Patent ID: 6730438
Filing Date: 2004-05-04
Classification: H01M,Y02E,Y02P,Y10T

Abstract:
A nonaqueous electrolyte secondary cell comprising an electrode unit (2) encased in a battery can and comprising a positive electrode (23) and a negative electrode (21) each in the form of a strip and a separator (22) interposed between the electrodes, the cell being adapted to deliver electric power generated by the electrode unit (2) to the outside via a positive terminal portion and a negative terminal portion which are provided on the container, a negative electrode current collector plate (3) comprising a plurality of layers including a copper layer (31) made of copper or an alloy consisting predominantly of copper, and a metal layer made of a metal not forming an intermetallic compound with lithium and having a lower laser beam reflectivity than copper or an alloy consisting predominantly of the metal, the copper layer (31) and the metal layer forming opposite surface layers of the collector plate (3), the copper layer (31) being welded to an edge of the negative electrode (21) projecting at one of opposite ends of the electrode unit (2) in the direction of a winding axis thereof, and the negative electrode current collector plate (3) being electrically connected to the negative terminal portion.