Investigation of the Lithium Solid Electrolyte Interphase in Vinylene Carbonate Electrolytes Using Cu||LiFePO 4 Cells

Abstract

The influence of vinylene carbonate (VC) on the plating/stripping of lithium was investigated using Cu||LiFePO4 cells. These cells allow for easy fabrication and in-situ generation of lithium, with no excess lithium to influence performance. Addition of VC to the electrolyte improves both capacity retention and efficiency. IR and XPS spectroscopy of the surface of the plated lithium suggests the presence of a significant amount of poly(VC) when the electrolyte (1.2 M LiPF6 in ethylene carbonate (EC): ethyl methyl carbonate (EMC) (3:7, vol)) contains 5% of added VC. This suggests employing additives that generate polymeric species on the surface of lithium improves plating/stripping performance in carbonate electrolytes.