CATHODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, MANUFACTURING METHOD THEREFOR, AND LITHIUM SECONDARY BATTERY COMPRISING SAME

The present invention relates to a positive electrode active material for a lithium secondary battery, which is a layered lithium transition metal oxide containing an excess of lithium and manganese, wherein the positive electrode active material is a secondary particle formed by aggregation of a plurality of primary particles, and the primary particles include plate-shaped particles and have an average aspect ratio of 5 to 90.