Phase-Field Modeling of Metal Plating on Battery Electrodes

Abstract

The growth of ramified metal deposits on battery electrodes during charging can lead to capacity loss as pieces of metal become electrically disconnected upon cycling or result in battery failure as metal dendrites penetrate the separator and short-circuit the cell. This undesirable metal plating can occur in Li-ion batteries under conditions of fast charging, overcharging, low temperature, or in the presence of battery separator defects. Nonuniform electrodeposition is also a challenge faced by next-generation battery technologies with pure metal anodes. Developing a better understanding of how different electrodeposit morphologies form inside batteries could lead to more effective strategies for preventing dendrite growth, making Li-ion batteries safer and metal anodes more practical. Phase-field modeling is a promising approach for modeling electrodeposition morphologies and has been used extensively to simulate a variety of complex microstructural evolution processes. We have developed a phase-field model of electrodeposition from a binary electrolyte that accounts for Butler-Volmer reaction kinetics, the metal-electrolyte surface energy, and ion transport via diffusion and migration. We validate our model with linear stability analyses and numerically simulate the formation of various morphologies under different conditions. In addition, we simulate dendrite growth through a porous battery separator and explore the effects of separator properties on the growth of the metal electrodeposits.