POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERIES AND METHOD FOR PRODUCING SAME

An object is to provide a positive electrode active material which can exhibit sufficient cycle characteristics in a non-aqueous electrolyte secondary battery. [0002] The positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention is represented by Composition Formula (2): Li[Ni[M]Mn]O(in the formula, M represents at least one element selected from the group consisting of Cu, Zn, Mg, Fe, Al, Co, Sc, Ti, V, Cr, Ga, Ge, Bi, Sn, Ca, B, and Zr, 0 ≤ a ≤ 1/6, and x represents the number of Li satisfying the atomic valence). In addition, the positive electrode active material for a non-aqueous electrolyte secondary battery is characterized in that it is obtained by reduction-ion exchange of a precursor of the positive electrode active material that is represented by Composition Formula (1) : Na[Ni[M]Mn]O(in the formula, M and a are as defined in Composition Formula (2)).