New theory of electrode potential shift for innovative rechargeable batteries

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H02039
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 36020:Energy-related chemistry
• Research Institution: Osaka University
• Principal Investigator: Yamada Yuki 大阪大学, 産業科学研究所, 教授 (30598488)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: リチウムイオン電池 / 電解液 / エネルギー密度 / 電極電位 / イオン液体

Outline of Final Research Achievements

To achieve higher energy density of lithium-ion batteries using high-capacity negative electrodes or high-potential positive electrodes that operate outside the potential window of the electrode, it is necessary to suppress the reduction and oxidation of the electrolyte. In this work, we aimed to suppress the reduction and oxidation of the electrolyte by shifting the electrode potential through electrolyte design. As a result, we found the downshift of the electrode potential using a strongly coordinating anion in lithium salt and the upshift of electrode potential using ionic liquid electrolytes. We also demonstrated that the charge-discharge efficiency of a high-capacity negative electrodes increased with the upshift of the electrode potential in ionic liquid electrolytes.

Free Research Field

電気化学

Academic Significance and Societal Importance of the Research Achievements

本研究で見いだした電極電位の大幅なアップシフト・ダウンシフトを可能にする電解液設計は、リチウムイオン電池において正極・負極材料の選択肢を大きく拡大するものである。高電位正極や高容量負極の採用が可能となることで、高エネルギー密度のリチウムイオン電池の実現が期待される。それにより、リチウムイオン電池を搭載した電気自動車の航続距離は大きく拡大されることになる。