| 摘要 |
Provided is a secondary battery, wherein the structure of a cap plate is improved to increase a welding characteristic with a case, thereby enhancing airtightness and reliability of a battery. The secondary battery comprises: an electrode group(10) including a separator(13), a positive electrode plate(11) and a negative electrode plate(12) disposed on both sides of the separator(13); a case(14) having the electrode group(10) within; and a cap plate(30) that is placed at the vertical hem of an opening of the case(14) and attached to the vertical hem of the case(14) in such a manner that external side hems form inclined planes(36) to the case(14). |
