Hierarchical Spatiotemporal Analyses of Nonequilibrium Reactions and the Design of Batteries

2016 Fiscal Year Final Research Report

• Project/Area Number: 25249141
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Energy engineering
• Research Institution: Kyoto University
• Principal Investigator: Uchimoto Yoshiharu 京都大学, 人間・環境学研究科, 教授 (50193909)
• Co-Investigator(Kenkyū-buntansha): 折笠 有基 京都大学, 人間・環境学研究科(研究院), 助教 (20589733)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 電気化学 / 蓄電池 / リチウムイオン二次電池 / 放射光 / 非平衡挙動

Outline of Final Research Achievements

Understanding of the reaction hierarchies of lithium-ion batteries (LiB) is essential background knowledge to improve their performance. Because the reactions in these devices are complicated and proceed in a nonequilibrium state, the kinetic factors and degradation mechanisms that govern them are not yet fully characterized.　　Phase transitions in active materials are accompanied by lithium insertion and extraction. The crystal structure during charge-discharge has generally been investigated through static measurements, in which thermodynamically stable states are characterized. In addition, the diffusion path of lithium ions has also been analyzed. Under real battery operating conditions, however, the crystal phase dynamically changes during lithium extraction/insertion. The dynamic phase transition is one of the critical parameters determining rate capability because the charge-discharge process of LIBs proceeds under nonequilibrium conditions.

Free Research Field

電気化学