摘要 |
A positive electrode active material for an electric device contains a first active material and a second active material. The first active material is composed of a transition metal oxide represented by formula (1): Li 1.5 [Ni a Co b Mn c [Li] d ]O 3 ...(1) (where, in the formula (1), a, b, c and d satisfy relationships: 0<d<0.5; a+b+c+d=1.5; and 1.0<a+b+c<1.5). The second active material is composed of a spinel-type transition metal oxide represented by formula (2) and having a crystal structure belonging to a space group Fd-3m: LiM a' Mn 2-a' O 4 ...(2) (where, in the formula (2), M is at least one metal element with a valence of 2 to 4, and a' satisfies a relationship: 0‰¤a'<2.0). A content ratio of the first active material and the second active material satisfies, in a mass ratio, a relationship represented by expression (3): 100:0<M A :M B <0:100...(3) (where, in the formula (3), M A is a mass of the first active material, and M B is a mass of the second active material). |