POSITIVE ELECTRODE ACTIVE MATERIAL AND LITHIUM SECONDARY BATTERY INCLUDING THE SAME

The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same, and more specifically, to a positive electrode active material including a lithium composite oxide containing at least nickel and titanium, wherein the titanium is present in an oxide form in at least a portion of the surface of the lithium composite oxide at the same time as being doped in the lithium composite oxide, and thus it is possible to simultaneously improve the output efficiency and high-temperature lifetime characteristics (high-temperature cycle capacity retention rate) of a lithium secondary battery using the positive electrode active material, and a lithium secondary battery including the same.