Method for evaluating suitability of negative electrode active material

Abstract

An evaluation method of a negative electrode active material for secondary battery includes measuring an X-ray diffraction of a battery cell stored in a charged state; calculating intensity integrals of extracted diffraction peaks, where the extracted diffraction peaks are extracted from X-ray diffraction peaks for a carbon interlayer compounds and a decomposed products contained respectively in a negative electrode active layer of a negative electrode from the measured X-ray diffraction; calculating a reaction rate constant k1 for the carbon interlayer compounds or a reaction rate constant k−1 for the decomposed products of the carbon interlayer compounds from the calculated intensity integral; and evaluating a material suitability of the negative electrode active material contained in the negative electrode active layer based on the calculated reaction rate constant.

Dependencies are inferred from the claim text.