POSITIVE ELECTRODE ACTIVE MATERIAL, POSITIVE ELECTRODE, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

PROBLEM TO BE SOLVED: To provide a positive electrode active material capable of achieving high charge and discharge cycle characteristics and a gas generation restraining effect in a battery. SOLUTION: The positive electrode active material includes a covering layer arranged on at least a part of the surface of lithium transition metal complex oxide. An absorption end of an X-ray giving intensity of 0.5 between 1302 eV and 1312 eV exists in a standardized X-ray absorption fine structure (XAFS) spectrum of the covering layer, and a ratio of intensity of a first neighboring peak in the vicinity of 1.6 to intensity of a second neighboring peak in the vicinity of 2.6 is 1.3-4.0 at an absolute value of a vector structure function around Mg calculated as a Fourier transformation of an extended X-ray absorption end fine structure (EXAFS). The lithium transition metal complex oxide has a stratified rock salt structure, and the covering layer uses the positive electrode active material, wherein a ratio of intensity at 1,318 eV to the intensity at 1,311 eV in the standardized X-ray absorption fine structure (XAFS) spectrum measured at a charged state is 0.9-1.6. COPYRIGHT: (C)2011,JPO&INPIT