POSITIVE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a positive active material for a nonaqueous electrolyte secondary battery having long life with a high initial capacity and reduced cycle deterioration in capacity. SOLUTION: A minimum transmittance (the maximum absorbance) T (min) of peaks due to a metal-oxygen octahedron which is observed in the vicinity of 550 cm<-1> is within a range of 500<=1/λ[T (min)]<=580 cm<-1> in a wave number (1/λ), in the infrared absorption spectra by a KBr method. The expression [T(440 cm<-1> )-T(480 cm<-1> )]/40 representing the inclination of a low wave number side is 0.17 or more in the absorption peaks due to the metal-oxygen tetrahedron observed in the vicinity of 550 cm<-1> , in the infrared absorption spectra by the KBr method [where T(440 cm<-1> ) and T(480 cm<-1> ) represent the transmittances in wave numbers of 440 cm<-1> and 480 cm<-1> respectively].