POSITIVE ELECTRODE ACTIVE MATERIALS, PREPARATION METHODS THEREOF, POSITIVE ELECTRODES, AND RECHARGEABLE LITHIUM BATTERIES

A positive electrode active material, a method of preparing the positive electrode active material, and a positive electrode and rechargeable lithium battery each including the positive electrode active material are provided. The positive electrode active material includes a lithium nickel-based composite oxide having a nickel content (e.g., amount) of greater than or equal to about 60 mol% based on 100 mol% of a total metal excluding lithium in the lithium nickel-based composite oxide, the lithium nickel-based composite oxide further including zirconium, and the positive electrode active material has a span ((D90-D10)/D50) value of about 1.10 to about 1.25 in the particle size distribution and is in the form of single particles.