A battery unit includes a housing assembly; an electrode assembly; a conductive plate; and a feedthrough assembly including a first washer and a rivet. The first washer includes a first gasket portion accommodated in the housing assembly, a second gasket portion disposed on an outer surface of the housing assembly, and a connecting portion connecting the first gasket portion and the second gasket portion. The housing is provided with a through hole for the connecting portion to run through. The rivet runs through and abuts against the first gasket portion, the connecting portion, and the second gasket portion to seal the through hole. The first washer and the rivet are mounted to the housing assembly via a clamping force applied to the first gasket portion and the second gasket portion after the rivet is riveted and deforms and a counterforce of the housing assembly.

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.

In order to create an electrochemical cell, comprising a housing, an electrochemical element arranged in an interior of the housing, and at least one cell terminal that comprises a terminal feed-through, which extends through a through-opening of the housing, which electrochemical cell is of simple construction and requires a low production expenditure but still reliably limits the short circuit current that arises in the case of a non-regular operating state, it is proposed that the electrochemical cell comprises an electrically conductive sealing element, which seals the through-opening of the housing and electrically conductively connects the cell terminal to the housing.

An embodiment of the present invention relates to a cylindrical secondary battery comprising: a cylindrical can having a bottom surface and a side portion extending from the bottom surface, one end of the side portion being open to form an opening; an electrode assembly accommodated in the can; and a cap assembly including a gasket which is inserted into the can with the electrode assembly inserted in the can to come into contact with the electrode assembly, and a cap plate which is disposed on the gasket and is electrically connected to the electrode assembly, wherein the can has, at the edge of the opening, a curling portion which presses the gasket to bring the gasket into contact with the cap plate.

An embodiment of the present invention relates to a cylindrical secondary battery comprising: a cylindrical can having a bottom surface and a side portion extending from the bottom surface, one end of the side portion being open to form an opening; an electrode assembly accommodated in the can; and a cap assembly including a gasket which is inserted into the can with the electrode assembly inserted in the can to come into contact with the electrode assembly, and a cap plate which is disposed on the gasket and is electrically connected to the electrode assembly, wherein the can has, at the edge of the opening, a curling portion which presses the gasket to bring the gasket into contact with the cap plate.

According to an embodiment of the present disclosure, there are provided a pouch-type secondary battery, including an electrode assembly, and a pouch film including an accommodating part in which the electrode assembly is disposed and a sealing part formed by fusion of edges of the accommodating part, wherein the sealing part includes a pattern sealing part on one or more sides among four sides of the pouch-type secondary battery, and the pattern sealing part includes a plurality of sealings provided with one or more discontinuous parts, and a battery module including the pouch-type secondary battery as a unit cell.

According to an embodiment of the present disclosure, there are provided a pouch-type secondary battery, including an electrode assembly, and a pouch film including an accommodating part in which the electrode assembly is disposed and a sealing part formed by fusion of edges of the accommodating part, wherein the sealing part includes a pattern sealing part on one or more sides among four sides of the pouch-type secondary battery, and the pattern sealing part includes a plurality of sealings provided with one or more discontinuous parts, and a battery module including the pouch-type secondary battery as a unit cell.

A sealed battery includes a battery can with a bottomed cylindrical shape having an opening, an electrode body accommodated in the battery can, and a sealing plate closing the opening of the battery can. The sealing plate has a first main surface facing an outside of the battery can and a second main surface opposite to the first main surface. The first main surface has a first groove therein with an arc shape. The second main surface has a second groove therein with an arc shape disposed to correspond to the first groove. The first groove has a central angle A1 smaller than a central angle A2 of the second groove. The first groove intersects a symmetry axis of the second groove on the second groove when viewed in a normal direction of the first main surface.

A sealed battery includes a battery can with a bottomed cylindrical shape having an opening, an electrode body accommodated in the battery can, and a sealing plate closing the opening of the battery can. The sealing plate has a first main surface facing an outside of the battery can and a second main surface opposite to the first main surface. The first main surface has a first groove therein with an arc shape. The second main surface has a second groove therein with an arc shape disposed to correspond to the first groove. The first groove has a central angle A1 smaller than a central angle A2 of the second groove. The first groove intersects a symmetry axis of the second groove on the second groove when viewed in a normal direction of the first main surface.

A battery housing structure and a button battery. The battery housing structure comprises an upper cover and a bottom housing; the bottom housing mates with the upper cover to form a sealing cavity; the sealing cavity is used for mounting of a cell assembly; the bottom housing is provided with a first blind groove. The button battery comprises the cell assembly and the battery housing structure, and the cell assembly is provided in the sealing cavity.