| 摘要 |
In this lithium ion secondary cell (100A), a plurality of wound electrode units (200A-200D) are respectively equipped with a belt-shaped positive electrode (220) and a belt-shaped negative electrode (240), the belt-shaped positive electrode (220) and the belt-shaped negative electrode (240) being wound in a state of juxtaposition with separators (262, 264) interposed therebetween. The plurality of wound electrode units (200A-200D) are bent to a flattened profile in a direction running straight along the winding axis (WL) in the wound state, and the plurality of wound electrode units (200A-200D) are accommodated within a cell case (300A) while in juxtaposition with the flat sections of the wound electrode units which have been bent to a flattened profile. In sub-electrodes (500A-500C), the electrode of opposite polarity from the electrode wound outermost about the wound electrode units (200A-200D) is formed on the outermost surface. The sub-electrodes (500A-500C) are disposed between the flat sections of the wound electrode units (200A-200D) which have been bent to a flattened profile. |
