| 摘要 |
PURPOSE:To obtain a flat cell with a high heavy load voltage at a low temperature and high reliability by directly welding the inner bottom surface of a positive electode can and the lower surface of a positive electrode black mix contacting with the inner bottom surface. CONSTITUTION:When a positive electrode can 1 is freely coupled with a hollow cylindrical body 11, a plurality of lugs le provided on the positive electrode can 1 is brought into contact with the lower surface 2a of a positive electrode black mix 2. A voltage is applied across a circular pillar 10 and a positive electrode can reception jig 12 while a force is applied between the positive electrode can 1 and the positive electrode black mix 2 at the existing position when all lugs le are concurrently brought into contact with the lower surface 2a, and with non-contact points left as they are even when the lower surface 2a is unable to get into contact with all corresponding lugs le simultaneously due to some variations of the lugs 13. That is, when a current is made to flow between the circular pillar 10 and the positive electrode can reception jig 12 with a force being applied, the current is focused on the portion of the lug 13, thus being momentarily welded to form a bead 8, and at the same time, the bottom surface 1b of the positive electrode can 1 and the lower surface 2a of the positive electrode black mix are brought near and in contract. The bead 8 is formed with part of the positive electrode black mix 2 in contract with the lug le being melted. |
