Sealed secondary battery, and method for manufacturing the battery

摘要

An electrode group 4 formed by stacking or winding a positive electrode plate 1 and a negative electrode plate 2 with a separator 3 interposed therebetween, is housed in a battery case 5. An opening of the battery case 5 is sealed with a sealing plate 10. A lead 11 extending from one of the positive and negative electrode plates in the electrode group 4 is laser-welded to the sealing plate 10 by application of a laser beam 12 having a spot diameter smaller than a thickness of the lead 11.