ADAPTER PIECE STRUCTURE, BATTERY CELL STRUCTURE AND ASSEMBLY PROCESS METHOD THEREFOR, AND LARGE-CAPACITY ENERGY STORAGE BATTERY

The present application provides an adapter piece structure, a battery cell structure and an assembly process therefor, as well as a battery for large-scale energy storage. The adapter piece structure includes a tab connecting portion and a terminal connecting portion, the tab connecting portion is configured to connect with a tab of a battery cell, and the terminal connecting portion is connected with the tab connecting portion. The terminal connecting portion has a first side, the first side has a clean area provided to be cleaned, and the clean area includes a welding area and an annular area arranged around a circumference of the welding area. The welding area is configured for welding the terminal connecting portion with a terminal of a cover plate.