19. A positive electrode active material for a nonaqueous electrolyte secondary battery, which is represented by the general formula (B): li1+uNixMnyCozMtO2The positive electrode active material is composed of lithium transition metal composite oxide particles having a hexagonal crystal structure and a layered structure, and in the general formula (B), -0.05. ltoreq. u.ltoreq.0.50, x + y + z + t 1, 0.3. ltoreq. x.ltoreq.0.95, 0.05. ltoreq. y.ltoreq.0.55, 0. ltoreq. z.ltoreq.0.4, 0. ltoreq. t.ltoreq.0.1, M is one or more additive elements selected from Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W,
the positive electrode active material for a nonaqueous electrolyte secondary battery is composed of secondary particles formed by aggregating a plurality of primary particles,
the secondary particles have a central portion having a hollow structure or a hollow structure, and a space portion having no primary particles and an outer shell portion electrically connected to the central portion outside the central portion,
and the average value of the ratio of the outer diameter of the central portion to the particle diameter of the secondary particles is 30 to 80%, the average value of the ratio of the thickness of the outer shell portion in the diameter direction to the particle diameter of the secondary particles is 5 to 25%,
the secondary particles have an average particle diameter of 1 to 15 [ mu ] m, and the [ (d90-d 10)/average particle diameter ] as an index indicating the width of the particle size distribution is 0.7 or less.
secondary particles
average particle diameter
1 to 15 [ mu
mu
secondary particles
particle size distribution
0.7 or less