| abstract |
(57) [Problem] To provide a battery using a lithium manganese composite oxide having good cycle life and high capacity storage characteristics at a high temperature as a positive electrode active material. SOLUTION: In a non-aqueous electrolyte secondary battery using a lithium manganese composite oxide as a positive electrode active material and a material capable of doping and undoping lithium as a negative electrode active material, La, Sr, Nd, and Sm are contained in the battery. Oxide or carbonate of at least one selected element, or La, S It contains a composite oxide of manganese and at least one element selected from r, Nd, and Sm. A non-aqueous electrolyte secondary battery containing iPF 6 or LiBF 4 . |