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

Positive electrode active materials for a rechargeable battery, positive electrodes including the positive electrode active material, and rechargeable lithium batteries including the positive electrode are provided. A positive electrode active material includes first particles including a compound represented by Chemical Formula 1 and having a first average particle diameter, and second particles including a compound represented by Chemical Formula 2 and having a second average particle diameter that is greater than the first average particle diameter. A mixing ratio of the first particles and the second particles is about 95:5 to about 99.5:0.5.