| 摘要 |
PROBLEM TO BE SOLVED: To provide a solvent for a lithium ion secondary battery improved in flame resistance, without a large change in electrolyte composition. SOLUTION: A thiophosphate base flame retarder expressed by (R1 S)3 P=O, where R1 is aryl, alkaryl, or aralkyl is added to a nonaqueous solvent base lithium ion secondary battery electrolyte at about 1/10-1/100 of a carbonate-base solvent to be a main composition of the electrolyte. A boiling point can therefore be raised, without hardly raising the viscosity of the electrolyte so as to be able to impart flame resistance. |
