POSITIVE ACTIVE MATERIAL FOR A LITHIUM SECONDARY BATTERY, METHOD OF PREPARING THEREOF, AND LITHIUM SECONDARY BATTERY COPRISING THE SAME

摘要

A positive active material for a lithium secondary battery is provided to improve a life characteristic at 4.5 V and to suppress a swelling phenomenon caused by a side reaction thereof with an electrolytic solution at high temperature. A positive active material for a lithium secondary battery includes: a compound capable of reversible intercalation/deintercalation of lithium; a lithium metal phosphate produced by combining a phosphate with lithium of the compound. The lithium metal phosphate is present from the surface to a predetermined depth of the compound. The compound capable of reversible intercalation/deintercalation of lithium is a lithium composite metal oxide or lithium chalcogenide. The lithium metal phosphate is contained in an amount of 0.01-2wt% based on total positive active material.