約9×10^<-5>Scm^<-1>と6桁以上導電率が上昇することがわかった。
日本学術振興会, 特定領域研究, 大阪府立大学, 17041015 - 温水処理を伴うゾルーゲル法による層状複水酸化物薄膜の直接合成
科学研究費助成事業 若手研究(B)
2005年 - 2006年
忠永 清治
層状複水酸化物(LDH)は、様々な陰イオンを層間に挿入できることが知られている陰イオン交換体である。このLDHは通常、沈殿として作製されるが、コーティング膜として様々な基材の上に形成できれば、LDHの応用が広がることが期待される。
本年度は、前年度に得られた知見をもとに、Zn-Al系LDH薄膜の組成や温水処理温度が結晶析出に与える影響、様々な有機アニオンが挿入されたZn-Al系LDH薄膜の形成、Mg-Al系およびNi-Al系LDH薄膜の作製について検討を行った。
Zn-Al系LDH薄膜の作製において、様々なZn/Al比を有する前駆体アモルファス膜を作製し、温水処理を行ったところ、Zn/Alの比が1のとき、最も多くのLDH結晶が析出することがわかった。また、温水処理温度を60℃とした場合は、100℃の場合と比べて比較的小さなサイズの微結晶が密度高く析出し、透明なLDH薄膜が得られることがわかった。
温水処理の溶液に様々な有機塩を溶かすことによって、様々な有機アニオンが挿入されたZn-Al系LDH薄膜が形成できた。スルホン化されたスピロピラン分子を含む温水処理した場合、x線回折測定の結果、2.658mmの層間隔に対応するピークが観察され、スピロピランが挿入されたLDH薄膜が形成されたことを確認した。
MgO-Al_2O_3系薄膜を作製し、この膜の温水処理によるLDHの析出条件の検討を行ったところ、中性条件下ではLDH結晶の析出は観察されなかったが、pH=12のNaOH溶液を用いて温水処理をおこなったときに最も多くの結晶が析出することがわかった。
日本学術振興会, 若手研究(B), 大阪府立大学, 17760546 - 金属酸化物ゲルの外部場温水処理による機能性ナノ微結晶分散薄膜の創製
科学研究費助成事業
2004年 - 2005年
松田 厚範, 逆井 基次, 武藤 浩行, 小暮 敏博, 忠永 清治, 打越 哲郎
(1)金属酸化物ゲルの組成探索と機構
・SiO_2-TiO_2系ゲル膜の振動温水処理によって生成するナノシート結晶が層状構造を有するレピドクロサイト型チタン酸であることを明らかにした。得られた薄膜が高い光触媒活性と超親水性・防曇性を示すことを実証した。膜組成依存性では、TiO_2含量が少なくなると、析出するアナターゼの形態が粒状から鋭錘状に変化し、さらにチタン酸シートに変化することがわかった。TiO_2溶解種濃度が低い条件で、シート状結晶が析出しやすくなると推察した。
(2)外部場温水処理による金属酸化物微結晶析出と表面組織制御
【電場中での温水処理による微結晶析出と表面組織制御】
・SiO_2-TiO_2系ゲル膜の直流電場温水処理では、負極側で生成する析出物が粒状からシート状へ変化することがわかった。直流印加電場が5Vcm^<-1>以上では、Ti^<4+>のTi^<3+>への還元により薄膜の光透過率が低下するが、交流電場温水処理ではこれを防げることを見出した。
・ZnOゲル膜を形成した導電性基板と対向電極の間に直流あるいは交流電圧を印加しながら温水処理を行った。その結果、直流電場温水処理によって負極側で析出する結晶が六角柱状に変化し、シリコン基板を用いた場合には、析出結晶が花弁状に変化することがわかった。
(3)超分子集合体を添加したゲル膜の温水処理による微結晶析出と表面組織制御
CTAB、P123、F127などの界面活性剤を添加したSiO_2-TiO_2系ゲル膜の温水処理によってアナターゼナノ微結晶が膜中に高分散析出し、紫外線照射によって界面活性剤鋳型を完全除去できることを明らかにした。
日本学術振興会, 基盤研究(B), 豊橋技術科学大学, 16360327 - メカニカルミリングによる全固体リチウム二次電池の作製と評価
科学研究費助成事業
2003年 - 2004年
辰己砂 昌弘, 忠永 清治, 林 晃敏
本研究によって得られた成果は以下の通りである。
1.メカノケミカル法により様々な組成のLi_2S-P_2S_5系ガラスを作製し、加熱結晶化によりガラスセラミックスを得た。70Li_2S・30P_2S_5(モル%)組成において析出した結晶相は、一連のチオリシコンとは異なる新規な結晶で、主にP_2S_7^<4->イオンから構成されていた。またこのガラスセラミックスは、室温で2.2x10^<-3>S/cmという極めて高い導電率を示した。
2.Li_2S-P_2S_5系ガラスについて、単体からのメカノケミカル合成を試みた。単体から作製したガラスの局所構造は、P_2S_5を用いたガラスと基本骨格において差は無いが、ホモボンドが存在することがわかった。しかし、加熱によりガラスセラミックス化するとホモボンドは減少することがわかった。
3.メカノケミカル法を用いてSnS-P_2S_5系負極材料を合成し、共通のガラスフォーマーを有するLi_2S-P_2S_5系固体電解質と組み合わせた全固体電池を試作した。このセルは、室温で50サイクル以上の充放電が可能であり、400mAh/g以上の高容量を保持することが分かった。
4.メカノケミカル法を用いたCuとSの直接反応によってCuS-S系正極複合体の合成に成功した。得られた正極複合体とLi_2S-P_2S_5系固体電解質を組み合わせたリチウム-硫黄系全固体電池は、正極活物質に対して600mAh/g以上の大きな放電容量を示し、サイクル劣化がほとんど見られなかった。
5.電池のレート特性の向上をめざし、様々な正極複合体の構築を検討した。活物質含量が少ない正極配合比においては、導電助剤の添加により高電流密度下でも充放電が可能となり、助剤としては、ファイバー形状を有するVGCFが少量の添加で優れた充放電特性を示した。また、低電流密度でサイクルを繰り返すことにより、高電流密度下においても高容量の保持が可能になった。
日本学術振興会, 基盤研究(B), 大阪府立大学, 15360350 - イオニクス素子の全固体化にむけた基礎研究
科学研究費助成事業
1999年 - 2004年
南 努, 脇原 將孝, 岩倉 千秋, こうじ谷 信三, 田中 功, 忠永 清治, 足立 吟也, 曽我 直弘
平成11年度〜15年度に実施した本特定領域の成果をまとめるために本の出版を行った。各班長および関連する企業の3名の研究者を中心に原稿を執筆し、シュプリンガーフェアラーク社より、"Solid State Ionics for Batteries"というタイトルで全世界で発売することとなった。以下に目次を示す。
1.Introduction
2.Recent progress in batteries and future problems
3.Recent development of amorphous solid electrolytes and their application to solid-state batteries
4.Recent development of electrode materials in lithium ion batteries
5.Construction of solid/solid interface between hydrogen storage alloy electrode and solid electrolyte for battery application
