Patent ID: 11894555

Abstract:
A positive electrode active material for a lithium ion secondary battery containing lithium nickel manganese complex oxide particles, wherein the lithium nickel manganese complex oxide particles are composed of secondary particles in which primary particles of a lithium nickel manganese complex oxide represented by a general formula LidNi1−a−b−cMnaMbZrcO2+α (where M is at least one element selected from Co, W, Mo, Mg, Ca, Al, Ti, Cr, and Ta, and is 0.05≤a<0.60, 0≤b<0.60, 0.00003≤c≤0.03, 0.05≤a+b+c≤0.60, 0.95≤d≤1.20, and −0.2≤α≤0.2), wherein at least a portion of zirconium is dispersed in the primary particle, and wherein an amount of a positive active material for a lithium ion secondary battery in which an amount of excessive lithium determined by a neutralization titration method is 0.02 mass % or more and 0.09 mass % or less.