LITHIUM SECONDARY BATTERY

摘要

Disclosed is a lithium secondary battery which comprises a positive electrode (1), a negative electrode (2) and an electrolyte solution containing a nonaqueous electrolyte solvent, and which is characterized in that the nonaqueous electrolyte solvent contains a fluorine-containing phosphoric acid ester represented by formula (1) and a fluorinated diether compound represented by formula (20). (In formula (1), at least one of R1, R2 and R3 represents a fluorine-containing alkyl group.) R4O-(R5O)n-R6 (20) (In formula (20), at least one of R4, R5 and R6 represents a group that is substituted by a fluorine atom; and n represents an integer of 1-4.) This secondary battery has high energy density and good cycle characteristics.