Patent ID: 10388944

Abstract:
A positive electrode active material includes a primary particle represented by Compositional Formula (1): Li1+xNiyCozM1−x−y−zO2   (1), where x is a number satisfying a relation represented by an expression −0.12≤x≤0.2; y is a number satisfying a relation represented by an expression 0.7≤y≤0.9; z is a number satisfying a relation represented by an expression 0.05≤z≤0.3; and M is at least one element selected from the group consisting of Mg, Al, Ti, Mn, Zr, Mo, and Nb; or a secondary particle into which the primary particle aggregates. The primary particle or the secondary particle includes a free lithium compound in a weight proportion of 0.1% or more and 2.0% or less, and the weight of lithium hydroxide in the free lithium compound is 60% or less of the weight of lithium carbonate in the free lithium compound.