| 摘要 |
A secondary battery has an electrode laminated body and a collector member. The laminated body is formed of a laminated electrode sheet. The collector member is bonded to a collector foil laminated portion of the electrode sheet not formed with an active material layer. The collector foil laminated portion and the collector member are bonded at overlapped portions by resistance welding using electrodes. When a pressure welding direction is a projection direction, an area ratio (Yd)/(Xd) is 1.2-4, in which Xd is a projection area of a surface of the electrode made contact with the collector foil laminated portion and Yd is a projection area of a surface of the electrode made contact with the collector member. |
