EVALUATION METHOD OF SECONDARY BATTERY CONDITIONS

摘要

PROBLEM TO BE SOLVED: To provide a method of evaluation of a secondary battery conditions, which judges speedily and simply by nondestructive testing the deterioration of the secondary battery formed of electrodes consisting of a positive sheet electrode made of a laminated positive layers and a negative laminated electrode including cathode active substance. SOLUTION: By using a computer tomography(CT), a CT value of at least one of the areas of either the above positive laminated layer or the above cathode laminated layer for the secondary battery is measured based on the photography principles of the X-ray computer tomography, a deterioration extent of the above secondary battery is evaluated. Image data for the cross section of the layer of the electrode body for the above secondary battery are obtained, from which conditions of laminated of the electrodes of the above secondary battery is evaluated.