POSITIVE ELECTRODE ACTIVE MATERIAL, ITS MANUFACTURING METHOD, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

PROBLEM TO BE SOLVED: To provide a positive electrode active material and its manufacturing method further improving chemical stability, and a nonaqueous electrolyte secondary battery of high capacity and excellent charge-discharge cycle characteristics using the positive electrode active material. SOLUTION: At least a part of the surface of composite oxide particles is provided with a coating layer formed of a metal oxide mainly composed of an oxide of nickel (Ni) and manganese (Mn) containing lithium (Li), and at least a part of the coating layer is provided with a surface layer containing molybdenum (Mo). Co diffused from the composite oxide particles exists in the coating layer and surface layer. The atomic ratio of Mo and Co as the average of the whole positive electrode active material is set to 0.001 or less, and the atomic ratio of Mo and Co on the surface of the positive electrode active material is set to ≥0.01 and ≤0.5. Bond energy of 3d5/2 by XPS (X-ray photoelectron spectroscopy) of Mo is set to 232.4 eV or less. Such a coating layer is formed by attaching Li, Ni, Mn and Mo to the surface of the composite oxide particles by a wet method and baking it. COPYRIGHT: (C)2008,JPO&INPIT