Current collector, pole piece, battery cell and lithium battery

The utility model discloses a current collector, pole piece, battery cell and lithium battery, the current collector comprises a main body part and a plurality of special-shaped parts, the main body part is strip-shaped, the plurality of special-shaped parts are arranged on the edge of the same side of the main body part, and the plurality of special-shaped parts are linearly arranged along the length direction of the main body part; the heights of the special-shaped parts are the same, and the widths of the special-shaped parts are gradually increased in the length direction of the main body part; the center lines of the special-shaped parts in the width direction are the centers of the special-shaped parts, and the center distance between every two adjacent special-shaped parts is gradually increased in the length direction of the main body part. The pole piece provided by the utility model comprises the current collector. The battery cell provided by the utility model comprises the pole piece. The lithium