Positive Electrode Active Material for Secondary Battery, Method of Preparing the Same, and Lithium Secondary Battery Including the Positive Electrode Active Material

A positive electrode material for a secondary battery and a method of making the same is disclosed herein. In some embodiments, a positive electrode active material includes a lithium composite transition metal oxide including nickel (Ni), cobalt (Co), and manganese (Mn), wherein the lithium composite transition metal oxide includes 60 mol % or more of the nickel (Ni) among metals excluding lithium, and a coating layer is formed on surfaces of particles of the lithium composite transition metal oxide, wherein the coating layer includes a lithium-polymer compound which is formed by a reaction of a lithium by-product with a polymer.