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 including the same, and more particularly, to a positive electrode active material which includes a lithium-rich lithium manganese-based oxide containing at least lithium, nickel, manganese and molybdenum, wherein the lithium manganese-based oxide includes at least one primary particle and a molybdenum-containing flux is used to improve the crystal growth of the primary particle, resulting in mitigation and/or prevention of a decrease in stability caused by lithium and manganese present in excessive amounts in the lithium manganese-based oxide, and a lithium secondary battery including the same.