What is claimed is:
1. Cathode active material for a non-aqueous electrolyte rechargeable battery comprising secondary particles that are formed by an aggregation of plural primary particles,
the cathode active material comprising layered hexagonal crystal lithium nickel manganese composite oxide particles that are expressed by the general expression (B): Li1+uNixMnyCozMtO2, where −0.05≤u≤0.50, x+y+z+t=1, 0.3≤x≤0.95, 0.05≤y≤0.55, 0≤z≤0.4, 0≤t≤0.1, and M is one or more additional element that is selected from among Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta and W,
the secondary particles having a center section comprising the aggregation of plural primary particles, the center section having a solid structure or hollow structure provided with a hollow part at its inside, an outer-shell section comprising the aggregation of plural primary particles and located on the outside of the center section, at least a hollow section located between the center section and the outer-shell section where there are no primary particles, and a connecting section electrically connecting between the outer-shell section and the center section;
the average value of the ratio of the center section outer diameter with respect to the particle size of the secondary particles being 30% to 80%, and the average value of the ratio of the outer-shell section radial direction thickness with respect to the particle size being 5% to 25%; and
the secondary particles having an average particle size of 1 μm to 15 μm, and an index [(d90−d10)/average particle size] that indicates the extent of the particle size distribution of 0.7 or less.
the secondary particles
average particle size
1 μm to 15 μm
μm
the secondary particles
particle size distribution
0.7 or less