SECONDARY BATTERY AND BATTERY MODULE

The present disclosure relates to a secondary battery and a battery module. The secondary battery includes: a casing including a receiving cavity and an opening which is in communication with the receiving cavity; an electrode assembly housed in the casing; a first top cover plate, which covers the opening and is connected with the casing, the first top cover plate including an insertion portion extending into the casing and an exposed portion disposed outside the casing; and a sealing member; the casing is provided with a first through hole, the insertion portion is provided with a second through hole, the second through hole includes an inlet which is in communication with the first through hole and an outlet which is in communication with the receiving cavity, and the sealing member is connected to the casing and seals the first through hole.