A busbar 91 is configured to electrically connect to the battery cell 400, and the busbar 91 is connected to the electrode terminal 5 through the opening of the accommodating portion to limit the movement of the fastener 80 in the direction z.

In a feasible implementation, the busbar 91 may be fastened to the electrode terminal 5 by welding.

Using the above structure, the fastener 80 cooperates with the electrode terminal 5 by using the accommodating portion. Therefore, the fastener 80 is unable to move in the direction x and the direction y. The busbar 91 is provided above the fastener 80, so that the fastener 80 cannot move in the direction z. The electrode terminal 5 and the busbar 91 work together, so that the fastener 80 is always fastened above the pressure relief mechanism 6 of the battery cell 400, to completely restrict the position of the fire prevention pipeline and realize the fixation of the relative position of the fire prevention pipeline to the pressure relief mechanism 6.

FIG. 7 to FIG. 9 are schematic structural diagrams of a fastener 80 in some embodiments.

The fastener 80 includes a main body 81 and a connecting portion 82 that is arranged on two sides of the main body 81. For example, two connecting portions 82 are respectively located on opposite sides of the main body 81 in the direction x.