| 摘要 |
PURPOSE: To hold constant the strength at which leads are welded to the inner bottom surface of an outer can by applying a solid-generated laser beam to the welded portions of the laser-beam lead and the inner bottom surface of the outer can after testing the laser once or more. CONSTITUTION: A sheet-shaped positive electrode 1 and negative electrode 2 are wound into a spiral shape with separators 3 between to fabricate a group of electrodes 5 having a center space 4, from which electrode leads are extended. Next, a laser beam is oscillated from a YAG laser oscillator 8, is passed through an optical fiber 9, focused by a convex lens 10, and irradiated to the center 7a of the bottom of an outer can 7 from outside so that the negative lead 2a is welded in place using a predetermined welding energy. In this case, the laser beam is irradiated to the welded part after one test or more. Then the positive lead 1a is welded to a sealing cover, an electrolyte is injected into the outer can 7, and then the sealing cover is mounted on the upper opening of the outer can 7 to seal the can to fabricate a lithium battery. |
