A battery cell includes a housing having an opening, a cover plate configured to close the opening, and an electrode assembly disposed in the housing and including a main body and a tab extending from an end of the main body along a first direction. The cover plate is located on a side of the main body along a second direction perpendicular to the first direction. The battery cell further includes a first insulation piece disposed between the electrode assembly and the cover plate to dielectrically insulate the electrode assembly from the cover plate, and a second insulation piece disposed between the main body and an inner surface of the housing to dielectrically insulate the tab from the housing. The second insulation piece and the first insulation piece are discretely disposed and connected to each other.