In some feasible implementations, the first weak zone 811 may also be provided to accommodate overflowing fire prevention medium when the pressure relief structure 6 is actuated and the fire prevention medium flowing to the battery cell 400 overflows, to prevent the overflowing fire prevention medium from flowing into adjacent battery cells. As shown in FIG. 5, the first weak zone 811 is provided as a through hole, or a through hole is formed when the pressure relief mechanism 6 is actuated. Due to the thickness of the fastener 80, the through hole may become a accommodating pool for accommodating the fire prevention medium.

The main body 81 of the fastener 80 is further provided with a buckle 812, which are provided on two sides of the first weak zone 811 along a central axis of the fire prevention pipeline 70, and are configured to fasten the fire prevention pipeline 70 to the fastener 80, as shown in FIG. 4. The buckles 812 are arranged and spaced apart from each other to fasten the fire prevention pipeline 70. In this way, processing technology can be simplified, and greater assembly deviations are allowed, helping assembly of the fire prevention pipeline 70 to the fastener 80.