Patent ID: 9496065
Filing Date: 2016-11-15
CPC Classification: C01G,H01B,H01G,H01M,Y02E,Y02T

Claim Text:
1. A positive electrode active material for an electric device, the positive electrode active material comprising: a first active material composed of a transition metal oxide represented by compositional formula (1): wherein Li is lithium, Ni is nickel, Co is cobalt, Mn is manganese, O is oxygen, a, b, c and d satisfy relationships: 0.1≦d≦0.4; a+b+c+d=1.5; and 1.1≦a+b+c≦1.4, the first active material having: a layered crystal structure region that has been changed to a spinel type crystal structure by performing charge or charge/discharge in a potential range of 4.3V or more to 4.8V or less with a spinel type crystal structure change ratio of 0.25 or more to less than 1.0, the spinel type crystal structure change ratio representing an amount of Li a layered crystal structure region that is not changed to the spinel type crystal structure; and a second active material composed of a spinel-type transition metal oxide represented by compositional formula (2) and having a crystal structure belonging to a space group Fd-3m: wherein, in formula (2), Li is lithium, M is at least one selected from the group consisting of aluminum, magnesium and chromium, Mn is manganese, O is oxygen, and a′ satisfies a relationship: 0≦a′≦0.5, wherein: a content ratio of the first active material and the second active material satisfies, in a mass ratio, a relationship represented by expression (3): wherein M a BET specific surface of the first active material is 0.8 m a median diameter of the first active material is 20 μm or less.