END COVER ASSEMBLY, BATTERY CELL, BATTERY PACK AND DEVICE

The present disclosure relates to an end cover assembly, a battery cell, a battery pack and a device. The end cover assembly includes a cover assembly, a terminal assembly, a sealing piece and a first connected flow channel. The cover assembly is provided with an installation hole, and the installation hole penetrates through the cover assembly along an axial direction of the installation hole; the terminal assembly is installed in the installation hole; the sealing piece is configured to seal the installation hole; the first connected flow channel is arranged in at least one of the terminal assembly and the cover assembly, and the first connected flow channel is configured as follows: when the sealing of the sealing piece is invalid, the first connected flow channel enables the inside and the outside of the housing to be communicated through the installation hole.