Patent ID: 7479347
Filing Date: 2009-01-20
Classification: H01M,Y02E

Abstract:
1. A prismatic battery having an electrode assembly mounted in a prismatic battery case, the prismatic battery comprising: a base plate mounted to an open upper end of the prismatic battery case, the base plate including an electrolyte injection hole having an inside upper end configured to have a downward taper incline structure; and a metal ball disposed within the electrolyte injection hole such that the metal ball is plastically deformed and seals the electrolyte injection hole, wherein the downward taper incline structure has a width corresponding to 5% to 30% and a depth corresponding to 10% to 25% of a radius of the metal ball prior to plastic deformation thereof, and the downward taper incline structure is inclined downward at an angle of 20 to 70 degrees from a surface defining the upper end of the base plate, and wherein an epoxy resin is disposed on the plastically deformed metal ball and the forcibly inserted region.