POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, METHOD FOR PRODUCING POSITIVE ELECTRODE ACTIVE MATERIAL, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

A positive electrode active material according to an exemplary embodiment of the present invention is a composite oxide represented by a composition formula LixNayNiaM1-aOd, where M is at least one element selected from the group consisting of transition metal elements and typical elements other than Li, Na, and Ni, 0.80≤x≤1.15, 0.02≤y≤0.20, 0.90≤x+y≤1.20, 0.40≤a≤0.95, and d is a value satisfying electrical neutrality. When 1 L of water is added to 1000 g of the composite oxide, the concentration of the alkali component eluted in water is less than 700 mmol/L.