NONAQUEOUS SOLVENT, NONAQUEOUS ELECTROLYTE SOLUTION USING SAME, AND NONAQUEOUS SECONDARY BATTERY

摘要

Disclosed is a nonaqueous solvent for a nonaqueous secondary battery, which contains a fluorinated cyclic carbonate that has at least one fluorine atom in each specific position of each molecule and a fluorinated phosphazene wherein at least one fluorine atom is bonded to a phosphorus atom in each phosphazene molecule and the ratio of the number of fluorine atoms to the number of phosphorus atoms is not less than 4/3. Since the fluorinated cyclic carbonate forms a good protective coating film by being reduced at a negative electrode, the cycle characteristics of a nonaqueous secondary battery are improved. Since the fluorinated phosphazene suppresses the generation of organic ions in the nonaqueous solvent, the generation of a gas within a nonaqueous secondary battery is reduced.