Patent ID: 8187743

Claim:
A secondary battery comprising: an upper battery assembly comprising an electrically conductive upper can housing a cap unit having an electrode terminal adapted to electrically connect to an external device and a gasket inserted between the cap unit and one end portion of the upper can for sealing and insulating the cap unit and the upper can; a lower battery assembly comprising an electrically conductive lower can housing an electrode assembly, the electrode assembly comprising a first electrode, a second electrode, and a separator between the first electrode and the second electrode for preventing a short circuit between the first electrode and the second electrode, the first electrode being connected to the cap unit and the second electrode being connected to the lower can, wherein the electrically conductive upper can and the electrically conductive lower can are fixed in direct contact with each other at an overlapping region between a portion of the electrically conductive upper can and a portion of the electrically conductive lower can, and the electrically conductive upper can and the electrically conductive lower can are fixed without a bead formed at the overlapping region; an upper insulation plate on and adjacent to an upper end of the electrode assembly; and a first electrode tap extending from the upper end of the electrode assembly, the first electrode tap being bent once to form a single bent portion, wherein a first side of the single bent portion contacts a surface of the upper insulation plate, and a second side of the single bent portion opposite to the first side contacts the cap unit to electrically connect the first electrode to the cap unit, and wherein an end of the lower battery assembly is in contact with the gasket.