Modeling First Stages of Solid-Electrolyte Interphase (SEI) in LiPF6/EC Electrolytes Using Molecular Dynamics Simulations

Abstract

The performance of lithium-ion batteries(LiB) using organic electrolytes depends strongly in the formation of a stable solid electrolyte interphase (SEI) film. Elucidating the dynamic evolution and spatial composition of the SEI can be very useful to study the stability of the structures and could also optimize the formation cycles of LiB. We propose a classical molecular dynamics simulation protocol for predicting the first stages of the SEI using a reaction method involving the decomposition of EC and LiPF6 molecules in the electrolyte. We are able to accelerate, on the order of nanoseconds, the formation of SEI components near the anode surface, such as gases (C2H4), inorganic (Li2CO3, and LiF) and organic (LEDC). We expect to expand this protocol to explore different electrolyte compositions and additives and for further advances in Li-ion battery technologyThis research is supported by the U.S. Department of Energy's Vehicle Technologies Office.