Patent ID: 7754378

Claim:
A secondary battery, comprising: an electrode assembly including positive and negative electrode plates; a can adapted to contain the electrode assembly and an electrolyte; a cap assembly including a cap plate having an electrolyte injection hole arranged on a side thereof and adapted to seal an opening of the can; a protective circuit module electrically coupled to the cap assembly; a sealing plate arranged on a surface of the cap plate and adapted to seal the electrolyte injection hole; and a welded portion welding said sealing plate to said cap plate and forming a complete circle entirely surrounding said electrolyte injection hole, wherein an inner side of said welded portion is spaced at least 0.1 mm from said electrolyte injection hole, wherein the sealing plate extends along a longitudinal direction, and wherein one side of the sealing plate is welded to the electrolyte injection hole, and wherein an electrode tab of the protective circuit module is connected to another side thereof.