| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery superior in endurance against high-rate charge/discharge.SOLUTION: A nonaqueous electrolyte secondary battery is provided according to the present invention, which comprises: a battery case; and a flat-shaped wound electrode body 80 and a nonaqueous electrolyte enclosed in the battery case. The wound electrode body 80 is formed by putting an elongated positive electrode sheet 10, an elongated negative electrode sheet 20, and a separator sheet 40 on one another and winding them together. In the positive electrode sheet 10 and the negative electrode sheet 20, a positive electrode active material layer 14 and a negative electrode active material layer 24, each having a predetermined width, are formed respectively. Opposing edge parts 28 of at least one active material layer of the positive electrode active material layer 14 and the negative electrode active material layer 24 in a widthwise direction are each formed by a material easier to squash when a pressure is applied thereto in comparison to a center part 26 in the widthwise direction. In addition, a thickness-increasing member is provided on each of parts of an outer peripheral surface of the wound electrode body, which correspond to both the edge parts.SELECTED DRAWING: Figure 3 |
