| abstract |
An object of the present invention is to provide a non-aqueous electrolyte secondary battery that is excellent in cycle characteristics even in a high-temperature environment and high in thermal stability. The non-aqueous electrolyte secondary battery of the present invention comprises at least one of an active material A and an active material C, and an active material B as positive electrode active materials. The active material A is Li x CoO 2 (0.9≦x≦1.2). The active material B is Li x Ni y Mn z M 1-y-z O 2 (0.9≦x≦1.2, 0.1≦y≦0.5, 0.2≦z≦0.5, 0.2≦1−y−z≦0.5 and 0.9≦y/z≦2.5; and M is at least one selected from the group consisting of Co, Mg, Al, Ti, Sr, Ca, V, Fe, Y, Zr, Mo, Tc, Ru, Ta, W and Re). The active material C is Li x Co 1-a M a O 2 (0.9≦x≦1.2 and 0.005≦a≦0.1; and M is at least one selected from the group consisting of Mg, Al, Ti, Sr, Mn, Ni, Ca, V, Fe, Y, Zr, Mo, Tc, Ru, Ta, W, Re, Yb, Cu, Zn and Ba). |