Abstract: A battery cell includes: a housing; at least one wound cell arranged in the housing, where each wound cell has a tab, and the tab at at least one end forms a flattened plane covering an end surface of the wound cell; a pole; and an adapting member connecting the pole to the tab of the at least one wound cell. In the battery cell, the tab at at least one end on the wound cell forms the flattened plane covering the end surface of the wound cell, which can reduce the battery space occupied by the tab, and increase the winding space, thereby improving the energy density of the battery cell. The flattened plane can be stably connected to the adapting member, overcoming the need to align a plurality of tabs for a stable connection to the adapting plate. This improves production line efficiency and reduces battery production costs.

Abstract: An electrode assembly is formed by winding an electrode plate and a separator, and the electrode plate includes a coating region and a plurality of tabs. When the electrode assembly is unfolded, the tabs each include a first part and a second part, and the second part is located on a side of the tab that is away from the coating region. Along a length direction of the electrode plate, two sides of the first part respectively have a first side cut and a second side cut that are opposite to each other, and two sides of the second part respectively have a third side cut and a fourth side cut that are opposite to each other. The first side cut and the third side cut are disposed located on a same side and connected to each other.

Abstract: An electrode assembly includes first and second electrode plates having opposite polarities, and stacked and wound in a winding direction to form a wound structure. The first electrode plate has a first winding starting end and includes a first segment and a second segment continuously arranged along the winding direction. The first segment is wound from the first winding starting end along the winding direction to form an inner turn layer, and the second segment is wound from a connecting position where it is connected with the first segment along the winding direction to form an outer turn layer. The first segment is provided with a reinforcing part wound to the connecting position along the winding direction and configured to reinforce the first segment.

Abstract: This application provides a secondary battery, a battery module, and a device using a secondary battery as a power supply. The secondary battery includes an electrode assembly, a cap assembly, and current collection members. The electrode assembly includes a main body and tabs that extend from the main body. The cap assembly includes a cap plate, electrode terminals, and an insulation baffle. The electrode terminals are disposed on the cap plate. The insulation baffle is connected to a side of the cap plate, where the side is close to the main body. The current collection members are at least partly located between the insulation baffle and the main body, and each of the current collection members includes a tab connection portion connected to one of the tabs. The insulation baffle contains a first recess.