The utility model relates to the technical field of batteries, and provides a battery, which comprises a pole structure, the battery shell comprises a cover plate, the cover plate comprises a main body and an extension section, the main body is arranged around the extension section, the wall thickness of the main body is greater than that of the extension section, and the pole structure is arranged in the pole through hole in a penetrating manner; the fixing part is arranged on the main body, the fixing part is arranged around the extension section, the fixing part is bent into a connecting section and a pressing section, the connecting section is arranged on the main body, and the pressing section is pressed on the pole structure, so that the pole structure is clamped between the pressing section and the extension section; wherein the cover plate and the fixing part are of an integrally-formed structure, the distance between one side, facing the pole structure, of the extending section and the outer surface of the main body in the direction perpendicular to the cover plate is H, and H is larger than or equal to 0.2 mm and smaller than or equal to 1 mm, so that when the cover plate and the fixing part are integrally formed, the structural strength of the fixing part and the extending section can be guaranteed, and reliable fixing of the pole structure is guaranteed; therefore, the safe use performance of the battery is improved.