BATTERY ASSEMBLY AND PREPARATION METHOD, BATTERY AND ELECTRIC VEHICLE

Provided is a battery assembly, which includes a cover plate and a pole. The pole penetrates the cover plate and is fixed with the cover plate by riveting. For the battery assembly provided by the application, the pole and the cover plate are fixed by riveting. Compared with the fixing method of welding, it not only simplifies the fixing operation, improves the production efficiency, but also reduces the production cost. Also provided are a preparation method of a battery assembly, a battery and an electric vehicle.