6.Polymer solid electrolytes for lithium-ion conduction
7.First principles calculations of lithium battery materials
日本学術振興会, 特定領域研究, 大阪府立大学, 11229101 - 中温作動型燃料電池用プロトン伝導体シートの作製と評価
科学研究費助成事業
2002年 - 2003年
松田 厚範, 武藤 浩行, 辰巳砂 昌弘, 忠永 清治, 逆井 基次
本研究課題では、ホスホシリケートゲルに電池構築に必要な成形性を付与し、シート化を試みることと、得られたプロトン伝導体シートを中温作動型燃料電池に応用するための基礎的な知見を得ることを目的とした。本研究課題の実施項目と得られた成果の概要を以下にまとめる。
1.プロトン伝導性無機-有機コンポジットシートの作製と電気特性評価
ホスホシリケートゲルとポリイミドからなるコンポジットのシート化技術を確立した。ホスホシリケートゲルを70wt%含む複合体シートは、130℃、相対湿度20%程度で10^<-3>Scm^<-1>以上の高い導電率を安定して示すことがわかった。これを電解質に用いた燃料電池は、150℃、相対湿度18%条件においてOCVが0.72V、最大電力密度が28mWcm^<-2>を示した。またこの条件において連続発電を確認した。
2.プロトン伝導性無機-有機ハイブリッドシートの作製と電気特性評価
3-グリシドキシプロピルトリメトキシシランを出発原料に用いることによって無機-有機ハイブリッドのシートを作製した。また、電気泳動法による大面積ハイブリッドの作製に関する基礎検討を行った。得られたプロトン伝導性ハイブリッドは、130℃、相対湿度0.7%の低湿度条件下で7×10^<-4>Scm^<-1>の導電率を示した。また、これを電解質に用いた燃料電池は、130℃で連続発電した。
3.ホスホシリケートゲルの化学的耐久性の改善
150℃で熱処理したスズおよびタンタル添加系のゲルは、30℃、相対湿度60%に3時間保持しても、90%以上のリン酸を保持することがわかった。しかし、プロトン伝導性が低下することも明らかとなった。
日本学術振興会, 基盤研究(C), 豊橋技術科学大学, 14550669 - アモルファス固体電解質材料の作製と特性評価
科学研究費助成事業
1999年 - 2003年
南 努, 松田 厚範, 忠永 清治, 辰巳砂 昌弘, 河村 純一, 町田 信也
本年度得られた成果は以下の通りである。
1.リチウムイオン濃度を高めたLi_2S-SiS_2-P_2S_5-Al_2S_3多成分系ガラスを比較的低温で結晶化させることによって、固相反応では得られない高イオン伝導性チオリシコン結晶がガラスから初晶として析出し、室温で1.2x10^<-3>Scm^<-1>の極めて高い導電率を示すことが分った。
2.メカノケミカル法を用いてSnS-P_2S_5系負極材料やCu-S系正極材料を合成し、共通のガラスフォーマーを有するLi_2S-P_2S_5系固体電解質と組み合わせた全固体電池を試作した。いずれの場合もサイクル特性に優れた二次電池として作動し、従来のリチウムイオン二次電池と比べると大きな充放電容量の得られることが分かった。
3.Li_2S-P_2S_5系固体電解質を用いたIn/LiCoO_2系全固体電池において導電助剤の検討を行ったところ、アセチレンブラックは初期不可逆容量の一因となることが分かった。一方、気相成長炭素繊維を用いると不可逆容量を低減することができ、高電流密度での充放電が可能になることが明らかになった。
4.ゾル-ゲル法によってホスホシリケート系ハイブリッドおよびコンポジット系シートを作製した。γ-グリシドキシプロピルトリメトキシシランを用いたハイブリッド系シートやポリイミドを用いたコンポジットシートを電解質膜とした固体高分子形燃料電池は、130℃以上、相対湿度数%の中温低加湿条件下でOCVが0.7-0.85V、最大出力が20-50mWcm^<-2>を示し、連続発電できることが分かった。
5.レーザー蒸着(PLD)法によって、SnO/Li-V-Si-O系ガラス/LiCoO_2系全固体薄膜リチウム二次電池を試作した。200μAcm^<-2>までは二次電池として作動可能であり、容量は大きくないものの、100サイクル以上の充放電を確認した。動作可能な薄膜二次電池が全プロセスPLD法を用いて作製できたことにより、将来のマイクロエレクトロニクスの電源素子として、そのプロセスの確立が望まれる。
日本学術振興会, 特定領域研究, 大阪府立大学, 11229204 - ゾル-ゲル法による高屈折率透明厚膜材料の作製と微細パターニング
科学研究費助成事業
2001年 - 2002年
南 努, 松田 厚範, 忠永 清治, 辰巳砂 昌弘, 仲間 健一
本研究では、以下の研究成果を得た。
1.高屈折率透明厚膜材料開発とキャラクタリゼーション
フェニルトリエトキシシラン、ベンジルトリエトキシシランなどを出発原料に用いて種々のシルセスキオキサン-金属酸化物系厚膜を作製した。検討を行った中で酸化物としてチタニアを加えた場合に、最も屈折率が大きくなることがわかった。さらに、2官能のアルコキシドであるジフェルニルジメトキシシランにチタニアを組み合わせた2成分系膜は、3官能アルコキシドであるフェニルトリメトキシシラン系よりも高い屈折率を示すことがわかった。また、チタニア含量が30%以下では、100℃以上に加熱することによって、粘性が低下し流動性を示すことがわかった。
2.シルセスキオキサン-チタニア系複合体厚膜材料のキャラクタリゼーション
紫外光照射に伴うシルセスキオキサン-チタニア系複合体厚膜材料の構造、組織および光学的性質の変化について検討を行った。複合化したチタニア成分が紫外光を吸収し、シルセスキオキサンのSi-C結合を開裂すると考察した。また、ビニルシルセスキオキサン-チタニア系において最も膜の硬度が大きく上昇することがわかった。
3.高屈折率透明厚膜材料の微細パターニング
ゾル-ゲル成型装置を用いて型プレスを行うエンボス法によって、フェニルシルセスキオキサン-チタニア系高屈折率透明厚膜の微細パターンを転写できることを確認した。
一方、チタニア薄膜表面をフルオロアルキルシランによって撥水処理した表面にフォトマスクを通して紫外光照射を行うと、紫外線照射部のみ親水性になる。これを用いて形成した撥水-親水パターン上にフェニルシスセスキオキサン厚膜を形成し加熱すると、ゲル膜が軟化した際に親水部分に選択的に流動し、液の表面張力によって球面のふくらみ形状を有するマイクロパターンが得られることがわかった。
日本学術振興会, 基盤研究(B), 大阪府立大学, 13555242 - メカノケミカル法による高リチウムイオン伝導性ガラスセラミックスの創製
科学研究費助成事業
2001年 - 2002年
辰己砂 昌弘, 松田 厚範, 忠永 清治, 南 努
本研究は、メカニカルミリング(MM)法により得られる非晶質微粒子を熱処理することにより、高イオン伝導性結晶を析出させた新しいタイプの固体電解質ガラスセラミックス材料を創製することを目的としている。2年間で得られた主な成果は以下の通りである。
(1)MMによるLi_2S-P_2S_5系、Li_2S-P_2S_5-SiS_2系およびLi_2S-P_2S_5-GeS_2系非晶質固体電解質材料の合成を試みた。その結果、何れの系でも広い組成域でガラスが得られた。これらのガラスは室温において10^<-4>Scm<-1>程度の高い導電率を示した。
