Abstract: Fluoroethylene carbonate (FEC) with a volume ratio of 2%was added to the electrolyte containing 1 mol·L-1 LiPF6 in ethylene carbonate (EC), dimethyl carbonate (DMC), and methyl ethyl carbonate (EMC) (1:1:1 by volume). The effects of FEC on lithiumion battery performance and on the mesocarbon microbead (MCMB) electrode/electrolyte interphase were studied by cyclic voltammetry (CV), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS). The results indicated that the application of a 2% (volume ratio) of FEC suppressed electrolyte decomposition and caused the formation of an excellent solid electrolyte interphase (SEI) film on the MCMB electrode. The battery resistance decreased while the specific capacity and cyclic stability of the battery increased.

Key words: Additive, Fluoroethylene carbonate, Lithiumion battery, Cyclic voltammetry, Energy dispersive spectroscopy, Electrochemical impedance spectroscopy