NOVELTY - A current collection terminal (5) is provided with several convex portions (51) from inner side in end surface of electric power generation element. The welding components (511) with openings (510) at lower ends (513) are formed by convex portions. The welding component is formed with specific thickness, such that the thickness of lower end side of convex portion is greater that that at the side of vertex (512). The positive and negative electrode collectors are exposed to end surface of power generation element, and are inserted into opening of convex portions.    USE - Battery e.g. lithium ion secondary battery mounted in vehicle such as motor vehicle. Can also be used in nickel-hydrogen battery and nickel cadmium battery.    ADVANTAGE - The exposed portions of the collector of the electric power generation element, and the occupancy portion of the collector which is not concerned in charging or discharging of battery are reduced, thus the energy density of the battery is improved. The thickness of lower end side of convex portion is greater that that at the side of vertices, thus the generation of perforation at the time of welding is prevented. The battery with high internal resistance and large tensile strength can be formed reliably. The amount of metal melted by the current collection terminal can be fully supplied to the clearance between collectors, as the clearance space is enlarged. The collectors can be inserted easily in the opening portion of convex portions, as the angle at the side of opening of vertex of convex portion is reduced. The generation of crack in the front-end of welding component at the time of press molding can be prevented by providing the folding point in the welding component. The junction of the collector and the current collector terminal can be increased by providing several convex portions in the collector terminal, thus the welding strength of the welding component is increased. The resistance between electric power generation element and positive electrode collector is reduced, thus the heavy current can be charged and discharged effectively.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the positive-electrode current collection terminal.    Positive-electrode current collection terminal (5)    Convex portion (51)    Opening of welding component (510)    Welding component (511)    Vertex of convex portion (512)    Lower end of convex portion (513)