METHOD FOR PREPARING CATHODE ACTIVE MATERIAL, CATHODE ACTIVE MATERIAL PREPARED BY USING THE SAME, AND LITHIUM SECONDARY BATTERIES COMPRISING THE SAME

摘要

The present invention relates to a method for preparing a positive electrode active material, comprising the steps of: mixing fluoride source to lithium metal composite oxide particles and primarily treating the same by heat, and forming a first engraving coating layer from surfaces of the lithium metal composite oxide particles to the inside; and mixing Li_(NH_4)_PO_4(+=3) to the lithium metal composite oxide particles in which the first engraving coating layer is formed and secondarily treating the same by heat, and forming a second engraving coating layer from surfaces of the lithium metal composite oxide particles in which the first engraving coating layer is formed to the inside, and to the positive electrode active material prepared by the method. According to the present invention, a lithium secondary battery using the positive electrode active material expresses high capacity due to a lithium metal phosphorus oxide having strong binding force with oxygen, and can highly improve lifespan properties since oxygen gas occurs less.