Patent ID: 7867644
Filing Date: 2011-01-11
Classification: H01M,Y02E,Y02P,Y10T

Abstract:
1. A secondary battery with a structure in which a wound assembly formed by winding a positive electrode and a negative electrode with a separator interposed therebetween is received in a battery container along with an electrolyte and in which electricity which is charged in and discharged from the wound assembly can be taken from positive and negative electrode terminals to an outside, wherein a positive or negative metal foil protrudes from at least an end of the wound assembly and a current collecting plate is welded to the edge of the protruding metal foil, and wherein said current collecting plate is provided, before a welding operation, with recessed portions on a surface at a side opposite to a side facing said wound assembly, convex portions between said recessed portions on the surface at the side opposite to a side facing said wound assembly, and a flat surface at the side facing said wound assembly; and, by welding, is provided with welded portions which are formed from said convex portions being melted by heating said convex portions from the side of said current collecting plate opposite to the side facing said wound assembly so as to weld the melted portions to the edge of said protruding metal foil.