Positive electrode active material for secondary battery and secondary battery including the same

A positive electrode active material for a secondary battery, the positive electrode active material comprising:

• a core including a lithium cobalt oxide;
• and
• a lithium-metal oxide and a metal oxide, which include at least one metal selected from the group consisting of aluminum (Al), magnesium (Mg), tungsten (W), molybdenum (Mo), zirconium (Zr), titanium (Ti), tantalum (Ta), iron (Fe), vanadium (V), chromium (Cr), barium (Ba), calcium (Ca), and niobium (Nb), on a surface of the core,
• wherein the lithium-metal oxide is a heat fused material of the lithium cobalt oxide and the metal oxide, and
• wherein the core is a heat fused material of the lithium cobalt oxide particles having first lithium cobalt oxide particles having an average particle diameter of 2 μm or less and second lithium cobalt oxide particles having an average particle diameter of 6 μm or more,
• wherein the first lithium cobalt oxide particles, are melted to be fused to the second lithium cobalt oxide particles.