| abstract |
A positive electrode active material for lithium secondary batteries disclosed herein comprises a lithium transition metal oxide of a layered structure, represented by formula Li1+αNixCoyMnzCaβMγO2 (where −0.05≤α≤0.2, x+y+z+β+γ≅1, 0.3≤x≤≤0.7, 0.1≤y≤0.4, 0.1≤z≤0.4, 0.0002≤β≤0.0025, 0.0002≤β+γ≤0.02, and in a case where γ>0, M is absent or represents one, two or more elements selected from the group consisting of Na, Mg, Al, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta and W). The tap density of the positive electrode active material ranges from 1.8 to 2.5 g/cm3. |