POSITIVE ELECTRODE ACTIVE MATERIAL AND LITHIUM SECONDARY BATTERY COMPRISING THE SAME

The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a bimodal-type positive electrode active material including a first lithium composite oxide, which is a small particle, and a second lithium composite oxide, which is a large particle, these particles having different particle diameters, wherein the positive electrode active material makes it possible to prevent deterioration in electrochemical properties and stability thereof, which are generated due to nonuniform formation of a coating layer at least partially coating surfaces of the small and large particles, a positive electrode including the positive electrode active material, and a lithium secondary battery using the same.