Cylinder type secondary battery

摘要

Disclosed is a cylindrical secondary battery that can improve pressing force of a gasket pressing a cap up and a safety vent. The cylindrical secondary battery prevents leakage of electrolyte by improving pressing force of the gasket by including a cap up whose terminal portion is formed thicker than the peripheral portion. By using the cap up of the above structure, a curled portion is formed at the edge of the cap up or safety vent so as to surround the end of the safety vent or cap up. Thus, internal resistance can be reduced when the vibration or external impact is applied to the battery, and assembling error can be prevented.

主权项

1. A cylindrical secondary battery, comprising:
a cylindrical can; an electrode assembly housed in the can; a cap assembly comprising a safety vent electrically coupled to the electrode assembly, and a cap up disposed on the safety vent; and a gasket comprising three surfaces that at least partially surround the cap up and the safety vent, wherein the cap up comprises a terminal portion and a peripheral portion, and the safety vent interrupts current and discharges gas from the battery, when an internal pressure of the battery is increased, wherein the peripheral portion comprises a region surrounded by the three surfaces of the gasket, and wherein the region of the peripheral portion is thinner than the terminal portion of the cap up.