Tab forming device of jellyroll-type electrode assembly and forming method using the same

A forming device for bending an electrode tab in a radial direction and flattening the same, the electrode tab being exposed to an end portion of an electrode assembly in an axial direction by extending a first electrode more axially than a separator, the electrode assembly being in a jelly-roll shape by laminating the first electrode, the separator, and a second electrode and winding them around a central axis, comprising:

• a forming jig bending the electrode tab, wherein the forming jig comprises:
• a pre-forming perimeter surface having an inner diameter that increases as it extends from a base end to a leading end in a pressing direction;
• and
• a bend inducing surface extending radially inward from the base end of the pre-forming perimeter surface, and inclined in an opposite direction to the pressing direction as it goes radially inward,
• wherein an inner radius of the leading end of the pre-forming perimeter surface is greater than an outermost radius of the electrode tab, and
• wherein an inner radius of the base end of the pre-forming perimeter surface is smaller than the outermost radius of the electrode tab.