| abstract |
(57) [Summary] [Problem] The electric capacity after 100 cycles has passed is 100 mA. To provide a non-aqueous secondary battery having a large capacity of h / g or more and a capacity retention rate of 100% or more after 100 cycles and a small decrease in capacity, a positive electrode active material for the battery, and a method for producing the same. In a composite oxide Li x Al y Mn 3-xy O z having a spinel structure composed of Li, Mn, Al and O, 1.0 <x ≦ 1.1, 0 <y <0.02, 3.5 < The above object is achieved by using a composite oxide in the range of z ≦ 4.5 as a positive electrode active material of a nonaqueous secondary battery. |