A battery cell, a battery, an electrical device, and a method and device for manufacturing the battery cell. In some embodiments, the battery cell comprises a battery core, a shell, an end cover, and a first insulating component. The battery core comprises a main body part and electrode tabs protruding from the main body part. The shell has a first opening and is configured to accommodate the battery core. The end cover is configured to cover the first opening. The first insulating component comprises an insulating main body and an insulating part, wherein the insulating main body is located on a side, facing the electrode tabs, of the end cover, and the insulating main body is configured to isolate the battery core from the end cover.