Internal short circuit of lithium metal batteries under mechanical abuse

Lithium metal materials are among the most promising anodes for high energy density batteries. Although the working principle is feasible electrochemically, the biggest bottleneck for the engineering application of 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 ISC behaviors, we first characterize the mechanical behaviors of each component material of LMBs and conduct ball indentation tests 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 be-haviors 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.

Automated summary

Lithium metal materials are promising anodes for high energy density batteries, but the biggest challenge for their engineering application is the safety concern. Understanding the internal short circuit (ISC) behaviors of lithium metal batteries (LMBs) under mechanical abusive loading is essential before commercialization. This study characterizes the mechanical behaviors of LMB components, establishes a physics-based model, and reveals the ISC process from mechanical deformation to triggering. The effects of factors like state-of-charge and cycle numbers on ISC behaviors are also studied.