Positive-electrode active material for nonaqueous-electrolyte secondary cell, and nonaqueous-electrolyte secondary cell

A positive-electrode active material includes a lithium transition metal composite oxide that contains at least 80 mol % of Ni in relation to the total molar amount of metal elements excluding Li. The lithium transition metal composite oxide includes secondary particles obtained by the aggregation of primary particles, at least one element A selected from Ca and Sr being present on the surface of the primary particles in an amount of 1 mol % or less in relation to the total molar amount of metal elements excluding Li, and S and at least one element B selected from Zr, Ti, Mn, Er, Pr, In, Sn, and Ba being present on the surface of the secondary particles.