Internal Short Circuit Behaviors of Lithium Metal Batteries Under Mechanical Abuse Loading

Abstract

Lithium metal materials are among the most promising anodes for high energy density batteries. Although the working principal is feasible electrochemically, the biggest bottleneck for the engineering application of the lithium metal batteries (LMBs) is the safety concern. The internal short circuit (ISC) behaviors of LMBs upon mechanical abusive loading is one of the mandatory safety issues that needs to be fully understood and cleared out before the commercialization of LMBs. Herein, to reveal the internal short circuit behaviors, we first characterize the mechanical behaviors of each component materials of the LMBs and conduct a ball indentation to serve as mechanical abusive loading scenarios. A detailed physics-based model of LMB is established and validated by the experiment. Based on the combination of the experiment and computational model, the entire process from mechanical deformation to the triggering of the ISC of the LMB upon mechanical abusive loading is revealed. Finally, effects on the ISC behaviors from the governing factors such as state-of-charge and cycle numbers are parametrically studied. Results provide a fundamental understanding towards the ISC behaviors of LMB and offer a detailed physics-based model for the design of future safe LMB cells.

Keywords: Lithium metal battery, Mechanical abuse, Internal short circuit, Battery safety, Experiment, Modeling