| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery element excellent in reliability furthermore.SOLUTION: The battery element has a lamination structure of a positive electrode, a separator and a negative electrode, and also has a flat cross section including a pair of flat parts facing each other and a pair of curved parts facing each other. The separator includes: a base material made of a porous resin; and a resin layer disposed on one side face or both side faces of the base material and comprising a single layer. The thickness of the resin layer of the separator at the curved part is larger than that of the resin layer of the separator at the flat part. The air permeability of the separator at the curved part is higher than that of the separator at the flat part continuous to the curved part. |
