Positive electrode active material for secondary battery and method for producing positive electrode active material for secondary battery

Abstract

A positive electrode active material for a secondary battery, which is one aspect of the present disclosure, is characterized by including a lithium-containing composite oxide composed of secondary particles in which primary particles are aggregated, and by that the lithium-containing composite oxide contains Ni at 85 mol % or more with respect to the total molar amount of metal elements excluding lithium, and Al, the Al concentration in the vicinity of the surface of the secondary particles is higher than the Al concentration in the central portion of the secondary particles, and a metal element M (M is at least one of Mg, Ca, Sr, Na, K, Zr, Co, Nb, W, and Mo) at 0.01-2.0 mol % and sulfate ions at 0.02 mol % or more with respect to the molar amount of the lithium-containing composite oxide are present on the surface of the primary particles.

Dependencies are inferred from the claim text.