END CAP ASSEMBLY, BATTERY CELL, BATTERY MODULE, AND ELECTRIC DEVICE

Provided are an end cover assembly, a battery cell, a battery module, and an electric device. The end cover assembly includes: a first end cover including a first plastic member provided with a first mounting portion and a first current collector provided with a first mating portion that is assemblable with the first mounting portion; and a second end cover including a second plastic member provided with a second mounting portion and a second current collector provided with a second mating portion that is assemblable with the second mounting portion. The first mounting portion is at least partially different from the second mounting portion and the first mating portion is at least partially different from the second mating portion, allow for mounting interference between the first mounting portion and the second mating portion and mounting interference between the second mounting portion and the first mating portion. Therefore, an operator can be promptly reminded of a matching error in components to correct this matching error in time. Therefore, an assembly of the first plastic member and the first current collector as well as an assembly of the second plastic member and the second current collector can be quickly and accurately completed. As a result, it is possible to effectively avoid the incorrect assembly between the components, which may result in the re-disassembly and re-assembly and thus affect the manufacturing and the manufacturing efficiency of a battery.