Positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

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

• a lithium-transition metal composite oxide containing nickel (Ni) in an amount of greater than or equal to 80 mol % with respect to a total number of moles of metal elements other than lithium (Li), wherein boron (B) is present at least on a particle surface of the lithium-transition metal composite oxide, wherein
• the lithium-transition metal composite oxide is a secondary particle formed by flocculation of a plurality of primary particles;
• the secondary particle comprises a plurality of secondary particles wherein those having a larger particle size than a volume-based 70% particle size (D70) are defined as first particles, those having a smaller particle size than a volume-based 30% particle size (D30) are defined as second particles;
• a coverage ratio of B on surfaces of the second particles is larger than a coverage ratio of B on surfaces of the first particles by 5% or greater, the coverage ratio being a ratio of an area of surfaces on which B is present to a total area of surfaces of each of the secondary particles.