Creation of new high-performance fluoride ion conductors using double salts

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14422
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26040:Structural materials and functional materials-related
• Research Institution: The University of Tokyo
• Principal Investigator: Kawahara Kazuaki 東京大学, 大学院工学系研究科(工学部), 助教 (90869570)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: フッ化物イオン電池 / フッ化物イオン伝導体 / 複塩

Outline of Final Research Achievements

In this study, we developed solid materials exhibiting high fluoride ion conductivity using double salts for room-temperature operation of fluoride ion batteries. Room temperature ionic conductivity of 10^-4 S/cm was achieved by using fluoride double salts containing Sb. In particular, it was discovered that the ionic conductivity can be improved by more than one order of magnitude compared to conventional materials by doping alkali metal or halogens. Additionally, to clarify the fluoride ion conduction mechanism of solid electrolytes, we developed a noise reduction method for atomic resolution electron microscope images of fluorides.

Free Research Field

エネルギー科学

Academic Significance and Societal Importance of the Research Achievements

本研究を通して、Sbを含むフッ化物複塩を用いることで、室温で10^-4 S/cm以上の高いフッ化物イオン伝導度を実現できることが分かった。特に、アルカリ金属やハロゲンの添加により、イオン伝導度を向上可能であることが分かった。本成果はこれまで検討されてこなかったフッ化物複塩がフッ化物イオン電池の室温動作、社会実装を実現する有望な材料候補であることを示している。