Cathode active material coated with F-dopped lithium metal manganese oxide, lithium-ion secondary battery comprising the same and the prepration method thereof

The present invention relates to a positive electrode active material coated with lithium manganese metal oxide having a spinel structure doped with fluorine, a lithium secondary battery comprising the same, and to a manufacturing method thereof. The positive electrode active material has enhanced stability, and can improve charging and discharging characteristics of the lithium secondary battery at a high temperature (55-60C) and with a high rate. Lithium ions easily penetrate through a lithium manganese metal oxide coating layer which is chemically stable. Thus, the positive electrode active material can be effectively applied to a high output lithium secondary battery.