Abstract: A cap assembly for a secondary battery includes: a cap plate; a current interrupt device (CID); a middle plate; and an insulator. The CID includes: a vent plate under the cap plate and including a vent portion protruding downward; and a sub-plate under the vent plate and connected to the vent portion. The middle plate is between the vent plate and the sub-plate and is electrically connected to the vent plate via the sub-plate. The insulator is between the vent plate and the middle plate, and the insulator includes a crosslinked polymer.

Abstract: A negative electrode for a rechargeable lithium battery includes a negative current collector; a negative active material layer on the negative current collector; and a negative electrode tab on an uncoated region of the negative current collector, the uncoated region not having a negative active material coated thereon, wherein the negative electrode tab has a three-layered structure of a nickel layer-copper layer-nickel layer. A rechargeable lithium battery includes the negative electrode.

Abstract: A cap assembly for a secondary battery includes: a cap plate; a current interrupt device (CID); a middle plate; and an insulator. The CID includes: a vent plate under the cap plate and including a vent portion protruding downward; and a sub-plate under the vent plate and connected to the vent portion. The middle plate is between the vent plate and the sub-plate and is electrically connected to the vent plate via the sub-plate. The insulator is between the vent plate and the middle plate, and the insulator includes a crosslinked polymer.

Abstract: A negative electrode for a rechargeable lithium battery includes a negative current collector; a negative active material layer on the negative current collector; and a negative electrode tab on an uncoated region of the negative current collector, the uncoated region not having a negative active material coated thereon, wherein the negative electrode tab has a three-layered structure of a nickel layer-copper layer-nickel layer. A rechargeable lithium battery includes the negative electrode.

Abstract: A center pin for a secondary battery and a secondary battery having the same, which optimizes a void volume of the secondary battery. The center pin is inserted into an electrode assembly of the secondary battery. The center pin has a longitudinal hole and includes a sealing member to seal a portion of the hole. The sealing member can include walls disposed within the center pin, to seal the portion of the hole. The sealing member can include a second center pin, which is inserted into the hole, to seal the portion of the hole.

Abstract: A center pin for a secondary battery and a secondary battery having the same, which optimizes a void volume of the secondary battery. The center pin is inserted into an electrode assembly of the secondary battery. The center pin has a longitudinal hole and includes a sealing member to seal a portion of the hole. The sealing member can include walls disposed within the center pin, to seal the portion of the hole. The sealing member can include a second center pin, which is inserted into the hole, to seal the portion of the hole.

Abstract: A rechargeable battery according to an embodiment of the present invention includes: an electrode assembly; a battery case accommodating the electrode assembly; and a cap assembly comprising: a cap plate comprising a top portion and at least one opening; and a vent member comprising two or more notches and a supporting portion, wherein the vent member is configured to break at the two or more notches and bend along two or more lines adjacent to the supporting portion.

Abstract: A secondary battery that includes a cylindrical can, an electrode assembly arranged in a jelly-role configuration within the cylindrical can and having a core extending about an axis thereof and a hollow center pin arranged within the core of the electrode assembly and having an inner diameter and an outer diameter, the outer diameter forming ones of a pair of radial lengths diametrically opposite from each other, each of said pair of radial lengths extending from the outer diameter of the center pin to an external surface of the core, wherein the sum of the pair of radial lengths is in the range of 5% to 54% of the inner diameter of the center pin.

Abstract: A center pin for a secondary battery and a secondary battery having the same, which optimizes a void volume of the secondary battery. The center pin is inserted into an electrode assembly of the secondary battery. The center pin has a longitudinal hole and includes a sealing member to seal a portion of the hole. The sealing member can include walls disposed within the center pin, to seal the portion of the hole. The sealing member can include a second center pin, which is inserted into the hole, to seal the portion of the hole.

Abstract: Disclosed is a rechargeable lithium battery that includes a positive electrode having an active mass density of about 3.4 g/cc to about 4.0 g/cc, a negative electrode, and an electrolyte including a non-aqueous organic solvent including a compound represented by Chemical Formula 1 in an amount of about 10 volume % to about 50 volume % based on the total amount of the non-aqueous organic solvent. Chemical Formula 1: CH3COO—R1, wherein R1 is a C1 to C4 linear or branched alkyl group.

Abstract: A cylindrical secondary battery including an electrode assembly including a positive electrode having a positive electrode active material layer containing lithium carbonate (Li2CO3), a negative electrode including a negative electrode active material layer, and a separator separating the positive electrode from the negative electrode, a can housing the electrode assembly, a cap assembly disposed on the can, and an electrolyte injected into the can. A content of the lithium carbonate (Li2CO3) is in the range of 1.0 to 1.5 wt % of the total weight of the positive electrode active material layer, a content of the electrolyte is in the range of 10.8 to 11.93 wt % of the total weight of a bare cell, and an operating pressure for interrupting current by the cap assembly is in the range of 7 to 9 kgf/cm2.

Abstract: An electrode assembly includes a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; and a separator separating the positive electrode and the negative electrode from each other, and the separator including a porous layer formed by a combination of a barium titanate (BaTiO3) and a binder.

Abstract: A rechargeable battery according to an embodiment of the present invention includes: an electrode assembly; a battery case accommodating the electrode assembly; and a cap assembly comprising: a cap plate comprising a top portion and at least one opening; and a vent member comprising two or more notches and a supporting portion, wherein the vent member is configured to break at the two or more notches and bend along two or more lines adjacent to the supporting portion.

Abstract: A secondary battery that includes a cylindrical can, an electrode assembly arranged in a jelly-role configuration within the cylindrical can and having a core extending about an axis thereof and a hollow center pin arranged within the core of the electrode assembly and having an inner diameter and an outer diameter, the outer diameter forming ones of a pair of radial lengths diametrically opposite from each other, each of said pair of radial lengths extending from the outer diameter of the center pin to an external surface of the core, wherein the sum of the pair of radial lengths is in the range of 5% to 54% of the inner diameter of the center pin.

Abstract: A cylindrical secondary battery including an electrode assembly including a positive electrode having a positive electrode active material layer containing lithium carbonate (Li2CO3), a negative electrode including a negative electrode active material layer, and a separator separating the positive electrode from the negative electrode, a can housing the electrode assembly, a cap assembly disposed on the can, and an electrolyte injected into the can. A content of the lithium carbonate (Li2CO3) is in the range of 1.0 to 1.5 wt % of the total weight of the positive electrode active material layer, a content of the electrolyte is in the range of 10.8 to 11.93 wt % of the total weight of a bare cell, and an operating pressure for interrupting current by the cap assembly is in the range of 7 to 9 kgf/cm2.

Abstract: A center pin for a secondary battery and a secondary battery having the same, which optimizes a void volume of the secondary battery. The center pin is inserted into an electrode assembly of the secondary battery. The center pin has a longitudinal hole and includes a sealing member to seal a portion of the hole. The sealing member can include walls disposed within the center pin, to seal the portion of the hole. The sealing member can include a second center pin, which is inserted into the hole, to seal the portion of the hole.

Abstract: An electrode assembly includes a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; and a separator separating the positive electrode and the negative electrode from each other, and the separator including a porous layer formed by a combination of a barium titanate (BaTiO3) and a binder.