Battery cell, pressure relief mechanism and electric equipment

Abstract

The invention provides a battery cell, a pressure relief mechanism and electric equipment, the battery cell comprises a shell, an adhesive film and an anti-corrosion layer, the shell comprises a first wall, and the first wall is provided with a first through hole. The adhesive film is used for sealing the first through hole and connected with the first wall to form a sealing face. The adhesive film is provided with a first surface facing the interior of the shell, the first surface is provided with a first edge, and the first edge is the outer contour of the first surface. The anti-corrosion layer is arranged on the inner surface of the first wall and the first surface and covers the first edge. The adhesive film can be heated and melted to form a pressure relief channel communicating the interior and the exterior of the shell. The possibility that electrolyte in the shell corrodes the sealing surface of the adhesive film and the first wall can be reduced, so that the sealing effect of the adhesive film on the first through hole is better, the safety of the battery cell is favorably improved, and the service life of the battery cell is prolonged; moreover, sealing can be formed between the anti-corrosion layer and the first surface, so that the sealing area of the first through hole by the adhesive film and the anti-corrosion layer is larger, and the sealing effect is better.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a pressure relief mechanism and an electrical device. Background Art

[0002] With the rapid development of electronic information technology, various electronic devices are also moving towards intelligence and multi-functions, and the performance requirements for batteries are becoming higher and higher.

[0003] Sealing the through holes of the battery cell casing with a film can improve the thermal sensitivity of the battery cell pressure relief. However, the sealing interface between the film and the metal parts will be corroded by the electrolyte, causing the sealing of the film to deteriorate or even fail, affecting the safety of the battery cell. Summary of the invention

[0004] The present application provides a battery cell, a pressure relief mechanism and an electrical device, which can improve the safety of the battery cell.

[0005] In a first aspect, the present application provides a battery cell, the battery cell comprising a shell, a film and an anti-corrosion layer, the shell comprising a first wall, the first wall being provided with a first through hole. The film is used to seal the first through hole, and the film is connected to the first wall to form a sealing surface. The film has a first surface facing the interior of the shell, the first surface has a first edge, and the first edge is the outer contour of the first surface. The anti-corrosion layer is provided on the inner surface and the first surface of the first wall, and covers the first edge. The film can be melted by heat to form a pressure relief channel connecting the interior and the exterior of the shell.

[0006] In the above technical solution, the outer shell includes a first wall, the first wall is provided with a first through hole, the adhesive film is used to seal the first through hole, the adhesive film can be heated and melted to form a pressure relief channel connecting the inside and outside of the outer shell, so that the thermal sensitivity of the pressure relief of the battery cell is better, the reliability of the pressure relief is higher, the safety of the battery cell can be improved, and compared with the notched groove pressure relief structure, this embodiment does not need to reserve a large space, the structure of the electrical equipment can be more compact, and the cost of preparing the battery cell is lower. By connecting the adhesive film with the first wall to form a sealing surface, the adhesive film has a first surface facing the inside of the outer shell, the first surface has a first edge, the anti-corrosion layer is provided on the inner surface of the first wall and the first surface, and covers the first edge, the first edge is the outer contour of the first surface, the possibility of the electrolyte inside the outer shell corroding the sealing surface of the adhesive film and the first wall can be reduced, so that the sealing effect of the adhesive film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell; and the anti-corrosion layer can form a seal with the first surface, so that the sealing area of ​​the adhesive film and the anti-corrosion layer to the first through hole is larger, and the sealing effect is better.

[0007] In some embodiments of the present application, the thickness of the anti-corrosion layer is H1, satisfying 10 nm ≤ H1 ≤ 2 mm.

[0008] In the above technical scheme, when the thickness H1 of the anti-corrosion layer is greater than or equal to 10nm, the anti-corrosion layer can have a better anti-corrosion effect on the electrolyte, and the sealing effect of the adhesive film on the first through hole can be better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell, and the sealing effect between the anti-corrosion layer and the first surface can be better; when the thickness H1 of the anti-corrosion layer is less than or equal to 2mm, the space occupied by the anti-corrosion layer can be smaller, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H1 of the anti-corrosion layer satisfies 10nm≤H1≤2mm, the anti-corrosion layer can have a better anti-corrosion effect on the electrolyte, and the sealing effect of the adhesive film on the first through hole can be better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell, and the sealing effect between the anti-corrosion layer and the first surface can be better, and the space occupied by the anti-corrosion layer can be smaller, which is beneficial to improving the energy density of the battery cell.

[0009] In some embodiments of the present application, 10 nm ≤ H1 ≤ 0.1 mm.

[0010] In the above technical scheme, when the thickness H1 of the anti-corrosion layer is greater than or equal to 10nm, the anti-corrosion layer can have a better anti-corrosion effect on the electrolyte, and the sealing effect of the adhesive film on the first through hole can be better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell, and the sealing effect between the anti-corrosion layer and the first surface can be better; when the thickness H1 of the anti-corrosion layer is less than or equal to 0.1mm, the space occupied by the anti-corrosion layer can be further reduced, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H1 of the anti-corrosion layer satisfies 10nm≤H1≤0.1mm, the anti-corrosion layer can have a better anti-corrosion effect on the electrolyte, and the sealing effect of the adhesive film on the first through hole can be better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell, and the sealing effect between the anti-corrosion layer and the first surface can be better, and the space occupied by the anti-corrosion layer can be further reduced, which is beneficial to improving the energy density of the battery cell.

