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 according to an aspect of the present disclosure contains a lithium metal composite oxide having secondary particles formed by the aggregation of primary particles, wherein W is present on the surface and inside of the secondary particles of the lithium metal composite oxide. The amount of W present on the surface of the secondary particles of the lithium metal composite oxide represented by general formula LiαNiaCobAlcMdWeOβ (in the formula, 0.9≤α≤1.2, 0.8≤a≤0.96, 0<b≤0.10, 0<c≤0.10, 0≤d≤0.1, 0.0003≤e/(a+b+c+d+e)≤0.002, 1.9≤β≤2.1, a+b+c+d=1, and M is at least one element selected from among Mn, Fe, Ti, Si, Nb, Zr, Mo, and Zn) is 25-45% of the total amount of W present on the surface and inside of the secondary particles of the lithium metal composite oxide.
1 . A positive electrode active material for non-aqueous electrolyte secondary batteries, including:
a lithium metal composite oxide having secondary particles, each of which is formed by aggregating primary particles and having W present on a surface of the secondary particles and inside the secondary particles of the lithium metal composite oxide, wherein
the positive electrode active material is represented by the formula Li α Ni a Co b Al c M d W e O β where 0.9≤α≤1.2, 0.8≤a≤0.96, 0<b≤0.10, 0<c≤0.10, 0≤d≤0.1, 0.0003≤e/(a+b+c+d+e)≤0.002, 1.9≤β≤2.1, a+b+c+d=1, M is at least one element selected from the group consisting of Mn, Fe, Ti, Si, Nb, Zr, Mo, and Zn, and
a proportion of W present on the surface of the secondary particles of the lithium metal composite oxide is 25% to 45% of a total amount of W present on the surface of the secondary particles and inside the secondary particles of the lithium metal composite oxide.
2 . A non-aqueous electrolyte secondary battery comprising a positive electrode including the positive electrode active material for non-aqueous electrolyte secondary batteries according to claim 1 , a negative electrode, and a non-aqueous electrolyte.