A cell includes a first current collector and a second current collector. A tail end of the first current collector exceeds a tail end of the second current collector by at least half a circle in a winding direction. The inventor of the present application finds that after the length of the first current collector is increased, and the tail end of the first current collector exceeds the tail end of the second current collector by at least half a circle, the following situation may occur: the outermost circle of the cell is the first current collector, the secondary outer circle is the first current collector, and the next secondary outer circle is the second current collector, such that both the outermost circle and the secondary outer circle of the cell are the first current collector.