Patent ID: 7799456

Claim:
A rechargeable battery comprising: an electrode assembly including a positive electrode, a negative electrode and a separator between the positive electrode and the negative electrode; a case housing the electrode assembly; a cap assembly sealing the case, the cap assembly including a cap plate having a first surface and a second surface, a positive terminal connected to the positive electrode and a negative terminal connected to the negative electrode; an electrolyte injection opening extending from the first surface to the second surface of the cap plate assembly; a groove in the cap plate and extending around a periphery of the electrolyte injection opening, wherein a height of an outer wall of the groove and a height of an inner wall of the groove are substantially equal; and an electrolyte sealing member engaged with the groove and covering and sealing the electrolyte injection opening, wherein the electrolyte sealing member has a slanted face extending around a circumference of the electrolyte sealing member, wherein a portion of the electrolyte sealing member protrudes from the first surface of the cap plate, wherein the electrolyte sealing member is welded to the cap plate and wherein the electrolyte sealing member and the cap plate are made of substantially the same material.