Effect of Charging Modes and Parameters on Lithium Dendrite Growth Studied by Phase-Field Modeling

The formation of lithium dendrites commonly occurs during the charging process of lithium metal batteries. It not only reduces the battery capacity but may even connect the positive and negative electrodes, causing a short circuit in the battery and leading to battery explosion and combustion. Consequently, the mitigation of lithium dendrite growth has emerged as a pressing challenge that necessitates immediate attention from the lithium battery industry. A numerical model based on the phase-field method has been proposed to investigate the effect of charging modes and key parameters on lithium dendrite growth. Simulation results indicate that the positive pulse voltage charging mode has more advantages than the constant voltage charging mode in mitigating lithium deposition and suppressing lithium dendrite growth during the charging process. Under the positive pulse voltage charging mode, the lithium dendrite grows faster with a sharp morphology at a higher duty cycle. The same applies to a longer charging cycle time and a higher charging voltage value. Using a combination of a higher charging voltage value and a lower duty cycle is proposed to suppress the growth of lithium dendrites, while ensuring the charging efficiency.