Competitive Solid-Electrolyte Interphase Formation on Working Lithium Anodes

The generation and evolutional behavior of the solid-electrolyte interphase (SEI) fatally dictate the performance of working anodes, especially lithium (Li) anodes. In this Opinion, we describe the critical rationale in understanding competitive SEI formation on a working Li metal anode. First, the fundamentals that determine the competitive SEI-forming reactions at the Li/electrolyte interface are analyzed. Moreover, we elucidate the kinetic competition between SEI growth and Li deposition in the case of exposure to fresh Li surfaces during the Li electroplating process. Several important factors involving electrolyte formulation, current density, and temperature that can intrinsically modulate the kinetic competition are comprehensively summarized. Finally, future research trends regarding dynamic SEI formation and its correlation with the manner of Li electroplating are addressed.