Cap assembly, battery cell, battery and electric-powered device

A battery cell comprising:

• an electrode assembly;
• and
• a cap assembly, the cap assembly comprising:
• a cap plate comprising a liquid injection hole;
• and
• a blocking device disposed on a side of the cap plate facing the electrode assembly and at least partially covering the liquid injection hole, the blocking device comprising at least:
• a first blocking plate that forms a first receiving cavity and that is connected with the cap plate along a first peripheral edge of the first blocking plate that surrounds the liquid injection hole;
• and
• a second blocking plate that is connected with the cap plate along a second peripheral edge of the second blocking plate arranged between the first peripheral edge and the liquid injection hole;
• wherein the first receiving cavity comprises a first sub-cavity defined between the first blocking plate and the second blocking plate and a second sub-cavity defined between the second blocking plate and the liquid injection hole;
• wherein each blocking plate is provided with a vent hole which penetrates through the blocking plate, each vent hole being adapted for communicating the liquid injection hole with a space located at a side of the blocking device facing away from the cap plate;
• and
• wherein each of the blocking plates are spaced apart in a first direction, and the first direction is a direction from the electrode assembly towards the cap plate.