| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium secondary battery having excellent charge/discharge cycle characteristics.SOLUTION: A nonaqueous electrolyte secondary battery includes: a positive electrode including a positive electrode active material capable of intercalating/deintercalating alkali metal ions; a negative electrode including a negative electrode active material capable of intercalating/deintercalating alkali metal ions; and a nonaqueous electrolyte. The positive electrode active material includes an alkali metal-transition metal complex oxide. The nonaqueous electrolyte includes 20 vol.% or more of a fluorine-containing phosphate ester relative to a solvent of the nonaqueous electrolyte, the fluorine-containing phosphate ester being represented by the following general formula (1) (in the formula, each of A and B represents a hydrogen atom or a fluorine atom while A and B are different with each other, and each of n and m represents an integer of 1-4). |
