End cover assembly, battery cell, battery, and electrical apparatus

An end cover assembly, being applied to a battery cell, the end cover assembly comprising:

• an end cover body which comprises a first edge and a second edge that are oppositely arranged in a width direction of the end cover assembly;
• a fool-proofing protrusion disposed on the end cover body and located on a side of the end cover body facing an interior of the battery cell;
• and
• an electrode terminal which passes through the end cover body, wherein the electrode terminal comprises a connecting area facing the interior of the battery cell, the connecting area is used for electrically connecting with a tab of an electrode assembly, and in the width direction, a distance from the connecting area to the first edge is larger than a distance from the connecting area to the second edge;
• wherein the fool-proofing protrusion is at least partially located on a side of the connecting area close to the first edge, and no protrusion protruding from the connecting area is provided at a location that is a mirror image of the fool-proofing protrusion with respect to a central plane parallel to the first edge and the second edge and orthogonally bisecting the end cover body.