Patent ID: 7588858

Claim:
A method of manufacturing a weldment, the method comprising: providing a pedestal to support two or more objects being welded, the pedestal having a plurality of layers stacked on top of each other, the plurality of layers including (a) a support layer having an upper support surface and made of a refractory metal with a melting point higher than melting points of the two or more objects being welded, (b) a heat release layer with thermal conductivity higher than that of the support layer, and (c) an adherence layer spacing the support layer from the heat release layer; providing a lithium-ion secondary battery cell having an aluminum-laminate film coating and a solid polymer electrolyte, the secondary battery cell capable of charging and discharging electricity; connecting a plate electrode to the secondary battery cell to conduct electricity during charging and discharging; and welding metal plates to the electrode by performing electric resistance welding by pressing a welding rod, the metal plates having a melting point higher than that of the electrode or which are thicker than the electrode and have the same melting point, wherein, the electrode is made of aluminum or an aluminum base alloy, and the metal plates are made of nickel or a nickel base alloy, and at least one of the metal plates is welded to each of an upper and lower side of the electrode, and one end of at least one of the metal plates is welded to the electrode and the other end thereof is formed in a shape having an external connection terminal.