Abstract: The invention relates to a cathode material of lithium cobalt oxide for a lithium ion secondary battery and preparation methods and applications thereof. A cathode material comprises a core material and a coating layer, wherein the core material is LixCo(1?y)AyO(2+z), wherein 1.0?x?1.11, 0?y?0.02, ?0.2<z<0.2, and A is one or two or more selected from the group consisting of Al, Mg, Y, Zr and Ti, wherein the coating layer is LiaMbBcOd, wherein M is a lithium ion active metal element and one or two or more selected from the group consisting of Co, Ni, Mn and Mo, and B is an inactive element, and one or two or more selected from the group consisting of Al, Mg, Ti, Zr and Y, and 0.95<b+c<2.5, and the molar ratio of Li to the active metal element M is 0<a/b<1. The battery prepared by the cathode material has advantages of high capacity, high compacted density and excellent cycling stability etc., under high voltage.
