A Thermodynamic Perspective for Formation of Solid Electrolyte Interphase in Lithium-Ion Batteries

This work studied the formation and growth of solid electrolyte interphase (SEI) under the assumption that the formation of an SEI layer is associated with the nucleation and growth of disk-like islands at the interface between an active material and nonaqueous electrolyte solution (NES). The supersaturation of NES favors the nucleation of the islands via lowering the Gibbs free energy with the contribution of interfacial energy and mismatch strain enegy to the nucleation process. Using a modified Lifshitz-Slyozov-Wagner model, the growth of the disk-like islands is analyzed. Explicit kinetic estimation for the change of the density and mean dimension of the islands as well as the degree of supersaturation of NES with time is obtained. The degree of supersaturation at time t is found to be proportional to the square root of time.