| 摘要 |
PROBLEM TO BE SOLVED: To provide an evaluation method allowing deteriorated condition of a positive electrode to be easily evaluated with high accuracy.SOLUTION: There is provided the evaluation method of a positive electrode of a lithium ion secondary battery, which contains two or more kinds of positive electrode active materials. The method comprises: a step of obtaining a first cyclic voltammogram curve using an abscissa axis as a positive electrode potential on the basis of a potential vs. Li/Liby performing the cyclic voltammetric measurement of a cell using a positive electrode prior to the prescribed charge and discharge of the lithium secondary battery as a working electrode; a step of obtaining a second cyclic voltammogram curve using an abscissa axis as a positive electrode potential on the basis of a potential vs. Li/Liby performing cyclic voltammetric measurement using the positive electrode after the prescribed charge and discharge of the lithium secondary battery as a working electrode; a step of deciding a determination peak that is an oxidation peak and/or a reduction peak belonging to at least one kind of positive electrode active material forming the positive electrode in the first cyclic voltammogram curve and the second cyclic voltammogram curve obtained; and a step of determining the extent of deterioration of the positive electrode active material based on a change in the determination peak in the second cyclic voltammogram curve relative to a determination peak in the first cyclic voltammogram curve. |
