SECONDARY BATTERY, BATTERY MODULE, BATTERY PACK, DEVICE, AND MANUFACTURING METHOD

The embodiments of the present disclosure provide a secondary battery, a battery module, a battery pack, a device, and a manufacturing method. The secondary battery includes: an electrode unit, including a main body portion and a first tab and a second tab extending out from the main body portion; a casing, including an accommodating cavity for accommodating the main body portion and a first opening which is in communication with the accommodating cavity; a first cover plate capping the first opening, the first cover plate including a first relief hole penetrating therethrough, the first tab passes through the first relief hole and is connected to a side of the first cover plate facing away from the accommodating cavity; and a sealing plate, which is sealingly connected to the side of the first cover plate facing away from the accommodating cavity and covers the first relief hole.