US Patent 7981542 Rechargeable battery

A rechargeable battery including: an electrode assembly; a can to house the electrode assembly; and a cap assembly to seal an opening of the can. The cap assembly includes: a cap plate; an insulation plate disposed upon a lower surface of the cap plate; a terminal plate disposed upon a lower surface of the insulation plate; and an electrode terminal extending through the cap plate, the insulation plate and the terminal plate, and which is electrically coupled to the electrode assembly. The cap plate includes a seat part defined therein, which has a thickness that is less than an overall thickness of the cap plate. The insulation plate is seated in the seat part, which has a width is the same as an overall width of the cap plate.