Lithium ion secondary battery

摘要

There is provided is a lithium ion secondary battery (20). The lithium ion secondary battery (20) includes: a positive electrode (21) having a positive electrode active material layer (21 a) containing a positive electrode active material containing a vanadium-based compound; and a negative electrode (22) having a negative electrode active material layer (22a) containing a negative electrode active material into which lithium ions can be inserted/removed reversibly. A vanadium-based compound is dispersed in the negative electrode active material layer (22a). As a result, a vanadium-based compound, corresponding to the vanadium-based compound contained in the positive electrode active material is dispersed in the negative electrode active material layer (22a).