Effect of 1,8-Naphthosultone Additive on High Temperature Performance of Lithium Ion Batteries

In this paper, we calculate the Lowest Unoccupied Molecular Orbital (LUMO) level of the 1,8-naphthosultone (1,8-NS) by density functional theory. The effects of 1,8-NS on the high temperature performances of lithium ion batteries are evaluated by battery test system. The electrochemical performances are measured by cyclic voltammetry and electrochemical impedance spectroscopic. By adding 1 wt % 1,8-NS into a commercial binary electrolyte of lithium ion battery, the initial discharge capacity and cycle stability of lithium ion battery are improved significantly at 60 degrees C. By X-ray photoelectron spectroscopy analysis, we suggest that the improvement may be attributed to the 1,8-NS being reduced to form Li2S, R-SO2Li and R-SO3Li phase on the graphite electrode. Thus, the reduction products covered on the graphite electrode may reduce the resistance of solid electrolyte interphase and suppress the battery swell.