Trans-scale simulation reveals snowball effect in Li dendrite growth processes

Li-based rechargeable batteries have played a critical role in the sustainable energy development strategy. However, the uncontrolled Li dendrites growth, which causes the poor cycling performance and safety concerns, has become their main drawback. Due to the sealed environment of the battery and the active reactivity of Li metal, in situ studies of Li dendrites are challenging. This work presents a trans-scale simulation method for modeling the Li dendrite growth process in Li-based batteries. First, a 2D Li metal battery model (2D LBM) was established to simulate Li nucleation sites at the nanoscale. Then, based on the growth process of nucleation sites in the 2D LBM, a phase-field model was established to simulate the Li dendrite growth process at the macroscopic scale. Furthermore, an in-situ observation experiment of the Li dendrite growth process was performed to illustrate the rationality of the simulation. This study shows the dynamic evolution of the micro-parameters inside the battery and reveals a snowball effect during the Li dendrite growth processes. This work provides a new perspective on understanding the mechanism of Li dendrite growth.