Phase-Field Simulations of Lithium Dendrite Growth with Open-Source Software

Dendrite growth is a long-standing challenge that has limited the applications of rechargeable lithium metal electrodes. Here, we have developed a grand potential-based nonlinear phase-field model to study the electrodeposition of lithium as relevant for a lithium metal anode, using open-source software package MOOSE. The dynamic morphological evolution under a large/small overpotential is studied in two dimensions, revealing important dendrite growth/stable deposition patterns. The corresponding temporal spatial distributions of ion concentration, overpotential, and driving force are studied, which demonstrate an intimate, dynamic competition between ion transport and electrochemical reactions, resulting in vastly different growth patterns. On the basis of the understanding from this model, we propose a "compositionally graded electrolyte" with higher local ion concentration as a way to potentially suppress dendrite formation. Given the importance of morphological evolution for lithium metal electrodes, widespread applications of phase-field models have been limited in part due to in-house or proprietary software. In order to spur growth of this field, we make all files available to enable future studies to study the many unsolved aspects related to morphology evolution of lithium metal electrodes.