Cover plate assembly, battery cell, battery and electric equipment

The utility model discloses a cover plate assembly, the cover plate assembly comprises a cover plate, a solder layer and a sealing member, the cover plate is provided with a liquid injection hole, and the cover plate is provided with a connecting ring surrounding the liquid injection hole; the sealing piece covers the connecting ring, and the welding flux layer is connected between the sealing piece and the connecting ring so as to connect the cover plate and the sealing piece in a sealing mode. The utility model further discloses a battery cell provided with the cover plate assembly, a battery and electric equipment.