16. 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 having solid or hollow structure, and at least a hollow section where there are no primary particles and an outer-shell section that is electrically connected to the center section on the outside of 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 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
an average particle size
1 μm to 15 μm
μm
the secondary particles
particle size distribution
0.7 or less