The application provides a battery cell, a manufacturing method and a manufacturing system therefor, a battery and an electric device. The battery cell in one embodiment of the application includes a casing having an opening and provided with a pressure relief mechanism which is actuated to relieve an internal pressure or temperature of the battery cell when the internal pressure or temperature reaches a threshold value; an electrode assembly accommodated in the casing, and including a body portion and a tab portion protruding therefrom; and a cover assembly for covering the opening. A first recessed portion is formed on one side, abutting against the body portion and facing the electrode assembly, of the cover assembly. The cover assembly is provided with at least one first channel. The first channel can reduce the gas accumulated between the electrode assembly and the cover assembly, thereby reducing the safety risk.

To solve the above problem, a venting device inserted into a sealing part of a pouch of a secondary battery according to the present invention includes: a housing inserted between confronting surfaces of the sealing part and sealed together with the sealing part; an element made of a metal and disposed in the housing and through which a passage is defined providing gas communication between an inside and an outside of the pouch; and a ball disposed at an outlet-side of the passage, the ball configured to open and close the passage, wherein, in the element, an edge of an inner circumference of a surface of the outlet-side of the passage is chamfered or filleted so as to face the ball, and the element includes: a surface treatment layer formed on the chamfered or filleted surface; and a layer made of a polymer and fused to the surface treatment layer.

To solve the above problem, a venting device inserted into a sealing part of a pouch of a secondary battery according to the present invention includes: a housing inserted between confronting surfaces of the sealing part and sealed together with the sealing part; an element made of a metal and disposed in the housing and through which a passage is defined providing gas communication between an inside and an outside of the pouch; and a ball disposed at an outlet-side of the passage, the ball configured to open and close the passage, wherein, in the element, an edge of an inner circumference of a surface of the outlet-side of the passage is chamfered or filleted so as to face the ball, and the element includes: a surface treatment layer formed on the chamfered or filleted surface; and a layer made of a polymer and fused to the surface treatment layer.

A ventilation component (1) includes a gas-permeable membrane (10), a ventilation valve (20), and a structural member (30). The ventilation component (1) is to be attached to a housing (2) having a ventilation opening (5). The ventilation valve (20) includes an elastic body, and is opened and closed by elastic deformation of the elastic body. The structural member (30) supports the gas-permeable membrane (10) and the ventilation valve (20). In an attached state where the ventilation component (1) is attached to the housing (2), ventilation between an inside of the housing (2) and an outside of the housing (2) is carried out via the gas-permeable membrane (10), and the ventilation valve (20) is opened to discharge a gas inside the housing 2 to the outside of the housing 2 when a difference between a pressure inside the housing (2) and a pressure outside the housing (2) is equal to or higher than a predetermined value. The elastic body included in the ventilation valve (20) is formed of a rubber whose rate of change in breaking strength is 95% to 120%.

The sealed battery according to the present disclosure is provided with: an electrode body including a negative electrode and a positive electrode having a positive electrode tab; a bottomed cylindrical exterior body for housing the electrode body; and a sealing body for sealing the opening portion of the exterior body via a gasket. The sealing body includes a metal valve body. The valve body has a peripheral edge portion and a reverse portion more protruding to the electrode body side than the peripheral edge portion. The positive electrode tab is led out from the electrode body, is connected to the reverse portion, and has a non-linear portion in a range surrounded by the electrode body and the reverse portion. The non-linear portion has a recess portion and a protrusion portion facing each other at both ends along the led-out direction of the positive electrode tab in a plan view.

The sealed battery according to the present disclosure is provided with: an electrode body including a negative electrode and a positive electrode having a positive electrode tab; a bottomed cylindrical exterior body for housing the electrode body; and a sealing body for sealing the opening portion of the exterior body via a gasket. The sealing body includes a metal valve body. The valve body has a peripheral edge portion and a reverse portion more protruding to the electrode body side than the peripheral edge portion. The positive electrode tab is led out from the electrode body, is connected to the reverse portion, and has a non-linear portion in a range surrounded by the electrode body and the reverse portion. The non-linear portion has a recess portion and a protrusion portion facing each other at both ends along the led-out direction of the positive electrode tab in a plan view.

A rechargeable battery according to an embodiment of the present invention includes: an electrode assembly; a case for receiving the electrode assembly; a cap plate combined to an opening of the case to close and seal an inside of the case and including a plurality of vent units; an elevation member penetrated and installed in the cap plate and moving by an internal pressure of the case; and a plurality of vent plates for closing and sealing the respective vent units, wherein the vent plate is connected to the elevation member through a connection member and links to the elevation member.

A rechargeable battery according to an embodiment of the present invention includes: an electrode assembly; a case for receiving the electrode assembly; a cap plate combined to an opening of the case to close and seal an inside of the case and including a plurality of vent units; an elevation member penetrated and installed in the cap plate and moving by an internal pressure of the case; and a plurality of vent plates for closing and sealing the respective vent units, wherein the vent plate is connected to the elevation member through a connection member and links to the elevation member.

Some embodiments of the present disclosure relate to a battery comprising a housing. In some embodiments, the housing comprises an opening. In some embodiments, the battery comprises at least one fluoropolymer membrane. In some embodiments, the at least one fluoropolymer membrane covers the opening of the housing. In some embodiments, the at least one fluoropolymer membrane has a crystallinity of 85% to 100%. In some embodiments, the at least one fluoropolymer membrane has a density of 2.0 g/cm.sup.3 to 2.2 g/cm.sup.3. In some embodiments, the at least one fluoropolymer membrane has a CO.sub.2 permeability to moisture permeability ratio of more than 0.5. A polytetrafluoroethylene film for electronic components, characterized in that the polytetrafluoroethylene film can have a density of 1.40 g/cm.sup.3 or higher and an air impermeability of 3,000 seconds or higher.

Some embodiments of the present disclosure relate to a battery comprising a housing. In some embodiments, the housing comprises an opening. In some embodiments, the battery comprises at least one fluoropolymer membrane. In some embodiments, the at least one fluoropolymer membrane covers the opening of the housing. In some embodiments, the at least one fluoropolymer membrane has a crystallinity of 85% to 100%. In some embodiments, the at least one fluoropolymer membrane has a density of 2.0 g/cm.sup.3 to 2.2 g/cm.sup.3. In some embodiments, the at least one fluoropolymer membrane has a CO.sub.2 permeability to moisture permeability ratio of more than 0.5. A polytetrafluoroethylene film for electronic components, characterized in that the polytetrafluoroethylene film can have a density of 1.40 g/cm.sup.3 or higher and an air impermeability of 3,000 seconds or higher.