Secondary battery
A secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a can having a closed upper surface with a rivet opening therein and an open lower surface to accommodate the electrode assembly, the can being electrically connected to the first electrode plate; a rivet terminal in the rivet opening and electrically connected to the second electrode plate; a gasket between the can and the rivet terminal; and a cap plate sealing the lower surface of the can.
1 . A secondary battery comprising:
an electrode assembly comprising a first electrode plate, a second electrode plate, and a separator;
a can having a closed upper surface with a rivet opening therein and an open lower surface to accommodate the electrode assembly, the can being electrically connected to the first electrode plate;
a rivet terminal in the rivet opening and electrically connected to the second electrode plate;
a first gasket between the can and the rivet terminal;
a cap plate sealing the lower surface of the can; and
a second gasket between the cap plate and the can to electrically insulate the cap plate and the can,
wherein the cap plate has a protruding portion and a recessed portion around the protruding portion, and
wherein the cap plate comprises a safety vent or a degassing structure in the recessed portion of the cap plate.
2 . The secondary battery of claim 1 , wherein the rivet terminal comprises:
a shaft extending through the rivet opening;
a first flange extending radially outwardly from an upper end of the shaft; and
a second flange extending radially outwardly from a lower end of the shaft.
3 . The secondary battery of claim 2 , wherein the first gasket comprises:
a first member between the upper surface of the can and the first flange;
a second member between the upper surface of the can and the second flange; and
a third member between the rivet opening and the shaft.
4 . The secondary battery of claim 3 , further comprising a reinforcement plate having higher rigidity than the rivet terminal and between the second flange and the second member.
5 . The secondary battery of claim 2 , wherein the ratio of a diameter of the first flange to a diameter of the upper surface of the can is in a range of 10% to 65%.