| abstract |
A positive electrode active material is provided for an electric device that contains a first active material comprising a transition metal oxide represented by formula (1): Li1.5[NiaCobMnc[Li]d]O3 (where a, b, c, and d satisfy the relationships: 0<d<0.5; a+b+c+d=1.5; and 1.0<a+b+c<1.5); and a second active material comprising a spinel transition metal oxide that has a crystal structure assigned to the space group Fd-3m, represented by formula (2): LiMa′Mn2−a′O4 (where M indicates at least one metal element having an atomic valence of 2-4, and a′ satisfies the relationship 0=a′<2.0). The fraction content of the first and second active material by mass ratio satisfies the relationship (3): 100:0 A:MB A indicates the mass of the first active material and MB indicates the mass of the second active material). |