The present invention is a method for manufacturing a secondary battery. An electrode assembly and an electrolyte are accommodated into a body of a battery case. The body of the battery case has an accommodation part and a gas pocket part, and a passage that extends from the accommodation part to the outside discharges an internal gas from the accommodation part through the gas pocket part. The battery case is seated in a seating step on a support block, which has an inclined part on a side surface thereof, to support the battery case. The body is pressed to discharge a gas accommodated in the accommodation part through the gas pocket part in the battery case. This method allows easy discharging of internal gas while reducing discharge of the electrolyte with the gas.

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%.

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%.

Certain aspects relate to a battery pack for electric vertical take-off and landing aircraft. Exemplary battery pack includes a first pouch cell, a second pouch cell, at least a sensor, where the at least a sensor is configured to sense battery pack data and transmit the battery pack data to a data storage system, and a vent configured to vent the ejecta from the first pouch cell. In some embodiments, battery pack may be configured to power at least a propulsor component.

Certain aspects relate to a battery pack for electric vertical take-off and landing aircraft. Exemplary battery pack includes a first pouch cell, a second pouch cell, at least a sensor, where the at least a sensor is configured to sense battery pack data and transmit the battery pack data to a data storage system, and a vent configured to vent the ejecta from the first pouch cell. In some embodiments, battery pack may be configured to power at least a propulsor component.

The present invention relates to a secondary battery which is capable of improving safety. As an example, a secondary battery which comprises an electrode assembly; a case which accommodates the electrode assembly; a cap assembly which is coupled to an upper portion of the case, and a gasket which is interposed between the cap assembly and the case, wherein the cap assembly comprises a cap-up, a safety vent which is installed at a lower portion of the cap-up, a cap-down which is installed at a lower portion of the safety vent, an insulator which is interposed between the safety vent and the cap-down, and a sub-plate which is located on a lower surface of the cap-down, and an insulation layer is formed on one surface of the safety vent, is disclosed.

The present invention relates to a secondary battery which is capable of improving safety. As an example, a secondary battery which comprises an electrode assembly; a case which accommodates the electrode assembly; a cap assembly which is coupled to an upper portion of the case, and a gasket which is interposed between the cap assembly and the case, wherein the cap assembly comprises a cap-up, a safety vent which is installed at a lower portion of the cap-up, a cap-down which is installed at a lower portion of the safety vent, an insulator which is interposed between the safety vent and the cap-down, and a sub-plate which is located on a lower surface of the cap-down, and an insulation layer is formed on one surface of the safety vent, is disclosed.

The present application provides an end cover assembly, a battery cell, a battery, an electric device and a method for preparing a battery cell and an apparatus for manufacturing a battery cell. The present application provides an end cover assembly, where the end cover assembly includes: a cover plate provided with a pressure relief hole; a fixing member fixed on the cover plate, the fixing member having a first through hole and a second through hole, and the first through hole being opposite to the pressure relief hole; and a gas permeable membrane covering at least a portion of the pressure relief hole, an edge part of the gas permeable membrane being connected to the fixing member, and a portion of the edge part being embedded into the second through hole, so as to prevent the edge part from moving relative to the fixing member.

The present application provides an end cover assembly, a battery cell, a battery, an electric device and a method for preparing a battery cell and an apparatus for manufacturing a battery cell. The present application provides an end cover assembly, where the end cover assembly includes: a cover plate provided with a pressure relief hole; a fixing member fixed on the cover plate, the fixing member having a first through hole and a second through hole, and the first through hole being opposite to the pressure relief hole; and a gas permeable membrane covering at least a portion of the pressure relief hole, an edge part of the gas permeable membrane being connected to the fixing member, and a portion of the edge part being embedded into the second through hole, so as to prevent the edge part from moving relative to the fixing member.