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 end, away from the cover plate, of the connecting ring, and the solder layer is located between the sealing piece and the connecting ring so that the sealing piece and the cover plate can be connected in a sealed mode. The utility model further discloses a battery cell, a battery and electric equipment which are provided with the cover plate assembly.