The present invention relates to a secondary battery capable of improving the coupling force between a safety vent and a cap-up. For example, disclosed is a secondary battery comprising: an electrode assembly; a case for accommodating the electrode assembly; a cap assembly coupled to the upper part of the case; and a gasket interposed between the cap assembly and the case, wherein the cap assembly includes a cap-up and a safety vent, which is provided at the lower part of the cap-up and has a vent extension part extending to the upper part of the cap-up so as to encompass the edge of the cap-up, a welding region, in which the safety vent and the cap-up are welded and coupled by laser welding, is formed in the vent extension part, and the welding region is formed in a line shape.

The present disclosure relates to a secondary battery, and provides a secondary battery capable of reducing heat generation and improving safety by reducing a welding area. To this end, the present disclosure provides a secondary battery comprising: an electrode assembly having a first tab and a second tab provided at the opposite side to the first tab; a first current collector which is welded on the first tab of the electrode assembly and has a diameter that is greater than the diameter of the electrode assembly; and a case assembly comprising a case which accommodates the electrode assembly and the first current collector, a second current collector which is in close contact with the second tab of the electrode assembly, and a terminal unit which is electrically connected to the second current collector and penetrates through the case,

The present disclosure relates to a secondary battery, and provides a secondary battery capable of reducing heat generation and improving safety by reducing a welding area. To this end, the present disclosure provides a secondary battery comprising: an electrode assembly having a first tab and a second tab provided at the opposite side to the first tab; a first current collector which is welded on the first tab of the electrode assembly and has a diameter that is greater than the diameter of the electrode assembly; and a case assembly comprising a case which accommodates the electrode assembly and the first current collector, a second current collector which is in close contact with the second tab of the electrode assembly, and a terminal unit which is electrically connected to the second current collector and penetrates through the case,

The present application provides a battery cover assembly and a cylindrical battery, the battery cover assembly includes an electrode post, a top cover and a sealing member. The electrode post includes a base plate portion, a boss portion on a side of the base plate portion, and a post portion on the boss portion. The top cover defines an assembly hole, the post portion extends through the assembly hole; the sealing member sleeves an outside of the post portion and abuts against the boss portion, the post portion and the top cover.

A battery can include an electrode assembly, a battery housing, a terminal and a cap. The electrode assembly can have a first electrode, a second electrode and a separator between the first electrode and the second electrode. Each of the first electrode and the second electrode can have a first portion including an active material corresponding to the separator, and a second portion exposed beyond the separator and not coated with the active material. The battery housing can have a first end with a first opening and a second end with a second opening opposite the first end. The terminal can be electrically connected to the second portion of the first electrode and exposed out of the battery housing through the first opening of the battery housing at the first end.

A cylindrical battery wherein a central part of a sealing plate, fixed by swaging to an opening of an external packaging can, is configured to be warped toward the inner part of the battery. One embodiment is provided with: an electrode body in which a positive electrode plate and a negative electrode plate are rolled with a separator being disposed therebetween; an electrolytic solution; an external packaging can which has a bottomed cylindrical shape and which houses the electrode body and the electrolytic solution; and a sealing plate which is fixed by swaging to an opening of the external packaging can with a gasket therebetween. In the sealing plate, prior to the swage fixing, an outer peripheral edge to be fixed by swaging to the external packaging can is formed inclined so as to be directed to the inner part of the battery, toward radially outward.

A nonaqueous electrolyte secondary battery representing an embodiment of a sealed battery of the present invention includes a bottomed cylindrical exterior case, a sealing member, a cylindrical wound electrode assembly and an electrolyte. An open end of the exterior case is crimped together with the sealing member via an insulating gasket so as to form a seal. The sealing member includes a lid having a thin and fragile portion, an insulating ring, and a terminal plate having a thin and fragile portion. The terminal plate is electrically connected to a positive electrode current collector leading out from the cylindrical wound electrode assembly. The lid and the terminal plate are electrically connected within an opening of the insulating ring. The lid is disposed so as to expose an outer side of at least a portion of the lid opposed to the opening of the insulating ring directly to an outside environment.

A nonaqueous electrolyte secondary battery representing an embodiment of a sealed battery of the present invention includes a bottomed cylindrical exterior case, a sealing member, a cylindrical wound electrode assembly and an electrolyte. An open end of the exterior case is crimped together with the sealing member via an insulating gasket so as to form a seal. The sealing member includes a lid having a thin and fragile portion, an insulating ring, and a terminal plate having a thin and fragile portion. The terminal plate is electrically connected to a positive electrode current collector leading out from the cylindrical wound electrode assembly. The lid and the terminal plate are electrically connected within an opening of the insulating ring. The lid is disposed so as to expose an outer side of at least a portion of the lid opposed to the opening of the insulating ring directly to an outside environment.

A sealed battery with a battery case that includes a bottomed cylindrical outer can and an opening-sealing body that closes an opening section of the outer can; and an electrode body that is accommodated inside the battery case. The opening-sealing body includes a metal plate, and the metal plate includes a protruding section that bulges toward the outside of the battery cast, and a flange section that is formed on the circumference of the protruding section. The protruding section includes an inclination section that inclines inward from the radial outside of the opening sealing body so as to be progressively separated from the electrode body, wherein a thin wall section, which has a thickness less than portions other than the inclination section and is preferably broken when the inner pressure of the battery case exceeds a predetermined threshold, is formed in at least a portion of the inclination section.

A secondary battery according to an embodiment of the present disclosure includes an electrode assembly, a battery case that houses the electrode assembly and has an opened upper party, and a cap assembly that is coupled to the opened upper part of the battery case.The cap assembly comprises a safety vent formed with a notch portion, and a gap formed by the notch portion is closed.