SECONDARY BATTERY AND BATTERY PACK

The present disclosure relates to a secondary battery and a battery pack, and the secondary battery (1) includes: an outer casing (10), comprising a case (110) and a cap assembly (120) connected to each other, the case (110) is provided with an opening (113), the cap assembly (120) includes a cap plate (121) and an electrode terminal (122) connected to the cap plate (121), wherein the cap plate (121) is adapted to cover the opening (113); an electrode assembly (20) accommodated in the case (110) and including a main body (210) and a tab (220) extending out from the main body (210), wherein the tab (220) is electrically connected to the electrode terminal (122); a vent (30) connected to the outer casing (10); and an insulating member (40) at least partially disposed between the electrode assembly (20) and the vent (30), wherein a projection of the vent (30) on the main body (210) is at least partially covered by the insulating member (40). The secondary battery and battery pack according to the embodiments of the present disclosure discloses can extend a path length for free lithium ions inside an electrode assembly to diffuse to a vent when a short circuit occurs, thereby prolonging the time required to corrode through the vent and thus prolonging a service life of the secondary battery