POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, POSITIVE ELECTRODE AND LITHIUM ION SECONDARY BATTERY USING THE SAME AND ESTIMATION SELECTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a positive electrode active material capable of implementing a lithium ion secondary battery having high cycle resistance.SOLUTION: A positive electrode active material containing mixed oxide of lithium, nickel, cobalt and manganese has one or more characteristics of the following characteristics measured by the transmission X-ray absorption spectroscopy: a characteristic associated with a peak intensity appearing in a normalized spectrum of a nickel K absorption end; a characteristic associated with a peak intensity appearing in a normalized spectrum of a cobalt K absorption end; a characteristic associated with a peak value caused by oxygen atoms as first nearest atoms to nickel atoms in a radial distribution function around the nickel atoms which is obtained from a nickel K absorption spectrum; a characteristic associated with a peak value caused by metal atoms as second nearest atoms; a characteristic associated with a peak value caused by oxygen atoms as first nearest atoms to cobalt atoms in a radial distribution function around cobalt atoms which is obtained from a cobalt K absorption spectrum; and a characteristic associated with a peak value caused by metal atoms as second nearest atoms.SELECTED DRAWING: None