(2)上記(1)で作製したガラスを様々な条件で熱処理することにより、室温での導電率が10^<-3>Scm^<-1>付近の極めて高い導電率を有するガラスセラミックスが得られた。
(3)上記(2)で得られたガラスセラミックス中には、現在室温で最も高い導電率を示すLi_<4-x>Ge_<1-x>PxS_4系チオリシコン結晶と類似の結晶がいずれも生成しており、これが高い導電率の得られる要因であることを見出した。
(4)Li_2S、単体リン、単体イオウを出発原料として、Li_2S-P_2S_5系ガラスおよびガラスセラミックスの合成をMM法により試みたところ、熱的・電気的性質においてLi_2SとP_2S_5から作製したものとほぼ同等の生成物が得られた。
(5)MM法によって得られたLi_2S-P_2S_5系ガラスセラミックスを固体電解質とし、負極にIn金属、正極にLiCoO_2を用いて全固体二次電池を試作し特性を評価した。その結果、初期数サイクルの不可逆容量が大きいものの、初期充電を容量規制で行うことによって放電容量が増大し、200サイクル経過後も放電容量約100mAhg^<-1>、充放電効率ほぼ100%の極めてサイクル特性に優れた全固体電池が得られた。
日本学術振興会, 基盤研究(B), 大阪府立大学, 13450359 - ゾル-ゲル法によって作製される薄膜の表面組織の制御と応用
科学研究費助成事業
2001年 - 2002年
南 努, 松田 厚範, 忠永 清治, 辰巳砂 昌弘
本研究は、ゾル-ゲル法による酸化物薄膜の作製において、液相法の特徴を生かして薄膜表面の組織をナノメーター領域で制御することによって、薄膜に機能性を付与した新しい材料を創製することを目的とし、以下の成果を得た。
(1)SiO_2-TiO_2系ゲル膜を沸騰水に浸漬した場合、膜表面にアナターゼ微結晶が析出し、微細な凹凸が形成されることがわかった。この薄膜は、高い触媒活性を示すことを確認した。また、温水処理温度の低温化について検討した結果、60℃の乾燥後、55℃の温水処理によって、アナターゼが膜表面に析出することがわかった。さらに、この温水処理時に基板に振動を与えることによって、層状構造を持つチタン酸ナノシート微結晶が析出することを見出した。このシート状結晶は、表面に微細な凹凸が形成され、水に対する接触角が5度以下の超親水性を示した。この超親水性は、暗所に2000時間保持した後も維持することを確認した。
(2)アセチルアセトンで化学修飾したチタンアルコキシドを用いて作製したシリカ-チタニアゲル膜に紫外光を照射すると、種々の溶液に対する溶解性が未照射部分より低くなることがわかった。この現象を利用し、フォトマスクを介してUV照射し、エッチングすることにより、シリカ-チタニア系ゲル膜のマイクロパターニングを行った。さらに、この膜を温水処理すると膜表面にアナターゼナノ微結晶生成することがわかった。
(3)アセト酢酸エチルで化学修飾したアルミニウムアルコキシドから作製したアルミナゲル膜を温水で処理することによって形成される、表面に微細な凹凸形状を持つ花弁状組織において、温水処理の低温化について検討した結果、40℃の処理でもこの花弁状組織が形成されることがわかった。一方、これらの薄膜が非常に低い光反射率を示すことがわかった。
日本学術振興会, 基盤研究(B), 大阪府立大学, 13450273 - ゾル-ゲル法による超撥水-超親水パターンの作製と応用
科学研究費助成事業 奨励研究(A)
2000年 - 2001年
忠永 清治
本研究は、ゾル-ゲル法によって作製した超撥水表面を、光照射等の手法を用いて局部的に親水化し、超撥水-超親水パターンを形成すること、およびこのパターンの応用を検討することを目的として行ったものである。今年度は、昨年度に得られた知見を基にさらに研究を進め、以下のような成果を得た。
(1)多数の円が規則正しくならんだフォトマスクを用いて紫外光を照射することによって得られた超撥水-超親水パターン上に、水を溶媒としたコロイダルシリカ、ポリエチレングリコール、加水分解したテトラメトキシシランからなるシリカゾルをコーティングすると、このゾルは、光照射部である親水部分にのみ残り、乾燥後、膨らみ形状を持つシリカマイクロパターンが形成できることがわかった。
(2)ポリエチレングリコール、テトラメトキシシランを加えない場合には、非常に小さい厚みのパターンしか形成できない。また、シリカゾルの濃度、ポリエチレングリコールの添加量を変化させることで、得られる膨らみパターンの厚みが制御できることがわかった。
(3)超撥水を得るために形成している凹凸の程度を変化させた撥水-親水パターンを形成し、マイクロパターン形成に及ぼす凹凸の影響について検討した結果、凹凸が小さい方がより大きな厚みを持つマイクロパターンが得られることがわかった。
(4)プロセスの低温化について検討した結果、全プロセス100℃以下で、超撥水-超親水パターンが形成できることがわかった。
日本学術振興会, 奨励研究(A), 大阪府立大学, 12750608 - ゾルーゲル法による透明厚膜の作製と微細加工プロセスへの応用
科学研究費助成事業
1999年 - 2000年
南 努, 松田 厚範, 忠永 清治, 辰巳砂 昌弘, 前田 浩一
本研究では、ゾルーゲル法をベースとして、微小光学素子等に応用可能な透明厚膜材料を探索し、その作製技術と微細パターニングプロセスを確立することを目的としている。以下に当該研究期間に得られた研究成果の概要を示す。
1.ゾルーゲル厚膜材料・組成の探索
ベンジルトリエトキシシランを出発原料に用いて作製した有機-無機複合微粒子を用いて、電気泳動電着法により作製した厚膜を熱処理を行うことにより透明厚膜を作製することに成功した。また、光硬化性無機-有機複合膜や、エンボスマイクロパターニング用高屈折率無機-有機複合膜を作製した。
2.ゾルーゲル厚膜材料のキャラクタリゼーション
メチルシルセスキオキサンーフェニルシルセスキオキサン系複合膜は、メチル基とフェニル基の割合が1:1の付近でクラックの発生が抑制され、最大膜厚が大きくなることがわかった。型プレスにより微細パターン形成のための最適条件について検討を行った。フェニルシルセスキオキサンおよびベンジルシルセスキオキサン厚膜は、チタンアルコキシドの添加によって、屈折率が最大1.64まで増大し、熱軟化がが起こりにくくなった。
3.ゾルーゲル微細加工プロセスの確率
ビニルトリメトキシシラン系光硬化性無機-有機複合体厚膜を用いて、ガラス基板上に幅3μmの光導波路を作製することができた。また、熱硬化性フェニルシルセスキオキサン系およびベンジルシルセスキオキサン系厚膜を用いて、エンボス法あるいは融液の表面張力を利用してマイクロレンズパターンなどを作製するこができた。
4・ゾルーゲル微小光学素子の設計および性能評価
マイクロレンズアレイ、光導波路などの試作とSEM、AFMによる形状を評価を行った。試作したマイクロレンズアレイは、実用レベルの良好な集光特性を示すこと実証した。
日本学術振興会, 基盤研究(B), 大阪府立大学, 11555239 - メカニカルミリングによる非晶質固体電解質材料の創製
科学研究費助成事業
1999年 - 2000年
辰巳砂 昌弘, 松田 厚範, 忠永 清治, 南 努
本研究は、メカニカルミリング(MM)による非晶質固体電解質材料の合成手法の確立を目的として行ったものである。2年間で得られた主な成果は以下の通りである。
