for covering a lower space of the cylindrical side wall the can 10 further includes depressions 19 on the side surface the depressions 19 have a surface in contact with an outer side surface of the electrode assembly 20 to prevent movement of the electrode assembly 20 inside the can 10 the depressions 19 will be described in greater detail with reference to fig3 a to 4e the electrode assembly 20 is inserted into the can through the opening of the can 10 the bottom surface of the electrode assembly is covered with a lower insulating plate 11 prior to the insertion of the electrode assembly 20 and the electrode tab 29 extending downward from the electrode assembly 20 is bent to be parallel with the bottom surface of the can 10 while bypassing an outer side of the lower insulating plate 11 in one exemplary embodiment the electrode assembly 20 is a cylindrical jelly roll which has a central hollow the lower insulating plate 11 has a hole in an area corresponding to i e aligned with the hollow of the electrode assembly 20 and a portion of the bent electrode tab 29 crosses the hole of the lower insulating plate 11 a welding rod is inserted from through the hollow of the electrode assembly to weld the electrode tab 29 crossing the central hole to the bottom surface of the can 10 accordingly the can 10 has the same polarity as the lower electrode tab 29 so that the can itself serves as one electrode terminal in another exemplary embodiment a central pin 13 may be provided to the can 10 and coupled in the.