| abstract |
[PROBLEMS] To provide a non-aqueous electrolyte secondary battery excellent in both low-temperature charge / discharge performance and high-temperature life performance. In A non-aqueous electrolyte secondary battery, the positive electrode active material Li x Mn y M z O 4 ( provided that, 1.05 <x < 1.2, 1.8 <y <1.95, 0 <z <0.15, M Is one or more elements selected from Al and Mg), and a cyclic carboxylate, and a cyclic carbonate having an unsaturated bond and soluble in the cyclic carboxylate; It is characterized by using an electrolyte containing LiBF 4 . |