2022 Fiscal Year Final Research Report

Study on H- conductors ~Development of material design guidelines for low -temperature operation~

Research Project

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Project/Area Number	20H02828
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 36010:Inorganic compounds and inorganic materials chemistry-related
Research Institution	Institute of Physical and Chemical Research (2022) Institute for Molecular Science (2020-2021)
Principal Investigator	Kobayashi Genki 国立研究開発法人理化学研究所, 開拓研究本部, 主任研究員 (30609847)
Co-Investigator(Kenkyū-buntansha)	桑原彰秀一般財団法人ファインセラミックスセンター, その他部局等, 主席研究員 (30378799) 野田泰斗京都大学, 理学研究科, 助教 (00631384) 竹入史隆分子科学研究所, 物質分子科学研究領域, 助教 (20824080)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	ヒドリドイオン導電体 / 混合導電体 / 固体電解質
Outline of Final Research Achievements	1) We found that the anion arrangement in layered perovskite type oxyhydrides can be controlled by tuning the size and valence of the compositional elements. 2) We found that the long-range orderings in the superlattice structure of layered perovskite-type Ba1.75LiH2.7O0.9 are successively losted with increasing temperature, and that the hydride superionic conductivity develops through the phase transition. Furthermore, we succeeded in lowering the phase transition temperature by substituting a part of Ba with K and a part of Li with Na, thereby extending the temperature range in which high conductivity is obtained. 3) Charge transfer resistance between hydrogen and hydride ions in a symmetric cell with a hydride ionic conductor sandwiched by mixed conductors was detected and electrochemical Ti to TiH2 hydrogenation was realized.
Free Research Field	無機固体化学、固体イオニクス、電気化学
Academic Significance and Societal Importance of the Research Achievements	中温域で10 mS/cmを超えるヒドリドイオン導電性を達成したこと、ヒドリドイオン導電体を混合導電体で挟んだ対称セルで、水素ガス-ヒドリドの可逆反応由来の電荷移動抵抗を観測することに成功したことは、ヒドリドのイオン導電現象を利用した電気化学デバイス開発に向けて研究が大きく進展したことを示している。ヒドリドのイオニクス研究は学術的な新規性の高さに留まらず、新たな水素利活用技術の創出にもつながる可能性を秘めており、社会的にも意義のある成果と言える。