Thermodynamics and Phase-Field Model of SEI Formation in Li-Metal Batteries

Understanding solid electrolyte interphase (SEI) formation mechanisms has been a long-standing challenge. This presentation will discuss the fundamental thermodynamics and kinetics of multiple electrochemical reactions at the electrode/electrolyte interface and an atomically informed phase-field model for studying the evolution of SEI products from nanoseconds to seconds. We analyze the role of electron tunneling in the stable thickness of SEI and the role of reactive and diffusive processes in the growth rate of different SEI products. This theoretical framework can be employed to effectively extract the timescale features and distinguish various kinetic processes during SEI formation, offering useful insights into improving battery performances through SEI engineering. It is generally applicable to processes taking place in multiphase and multicomponent electrochemical systems.