Provided is a wound cell, formed by winding of a first and second separator, a first and second electrode plate from start ends thereof, outermost circle of second electrode plate includes second single-side coated area, surface of which facing center of the wound cell is second blank current collector area not coated with second active material, portion of first electrode plate opposite to second blank current collector area includes first single-side coated area, surface of which away from the center of the wound cell is first blank current collector area not coated with first active material; tail end of first electrode plate contains first blank foil area, portion of second electrode plate opposite to first blank foil area contains second blank foil area; start ends of first and second single-side coated area are located at two opposite sides in thickness direction of the cell.