Battery cell and battery

The utility model relates to a battery cell. The battery cell comprises a pole piece, a plurality of tabs and a tab connecting piece, the tab connecting piece extends out of the side edge of the pole piece, and the tabs are arranged in a first direction; the tab connecting piece comprises a main body, one end of the main body is a first connecting part, the other end of the main body is a second connecting part, the first connecting part is connected to the tabs, the second connecting part is used for leading out current, and the width of the first connecting part is larger than that of the second connecting part. According to the scheme provided by the invention, the problem that in the production process, due to the fact that the second connecting part is wide, the contact area is large, scratches and collisions are likely to occur, and the risk of short circuit is increased can be solved, meanwhile, it is avoided that die cutting is carried out on the tabs by adjusting die cutting parameters for many times