Positive electrode active material including solid solution active material, positive electrode including the positive electrode active material, and nonaqueous electrolyte secondary battery using the positive electrode

摘要

[Object] To provide a method capable of suppressing elution of a transition metal, particularly manganese, in a positive electrode active material for a non-aqueous electrolyte secondary battery. [Solving means] The present invention provides a positive electrode active material for a non-aqueous electrolyte secondary battery, including: a solid solution active material represented by the composition formula (1): [Numerical formula 1] €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒLi 1.5 [Ni a Mn b Co c[ Li] d [X] c ]O z €ƒ€ƒ€ƒ€ƒ€ƒ(1) wherein X represents at least one selected from Ti, Zr and Nb, 0 ‰¤ e ‰¤ 0.5, a + b + c + d + e = 1.5, 0.1 ‰¤ d ‰¤ 0.4, and 1.1 ‰¤ [a + b + c + e] ‰¤ 1.4, and z represents the number of oxygen atoms satisfying an atomic valence; and an alumina layer on the surface of the solid solution active material and a region in which Al element is present on the side of the surface of the solid solution active material in the interface between the solid solution active material and the alumina layer. [Selected Figure] FIG. 17