Patent ID: 7316865

Claim:
A surface-treated positive active material comprising: a positive active material; and a surface-treatment layer formed on the positive active material including at least one compound selected from the group consisting of a coating-element-containing hydroxide, a coating-element-containing oxyhydroxide, a coating-element-containing oxycarbonate, a coating-element-containing hydroxycarbonate, and a mixture thereof, wherein the surface-treatment layer is formed on the positive active material by a process comprising: adding a coating element or a coating-element-containing compound to an organic solvent to prepare an organic suspension; adding water to the suspension to prepare a coating liquid; coating the positive active material with the coating liquid; and drying the coated positive active material, thereby forming the surface-treatment layer on the positive active material, and wherein the coating element is at least one selected from a group consisting of an alkali metal, an alkaline earth metal, a group 13 element of the Periodic Table, a group 14 element of the Periodic Table, a group 15 element of the Periodic Table, a transition metal, and a combination thereof.