Abstract: A rechargeable battery includes an electrode assembly having a first electrode, a separator, and a second electrode; a case accommodating the electrode assembly; an electrode terminal; a first current collecting plate connecting the first electrode to the electrode terminal; a vent plate; a second current collecting plate connecting the second electrode to a beading portion of the case at an inner side of the vent plate; and a gasket between the second collecting plate and the vent plate and between the second collecting plate. The second current collecting plate includes a base portion on the second electrode, a bottom welding portion extending in a radial direction from the base portion and welded to the second electrode, and a wing welding portion spaced apart from the bottom welding portion and connected to the base portion by an elastic portion and welded to the beading portion.

Abstract: A rechargeable battery includes: an electrode assembly including a first electrode, a separator, and a second electrode; a case containing the electrode assembly; an electrode terminal in a first opening at a side of the case, the electrode terminal insulated from the case; a first current collector plate connecting the first electrode to the electrode terminal; a bent plate sealing a second opening at another side of the case; a second current collector plate connecting the second electrode to a beading portion of the case inside the bent plate; and a gasket between the second current collector plate and the bent plate and between the bent plate and the case to seal the case with a crimping portion connected to the beading portion.

Abstract: A secondary battery includes: a cylindrical can; an electrode assembly accommodated in the cylindrical can with an electrolyte; and a cap assembly sealing the cylindrical can. The cap assembly includes a cap-up having a terminal portion, a bent portion downwardly bent from the terminal portion, and an extending portion outwardly extending from the bent portion. The terminal portion has a smaller thickness than the extending portion, and a top-end height of the terminal portion of the cap-up is equal to or less than that of the cylindrical can.

Abstract: A secondary battery includes an electrode assembly, a case accommodating the electrode assembly, and a cap assembly coupled to a top portion of the case. The cap assembly includes a cap-up, a safety vent under the cap-up, a cap-down under the safety vent, an insulator between the safety vent and the cap-down, and a sub-plate on a bottom surface of the cap-down. Laser patterns formed by using a laser beam are on a bottom surface of the safety vent and a top surface of the cap-down.

Abstract: A separator includes a porous base, and a first coating layer on a surface of the porous base, the first coating layer including a (meth)acrylic acid ester-based polymer having a glass transition temperature of about 10° C. to about 60° C. The first coating layer may be positioned opposite to a cathode of the lithium secondary battery. The separator may further include a second coating layer on a surface of the porous base opposite to the first coating layer and comprising a (meth)acrylic acid ester-based polymer.

Abstract: A secondary battery includes a cylindrical can; an electrode assembly accommodated in the cylindrical can with an electrolyte; a cap assembly sealing the cylindrical can, a top-end height of the cap assembly being equal to or less than a top-end height of the cylindrical can; and an insulation layer on a surface of the cap assembly that is exposed to the outside of the cylindrical can.

Abstract: A secondary battery includes an electrode assembly, a case accommodating the electrode assembly, and a cap assembly coupled to a top portion of the case. The cap assembly includes a cap-up, a safety vent under the cap-up, a cap-down under the safety vent, an insulator between the safety vent and the cap-down, and a sub-plate on a bottom surface of the cap-down. Laser patterns formed by using a laser beam are on a bottom surface of the safety vent and a top surface of the cap-down.

Abstract: A secondary battery includes: a cylindrical can; an electrode assembly accommodated in the cylindrical can with an electrolyte; and a cap assembly sealing the cylindrical can. The cap assembly includes a cap-up having a terminal portion, a bent portion downwardly bent from the terminal portion, and an extending portion outwardly extending from the bent portion. The terminal portion has a smaller thickness than the extending portion, and a top-end height of the terminal portion of the cap-up is equal to or less than that of the cylindrical can.

Abstract: A secondary battery includes a cylindrical can; an electrode assembly accommodated in the cylindrical can with an electrolyte; a cap assembly sealing the cylindrical can, a top-end height of the cap assembly being equal to or less than a top-end height of the cylindrical can; and an insulation layer on a surface of the cap assembly that is exposed to the outside of the cylindrical can.

Abstract: A separator includes a porous base, and a first coating layer on a surface of the porous base, the first coating layer including a (meth)acrylic acid ester-based polymer having a glass transition temperature of about 10° C. to about 60° C. The first coating layer may be positioned opposite to a cathode of the lithium secondary battery. The separator may further include a second coating layer on a surface of the porous base opposite to the first coating layer and comprising a (meth)acrylic acid ester-based polymer.