Regulating electrodeposition behavior through enhanced mass transfer for stable lithium metal anodes

Abstract

Ultrasonic wave is introduced into the electrodeposition process of lithium metal to accelerate the Li + mass transfer. The results show that enhanced mass transfer can inhibit the growth of lithium dendrites and optimize the electrochemical performance of lithium anode. • Regulating electrodeposition behavior of Li metal based on mass transfer process. • Uniform ion flux distribution is achieved by ultrasonic wave. • The enhanced mass transfer improves the electrochemical performance of Li anodes. Electrode process kinetics is a key part that determines the morphology of metal electrodeposition. However, the liquid-phase mass transfer process and its effect on lithium (Li) metal electrodeposition are still poorly understood. Herein, the effect of mass transfer on the electrodeposition behavior of Li metal is explored. Experiments and COMSOL Multiphysics simulations reveal that the enhanced mass transfer, which is induced by ultrasonic wave, can homogenize the ion flow on the surface of electrode to obtain uniform Li nucleation. Meanwhile, the rapid mass transfer of Li + provides sufficient cations around the germinated Li to avoid preferential growth of Li in a specific direction. Based on the simultaneous regulation of nucleation and growth behavior, a smooth and compact Li deposits can be achieved, which exhibit a small polarization voltage during repeated Li plating/striping and a considerably enhanced cyclability. This work enriches the fundamental understanding of Li electrodeposition without dendrite structure and affords fresh guidance to develop dendrite-free metal anodes for metal-based batteries.