Single-ion conducting liquid electrolytes based on control of ion-ion correlated motions

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02837
• 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: Yokohama National University
• Principal Investigator: Ueno Kazuhide 横浜国立大学, 大学院工学研究院, 准教授 (30637377)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: Liイオン輸率 / 溶融Li塩錯体 / イオン運動相関 / イオン伝導率

Outline of Final Research Achievements

The purpose of this work is to clarify factors that achieve both high ionic conductivity and high Li transference number in liquid electrolytes used for next-generation high-capacity and high-power Li-based secondary batteries. We experimentally determined the ion-ion correlated motions and investigated their relationship with molecular structures of highly concentrated electrolytes with different salts and solvents. We found that more associative Li salt shows higher Li transference number while lowering ionic conductivity. Combined use of weakly-coordinating solvents and counter-anions was found to be effective to achieve high ionic conductivity and Li transference number.

Free Research Field

有機イオニクス材料

Academic Significance and Societal Importance of the Research Achievements

本研究の目的は次世代高容量・高出力Li系二次電池の実現へ向け、高イオン伝導性と高Li輸率を両立する液体電解質材料に関する研究で重要な社会的意義を有する。また、方法論として、材料化学的な見地から行われてきた従来の電解質設計にOnsager相反定理および線形応用理論による普遍的なイオン伝導の考え方を取り入れ、これまで考慮されてこなかったイオン伝導のOnsager係数および相互相関項を実験的に決定し、電解質構造など分子レベルの情報との相関性を明らかにすることで、高いイオン伝導性と高いLi輸率を発現する分子論的条件の検討を行い、学術的にも意義深いと言える。