A button-type secondary battery including an electrode assembly having a first and second electrode tabs; a lower can having an accommodation part, in which the electrode assembly is accommodated and to which the first electrode tab is connected, and a flange part on an outer circumferential surface of the accommodation part; an upper cap on the accommodation part covering the accommodation part and a curl part on an outer circumferential surface of the cover part; a terminal member coupled to the upper cap and connected to the second electrode tab; and an insulating member configured to insulate the terminal member and the upper cap from each other and seal a gap between the terminal member and the upper cap. The flange part and the curl part are coupled to each other in a seaming manner to seal a gap between the lower can and the upper cap.

A button-type secondary battery including an electrode assembly having a first and second electrode tabs; a lower can having an accommodation part, in which the electrode assembly is accommodated and to which the first electrode tab is connected, and a flange part on an outer circumferential surface of the accommodation part; an upper cap on the accommodation part covering the accommodation part and a curl part on an outer circumferential surface of the cover part; a terminal member coupled to the upper cap and connected to the second electrode tab; and an insulating member configured to insulate the terminal member and the upper cap from each other and seal a gap between the terminal member and the upper cap. The flange part and the curl part are coupled to each other in a seaming manner to seal a gap between the lower can and the upper cap.

The present invention relates to a battery cell. The battery cell comprises: an electrode assembly provided with an electrode tab; a case which accommodates the electrode assembly and of which at least a portion of an edge is sealed to provide a sealing surface; an electrode lead coupled to the electrode tab and led out of the case; a lead film disposed on each of top and bottom surfaces of the lead electrode disposed on the sealing surface of the case and coupled together with the sealing surface; and a main gas discharge tube disposed in the case and having one end buried in the lead film.

A rechargeable battery according to an embodiment of the present invention includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a case including an opening in one side and receiving the electrode assembly; and a cap assembly combined to the opening and closing and sealing the case, wherein the cap assembly includes a cap plate combined to the opening and including a terminal hole, a terminal plate combined to the top of the cap plate to cover the terminal hole, an upper insulator disposed at the top of the cap plate to be provided between the cap plate and the terminal plate, and a lower insulator disposed at a bottom of the cap plate and including an edge disposed near the case and extending downward.

A rechargeable battery according to an embodiment of the present invention includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a case including an opening in one side and receiving the electrode assembly; and a cap assembly combined to the opening and closing and sealing the case, wherein the cap assembly includes a cap plate combined to the opening and including a terminal hole, a terminal plate combined to the top of the cap plate to cover the terminal hole, an upper insulator disposed at the top of the cap plate to be provided between the cap plate and the terminal plate, and a lower insulator disposed at a bottom of the cap plate and including an edge disposed near the case and extending downward.

A cell, including an electrode assembly and a shell. The electrode assembly includes tabs, and the electrode assembly is disposed in the shell. The shell includes a packaging part and a sealing part connected to the packaging part, where the sealing part is formed by extending the packaging part outward, the electrode assembly is located in the packaging part, and the tabs penetrate out of the sealing part. The packaging part includes a side wall, where notches are provided in the sealing part, the notches are formed by recessing an exterior circumferential edge of the sealing part towards a joint of the sealing part and the packaging part, and the sealing part is attached to the side wall.

A cell, including an electrode assembly and a shell. The electrode assembly includes tabs, and the electrode assembly is disposed in the shell. The shell includes a packaging part and a sealing part connected to the packaging part, where the sealing part is formed by extending the packaging part outward, the electrode assembly is located in the packaging part, and the tabs penetrate out of the sealing part. The packaging part includes a side wall, where notches are provided in the sealing part, the notches are formed by recessing an exterior circumferential edge of the sealing part towards a joint of the sealing part and the packaging part, and the sealing part is attached to the side wall.

A sealing member containing a copolymer containing tetrafluoroethylene unit and a perfluoro(propyl vinyl ether) unit, wherein the copolymer has a content of the perfluoro (propyl vinyl ether) unit of 4.0 to 6.0% by mass with respect to the whole of the monomer units, a melt flow rate of 26 to 37 g/10 min, and the number of functional groups of —CF═CF.sub.2, —CF.sub.2H, —COF, —COOH, —COOCH.sub.3, —CONH.sub.2 and —CH.sub.2OH of more than 50 per 10.sup.6 main-chain carbon atoms, wherein the sealing member has a thickness of 0.5 to 2.5 mm and a sealing area of 0.5 to 50 cm.sup.2, and wherein the sealing member is in a state of being compressed at a compression deformation rate of 20 to 60%. Also disclosed is a power storage assembly including the sealing member.

A sealing member containing a copolymer containing tetrafluoroethylene unit and a perfluoro(propyl vinyl ether) unit, wherein the copolymer has a content of the perfluoro (propyl vinyl ether) unit of 4.0 to 6.0% by mass with respect to the whole of the monomer units, a melt flow rate of 26 to 37 g/10 min, and the number of functional groups of —CF═CF.sub.2, —CF.sub.2H, —COF, —COOH, —COOCH.sub.3, —CONH.sub.2 and —CH.sub.2OH of more than 50 per 10.sup.6 main-chain carbon atoms, wherein the sealing member has a thickness of 0.5 to 2.5 mm and a sealing area of 0.5 to 50 cm.sup.2, and wherein the sealing member is in a state of being compressed at a compression deformation rate of 20 to 60%. Also disclosed is a power storage assembly including the sealing member.

A secondary battery includes a jelly roll-type electrode assembly impregnated with an electrolyte solution; a battery case for housing the electrode assembly and the electrolyte solution; a cap assembly coupled with an upper portion of the battery case; and a reference electrode in which one end is immersed with the electrolyte solution and the other end is exposed to the outside through the battery case and the cap assembly.