Lithium cobalt oxide cathode material with core-shell structure and preparation method thereof

The invention relates to a lithium cobalt oxide cathode material with a core-shell structure and a preparation method thereof. The chemical formula of the lithium cobalt oxide cathode material with acore-shell structure is (1-x)LiaCo(1-b)M1bO[delta] 1*xLicCo(1-d)M2dO[delta]2, wherein LiaCo(1-b)M1bO[delta]1 is a core, LicCo(1-d)M2dO[delta]2 is a shell, M1 is an element having +2, +3 valences, andM2 is an element having +4, +5, +6 valences. The invention provides four methods for preparing the lithium cobalt oxide cathode material, no interface is formed between the core and the shell, and a transition region with gradient distribution and co-doping of M1 and M2 is generated. The lithium cobalt oxide with a core-shell structure has good structural stability and safety performance as a cathode material of a lithium ion battery, the surface of the lithium cobalt oxide is protected, meanwhile, de-intercalation/intercalation and diffusion of Li ions are not hindered, and the lithium cobaltoxide cathode material has