A method for cleaning the surface of a metal wire (2) or a metal strip, in particular of a metal wire (2) or a metal strip used as an intermediate electrode of a roll seam welding machine, wherein the metal wire (2) or the metal strip is guided under tensile stress in the longitudinal direction of the wire or the strip along a plurality of wiping bodies (4) arranged at a distance one behind the other in the longitudinal direction of the wire or the strip, in such a way that the wire or the strip sections (5a-5g) each lying between two successive wiping bodies (4) together form a bow-shaped wire section. It has turned out that this enables an intensive and reliable cleaning with constant cleaning quality.

An electrode tab welding device according to an embodiment of the present invention may weld a plurality of electrode tabs of an electrode assembly. The electrode tab welding device may include: a pair of tab guides that gather the plurality of electrode tabs; a pair of aligning rollers that rotate in a direction, in which the outermost electrode tab is pushed toward the electrode assembly, while pressing the plurality of electrode tabs gathered by the pair of tab guides; and a welding part that welds the plurality of electrode tabs, which are aligned by the pair of aligning rollers, to each other.