Secondary battery

1. A secondary battery, comprising:

a case;

an electrode assembly including a positive electrode, a negative electrode, and a separator interposed therebetween, the electrode assembly being arranged within the case;

a cap assembly affixed to the case and adapted to seal the case, the cap assembly being electrically connected to the electrode assembly; and

a pair of current collecting plates adapted to be respectively electrically connected to the positive and negative electrodes;

wherein each electrode includes an un-coated region absent an active material, the un-coated region of each electrode contacting its respective current collecting plate; and

wherein each un-coated region includes a plurality of independent regions separated from one other, the plurality of independent regions being bent and affixed to their respective current collecting plate,

wherein the independent regions comprise convex and concave portions arranged in a line end of their respective un-coated region in a longitudinal direction of the un-coated region.

2. The secondary battery of claim 1 , wherein the widths of the independent regions become gradually wider from one side of the respective electrode to the other side of the electrode in the longitudinal direction of the electrode.

3. The secondary battery of claim 2 , wherein the widths of the independent regions are narrower in a central area of the electrode assembly than in an outer part of the electrode assembly.

4. The secondary battery of claim 1 , wherein the convex portions comprise an angled shape.

5. The secondary battery of claim 1 , wherein the convex portions comprise a round shape.