(1)MMによるLi_2S-SiS_2-LixMOy(LixMOy=Li_4SiO_4、Li_3PO_4)系非晶質固体電解質材料の合成を試みたところ、約20時間のMMで、非晶体の得られることが分かった。これらの非晶体は、室温において10^<-4>Scm^<-1>以上の導電率を有し、リチウムイオン輸率が1で、10V以上の極めて広い電位窓を有することが明らかになった。
(2)MMにより得られた非晶質材料に対し、固体高分解能NMR、XPS等の分光学的測定を行い、局所構造を調べた。その結果、融液急冷により得られるガラスに存在するのと同様の構造単位が、MM非晶体中にも多く存在することが明らかになった。
(3)様々なリチウム化合物とSiS_2を出発原料にMMを行うことにより、非晶質固体電解質材料の合成を試みた。、リチウム化合物としてLi_2S、Li_2O、Li_3Nを用いた場合、得られた試料は室温において10^<-4>Scm^<-1>以上の高い導電率を有することが分かった。
(4)MMにより、Li_2S-P_2S_5系非晶質試料を作製したところ、Li_2S-SiS_2系と同等の高いリチウムイオン伝導性が得られたが、これをさらに結晶化温度以上に加熱することにより、10^<-3>Scm^<-1>オーダーに迫る高いイオン伝導性を有するガラスセラミックスの得られることを見い出した。
(5)MM時間を変化させて作製した95(0.6Li_2S・0.4SiS_2)・5Li_4SiO_4試料を固体電解質として用い、InおよびLiCoO_2をそれぞれ負極、正極とする全固体リチウム二次電池を構成し、充放電挙動について検討したところ、10時間のMMにより、80mAhg^<-1>以上の放電容量を示す全固体リチウム二次電池の得られることが明らかになった。
日本学術振興会, 基盤研究(B), 大阪府立大学, 11450336 - 液相より作製した薄膜の表面組織制御に関する研究
科学研究費助成事業
1999年 - 2000年
南 努, 松田 厚範, 忠永 清治, 辰巳砂 昌弘
本研究は、ゾル-ゲル法による酸化物薄膜の作製において、液相法の特徴を生かして薄膜表面の組織をナノメーター領域で制御することによって、薄膜に機能性を付与した新しい材料を創製することを目的として行ったものである。以下に得られた成果の概要を示す。
(1)アモルファスのアルミナゲル薄膜を沸騰水処理することによって得られる微細な凹凸を持つ花弁状組織の上に、TiO_2系薄膜およびフルオロアルキルシランをコーティングすることによって得られた超撥水表面は、紫外光照射により表面が超親水化することがわかった。
(2)アセト酢酸エチルで化学修飾したアルミニウムアルコキシドから作製したアルミナゲル薄膜を60℃の温水に浸漬することによって、表面に微細な凹凸形状を持つ花弁状組織が形成されることを見出した。この表面に、加水分解したフルオロアルキルトリメトキシシランをコーティングすることによって、超撥水表面を作製できることがわかった。
(3)種々の有機高分子を含有する均質・透明、平滑なシリカゲル膜をPET基板上に形成できた。その中で、ポリビニルアルコールを添加した系が水蒸気・酸素透過性の低減に最も効果的であることがわかった。
(4)酢酸イットリウム、酢酸マンガンを出発原料としてYMnO_3薄膜を形成する際、熱処理を真空中で行うことによって、非常に緻密で平滑な表面を持つYMnO_3薄膜が得られることがわかった。この薄膜は、非常に小さい漏れ電流を示し、液相から作製したYMnO_3薄膜としては、初めて強誘電性が室温で発現することを見出した。
(5)有機高分子を含むSiO_2-TiO_2系ゲル膜を沸騰水に浸漬した場合、膜中にアナターゼ微結晶が高分散で析出することがわかった。また、有機高分子を含まない場合には、膜の表面にアナターゼ微結晶が析出し、微細な凹凸が形成されることがわかった。
日本学術振興会, 基盤研究(B), 大阪府立大学, 11450252 - ゾル-ゲル法による超撥水および超親水膜の作製と応用
科学研究費助成事業
1997年 - 1998年
南 努, 稲葉 博司, 松田 厚範, 忠永 清治, 辰巳砂 昌弘
本研究は、ゾル-ゲル法を用いて、種々の表面エネルギーや微細組織を持つ薄膜を形成し、超撥水性、超親水性を発現させ、種々の基板にこれらの機能を付与した新しい材料を開発することを目的としている。すなわち、溶液組成や結晶化挙動を制御することによって表面状態や組織を精密に制御し、超撥水性、超親水性薄膜を得ることを目標とした。
本研究で得られた成果の概要を以下に示す。
1. アセト酢酸エチルで化学修飾されたAl(O-sec-Bu)3を出発原料として用いて作製したアモルファスのアルミナ薄膜を沸騰水中に浸漬すると、数十nmオーダーの凹凸を持つベーマイト相の表面が得られることがわかった。
2. この微細な凹凸を持つ組織を持つアルミナ薄膜に加水分解したフルオロアルキルシランをコーティングすると水に対する接触角が165ﾟとなり、超撥水透明薄膜が得られた。
3. フルオロアルキルシランをコーティングした後の熱処理温度を変化させて、水に対する接触角を測定したところ、450℃までの熱処理では超撥水状態を示したが、500℃の熱処理によってフルオロアルキル鎖が分解し、超親水状態になることがわかった。
4. オルガノトリエトキシシランを加水分解してアルミナ花弁状組織に塗布することにより、フッ素を含まない超撥水膜を作製することができた。有機官能基の大きさと溶液濃度によって撥水性が変化することがわかった。
5. アルミナ花弁状組織を用いない超撥水性薄膜の作製を試みた。検討したオルガノアルコキシシランの中で、ジメチルジエトキシシランとフェニルトリエトキシシランを用いた場合に透明な超撥水薄膜が得られた。薄膜の表面SEM観察から、フラクタル的な微細凹凸が形成されていることを確認した。さらに600℃以上で熱処理することにより有機官能基が燃焼分解し、薄膜は超撥水性から超親水性に変化することを見い出した。
日本学術振興会, 基盤研究(B), 大阪府立大学, 09555195 - ゾル-ゲル法による制御された組織を持つ酸化物コーティング膜の作製
科学研究費助成事業
1997年 - 1998年
南 努, 松田 厚範, 忠永 清治, 辰巳砂 昌弘
本研究では、これまでのゾル-ゲル法による酸化物薄膜の作製方法、およびゾル-ゲル電気泳動電着法による酸化物厚膜の作製方法に関する知見を基に、液相法の特徴を生かして薄膜および厚膜表面の組織をナノメーターの領域で制御することによって、膜に機能性を付与した新しい材料を創製することを目的とした。
本研究で得られた成果の概要を以下に示す。
1. ポリビニルトリエトキシシラン-テトラエトキシシラン系から、ゾル-ゲル法によりポリイミド基板上に有機-無機複合コーティング膜を作製した。広い組成範囲でクラックのない柔軟性のある膜を作製することができた。
2. シリカ微粒子を含むゾル溶液にカチオン性の高分子界面活性剤であるポリエチレンイミンを加えた溶液を用いてステンレス基板上への電気泳動電着を行った。0.01mass%のポリエチレンイミンを添加した場合に膜厚は約20μmとなり、熱処理を行ってもクラックのない厚膜が得られた。
3. 酢酸イットリウム、酢酸マンガンを用いてYMnO_3系強誘電体薄膜を作製した。さらに、5〜10%イットリウムが過剰の組成において緻密で平滑な表面を持つ薄膜を得ることができ、良い誘電特性を示すことを見い出した。
4. YMnO3薄膜をラッピドサーマルアニーリング(RTA)を用いて熱処理を行うことにより、通常の熱処理に比べて非常に結晶性のよい緻密な組織を有する薄膜を作製することができた。
