POSITIVE ELECTRODE ACTIVE MATERIAL FOR RECHARGEABLE LITHIUM BATTERY, PREPARATION METHOD OF THE SAME, AND RECHARGEABLE LITHIUM BATTERY INCLUDING THE SAME

A positive electrode active material for a rechargeable lithium battery, a preparation method of the same, and a rechargeable lithium battery including the same are provided. A positive electrode active material includes a first particle including a compound represented by Formula 1 and having a first average particle diameter, and a second particle including a compound represented by Formula 2 and having a second average particle diameter smaller than the first average particle diameter. An amount of the second particle is equal to or greater than an amount of the first particle.