| abstract |
Provided is a positive electrode active material capable of simultaneously improving battery capacity, output characteristics, and cycle characteristics of a secondary battery when used as a positive electrode material of a nonaqueous electrolyte secondary battery. A composite hydroxide particle, which is a precursor of a positive electrode active material, is nucleated by adjusting the pH value of a reaction aqueous solution to a range of 12.0 to 14.0 (nucleation step). When the nuclei are grown by adjusting the pH value of the reaction aqueous solution to the range of 10.5 to 12.0 (particle growth step), the reaction atmosphere in the reaction field is changed in the initial stage of the nucleation step and the particle growth step. The oxygen concentration was adjusted to a non-oxidizing atmosphere with an oxygen concentration of 5% by volume or less, and an oxidizing gas was directly introduced into the reaction aqueous solution while continuing the supply of the raw material aqueous solution in the course of the particle growth process. The atmosphere is controlled at least once by switching to an oxidizing atmosphere exceeding volume%, and further switching to a non-oxidizing atmosphere by directly introducing an inert gas into the reaction aqueous solution while continuing to supply the raw material aqueous solution. [Selection] Figure 2 |