| abstract |
(57) [Summary] [Problem] A flat portion of a discharge curve shows an operating voltage of 4.5 V or more based on a metal lithium potential, and a large discharge capacity in a high potential region of 4.5 V or more, and load characteristics are high. An excellent positive electrode active material for a non-aqueous secondary battery and a non-aqueous secondary battery are provided. A general formula LiNi x M y Mn 2-xy O 4 (where M is at least one element containing at least one of trivalent Fe and Co, x, y Is 2x + y + ≧ 1.00, 0 <y ≦ 0.30) A positive electrode active material for a non-aqueous secondary battery is composed of a spinel type lithium nickel manganese composite oxide represented by the following formula, and a non-aqueous secondary battery is composed using the positive electrode active material. |