COMPOSITE POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, METHOD OF PREPARING THE SAME, POSITIVE ELECTRODE FOR LITHIUM SECONDARY BATTERY INCLUDING THE SAME, AND LITHIUM SECONDARY BATTERY INCLUDING THE POSITIVE ELECTRODE

A method of preparing a composite positive electrode active material for a lithium secondary battery includes surface-treating a nickel-based active material using carbon dioxide to form a lithium carbonate layer on the surface of the nickel-based active material, mixing the nickel-based active material having the lithium carbonate layer on the surface thereof with a metal precursor including at least one metal selected from cobalt (Co), aluminum (Al), magnesium (Mg), and gallium (Ga) to prepare a mixture, and heat-treating the mixture. A composite positive electrode active material for a lithium secondary battery may be obtained according to the method; and used in a positive electrode for a lithium secondary battery.