| 摘要 |
PROBLEM TO BE SOLVED: To provide a cylindrical secondary battery wherein the contact area of the welding projection of a collector housed in the secondary battery is increased although it is inexpensively structured so as to only make a simple shape change, welding strength of a battery case and the collector is improved, and vibration resistance and impact resistance are strengthened, and electric resistance can be reduced. SOLUTION: A group of electrodes 5 formed by spirally winding a belt-like positive electrode plate 1 and a belt like negative electrode plate 2 with a separator 5 interposed between them are housed in the bottomed cylindrical battery case 9 through the collector 8, and the linear welding projection 14 having a straight line shape or a curved shape, which is in the shape of a projecting part, and the outer surface of which is formed by a plane, is provided in the collector 8 bonded to the bottom part in the battery case 9. COPYRIGHT: (C)2008,JPO&INPIT |