5. チタニア-シリカ系ゾル-ゲル薄膜を温水処理することにより、アナターゼナノ微結晶が均一に分散した透明薄膜が100℃以下の低温で作製できることを見い出した。
6. フェニルシルセスキオキサン粒子を電気泳動電着に用いることによりITOコートガラス基板に厚膜を形成した。得られた厚膜は400℃で熱処理を行うことにより透明性が飛躍的に向上した。
日本学術振興会, 基盤研究(B), 大阪府立大学, 09450328 - ゾルーゲル法によるYMnO＿3強誘電体薄膜の作製と特性評価
科学研究費助成事業 奨励研究(A)
1997年 - 1998年
忠永 清治
MFS型(金属-強誘電体-半導体)不揮発性メモリーへ応用できると考えられる、YMnO_3系複合酸化物薄膜をゾル-ゲル法によって作製し、その結晶化温度の低温化、誘電特性を評価した。
YMnO_3系強誘電体薄膜を作製する際の出発原料として、酢酸イットリウム、酢酸マンガン、溶媒として2-エトキシエタノール、添加剤としてジエタノールアミンを用いた場合に、約100〜500nmの膜厚を持つ均質な薄膜が得られることを見い出した。また、これらの出発原料を混合して作製した溶液でコーティングを行った場合には、900℃以上の熱処理で単相のYMnO_3が作製できるのに対し、出発原料を還流し、イットリウムおよびマンガンのアルコキシドを生成させてからコーティングを行うと、結晶化温度が低下し、800℃の熱処理で単相が得られることがわかった。走査型電子顕微鏡により表面の組織を観察したところ、粒子が大きく成長し、その粒子間に数十nm以上の穴の存在する組織であることが確認された。また、電気的特性に関しては、リ-ク電流が非常に大きく、十分な誘電特性の評価を行うことができなかった。
さらに、出発組成における、イットリウムとマンガンの比をわずかに変化させて薄膜を作製した場合、5〜10%イットリウムが過剰の組成において緻密で平滑な表面を持つ薄膜を得ることができた。この薄膜において測定した誘電率は約20、損失係数は約0.05、また、リ-ク電流は1Vの印加で10^<-4>A・cm^<-2>となった。但し、緻密化が十分でないために、細孔や粒界が存在し、低周波数における損失が大きく現れた。
日本学術振興会, 奨励研究(A), 大阪府立大学, 09750755 - 新規な超イオン伝導ガラスの創製とキャラクタリゼーション
科学研究費助成事業
1997年 - 1997年
南 努, 松田 厚範, 忠永 清治, 辰巳砂 昌弘
Li_2S-SiS_2系をベースとするオキシスルフィドガラスは、全固体リチウムイオン二次電池の電解質の有力な候補である。我々は、(1-y)[xLi_2S・(100-x)SiS_2]・y[xLi_2O・(100-x)P_2O_5](45
Li_2S-SiS_2系ガラスに対する、Li_3AlO_3およびLi_3AlS_3の添加の効果についても検討を行った。いずれの化合物を添加した場合においても、結晶化に対する安定性の向上および伝導の活性化エネルギーの減少がみられた。Li_3AlO_3を添加した系においては、硫黄と酸素の両方が配位したシリコンを含む構造単位が存在することがわかった。Li_3AlS_3を添加した系においては、^<27>AlNMRスペクトルによって、硫黄6配位のアルミニウムをもつ構造単位が多く存在することがわかった。この構造単位の存在が高いイオン伝導度に寄与していると考えられる。
日本学術振興会, 重点領域研究, 大阪府立大学, 09215233 - 酸化物ガラスおよびその融体における局所構造とフラジリティの相関
科学研究費助成事業
1996年 - 1996年
辰巳砂 昌弘, 忠永 清治
本研究では、実用上重要な種々の酸化物系ニューガラスに対し、その融液から過冷却液体に至る幅広い粘度域での粘性係数の温度依存性を測定し、系や組成とFragilityの関係を明らかにした。一方で、様々な回析および分光学的手段を用いてそれぞれのガラスおよび融液の構造解析を行い、局所構造の組成依存性を検討した。本年度得られた成果は以下の通りである。
混合アニオン系として作製したSnX_2-P_2O_5(X=F,Cl)系ガラスでは、SnX_2含量の少ない組成ではEη/TgからみたFragilityは一定であるが、SnX_2含量の多い組成では、SnX_2含量の増加に伴ってFragilityは増加した。このとき、Fragilityが一定であったガラスでは局所構造が類似しているが、SnX_2含量の多い組成ではFragilityが大きいものほど、非架橋酸素の割合が多いピロリン酸グループやP-FやSn-Cl結合が多く存在することが確認された。このことから、イオン結合性の増加がFragilityの増加に寄与していると考えられる。
混合アルカリ系として作製したLi_2O-Na_2O-B_2O_3系ガラスでは、△CpからみたFragilityはほぼ一定であるが、Eη/Tgの観点からみるとアルカリを混合することでStrongになっていることが明らかとなった。この系の局所構造はアルカリ混合比によって変化せず、△CpからみたFragilityの傾向と一致した。
混合フォーマ-系として作製したNa_2O-SiO_2-B_2O_3系およびAgI-Ag_2MoO_4-Ag_2PO_<3.5>系ガラスではガラスフォーマ-を混合することによって△CpとEη/Tgの両方の観点からみてStrongになることが明らかになった。また、混合アルカリ系とは異なり、フォーマ-を混合することによって局所構造が大きく変化しており、△CpからみたFragilityと局所構造の間には密接な関係があることがわかった。
日本学術振興会, 基盤研究(C), 大阪府立大学, 08650993 - 新規な超イオン伝導ガラスの創製とキャラクタリゼーション
科学研究費助成事業
1996年 - 1996年
南 努, 忠永 清治, 辰巳砂 昌弘
本研究は、Li_2S-SiS_2系をベースとするLi_2S-SiS_2-Li_4SiO_4系オキシスルフィド系ガラスのイオン伝導度および熱的安定性における混合アニオン効果に着目し、このガラスの構造解析を行うことによりこの効果の本質的理解を深めながら応用展開することを目的としている。ここでは、このような系のガラスの高いイオン伝導性および優れた熱的安定性とガラス構造の関係について明らかにした。本年度得られた成果は以下の通りである。
1)^<29>Si MAS-NMR測定の結果から、ベースガラスに少量のLi_4SiO_4を添加すると、硫黄と酸素の両方の配位したケイ素がガラス中に多量に存在することがわかった。一方、多量のLi_4SiO_4を添加すると、このようなケイ素は減少した。
2)X線光電子スペクトルの結果から、少量のLi_4SiO_4を添加したガラス中では、硫黄は非架橋状態、酸素は架橋状態で主に存在し、多量に添加するとS^<2->や非架橋酸素が多く存在することが明らかになった。
3)5mol%のLi_4SiO_4を添加したガラス中には非架橋硫黄、架橋酸素が主に存在し、これらはリチウムイオンをトラップしにくいために、このガラスは高い伝導性を示すものと考えられる。さらに添加するとリチウムイオンをより強くトラップすると考えられるS^<2->や非架橋酸素の割合が増加するため、ガラスの伝導性は低下すると解釈することができる。
4)5mol%のLi_4SiO_4を添加したガラスは広い電位領域において高い電気化学的安定性を示すが、これは、このガラス中ではアニオン種の酸化反応の速度が非常に遅く、実際に酸化されるまでに大きな過電圧が生じるためと考えられる。20mol%のLi_4SiO_4を添加したガラス中では、S^<2->が多く存在し、これが電気化学的に酸化されることにより、ガラスの電気化学的安定性が低下するものと考えられる。
