Abstract: Disclosed is a method for preparing a cathode active material for a lithium secondary battery, and the preparing method includes: adding a phosphorus compound to a transition metal oxide dispersion liquid to prepare a coating liquid; drying the coating liquid to prepare a powder including phosphorus oxide coated on the surface of the transition metal oxide; and dry-mixing the powder coated with the phosphorus oxide with a lithium intercalation compound, and then firing the mixture to form a solid solution compound of Li-M1-M2-P—O (where M1 is a transition metal derived from transition metal oxide, and M2 is a metal derived from lithium intercalation compound) on the surface of the lithium intercalation compound. The method for preparing a cathode active material for a lithium secondary battery simplifies the conventional preparing process to save process cost, and it provides comparable electrochemical characteristics to a cathode active material obtained from a wet process.

Abstract: The present invention relates to a positive active material for a rechargeable lithium battery, a method of preparing the same, and a rechargeable lithium battery including the same. More particularly, the present invention relates to a positive active material for a rechargeable lithium battery including a compound that can reversibly intercalate/deintercalate lithium and a lithium metal phosphate produced through binding with lithium of the compound, the lithium metal phosphate existing from the surface of the compound to a predetermined depth, a method of preparing the positive active material, and a rechargeable lithium battery having the positive active material. The positive active material can accomplish excellent cycle-life characteristic and also, suppress battery swelling at a high temperature.