Cover plate assembly and single battery

The utility model belongs to the technical field of heat energy generated by terminal columns, and discloses a cover plate assembly and a single battery, the cover plate assembly comprises a cover plate, a pole column and an insulating piece, the pole column comprises a terminal column, a first protruding part arranged on the side wall of the terminal column in a protruding mode and a first groove formed in the side wall of the terminal column, the insulating part wraps the side wall of the terminal column, the insulating part is provided with a second groove and a second protruding part, the first protruding part is embedded in the second groove, and the distance b between the groove bottom of the second groove and the side, away from the side wall of the terminal column, of the insulating part is smaller than the distance a between the side wall of the terminal column and the side, away from the side wall of the terminal column, of the insulating part. According to the cover plate assembly, the problem that