Abstract: An electrode plate extension device includes a first roller and a second roller. The first roller includes a first body and a protrusion. The protrusion is provided on an outer peripheral surface of the first body and extends in a circumferential direction of the first body. The second roller includes a second body and a groove. The groove is provided in an outer peripheral surface of the second body and extends in a circumferential direction of the second body. The first roller and the second roller are arranged in parallel, a gap for allowing an electrode plate to pass is formed between the first roller and the second roller, the protrusion is positioned corresponding to the groove, and the protrusion is configured to press against an uncoated region of the electrode plate to cause a plastic deformation of the uncoated region.