| 摘要 |
The present invention relates to a cathode active material including lithium-nickel-based transition metal composite oxide doped with an alkali earth metal having +2-valent oxidation water represented by the chemical formula 1, and a phosphorylated material coating layer formed on an external surface of the composite oxide, wherein a lithium byproduct is reduced, and structural stability is improved. Accordingly, a secondary battery including the cathode active material has excellent capacity properties, improved structural stability during charging and discharging, and excellent lifecycle properties as swelling is controlled. Thus, the same can be usefully applied to the industry, especially, the industry of electric vehicles and the like which needs high capacity and long lifecycle properties. [Chemical Formula 1] In the chemical formula 1, M is one or more elements selected from the group consisting of Mn, Co, Cr, Fe, V, and Zr. A is one or more alkali earth metals having +2-valent oxidation water. D is one or more elements selected from the group consisting of S, N, F, Cl, Br, I, and P. |
