HIGH RATE CHARGING AND DISCHARGING CYLINDRICAL SECONDARY BATTERY

Disclosed herein is a cylindrical secondary battery including a cap assembly constructed in a structure in which a vent, which intercepts electric current and discharges pressurized gas when the interior pressure of the battery is increased due to abnormal operation of the battery, is in contact with a top cap having a protruding central part, wherein the end of the vent is bent to surround the outer circumferential surface of the top cap, and a groove for preventing the leakage of an electrolyte and preventing the occurrence of defectiveness of the battery during the assembly of the battery is formed at interfaces between the vent and the top cap such that the groove is arranged in parallel with the outer circumferential surface of the top cap. The secondary battery according to the present invention has the effect of accomplishing high charging and discharging rate, providing uniform output even when external physical impacts, such as vibration or dropping, are applied to the secondary battery, and preventing the occurrence of defectiveness during the assembly of the secondary battery. Furthermore, the leakage of the electrolyte out of the battery is restrained under these conditions. Consequently, the secondary battery according to the present invention can be preferably used as a high-output power source.