POWER STORAGE DEVICE AND METHOD FOR MANUFACTURING LITHIUM ION RECHARGEABLE BATTERY

The power storage device comprises an electrode assembly including a positive electrode, a separator, and a negative electrode, and an electrolyte solution. The negative electrode comprises a negative electrode current collector and a negative electrode active material layer. The active material layer comprises a surplus region A not facing the positive electrode active material layer, an end region B facing a region in the positive electrode active material layer, the region extending from an end of the positive electrode active material layer toward a center of the positive electrode active material layer by a length of 5% of a length from the center to the end, and a center region C. A negative electrode potential VA and a negative electrode potential VC after the positive electrode and the negative electrode are short-circuited satisfy Formulas below: (1): VA≤2.0 V, (2): VC≤1.0 V, (3): VA/VC≥0.7.