The mechanism of external pressure suppressing dendrites growth in Li metal batteries

Li metal is considered an ideal anode material for application in the next-generation secondary batteries. However, the commercial application of Li metal batteries has not yet been achieved due to the safety concern caused by Li dendrites growth. Despite the fact that many recent experimental studies found that external pressure suppresses the Li dendrites growth, the mechanism of the external pressure effect on Li dendrites remains poorly understood on the atomic scale. Herein, the large-scale molecular dynamics simulations of Li dendrites growth under different external pressure were performed with a machine learning potential, which has the quantum-mechanical accuracy. The simulation results reveal that the external pressure promotes the process of Li self-healing. With the increase of external pressure, the hole defects and Li dendrites would gradually fuse and disappear. This work provides a new perspective for understanding the mechanism for the impact of external pressure on Li dendrites.