POSITIVE ELECTRODE ACTIVE MATERIAL AND LITHIUM SECONDARY CELL USING SAME

摘要

The positive electrode active material for a lithium secondary cell disclosed herein comprises a lithium transition metal oxide having a laminar structure represented by the general formula Li1+αNixCoyMnzCa&bgr;MγO2 (-0.05≤α≤0.2, x+y+z+&bgr;+γ≈1, 0.3≤x≤0.7, 0.1≤y≤0.4, 0.1≤z≤0.4, 0.0002≤&bgr;≤0.0025 and 0.0002≤&bgr;+γ≤0.02; when γ>0, M represents one or more elements selected from the group consisting of Na, Mg, Al, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta and W), and the tap density is 1.8 to 2.5 g/cm3.