Abstract: There is a provided a secondary battery capable of preventing unloading and rotating caused by possible vibration or shock by increasing a coupling force among the vent plate, the insulator, and the cap-down that compose the cap assembly of the secondary battery. To increase the coupling force among the vent plate, the insulator, and the cap-down, protrusions and corresponding grooves or holes, and grooves with step areas may be formed. Alternatively, a plurality of insulators may be formed in a divided form. A secondary battery with a reliable cap assembly can be implemented through such a structural change.

Abstract: A rechargeable battery that prevents a concentration of stress on a coupling portion of a lead tab and a cap assembly at a time of bending the lead tab so as to not damage the coupling portion includes: an electrode assembly having a first electrode, a second electrode, and a separator interposed between the first and second electrodes; a case to receive the electrode assembly and having an open top portion; a cap assembly arranged on the top portion of the case; a lead tab having one end affixed to the cap assembly to electrically connect the cap assembly to the first electrode; and a stopper fixed to the cap assembly and having one end arranged on the lead tab, the stopper allowing a portion of the lead tab contacting the one end of the stopper to be bent when the lead tab is bent.

Abstract: A rechargeable battery that prevents a concentration of stress on a coupling portion of a lead tab and a cap assembly at a time of bending the lead tab so as to not damage the coupling portion includes: an electrode assembly having a first electrode, a second electrode, and a separator interposed between the first and second electrodes; a case to receive the electrode assembly and having an open top portion; a cap assembly arranged on the top portion of the case; a lead tab having one end affixed to the cap assembly to electrically connect the cap assembly to the first electrode; and a stopper fixed to the cap assembly and having one end arranged on the lead tab, the stopper allowing a portion of the lead tab contacting the one end of the stopper to be bent when the lead tab is bent.

Abstract: A secondary battery has a depression having a thickness less than that of other portions of the periphery of a cap plate or a can. The depression includes a rupture section having a smallest thickness in the depression and further includes wrinkles between the rupture section and the periphery of the depression. Furthermore, the secondary battery is manufactured by a method including: a first coining step of forming the thickness of some portions of the cap plate or the can to be less than that of other peripheral portions thereof; a second coining step of forming wrinkles on the periphery of some portions where the first coining has been performed; and a third coining step of forming a rupture section having the smallest thickness in the depression on an inner side of the wrinkles.

Abstract: A sealed type battery is disclosed which can reduce variations in the operating pressure of a safety valve, improve the reliability for the airtightness of a battery vessel, remove the contact of electrode plates and the case due to the rightward or leftward deviation of a group of electrode plates in the direction of the winding shaft, remarkably reduce the internal short-circuiting production rate, and realize cost lowering or reduction in the number of working steps. The battery is equipped with a safety valve in which a cover plate having a hole, a metal thin plate and a holding plate of metal having a hole are stacked with the metal thin plate sandwiched and integrally fixed by laser welding.