Pretreatment of Graphite Anodes with Lithium Sulfate to Improve the Cycle Performance of Lithium-Ion Batteries

Graphite electrode surfaces are pretreated by spray-deposition method with 0.5 mol L-1 Li2SO4 aqueous solution. The physical and electrochemical properties of a solid electrolyte interphase (SEI) film formed on the surface of Li2SO4-treated graphite electrode are investigated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical measurements. The results show that the SEI film formed, promoted by Li2SO4, is thin, stable, effective, and elastic to accommodate volume changes of graphite electrode during electrochemical cycles. Due to the fact that the Li/mesophase carbon microbeads (MCMB) cell based on Li2SO4-treated graphite electrode exhibits excellent cycling performance and low interfacial impedance, we can deduce that such modifies have positive implications for lithium-ion batteries (LIBs), offering the possibility of faster-charging LIBs and LIBs that are suitable for rate-demanding applications, such electric vehicles and hybrid electric vehicles.