Method of manufacturing prismatic battery

Abstract

A prismatic battery with highly reliable sealing properties and its manufacturing method, wherein a negative collector is welded to one end of an electrode plate group accommodated in a prismatic case, the collector being connected to an electrode pole that functions as the negative electrode terminal, and the electrode pole is fitted into a support cylinder that is provided on an upper lid for closing one open end of the case. An insulating gasket is interposed between an inner periphery of the support cylinder and an outer periphery of the electrode pole, the support cylinder being formed with at least one annular crimped portion that has an arc-shaped longitudinal cross section.

1 . A method for manufacturing a prismatic battery comprising:
 preparing an electrode plate group;   welding a current collector to at least one end of the electrode plate group;   hermetically welding a first lid to one open end of a prismatic case having open ends, the first lid including an electrode terminal provided with an insulating member;   inserting the electrode plate group into the case from the other open end thereof; and   hermetically welding a second lid to the other open end of the case, the second lid being connected to the other end of the electrode plate group.   
   
   
       2 . The method for manufacturing a prismatic battery according to  claim 1 , wherein said hermetically welding the first and second lids to open ends of the case includes:
 fitting the lid that has a generally planar shape conforming to an inner periphery of the open end of the case and a skirt protruding from an outer peripheral edge of the lid to the outside of the case; and   projecting a laser beam from an inner side of the skirt of the lid toward the edge of the skirt to fuse together the open end edge of the case and the edge of the skirt.   
   
   
       3 . The method for manufacturing a prismatic battery according to  claim 1 , wherein the second lid is a current collector and is welded to the other end of the electrode plate group prior to said inserting the electrode plate group into the case. 
   
   
       4 . The method for manufacturing a prismatic battery according to  claim 1 , further comprising:
 forming a support cylinder in the first lid for closing the one open end of the case;   welding an electrode pole serving as one electrode terminal to the current collector welded to one end of the electrode plate group, wherein the electrode pole is fitted in the support cylinder;   mounting an insulating gasket to the electrode pole prior to said inserting the electrode plate group into the case; and   compressing the insulating gasket by crimping the support cylinder to provide a seal between the electrode pole and the support cylinder after said inserting the electrode plate group into the case.   
   
   
       5 . The method for manufacturing a prismatic battery according to  claim 1 , further comprising:
 fixedly attaching an electrode pole that functions as one electrode terminal of one polarity to the current collector of the same polarity via a buffer;   welding the current collector of the one polarity to one end of the electrode plate group;   assembling an insulating frame that covers at least an outer periphery of the current collector welded to the electrode plate group and an exposed portion of electrode core material at one end of the electrode plate group; and   assembling an insulating gasket that fits onto the electrode pole and a cover that covers the buffer.   
   
   
       6 . The method for manufacturing a prismatic battery according to  claim 2 , wherein the second lid is a current collector and is welded to the other end of the electrode plate group prior to said inserting the electrode plate group into the case.