NONAQUEOUS ELECTROLYTE SOLUTION FOR LITHIUM BATTERY CONTAINING SILYL ESTER COMPOUND AND TETRAFLUOROBORATE SALT, AND LITHIUM ION SECONDARY BATTERY USING THE NONAQUEOUS ELECTROLYTE SOLUTION

摘要

PURPOSE: A nonaqueous electrolyte solution for a lithium battery and a lithium ion secondary battery using the nonaqueous electrolyte solution are provided, to prevent the reductive cleavage of an electrolyte solution at an anode, to reduce the interface resistance between an anode or a cathode and the corresponding electrolyte solution and to inhibit the deterioration of lithium ion conductivity due to thickening. CONSTITUTION: The nonaqueous electrolyte solution comprises a lithium sa a nonaqueous solvent; 0.1-10 wt% of a silyl ester compound; and 0.01 wt% or more of a tetrafluoroborate salt. Preferably the ratio of the tetrafluoroborate salt to the silyl ester compound (the amount of the tetrafluoroborate salt / the amount of the silyl ester compound) is 0.05 or more. Preferably the silyl ester compound is trimethylsilyl phosphate and the tetrafluoroborate salt is lithium tetrafluoroborate.