| 摘要 |
PURPOSE: To prevent short circuit and insulation defect of a bending portion in the vicinity of the center of a non-circular spiral electrode body. CONSTITUTION: A battery contains a spiral electrode, and the spiral electrode is formed by winding a positive electrode plate 2A and a negative electrode plate 2B into non-circular spiral-like via a separator 2C. In the battery winding start positions of + and -electrodes are dislocated, and only an earlier wound electrode plate 3 is positioned at the bending portion of the electrode plate closest to the center. The winding start position of the later wound electrode plate 4 is positioned retreating from the first bending portion of the earlier wound electrode plate 3. The first bending portion of the earlier wound electrode plate 3 confronts the earlier wound electrode plate 3 wound outside the same. Thereby, even if the earlier wound electrode plate 3 damages the separator 2C at the first bending portion bent with the smallest radius of curvature, insulation performance of a non-circular spiral electrode body is not allowed to deteriorate, as the same electrode plate confronts mutually. |
