Self-Healing Mechanism of Lithium in Lithium Metal

Adv Sci (Weinh). 2022 Apr;9(12):e2105574. doi: 10.1002/advs.202105574. Epub 2022 Feb 25.

Abstract

Li is an ideal anode material for use in state-of-the-art secondary batteries. However, Li-dendrite growth is a safety concern and results in low coulombic efficiency, which significantly restricts the commercial application of Li secondary batteries. Unfortunately, the Li-deposition (growth) mechanism is poorly understood on the atomic scale. Here, machine learning is used to construct a Li potential model with quantum-mechanical computational accuracy. Molecular dynamics simulations in this study with this model reveal two self-healing mechanisms in a large Li-metal system, viz. surface self-healing, and bulk self-healing. It is concluded that self-healing occurs rapidly in nanoscale; thus, minimizing the voids between the Li grains using several comprehensive methods can effectively facilitate the formation of dendrite-free Li.

Keywords: Li deposition; dendrite growth; dendrite morphology; molecular dynamic simulation; neural network; potential; self-healing.