NONAQUEOUS ELECTROLYTE SOLUTION AND LITHIUM SECONDARY BATTERY

摘要

[PROBLEMS] Disclosed is a lithium secondary battery wherein overcharge safety of the battery is realized while improving cycle characteristics and storage characteristics at high temperatures and suppressing swelling of the battery case caused by gas generation. [MEANS FOR SOLVING PROBLEMS] A nonaqueous electrolyte solution for lithium secondary batteries wherein an electrolyte is dissolved in a nonaqueous solvent containing a cyclic carbonate compound, a chain carbonate compound and a cyclohexylbenzene compound wherein one or two halogen atoms are bonded to a benzene ring, is characterized by having the volume ratio between the cyclic carbonate compound and the chain carbonate compound in the nonaqueous solvent within the range from 20:80 to 40:60, or by further containing a small amount of a branched alkylbenzene compound.