日本学術振興会, 重点領域研究, 大阪府立大学, 08229240 - 新規な超イオン伝導ガラスの創製とキャラクタリゼーション
科学研究費助成事業
1995年 - 1995年
南 努, 忠永 清治, 辰巳砂 昌弘
本研究は、安定でイオン伝導性の高いガラス材料を設計する場合、必ずしも均質ガラスである必要はなく、伝導性の高いガラス相と安定性の高いガラス相を組み合わせた分相ガラスも視野に入れるべきであるという立場に立ち、不均質構造を有する新しい超イオン伝導ガラスを創製すべく、その基礎的検討を推進するものである。本研究で得られた成果を以下に示す。
1 AgI-Ag_2O-B_2O_3系超急冷試料の微細組織と組成の関係を調べた。その結果、通常のアイロンプレス法で作製できる組成のガラスは均質であるのに対し、超急冷法でのみ得られるAgI含量の多い組成のガラスは、基本的に不均質な組織を有していることが分かった。また、このような不均質ガラスの得られる組成域よりもわずかにAgI含量の多い組成域でα-AgIが常温凍結できることが分かった。
2 AgI-Ag_2O-B_2O_3系超急冷却試料のイオン伝導度と組成の関係を検討した。不均質ガラスの伝導度は、通常の均質超イオン伝導ガラスよりも高く、α-AgI常温凍結複合体よりも低い値を示した。また、均質ガラスにおいては、測定温度域内でArrhenius式に従うのに対し、不均質ガラスにおいては270K付近で折れ曲がりがみられた。この折れ曲がりは、α-AgI常温凍結複合体において明確にみられるAg^+イオンの秩序-無秩序転移に由来する伝導度異常に関係したものと考えられる。
3 AgI-Ag_2O-B_2O_3系において、不均質ガラスが、通常の均質ガラス生成域とα-AgI常温凍結複合体生成域の間の組成域で生成することから、このガラスはAgIに富むガラス相がAgIの少ないガラス相中に分散した分相ガラスと考えられる。またこのうち、AgIに富むガラス相は、均質ガラス中に存在すると考えられているAgI類似のクラスターがAgI濃度の増加の伴い成長したものではないかと考えられる。
日本学術振興会, 重点領域研究, 大阪府立大学, 07239240 - ゾル-ゲル法による高分子フィルムへの無機-有機複合体薄膜のコーティング
科学研究費助成事業 奨励研究(A)
1995年 - 1995年
忠永 清治
ゾル-ゲル法は、各種基板に酸化物薄膜をコーティングする非常に有効な手段であるが、コーティングを行う基板としては、ガラス、セラミックス金属など高温での熱処理に耐えられるものが使われてきており、高分子フィルムのような耐熱性の小さい基板への無機膜のコーティングの研究はほとんど行われていない。本研究ではゾル-ゲル法によって、透明高分子フィルムであるナイロン-6フィルムに柔軟性のある無機-有機複合体薄膜をコーティングすることによって、高分子および無機膜両方の特性を兼ね備えた新しい材料を開発することを目的として行ったものである。得られた成果を以下に示す。
1.ビニルトリエトキシシランを原料とし、ビニル基をAIBNを開始剤としてアルゴン雰囲気下でラジカル重合させることによって、無機-有機複合体の前駆体である、ポリビニルトリエトキシシラン(PVTES)が合成できることがわかった。
2.PVTESもしくはPVTES-Si(OC_2H_5)_4系を出発原料として加水分解重縮合させた溶液をコーティング溶液とすることによってナイロン-6基板およびPET基板に均一なクラックのない無機-有機複合体薄膜を形成することができた。
3.得られた無機-有機複合体薄膜の鉛筆硬度測定をおこなったところ、PVTES-Si(OC_2H_5)_4系、およびPVTES単成分いずれの系においても150℃の熱処理によって9Hの硬度を示し、耐摩耗性に優れていることがわかった。また、ダイナミック硬度測定では、出発原料中のSi(OC_2H_5)_4の割合が増加するにつれて膜の微小硬度は増大した。
4.原子間力顕微鏡観察により、この無機-有機複合体薄膜の表面は1nm以下の凹凸しか存在しない極めて平滑な表面を持つことがわかった。
日本学術振興会, 奨励研究(A), 大阪府立大学, 07750931 - 超イオン伝導性メゾスコピック複合材料の開発と応用
科学研究費助成事業
1994年 - 1995年
南 努, 近藤 繁雄, 棚橋 一郎, 町田 信也, 忠永 清治, 辰巳砂 昌弘, 小和田 善之
本研究では、結晶材料と非晶質材料を複合化することによって、両者の特徴を生かした新しいタイプの超イオン伝導材料を創製し、その生成機構やイオン伝導機構を明らかにするとともに、全固体二次電池やエレクトロクロミック表示素子、電気二重層キャパシターなど、種々の電気化学素子への応用を図ることを目的としている。本研究で得られた成果を以下に示す。
1 AgIを多量に含む融液を超急冷することにより、α-AgIをガラスマトリックス中に分散した複合体を作製した。この複合体は、室温で極めて高いイオン伝導度を示し、伝導の活性化エネルギーは、α-AgIと超イオン伝導ガラスの中間の値を示すことがわかった。
2 AgIとガラスマトリックスからなるメゾスコピック複合体の生成プロセスを理解するために結晶化の速度論的検討を行った。その結果、α-AgIの核は、その数を増すことなく3次元的に成長する結晶成長機構を有し、活性化エネルギーは、通常の酸化物系のガラスよりも小さい値をとることがわかった。
3 種々のプレンステッド酸をシリカゲルにドープした複合体を作製した。HClO_4,WPA,H_2SO_4,H_3PO_4をドープした場合に、室温において、10^<-4>〜10^<-1>Scm^<-1>と高い伝導性を示すバルク状複合シリカゲルおよび複合シリカゲル薄膜が得られた。高い伝導性を示したドーパントは、H_2Oとの相互作用が強く、酸性度が高い電解質であることが分かった。
4 HClO_4をドープしたシリカゲル薄膜をWO_3を着色層とするエレクトロクロミック素子の電解質に応用したところ、良好な着消色特性が得られた。
5 H_3PO_4をドープした複合シリカゲルの赤外吸収スペクトルを測定したところ、H_2Oの吸着量が多いほど、オルトリン酸に帰属されるピークの強度が増し、それに伴って伝導度も向上した。添加したリン酸はオルトリン酸の状態でゲル中に安定に存在し、プロトン伝導に有利な水素結合のネットワークを形成しているものと思われる。
日本学術振興会, 試験研究(B), 大阪府立大学, 06555189 - ゾル-ゲル法による高分子フィルムへの無機膜コーティングとゲル膜の特性評価
科学研究費助成事業 奨励研究(A)
1994年 - 1994年
忠永 清治
ゾル-ゲル法は、各種基板に酸化物薄膜をコーティングする非常に有効な手段であるが、コーティングを行う基板としては、ガラス、セラミックス金属など高温での熱処理に耐えられるものが使われてきており、高分子フィルムのような耐熱性の小さい基板への無機膜のコーティングの研究はほとんど行われていない。本研究ではゾル-ゲル法によって、透明高分子フィルムであるナイロン-6フィルムの酸化物薄膜をコーティングを行い、その特性を明らかにすることを目的として行ったものである。得られた成果を以下に示す。
1.4官能アルコキシドであるテトラエトキシシラン(TEOS)を原料を用いた場合にはコーティング膜はクラックを生じたが、出発原料に3官能アルコキシドであるメチルトリエトキシシラン(MTES)を加えることによってクラックのない均一な薄膜をコーティングできることがわかった。
