Welding device and electrode assembly manufactured using the welding device

An electrode assembly comprising:

• a first electrode;
• a second electrode;
• and
• a separator disposed between the first electrode and the second electrode,
• wherein at least one of the first electrode or the second electrode comprises:
• an electrode substrate comprising an insulation layer;
• a first metal layer disposed on a first surface of the insulation layer, the first metal layer comprising a first metal layer non-coated portion where no active material is provided;
• a second metal layer disposed on a second surface of the insulation layer, the second metal layer comprising a non-coated second metal layer portion where no active material is provided;
• the electrode substrate having a first electrode mixture layer formed on a first metal layer part of the first metal layer on which the active material is applied;
• and
• the electrode substrate having a second electrode mixture layer formed on a second metal layer part of the second metal layer on which the active material is applied;
• a first substrate tab extending in a first direction from a first point on the first metal layer non-coated portion;
• and
• a second substrate tab extending in the first direction from a second point on the second metal layer non-coated portion, the second substrate tab facing the first substrate tab,
• wherein only a part of a region between the first substrate tab and the second substrate tab is welded.