Cylindrical Battery With Enhanced Sealing

A method for sealing a cylindrical battery comprising:

• bending an upper part of a cylindrical can to form a crimped portion wrapping around an outer periphery of a gasket, the gasket interposed between the cylindrical can and a cap assembly mounted to an opening of the cylindrical can, the cylindrical can having an electrode assembly received therein;
• and
• further bending an end of the crimped portion into the gasket to form a bent portion,
• wherein a length of the bent portion is less than 0.175 mm.

A crimping apparatus for crimping an upper part of a cylindrical can of a cylindrical battery to form a crimped portion configured to wrap around an outer periphery of a gasket, the crimping apparatus comprising:

• three jaws configured to fix a cylindrical side surface of the cylindrical can;
• at least one crimping unit configured to stepwise crimp the cylindrical battery;
• and
• a final crimping unit configured to crimp the cylindrical battery,
• wherein
• the final crimping unit is configured such that a length of a bent portion obtained as a result of the final crimping unit further bending an end of the crimped portion into the gasket is less than 0.175 mm.