2.シリカ系薄膜をコーティングしたナイロン-6基板について水蒸気透過速度を測定したところ、コーティングによって透過速度を抑制できることがわかった。組成依存性については、MTESに対するTEOSの比が大きくなるにつれてより抑制できることがわかった。
3.シランカップリング剤であるγ-アミノプロピルトリエトキシシランを加水分解した溶液でナイロン-6基板を前処理し、その後シリカ系のコーティングを行うと、コーティングフィルムとナイロン-6フィルムの密着性が向上した。また、水蒸気透過速度も抑制されることが明かとなった。
4.コーティング薄膜に紫外線を照射することによって、コーティング膜の緻密化が起こり、水蒸気透過速度も若干抑えられることがわかった。また、コーティング膜と基板の密着性がかなり改善された。
日本学術振興会, 奨励研究(A), 大阪府立大学, 06750699 - 化学修飾されたゲル膜の光分解による機能性薄膜の作製と特性評価
科学研究費助成事業
1993年 - 1994年
峠 登, 忠永 清治
ゾル-ゲル法において金属アルコキシドをβ-ジケトンで化学修飾すると、加水分解反応が抑制されると同時に、生成するゲル膜が光感応性を示すようになり、薄膜の微細加工が可能となる。本研究は、化学修飾されたゲル膜の光分解を利用した薄膜の作製と微細加工、および生成する薄膜の特性評価を目的として行ったものであり、以下の成果を得た。
(1)^<27>Al NMRから、Al-ブトキシドをアセト酢酸エチルEAcAcで化学修飾すると、Alが6配位された構造単位が生成し、前駆体の大部分は4配位された1個のAlと6配位された2個のAlから成る三量体を形成していることが明らかとなった。また、AlブトキシドのAlは、イソプロピルアルコール中では4配位であるが、ジアセトンアルコール中では5配位をとっていた。
(2)アセチルアセトンAcAcまたはベンゾイルアセトンBzAcで化学修飾されたZr-、Ti、またはAl-ブトキシドから生成スルゲル膜に紫外線を照射すると、ゲル膜中のキレート環が分解され、同時に酸やアルコールに対する溶解度が変化することを見いだした。
化学修飾されたゲル膜への紫外線照射によって生じる、ゲル膜の溶解度の変化を利用して、ZrO_2、TiO_2、およびAl_2O_3薄膜の微細パタ-ニングプロセスを開発した。
AcAcで化学修飾したZr-およびTi-ブトキシド、ならびに酢酸鉛三水和物、および硝酸ランタンを原料として、PZTおよびPLZT強誘電体薄膜を作製した。Pt基板上に形成したゲル膜を700℃で熱処理することにより、組成ずれのないペロブスカイト単一相の薄膜が得られた。
BzAcで化学修飾されたZr-およびTi-ブトキシド、ならびに酢酸鉛三水和物を原料として得られるゲル膜に紫外線を照射すると、ゲル膜のアルコールに対する溶解度が減少し、この現象を利用してPZT強誘電体のような多成分系薄膜もパタ-ニングできることを実証した。
日本学術振興会, 一般研究(B), 近畿大学, 05453081 - 融液超急冷法による機能性高温相のガラスマトリックス中への常温凍結
科学研究費助成事業
1992年 - 1994年
南 努, 忠永 清治, 辰巳砂 昌弘, 峠 登
α-AgIは、147°C以上で安定な「超イオン伝導体」であるが、147°C以下では伝導性の低いβ-AgIに転移してしまう。ところが、AgIを極端に多量に含む融液を10^5K/s以上の冷却速度で超急冷すると、α→β転移が阻止され、常温でα-AgIがガラスマトリックス中に凍結された一種の複合体が得られることがわかった。本研究では、このようなα-AgI常温凍結複合体のキャラクタリゼーションを行うとともに、凍結条件を最適化し、また凍結機構を明らかにした。得られた成果を以下に示す。
(1)AgIを多量に含むAgI-Ag_2O-M_xO_y(M_xO_y=B_2O_3,GeO_2,P_2O_5,Mo0_3,WO_3,V_2O_5)系の融液を超急冷することにより、ガラス生成域よりわずかにAgI含量の多い組成域において、α-AgIをガラスマトリックス中に常温で凍結できることがわかった。
(2)ガラス転移温度(Tg)の高いガラスマトリックスの方が、AgIのα→β転移抑制効果が大きく、容易にα-AgIが凍結できた。
(3)α-AgIを常温凍結した複合体は、室温で極めて高いイオン伝導度を示すことがわかった。また、伝導の活性化エネルギーは、α-AgIと超イオン伝導ガラスの中間の値を示した。
(4)α-AgI常温凍結複合体には、数十nmの粒径を持つα-AgI微粒子がガラスマトリックス中に均一に分散して存在することがわかった。また、β-AgIの析出した試料には、数百nm程度の粒径を持つ比較的大きなβ-AgI結晶が密に存在することがわかった。
(5)常温凍結されたα-AgIは、周囲のマトリックスガラスから応力を受け、歪んだ状態で存在していることがわかった。
(6)α-AgI常温凍結試料中のα-AgI結晶格子の不均一歪は、室温以下においてさらに増大することがわかった。また、それと同時に、低温になると、銀イオンの部分的な秩序化が起こっていることがわかった。
日本学術振興会, 一般研究(A), 大阪府立大学, 04403015 - ゾル-ゲル法による多成分系エアロゲルの作製とキャラクタリゼーション
科学研究費助成事業 奨励研究(A)
1993年 - 1993年
忠永 清治
エアロゲルは、ゾル-ゲル法で作製したゲルを超臨界乾燥することによって得られる気孔率90%以上の極めて密度の小さい多孔質体であるが、これまではおもにシリカ単成分のみの研究が行われ、多成分系のゲルを容易に作製できるというゾル-ゲル法の特徴を活かした多成分系のエアロゲルの作製はほとんど報告されていない。本研究は、ゾル-ゲル法によって作製したSiO_2-Al_2O_3 2成分系ゲルを超臨界乾燥させることによってエアロゲルを作製し、その特性を評価することを目的として行ったものである。得られた成果を以下に示す。
1.Al_2O_3成分の原料としてAl(O-Bu)_3用いる際、加水分解速度を制御するためにアセト酢酸エチルによって化学修飾することが効果的であった。この化学修飾されたAl-アルコキシドの加水分解挙動を調べたところ、ゲル化点においても約70%のアセト酢酸エチルが配位したままであることがわかった。
2.化学修飾されたAl(O-Bu)_3とテトラエトキシシランを原料とし、溶媒としてイソプロピルアルコールを用いてウェットゲルを作製した。このウェットゲルを、270℃、12MPaの条件で超臨界乾燥を行うことによって、エアロゲルを作製することができた。このエアロゲルは、半透明、密度約0.17g/cm^3、収縮率約20%であった。
3.種々のSi/Al=0.2付近で極大を示すことがわかった。Si/Al=0.17の場合、800℃で432m^2/g、1000℃で296m^2/gという値が得られ、高温で熱処理しても大きな比表面積を維持していることがわかった。
4.窒素吸着法によって細孔分布を求めたところ、100-200A程度の比較的大きな細孔が多く存在することがわかった。
日本学術振興会, 奨励研究(A), 大阪府立大学, 05750618
産業財産権
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特許権, 中許 昌美, 山本 真理, 柏木 行康, 辰巳砂 昌弘, 忠永 清治, 林 晃敏, 高野 浩次, 地方独立行政法人 大阪市立工業研究所, 公立大学法人大阪府立大学, 奥野製薬工業株式会社
