A battery cell includes a housing, an electrode component, and an electrode terminal. The outer surface of the housing is provided with a recess. The electrode component is accommodated within the housing. At least a part of the electrode terminal is accommodated within the recess, and the electrode terminal is configured to be electrically connected to the electrode component to export electric energy of the electrode component. The recess is configured to accommodate at least a part of a busbar of a battery, the busbar is configured to connect electrode terminals of a plurality of battery cells to electrically connect the plurality of battery cells.