Electrode assembly and secondary battery including the same

An electrode assembly comprising:

• a separator;
• and
• an electrode that is wound with the separator therebetween, and comprises an electrode current collector comprising a coated region and an uncoated region, and an active material layer formed on the coated region of the electrode current collector,
• wherein the uncoated region comprises a tab region including protrusions that extend in a direction perpendicular to the winding direction of the electrode and parallel to the coated region,
• wherein the tab region comprises a first tab region and a second tab region, which are adjacent to each other, and the protrusions comprise first protrusions included in the first tab region and second protrusions included in the second tab region, and
• wherein the first tab region is disposed closer to a winding start part of the electrode assembly than the second tab region, and a width of each of the first protrusions is greater than that of each of the second protrusions.