Abstract: A steel sheet for a battery case includes about 0.02 wt % to about 0.08 wt % carbon (C); about 0.01 wt % to about 0.1 wt % niobium (Nb); and the balance of iron (Fe). Further aspects provide for a battery case manufactured from the steel sheet for a battery case and provided with an opening. Further aspects provide for a cylindrical secondary battery comprising a cylindrical case manufactured from the steel sheet for a battery case, a cap assembly sealing the cylindrical case, and an electrode assembly disposed inside the cylindrical case.

Abstract: A secondary battery includes: an electrode assembly including: a first electrode plate; a second electrode plate; and a separator between the first electrode plate and the second electrode plate; a case configured to accommodate the electrode assembly; a cap assembly electrically connected to the second electrode plate of the electrode assembly; and an insulator coupled to an upper side of the electrode assembly, wherein the insulator includes: an insulating upper portion configured to cover the upper side of the electrode assembly; an insulating side portion between the case and a side portion of the electrode assembly; and an insulating core portion inserted into a hollow portion of the electrode assembly to support the electrode assembly.

Abstract: A secondary battery includes: an electrode assembly; a case including an opening and accommodating the electrode assembly; a cap assembly sealing the opening of the case and having a valve hole formed therein; and a valve vertically movably installed in the valve hole and selectively openable and closeable, to allow an internal gas to be discharged.

Abstract: The present invention relates to a cylindrical lithium ion secondary battery which, when an upper end of a cylindrical can is clamped, can prevent deformation of a cap assembly so as to improve safety. For an example, a cylindrical lithium ion secondary battery is disclosed, the battery comprising: a cylindrical can; an electrode assembly received in the cylindrical can; and a cap assembly for sealing the cylindrical can, wherein: the cap assembly comprises a top plate having a notch formed thereon, a support plate disposed in close contact with a lower surface of the top plate and including a first through-hole formed through the center thereof, and a bottom plate electrically connected with the electrode assembly and connected to the lower surface of the top plate through the first through-hole; and the support plate has a strength greater than a strength of the top plate.

Abstract: An embodiment of the present invention relates to a cylindrical secondary battery comprising: a cylindrical can having one opened end to form an opening; an electrode assembly accommodated in the cylindrical can; and a cap assembly including a vent plate which is disposed on the outermost side in the direction away from the opening and which has at least one notch, a cap down which is disposed to be spaced apart from the vent plate in the direction of the opening and which is electrically connected to the electrode assembly, a support plate which is disposed between the vent plate and the cap down so as to be coupled to the vent plate, and an insulating member which is inserted between the support plate and the cap down to insulate the support plate and the cap down from each other, wherein, when the gas inside the can is discharged toward the opening, the vent plate is ruptured to be separated from the cap assembly.

Abstract: The present invention relates to a cylindrical lithium ion secondary battery which, when an upper end of a cylindrical can is clamped, can prevent deformation of a cap assembly so as to improve safety. For an example, a cylindrical lithium ion secondary battery is disclosed, the battery comprising: a cylindrical can; an electrode assembly received in the cylindrical can; and a cap assembly for sealing the cylindrical can, wherein: the cap assembly comprises a top plate having a notch formed thereon, a support plate disposed in close contact with a lower surface of the top plate and including a first through-hole formed through the center thereof, and a bottom plate electrically connected with the electrode assembly and connected to the lower surface of the top plate through the first through-hole; and the support plate has a strength greater than a strength of the top plate.

Abstract: The present disclosure provides a secondary battery capable of increasing an operation time till a breakdown of a safety vent at a high temperature environment. As an example, disclosed is a secondary battery comprising: a can having a space therein; an electrode assembly accommodated in the space of the can; and a cap assembly for sealing the electrode assembly by blocking the can, wherein the cap assembly comprises a cap-up, a cap-down under the cap-up, and a safety vent between the cap-up and the cap-down, wherein the safety vent comprises a support protrusion formed on a contact surface coupled to the cap-up.

Abstract: A secondary battery includes: a cylindrical case; an electrode assembly in the cylindrical case; and a cap plate electrically connected to the electrode assembly and sealing the cylindrical case. The cap plate has a first flat portion at a center of the cap plate, a second flat portion outside the first flat portion, and a vent portion between the first flat portion and the second flat portion, and the vent portion has a thickness smaller than a thickness of the first flat portion or a thickness of the second flat portion.

Abstract: A secondary battery includes: a cylindrical case; an electrode assembly in the cylindrical case; and a cap assembly configured to seal the cylindrical case and including a cap-down electrically connected to the electrode assembly, a cap-up coupled to an upper portion of the cap-down, and a vent plate between the cap-down and the cap-up, wherein the vent plate includes: a first plate; and a second plate coupled to the outside of the first plate, wherein the first plate has rigidity less than that of the second plate.

Abstract: Provided is a cylindrical secondary battery. The cylindrical secondary battery includes a cylindrical can, an electrode assembly in which a first electrode plate, a second electrode plate, and a separator are wound and which is accommodated in the can, and a cap assembly which is insulated from the can and electrically connected to the electrode assembly and through which a degassing hole passes to communicate with the inside of the can. According to the embodiment, since a degassing function is applied to remove the gas generated before the product shipment, deformation of the can and the cap assembly may be reduced. In addition, swelling of the electrode assembly due to the generation of the internal gas may be prevented from occurring to reduce performance deterioration of the secondary battery.

