SECONDARY BATTERY HAVING IMPROVED SAFETY

摘要

The present invention relates to a secondary battery having improved safety. According to one aspect of the present invention, a pouch-type secondary battery comprises: an electrode assembly; a pouch exterior material constituted by a first pouch part and a second pouch part; and a double electrode lead that includes a first electrode lead attached to the first pouch part and a second electrode lead attached to the second pouch part. The secondary battery can prevent excessive charging by shutting off a current using a volume expansion phenomenon caused by swelling or pressure that is generated while overcharging. In addition, when a pressure is increased by an additional reaction, venting is generated in each inner lead part of the double electrode lead to increase the safety of a battery cell, module, and pack that are constituted by a pouch, thereby increasing the lifetime of the battery.