NONAQUEOUS ELECTROLYTE, AND LITHIUM-ION SECONDARY CELL AND LITHIUM-ION CAPACITOR USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte which is excellent in output characteristics and high-temperature cycle characteristics and causes little eluted metal, and a lithium-ion secondary cell and a lithium-ion capacitor containing the nonaqueous electrolyte.SOLUTION: The present invention provides: (1) a nonaqueous electrolyte where lithium hexafluorophosphate is dissolved in a nonaqueous solvent containing a cyclic carbonate and a chain carbonate, characterized by containing a C2 or greater chain ether compound that has a methoxy group and is a lithium difluorophosphate dissolution aid, where the ratio (vol%/mass%) of the proportion (vol%) of the dissolution aid to the total volume of the nonaqueous solvent to the amount (mass%) of lithium difluorophosphate in the nonaqueous electrolyte is not less than 0.1 nor more than 5, and the lithium difluorophosphate is dissolved in an amount of 1.2 mass% or more at 25°C; and (2) a lithium-ion secondary cell and a lithium-ion capacitor characterized in that the nonaqueous electrolyte is used therein.SELECTED DRAWING: None