Nonflammable Hydrofluoroether for Lithium-Ion Batteries: Enhanced Rate Capability, Cyclability, and Low-Temperature Performance

A hydrofluoroether, 2-trifluoromethyl-3-methoxyperfluoropentane (TMMP), was investigated as a nonflammable electrolyte for lithium-ion batteries. This paper reports on the psychochemical properties of the TMMP-mixed electrolyte [ lithium bis(pentafluoroethylsulfonyl) imide (LiBETI)/ethylene carbonate+diethyl carbonate (5:45:50)] in relation with the battery performances. The TMMP-mixed electrolyte showed effective nonflammability with prolonged ignition time . No differences in oxidative and reductive decomposition currents were observed in the operation voltage range of lithium-ion batteries ( vs ) for the electrolytes with and without TMMP. At a high rate of , 75% of the capacity (obtained at ) was obtained for the TMMP-mixed electrolyte, while less than 40% was obtained for the electrolytes without TMMP [ LiBETI/ (50:50) and (5:95)]. The low-temperature performance and cyclability were also significantly improved for the TMMP-mixed electrolyte.