2. 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 comprising 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, a hollow section located between the center section, and outer-shell section where there are no primary particles, at least one inner-shell section comprising the aggregation of plural primary particles and located between the center section and the outer-shell section, the at least one inner-shell section separated from the center section and the outer-shell section by the hollow section, and a connecting section electrically connecting among the outer-shell section, the inner-shell section and the center section; 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