TOP COVER ASSEMBLY, BATTERY CELL, AND BATTERY PACK

A top cover assembly, a battery cell, and a battery pack are provided in this application. The top cover assembly includes a cover plate, a terminal plate, and a sealant. A through hole is formed through the cover plate. The through hole is configured to be in communication with an interior of the battery cell. The terminal plate is installed on the cover plate and covers the through hole. A first overflow groove is formed in the terminal plate at a position corresponding to the through hole, and a groove opening of the first overflow groove faces the through hole. The sealant is interposed between the cover plate and the terminal plate, and the sealant is partially filled into the first overflow groove.