锂离子电池介尺度电化学反应非均匀性

Mesoscale reaction heterogeneities in lithium-ion batteries

锂离子电池是重要的一类能量存储与转化装置。本文从化工角度上出发,将电池视为一类“特殊的”化工反应器,其中也存在着“三传一反”:电子传输、离子传输、热量传递和电化学反应。电极是这些传递与反应过程发生的主要场所;在不同空间与时间尺度上,电极中的传递与反应过程具有不均匀性,进而导致电池材料的利用与失效的差异。本文进一步讨论了研究电极反应不均匀性的必要性,并从准二维电极模拟计算与多尺度表征分析技术两个角度,对不均匀电极反应过程的传质、传热过程、电化学反应过程、电极结构演变规律、电极失效机制等方面的研究进行综述,对未来高性能、长寿命和具备快充性能的电池开发具有一定的指导意义。

Lithium-ion batteries are energy-storage and conversion devices that play an important role in human society.From the chemical engineering perspective,lithium-ion battery could be considered as a special chemical reactor because it shares similar characteristics in transport and reaction phenomena,such as lithium-ion transport,electron transport,heat transport,and electrochemical reactions.These processes take place in the battery electrode with significant heterogeneities in transport and reactions across different length and time scales.Such heterogeneities lead to difference in the performance and deactivation of electrode materials.Here we first discuss the importance of studying electrode reaction heterogeneity and then review the research progress on both theoretical and experimental studies,with a focus on the results obtained from the pseudo two-dimensional modellings and multiscale characterization techniques.This review may guide the design and development of high-performance,long cycle-life,and fast-charging batteries.