NONAQUEOUS ELECTROLYTE SOLUTION AND LITHIUM SECONDARY BATTERY USING SAME

摘要

Disclosed is a nonaqueous electrolyte solution suitable for a lithium secondary battery having high energy density wherein capacity decrease due to charge/discharge cycles is extremely small and no gas is generated during the charging/storing period. Specifically disclosed is a nonaqueous electrolyte solution wherein a nonaqueous solvent contains a fluorinated solvent composed of a chain fluorinated carbonate (a1) and a fluorinated ethylene carbonate (a2) in such an amount that the total amount of the fluorinated solvent in the nonaqueous solvent is within a range of 50-100 wt%.