Positive electrode active material for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery

A positive electrode active material for a non-aqueous electrolyte secondary battery, including

• a lithium-containing composite oxide having a layered rock-salt structure and represented by the general formula LixNiaCobMncM1dO2-y, wherein 0.95≤x≤1.05, 0.75≤a<0.95, 0≤b≤0.15, 0≤c≤0.25, 0≤d≤0.10, 0≤y≤0.05, a+b+c+d=1, and M1 represents at least one element selected from the group consisting of W, Mg, Mo, Nb, Ti, Si, Al, and Zr, wherein
• the lithium-containing composite oxide includes secondary particles each formed by aggregation of primary particles, and
• on surfaces of the secondary particles or on interfaces between the primary particles, a sulfonate compound represented by the general formula I, at least one element selected from the group consisting of Ca and Sr, and at least one element selected from the group consisting of W, Mo, Ti, Si, Nb, and Zr, are present,
• wherein A represents a group I element or a group II element, R represents a hydrocarbon group, and “n” represents 1 or 2.