| 摘要 |
A positive active material for a lithium secondary battery is provided to improve ion conductivity and to ensure excellent electrochemical characteristic at high rate, long lifetime and thermal stability. A positive active material for a lithium secondary battery comprises lithium composite oxides represented by chemical formula 1: Li{Li_z[M^1_x(Mn_(0.4-y)M^2_(0.6+y))_(1-x)]}O_2. The lithium composite oxides have a second particle shape in which a first particle is assembled and the second particle has a spherical shape. The first particle has the average particle long diameter of 50 nm - 2.5 micron. In chemical formula 1, M^1 is Co; M^2 is selected from the group consisting of Ni, Ti, Mg, Cu, Zn, Fe, Al and their combinations; 0 <= z <= 0.05, 0.1 <= x <= 0.35, 0 <= y <= 0.25; and the oxidation number of Ni is oxidation state between 2.01-2.4. |
