Cylindrical secondary battery
A cylindrical secondary battery includes: an electrode assembly including a first electrode plate and a second electrode plate; a can having a bottom portion and a cylindrical side portion, accommodating the electrode assembly, and electrically connected to the first electrode plate; and a cap assembly. The cap assembly includes: a cap plate coupled to one end of the side portion of the can and electrically connected to the second electrode plate; a gasket insulating the cap plate and the side portion from each other; and a sub-plate covering at least a portion of the cap plate and at least a top portion of the side portion.
1 . A cylindrical secondary battery comprising:
an electrode assembly comprising a first electrode plate and a second electrode plate;
a can having a bottom portion and a cylindrical side portion, accommodating the electrode assembly, and electrically connected to the first electrode plate; and
a cap assembly comprising:
a cap plate coupled to one end of the side portion of the can and being electrically connected to the second electrode plate;
a gasket insulating the cap plate and the side portion from each other; and
a sub-plate covering at least a portion of the cap plate and at least a top portion of the side portion,
wherein the sub-plate comprises:
a base;
a plurality of extending portions extending outwardly from an outer edge of the base; and
arc-shaped bending portions respectively extending from an end of each of the extending portions in a circumferential direction of the base, and
wherein the bending portions have an arc shape that matches a circumferential shape of the side portion of the can.
2 . The cylindrical secondary battery of claim 1 , wherein the cap assembly further comprises an insulation member comprising an insulating material and being arranged between the sub-plate and the cap plate.
3 . The cylindrical secondary battery of claim 2 , wherein the can has a beading part adjacent an open end of the side portion and being inwardly concavely bent and a crimping part spaced apart from the beading part and being a bent end of the side portion, and
wherein the sub-plate covers at least a portion of the crimping part.
4 . The cylindrical secondary battery of claim 3 , wherein the cap plate comprises a positive electrode terminal protruding outwardly from a plate surface, and
wherein the base is ring-shaped between an outer edge of the positive electrode terminal and a top end of the gasket.
5 . The cylindrical secondary battery of claim 4 , wherein a width or diameter of the base is smaller than a distance between the outer edge of the positive electrode terminal and the top end of the gasket.
6 . The cylindrical secondary battery claim 5 , wherein at least a portion of the base, at least portions of the extending portions, and the bending portions are welded to the can.
7 . The cylindrical secondary battery of claim 1 , further comprising:
a first electrode current collector plate electrically connected to the first electrode plate and electrically connected to the bottom portion; and
a second electrode current collector plate electrically connected to the second electrode plate and electrically connected to the cap plate,
wherein the first electrode plate is a negative electrode plate, and the second electrode plate is a positive electrode plate.