| abstract |
Provided are a positive electrode active material capable of realizing an excellent discharge operating voltage and initial rate characteristics while maintaining a high discharge capacity, and a positive electrode for an electric device and an electric device using the positive electrode active material. The positive electrode active material is Li 1.5 [Ni a Co b Mn c [Li] d ] O 3 (a, b, c and d are a + b + c + d = 1.5, 0.1 <d ≦ 0). .4, 1.1 ≦ a + b + c <1.4, 0.2 ≦ a ≦ 0.7, 0 <b / a <1 is satisfied), and a potential of 4.3V to 4.8V A solid solution lithium-containing transition metal oxide A having a layered structure portion that changes into a spinel structure by charging / discharging in a range, and having a spinel structure change ratio of 0.25 or more and less than 1.0, and LiM X Mn 2− X O 4 (M represents Cr or Al and satisfies the relationship of 0 ≦ x <2) and contains a lithium-containing transition metal oxide B having a spinel structure. [Selection figure] None |