| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte and a secondary battery, improved in flame retardancy without deteriorating basic performance thereof and while even improving the performance, if possible.SOLUTION: An electrolyte for a nonaqueous secondary battery contains, in an aprotic solvent, a metal salt that contains ions of group I or group II metal of the periodic table and a specific cyclic compound that has phosphorus atoms and nitrogen atoms. The aprotic solvent is a solvent that contains at least one of a carboxylic acid ester compound and a carbonic acid ester compound, and the ratio (M/Ms) between the mass (M) of the cyclic compound and the mass (Ms) of the aprotic solvent containing the metal salt is 0.005-1. |
