A wound cell , comprising: a first electrode plate comprising a first current collector and an active substance coated on the first current collector ; and a second electrode plate comprising a second current collector and the active substance coated on the second current collector , wherein the first electrode plate comprises an empty foil segment referring to a portion of the first current collector , one side of the portion of the first current collector being coated with the active substance and the other side of the portion of the first current collector being not coated with the active substance , and the empty foil segment comprises a bent segment being an area where the first electrode plate is bent for the first time, a first extension segment extending from an end of the bent segment , and a second extension segment extending from the other end of the bent segment , and the second electrode plate comprises a second head segment referring to a segment between a starting end of the second electrode plate in a winding direction of the wound cell and a first bend segment of the second electrode plate ; a portion of the second current collector in the second head segment is coated with the active substance on both sides, one side of the empty foil segment facing the second head segment is not coated with the active substance , the empty foil segment comprises a starting end and an ending end in the winding direction, and projections of the starting end and the ending end of the empty foil segment in a thickness direction from the first extension segment to the second extension segment fall on the second head segment . a first electrode plate comprising a first current collector and an active substance coated on the first current collector ; and a second electrode plate comprising a second current collector and the active substance coated on the second current collector , wherein the first electrode plate comprises an empty foil segment referring to a portion of the first current collector , one side of the portion of the first current collector being coated with the active substance and the other side of the portion of the first current collector being not coated with the active substance , and the empty foil segment comprises a bent segment being an area where the first electrode plate is bent for the first time, a first extension segment extending from an end of the bent segment , and a second extension segment extending from the other end of the bent segment , and the second electrode plate comprises a second head segment referring to a segment between a starting end of the second electrode plate in a winding direction of the wound cell and a first bend segment of the second electrode plate ; a portion of the second current collector in the second head segment is coated with the active substance on both sides, one side of the empty foil segment facing the second head segment is not coated with the active substance , the empty foil segment comprises a starting end and an ending end in the winding direction, and projections of the starting end and the ending end of the empty foil segment in a thickness direction from the first extension segment to the second extension segment fall on the second head segment . <EOS>