NOVELTY - Cylinder type secondary battery comprises a can having an opening; an electrode assembly in the can; a cap assembly covering the opening of the can; an upper insulating plate between the electrode assembly and the cap assembly; a support plate on the upper insulating plate; the support plate having a peripheral edge; and a first electrode tab extending from the electrode assembly, the first electrode tab having a first section contacting the support plate, a second section contacting the cap assembly, and a bent section between the first section and the second section.    USE - The cylinder type secondary battery is useful for compact and lightweight mobile electronic/electric appliances such as cellular phones, notebook computers, and camcorders. It can also be used for high-output products such as hybrid automobiles, and power tools.    ADVANTAGE - The invention provides cylinder type secondary battery capable of preventing stress concentration on bent portion of electrode tab.    DETAILED DESCRIPTION - Cylinder type secondary battery comprises a can having an opening; an electrode assembly in the can; a cap assembly covering the opening of the can; an upper insulating plate between the electrode assembly and the cap assembly; a support plate on the upper insulating plate; the support plate having a peripheral edge, where an area of the support plate is smaller than an area of the upper insulating plate; and a first electrode tab extending from the electrode assembly, the first electrode tab having a first section contacting the support plate, a second section contacting the cap assembly, and a bent section between the first section and the second section, where a portion of the bent section protrudes from the peripheral edge of the support plate; or cylinder type secondary battery comprises a can having an opening; an electrode assembly in the can; a cap assembly covering the opening of the can; an upper insulating plate between the electrode assembly and the cap assembly, the upper insulating plate including a central section and a peripheral section surrounding the central section, where the central section has a peripheral edge and where a thickness of the central section is greater than a thickness of the peripheral section; and a first electrode tab extending from the electrode assembly, the first electrode tab having a first section contacting the central section of the upper insulating plate, a second section contacting the cap assembly, and a bent section between the first section and the second section, where a portion of the bent section is adjacent to and overlaps the peripheral edge of the central section; or cylinder type secondary battery comprises a can having an opening; an electrode assembly in the can; a cap assembly covering the opening of the can; an upper insulating plate between the electrode assembly and the cap assembly; a support plate on the upper insulating plate; the support plate having a peripheral edge, where an area of the support plate is smaller than an area of the upper insulating plate; and a first electrode tab extending from the electrode assembly, the first electrode tab having a first section contacting the support plate, a second section contacting the cap assembly, and a bent section between the first section and the second section, where an outer radius of curvature of the bent portion is from about 0.5 mm to about 0.6 mm. An INDEPENDENT CLAIM is a method of assembling cylinder type secondary battery comprising inserting an electrode assembly into a can having an opening, the electrode assembly including a first electrode tab extending from the electrode assembly; placing an upper insulating plate on the electrode assembly; placing a support plate on the upper insulating plate, the support plate having a substantially planar surface and a peripheral edge, where an area of the support plate is smaller than an area of the upper insulating plate; configuring a first section of the first electrode tab to extend substantially parallel to the substantially planar surface of the upper insulating plate; bending a second section of the first electrode tab to extend substantially parallel to the first section of the first electrode tab and to form a bent section between the first section and the second section; covering the opening of the can with a cap assembly such that the second section of the first electrode tab contacts the cap assembly; forming a bead portion around a periphery of the can such that the bead portion contacts the upper insulating plate; and pressing the cap assembly to move the cap assembly toward the electrode assembly such that a portion of the bent section moves closer to the electrode assembly and next to the peripheral edge of the support plate.