Positive Electrode Active Material, Method of Preparing the Positive Electrode Active Material, and Positive Electrode and Lithium Secondary Battery Which Include the Positive Electrode Active Material

A positive electrode active material includes a nickel-based lithium transition metal oxide containing nickel in an amount of 60 mol % or more based on a total number of moles of metals excluding lithium, wherein cobalt is included in an amount of greater than 0 ppm to 6,000 ppm or less on a surface of the nickel-based lithium transition metal oxide. A method of preparing the positive electrode active material, a positive electrode for a lithium secondary battery and a lithium secondary battery which includes the positive electrode active material are also provided.