Abstract: An embodiment of the present invention relates to a secondary battery, and a technical issue to address is to provide a secondary battery having excellent stability. To this end, disclosed is a secondary battery, comprising: an electrode assembly; a can which accommodates the electrode assembly and an electrolyte, and has a beading part formed above the electrode assembly; a cap assembly for sealing the can; and an adsorption member which is disposed in a space including at least a gap between the electrode assembly and the beading part, and which reacts with the electrolyte after a specific time period lapses after coming into contact with the electrolyte, thereby adsorbing the electrolyte.

Abstract: A secondary battery includes: an electrode assembly; a case including an opening and accommodating the electrode assembly; a cap assembly sealing the opening of the case and having a valve hole formed therein; and a valve vertically movably installed in the valve hole and selectively openable and closeable, to allow an internal gas to be discharged.

Abstract: Various embodiments of the present invention relate to a secondary battery, wherein a technical problem to be solved is to provide a secondary battery capable of maintaining an electrical insulating state between a case (can) and a cap assembly even after a gasket is melted due to short-circuiting and heat generation. To this end, the present invention provides a secondary battery comprising: a cylindrical can; an electrode assembly received, along with an electrolyte, in the cylindrical can; a cap assembly for sealing the cylindrical can; and a gasket interposed between the cylindrical can and the cap assembly, wherein the gasket further includes an insulating member having a melting temperature higher than a melting temperature of the gasket.

Abstract: The present invention provides a cylindrical secondary battery which can have increased safety and capacity, and enhanced scratch resistance and pressure resistance on an external contact surface. To this end, a cylindrical secondary battery is disclosed, the battery comprising: a cylindrical case; an electrode assembly received in the case; and a cap assembly for sealing the case, wherein the cap assembly comprises a top plate having a notch formed on at least one surface thereof, a middle plate coupled to the top plate and including a first through-hole formed through the center thereof, and a bottom plate electrically connected with the electrode assembly and coupled to the top plate through the first through-hole of the middle plate, and includes a surface-treated region formed by surface-treating a surface of the top plate so as to have a concave-convex structure.

Abstract: The present invention relates to a secondary battery capable of improving insulation safety. For example, the secondary battery includes: an electrode assembly; a case configured to accommodate the electrode assembly; and a cap assembly coupled to an upper portion of the case, wherein the cap assembly includes a cap-up, a safety vent installed below the cap-up and having a vent extension part extending to an upper side of the cap-up to surround an edge of the cap-up, and an insulation washer attached to upper portions of the vent extension part and the cap-up, and a welding area having a thickness less than that of surroundings is formed on the vent extension part.

Abstract: The present invention relates to a cylindrical lithium ion secondary battery which, when an upper end of a cylindrical can is clamped, can prevent deformation of a cap assembly so as to improve safety. For an example, a cylindrical lithium ion secondary battery is disclosed, the battery comprising: a cylindrical can; an electrode assembly received in the cylindrical can; and a cap assembly for sealing the cylindrical can, wherein: the cap assembly comprises a top plate having a notch formed thereon, a support plate disposed in close contact with a lower surface of the top plate and including a first through-hole formed through the center thereof, and a bottom plate electrically connected with the electrode assembly and connected to the lower surface of the top plate through the first through-hole; and the support plate has a strength greater than a strength of the top plate.

Abstract: Various embodiments of the present invention relate to a cylindrical lithium ion secondary battery. A problem to be solved is to provide a cylindrical lithium ion secondary battery which, when internal gas pressure is larger than predetermined first reference pressure (operating pressure) and is smaller than predetermined second reference pressure (breaking pressure) during overcharging, can maintain an internal sealing while a current path is blocked by a cap assembly.

Abstract: Disclosed is a secondary battery comprising: an electrode assembly including a first electrode, a second electrode, and a separator interposed therebetween; a can in which the electrode assembly and an electrolyte are received; a cap assembly for sealing the can; and a washer disposed between the can and the can assembly and including at least one moisture-blocking film layer and reinforcing film layer.

Abstract: The present invention provides a cylindrical secondary battery which can have increased safety and capacity, and enhanced scratch resistance and pressure resistance on an external contact surface. To this end, a cylindrical secondary battery is disclosed, the battery comprising: a cylindrical case; an electrode assembly received in the case; and a cap assembly for sealing the case, wherein the cap assembly comprises a top plate having a notch formed on at least one surface thereof, a middle plate coupled to the top plate and including a first through-hole formed through the center thereof, and a bottom plate electrically connected with the electrode assembly and coupled to the top plate through the first through-hole of the middle plate, and includes a surface-treated region formed by surface-treating a surface of the top plate so as to have a concave-convex structure.

Abstract: Various embodiments of the present invention relate to a secondary battery, wherein a technical problem to be solved is to provide a secondary battery capable of maintaining an electrical insulating state between a case (can) and a cap assembly even after a gasket is melted due to short-circuiting and heat generation. To this end, the present invention provides a secondary battery comprising: a cylindrical can; an electrode assembly received, along with an electrolyte, in the cylindrical can; a cap assembly for sealing the cylindrical can; and a gasket interposed between the cylindrical can and the cap assembly, wherein the gasket further includes an insulating member having a melting temperature higher than a melting temperature of the gasket.