Abstract: A method for preparing a cathode active material for a lithium secondary battery is provided. 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 L1-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: 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 an electrochemical cell including a compound having a nano-shape and represented by the following Formula 1. Lix[Li1-y-zM1yM2z]O2-?D???[Formula 1] wherein, 0.8?x?1.1, 0?y?0.5, 0?z?0.5, and 0???0.05, M1 and M2 are independently selected from transition elements, and D is selected from the group consisting of O, F, S, P, and combinations thereof. The positive active material of the present invention has high reversible capacity and an excellent cycle life characteristic, and in particular, an excellent cycle life characteristic at a high rate.