METHOD FOR MANUFACTURING ACTIVE MATERIAL OF POSITIVE PLATE AND METHOD FOR MANUFACTURING NONAQUEOUS ELECTROLYTE SECONDARY CELL

In a method for producing a positive electrode active material including a mixing step of mixing a plurality of substances to give a precursor and a sintering step of sintering and reacting said precursor obtained by said mixing step, in which these substances prove a starting material for synthesis of a compound represented by the general formula LixMyPO4 where x is such that 0 < x ≤ 2, y is such that 0.8 ≤ y ≤ 1.2 and M includes at lest one of 3d transition metals,, a reducing agent is added in the above mixing step to said precursor to render it possible to prepare a positive electrode active material capable of reversibly and satisfactorily doping/undoping lithium.