Development and thin film formation of highly Li-ion conductive glass fiber/solid electrolyte composites

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K18824
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 26:Materials engineering and related fields
• Research Institution: Toyohashi University of Technology
• Principal Investigator: Matsuda Atsunori 豊橋技術科学大学, 工学(系)研究科(研究院), 教授 (70295723)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 全固体電池 / 固体電解質 / リチウムイオン / ガラスファイバ / 極薄シート / Li7P2S8I / Li7P3S11 / 電気化学安定性

Outline of Final Research Achievements

Using the liquid-phase shaking method, a sheet with a film thickness of 40~50μm was prepared in which glass fiber was added to the Li7P2S8I (LPSI) electrolyte, and the heat treatment temperature was optimized. As a result, a room temperature conductivity of 0.47 mS/cm was obtained. Next, we worked on fabricating Li7P3S11/SiO2 fiber electrolyte sheets with higher conductivity than LPSI. As a result, a very high conductivity of 0.94 mS/cm was achieved at room temperature. We fabricated an all-solid-state battery using an LPSI/glass fiber electrolyte sheet a heat-treated at 150 oC, the positive electrode active material of NMC and the negative electrode active material of Graphite. The fabicated battery showed very high performance for the first time.

Free Research Field

機能性無機材料科学

Academic Significance and Societal Importance of the Research Achievements

液相から調製したガラスファイバ/硫化物系固体電解質複合体が絶縁性のガラスファイバを含むにもかかわらず、非常に高いリチウムイオン伝導性を示という興味深い知見を得た。これに基づいて、界面構造解析と高伝導性・極薄電解質膜創製を行い、全固体電池に応用することで研究のブレークスルーをもたらすことができる。本手法によって作製した電解質シートは高い伝導性を示し、これを用いて構築した全固体リチウム電池は、優れた充放電特性を示した。以上の成果は、全固体電池の研究開発分野に貢献するものである。