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特許権, 麻田 篤志, 猪野 寿一, 辰巳砂 昌弘, 忠永 清治, 日本板硝子株式会社, 公立大学法人大阪府立大学
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2010年10月15日
201103076378896223 - 光学用透明部材及びそれを用いた光学系
特許権, 山田 雅之, 小谷 佳範, 田中 博幸, 奥野 丈晴, 南 努, 辰巳砂 昌弘, 忠永 清治, キヤノン株式会社, 公立大学法人大阪府立大学
特願2006-039787, 2006年02月16日
特開2006-259711, 2006年09月28日
特許第4520418号
2010年05月28日
201103058802723743 - ガラス基材の曲げ強度の向上方法
特許権, 辰巳砂 昌弘, 忠永 清治, 本城 啓司, セントラル硝子株式会社, 辰巳砂 昌弘
特願2005-056829, 2005年03月02日
特開2006-240904, 2006年09月14日
特許第4489614号
2010年04月09日
201103056857494597 - 透明反射防止膜、その製造方法および光学部材
特許権, 小谷 佳範, 山田 雅之, 張 祖依, 久保田 純, 南 努, 辰巳砂 昌弘, 忠永 清治, 松田 厚範, キヤノン株式会社, 公立大学法人大阪府立大学
特願2004-046256, 2004年02月23日
特開2005-234447, 2005年09月02日
特許第4488764号
2010年04月09日
201103023181526134 - 多孔質シリカ系薄膜の製造方法
特許権, 番場 昭典, 辰巳砂 昌弘, 忠永 清治, 松田 厚範, 宇部日東化成株式会社, 辰巳砂 昌弘
特願2003-054059, 2003年02月28日
特開2004-266068, 2004年09月24日
特許第4447846号
2010年01月29日
201103095318308700 - 電界発光体の製造方法および電界発光体、電界発光表示装置
特許権, 福地 隆, 坪井 眞三, 南 努, 辰巳砂 昌弘, 忠永 清治, 松田 厚範, 日本電気株式会社, 南 努, 辰巳砂 昌弘, 忠永 清治, 松田 厚範
特願2003-543355, 2002年11月07日
特許第4394446号
2009年10月23日
201103052376934091 - ガラス基材の曲げ強度の向上方法
特許権, 辰巳砂 昌弘, 忠永 清治, 本城 啓司, セントラル硝子株式会社, 辰巳砂 昌弘
特願2004-055800, 2004年03月01日
特開2005-247587, 2005年09月15日
特許第4363635号
2009年08月28日
201103074326246376 - 表面微細凹凸組織の低温形成法および当該組織を有する基体
特許権, 南, 努, 忠永 清治, 松田 厚範, 財団法人大阪産業振興機構
特願平11-193858, 1999年07月08日
特開2001-017907, 2001年01月23日
特許第4247354号
2009年01月23日
201103098583655526 - 光学部材および光学部材の製造方法
特許権, 小谷 佳範, 山田 雅之, 張 祖依, 久保田 純, 南 努, 辰巳砂 昌弘, 忠永 清治, 松田 厚範, キヤノン株式会社, 公立大学法人大阪府立大学
特願2005-006760, 2005年01月13日
特開2005-275372, 2005年10月06日
特許第4182236号
2008年09月12日
201103053254475530 - チタニアナノ微結晶膜とこのパターンを備えた物品並びにその製造方法
特許権, 辰巳砂 昌弘, 小暮 敏博, 南 努, 忠永 清治, 松田 厚範, 独立行政法人科学技術振興機構
特願2003-045197, 2003年02月21日
特開2004-249266, 2004年09月09日
特許第4083036号
2008年02月22日
201103087723681334 - 光学複合体膜とその製造方法ならびにその光学複合体膜を備えた光素子
特許権, 南 努, 辰巳砂 昌弘, 忠永 清治, 松田 厚範, 独立行政法人科学技術振興機構
特願2000-289531, 2000年09月22日
特開2002-098801, 2002年04月05日
特許第4017330号
2007年09月28日
201103009317098040 - ホスホシリケートゲル、プロトン伝導性材料およびその製造方法
特許権, 南 努, 辰巳砂 昌弘, 忠永 清治, 松田 厚範, 南 努, JSR株式会社
特願2001-329216, 2001年10月26日
特開2003-137527, 2003年05月14日
特許第3998945号
2007年08月17日
201103097616357686 - チタニアナノ微結晶分散薄膜パターンの製造方法
特許権, 辰巳砂 昌弘, 小暮 敏博, 南 努, 忠永 清治, 松田 厚範, 独立行政法人科学技術振興機構
特願2002-237606, 2002年08月16日
特開2004-074006, 2004年03月11日
特許第3960882号
2007年05月25日
201103018977738121 - プロトン伝導性材料およびその製造方法
特許権, 南 努, 辰巳砂 昌弘, 忠永 清治, 松田 厚範, 竹谷 行彦, テイカ株式会社, 辰巳砂 昌弘
特願2002-080443, 2002年03月22日
特開2003-281931, 2003年10月03日
特許第3916139号
2007年02月16日
201103081057102970 - 透明厚膜の製造方法
特許権, 仲間 健一, 新毛 勝秀, 南 努, 辰巳砂 昌弘, 松田 厚範, 忠永 清治, 日本板硝子株式会社
特願平10-015820, 1998年01月28日
特開平11-209896, 1999年08月03日
特許第3887926号
2006年12月08日
201103092975881925 - プロトン伝導性材料、プロトン伝導性膜およびその製造方法
特許権, 南 努, 辰巳砂 昌弘, 忠永 清治, 松田 厚範, 南 努, JSR株式会社
特願2001-329215, 2001年10月26日
特開2003-132732, 2003年05月09日
特許第3881213号
2006年11月17日
201103055741039667 - 超撥水撥油防汚性膜及びその形成法
特許権, 南 努, 忠永 清治, 稲葉 博司, 湯浅 章, 赤松 佳則, 山本 秀樹, セントラル硝子株式会社, 南 努, 忠永 清治
特願平8-009982, 1996年01月24日
特開平9-202650, 1997年08月05日
特許第3688042号
2005年06月17日
201103058014437276 - 撥水性酸化物皮膜の形成法
特許権, 南 努, 辰巳砂 昌弘, 忠永 清治, 稲葉 博司, 湯浅 章, セントラル硝子株式会社, 南 努, 辰巳砂 昌弘
特願平7-037979, 1995年02月27日
特開平8-231247, 1996年09月10日
特許第3395928号
2003年02月07日
201103066666791589
