Investigation of a suppression mechanism of solid-electrolyte interface formation for improving cycle life in Li-ion batteries

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K22549
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0502:Inorganic/coordination chemistry, analytical chemistry, inorganic materials chemistry, energy-related chemistry, and related fields
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Yasuhara Sou 東京工業大学, 物質理工学院, 助教 (20880032)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: リチウムイオン二次電池 / エピタキシャル薄膜 / 電極界面 / 固体電解質界面 / 副反応抑制

Outline of Final Research Achievements

An epitaxial thin film of a cathode material in Li-ion batteries was prepared for investigating a degradation mechanism during charge-discharge cycles. After charge-discharging thin films, chemical analysis was carried out onto the film surface and the cross-section. A suppression of the electrolyte decomposition was observed by introducing a surface supporting material, resulting in enhancing cycle performance at a triple-phase interface consistent of a supporting material, an active material and an electrolyte. Finally, I suggest engineering of triple-phase interfaces is a key approach to improve the performance of Li-ion batteries.

Free Research Field

無機機能性材料

Academic Significance and Societal Importance of the Research Achievements

本研究では、二次電池シェアの大部分を占めるリチウムイオン二次電池の副反応を抑制する機構を解明し、長寿命化を目指す設計指針を提示した。具体的には、電極活物質への表面担持という簡便な手法により三相界面を導入し、充放電反応中の副反応を抑制できる機構を明らかにした。持続可能な社会実現に向けて蓄電技術はその中核を担うものであり、リチウムイオン二次電池の長寿命化を達成する手段を提示した本研究は、次世代蓄電デバイスの設計に重要な指針となりうる。