TRANSITION METAL OXIDE CONTAINING SOLID SOLUTION LITHIUM, NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY CATHODE, AND NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY

A transition metal oxide containing solid solution lithium according to the present invention contains a transition metal oxide containing lithium, which is represented by a chemical formula: Li 1.5 [Ni a Co b Mn c [Li] d ]O 3 (where Li is lithium, Ni is nickel, Co is cobalt, Mn is manganese, O is oxygen, a, b, c and d satisfy relationships: 0 < a < 1.4; 0 ‰¤ b < 1.4; 0 < c < 1.4; 0.1 < d ‰¤ 0.4; a+b+c+d = 1.5; and 1.1 ‰¤ a+b+c < 1.4). The transition metal oxide containing lithium includes: a layered structure region; and a region changed to a spinel structure by being subjected to charge or charge/discharge in a predetermined potential range. When a ratio of an entire change from Li 2 MnO 3 with a layered structure in a region to be changed to the spinel structure to LiMn 2 O 4 with the spinel structure is defined to be 1, a spinel structure change ratio of the transition metal oxide containing lithium is 0.25 or more to less than 1.0.