| 摘要 |
PROBLEM TO BE SOLVED: To provide a cell enabling providing a function for releasing internal pressure abnormally raised in a small-sized battery, such as a coin-type battery, particularly a secondary battery. SOLUTION: A side peripheral portion of a sealing case 4 containing a generating device is covered with a cap case 3 via a gasket 6 to seal an internal space by caulking work that an open end of the cap case 3 is bent inside. The open end of the cap case 3 is provided as a caulked height-reduced site 11, that the height of a side peripheral portion 3c is reduced within a prescribed angle range. Since sealing strength is lowered at the caulked height-reduced site 11, the internal pressure in released by looseness of the gasket 6 produced by deformation of the caulked height-reduced site 11, when the internal pressure is abnormally raised, thereby preventing a cell from breaking. |
