Slitter

A slitter comprising:

• an upper knife disposed above an electrode plate, thereby configured to cut the electrode plate;
• a lower knife disposed below the electrode plate to partially overlap the upper knife, thereby configured to cut the electrode plate together with the upper knife,
• wherein the upper knife comprises:
• a first inner surface extending at an incline from a tip formed at a lowermost end to contact an inner surface of the lower knife;
• an outer circumferential surface extending at an incline from the tip to a side opposite the lower knife;
• and
• a support surface,
• wherein the incline of the first inner surface has a first angle from a vertical line (V) that is perpendicular to a rotation axis that serves as a rotation center of the upper knife,
• wherein the incline of the outer circumferential surface has a second angle from the vertical line,
• wherein the upper knife and the lower knife are rotary knives,
• wherein an outer surface of the lower knife is planar and a thickness of the lower knife is constant,
• wherein the upper knife further comprises a second inner surface extending inward from the first inner surface, and
• wherein the second inner surface is inclined at a third angle from the vertical line, the third angle being an acute angle, the second inner surface extending toward an inner side of the upper knife to define a stepped portion with respect to the support surface of the upper knife.