MechanicsDriven Anode Material Failure in Battery Safety and Capacity Deterioration Issues: A Review

Abstract

Highcapacity anodes, such as Si, have attracted tremendous research interest over the last two decades because of the requirement for the high energy density of nextgeneration lithiumion batteries (LIBs). The mechanical integrity and stability of such materials during cycling are critical because their volume considerably changes. The volume changes/deformation result in mechanical stresses, which lead to mechanical failures, including cracks, fragmentation, and debonding. These phenomena accelerate capacity fading during electrochemical cycling and thus limit the application of highcapacity anodes. Experimental studies have been performed to characterize the deformation and failure behavior of these highcapacity materials directly, providing fundamental insights into the degradation processes. Modeling works have focused on elucidating the underlying mechanisms and providing design tools for nextgeneration battery design. This review presents an overview of the fundamental understanding and theoretical analysis of the electrochemical degradation and safety issues of LIBs where mechanics dominates. We first introduce the stress generation and failure behavior of highcapacity anodes from the experimental and computational aspects, respectively. Then, we summarize and discuss the strategies of stress mitigation and failure suppression. Finally, we conclude the significant points and outlook critical bottlenecks in further developing and spreading highcapacity materials of LIBs.