[0011] In some embodiments of the present application, the material of the anti-corrosion layer includes at least one of ceramics, polypropylene, fluoride, polyvinylidene fluoride, carbon-based materials, titanium, and nickel-based materials.

[0012] In the above technical solution, by making the material of the anti-corrosion layer include at least one of ceramic, polypropylene, fluoride, polyvinylidene fluoride, carbon-based material, titanium, and nickel-based material, the anti-corrosion layer can have better corrosion resistance to the electrolyte, and the adhesive film can have better sealing effect on the first through hole, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell.

[0013] In some embodiments of the present application, the melting point of the adhesive film is T1, satisfying 100°C≤T1≤130°C; the melting point of the anti-corrosion layer is T2, satisfying 90°C≤T2≤130°C.

[0014] In the above technical scheme, when the melting point T1 of the adhesive film is greater than or equal to 100°C, the possibility of the adhesive film melting and failing when the battery cell does not have thermal runaway can be reduced, thereby improving the sealing reliability of the adhesive film to the first through hole and improving the safety of the battery cell; when the melting point T1 of the adhesive film is less than or equal to 130°C, the adhesive film can melt when the battery cell has thermal runaway so as to quickly open the first through hole, thereby making the battery cell more sensitive to pressure relief; therefore, when the melting point T1 of the adhesive film satisfies 100°C≤T1≤130°C, it can not only improve the sealing reliability of the adhesive film to the first through hole and improve the safety of the battery cell, but also make the battery cell more sensitive to pressure relief. When the melting point T2 of the anti-corrosion layer is greater than or equal to 90°C, the possibility of the anti-corrosion layer melting and failing when the battery cell does not have thermal runaway can be reduced, the reliability of the anti-corrosion layer to the corrosion of the electrolyte can be improved, and the service life of the battery cell can be extended; when the melting point T2 of the anti-corrosion layer is less than or equal to 130°C, the anti-corrosion layer can be melted when the battery cell is in thermal runaway, so as to quickly open the first through hole, so that the sensitivity of the pressure relief of the battery cell is higher; therefore, when the melting point T2 of the anti-corrosion layer satisfies 90°C≤T2≤130°C, it can not only improve the reliability of the anti-corrosion layer to the corrosion of the electrolyte, which is conducive to extending the service life of the battery cell, but also make the sensitivity of the pressure relief of the battery cell higher. The melting points of the adhesive film and the anti-corrosion layer are close, so that when the battery cell is in thermal runaway, both the adhesive film and the anti-corrosion layer can be melted, so as to quickly open the first through hole, so that the sensitivity of the pressure relief of the battery cell is higher.

[0015] In some embodiments of the present application, the melting point T2 of the anti-corrosion layer is lower than the melting point T1 of the adhesive film.

[0016] In the above technical solution, by making the melting point T2 of the anti-corrosion layer lower than the melting point T1 of the adhesive film, the anti-corrosion layer can be melted first when pressure relief is required, thereby achieving a better pressure relief effect.

[0017] In some embodiments of the present application, the area on the inner surface of the first wall covered by the anti-corrosion layer is the first area, and along the radial direction of the first through hole, the width of the first area is W1, satisfying 10 μm≤W1≤3 mm.

[0018] In the above technical solution, when W1≥10μm, the path of the electrolyte from the first area to the first edge can be longer, thereby further reducing the possibility of the electrolyte corroding the sealing surface between the film and the first wall, so that the sealing effect of the film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell; when W1≤3mm, the space occupied by the anti-corrosion layer can be smaller, and the film can be adapted to more battery cells of different sizes; therefore, when 10μm≤W1≤3mm, it can not only make the sealing effect of the film on the first through hole better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell, but also make the space occupied by the anti-corrosion layer smaller, so that the film can be adapted to more battery cells of different sizes.

[0019] In some embodiments of the present application, 100 μm≤W1≤3 mm.

[0020] In the above technical solution, when W1≥100μm, the path of the electrolyte from the first area to the first edge can be further lengthened, thereby further reducing the possibility of the electrolyte corroding the sealing surface between the adhesive film and the first wall, so that the adhesive film has a better sealing effect on the first through hole, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell; when W1≤3mm, the space occupied by the anti-corrosion layer can be smaller, so that the adhesive film can be adapted to more battery cells of different sizes; therefore, when 100μm≤W1≤3mm, it can not only further improve the sealing effect of the adhesive film on the first through hole, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell, but also make the space occupied by the anti-corrosion layer smaller, so that the adhesive film can be adapted to more battery cells of different sizes.

[0021] In some embodiments of the present application, the area of ​​the first surface covered by the anti-corrosion layer is the second area, and along the radial direction of the first through hole, the width of the second area is W2, satisfying 10 μm≤W2≤3 mm.

[0022] In the above technical scheme, when W2≥10μm, the path of the electrolyte from the second area to the first edge can be longer, thereby further reducing the possibility of the electrolyte corroding the sealing surface between the film and the first wall, so that the sealing effect of the film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell; when W2≤3mm, the space occupied by the anti-corrosion layer can be smaller, and the film can be adapted to more battery cells of different sizes; therefore, when 10μm≤W2≤3mm, it can not only make the sealing effect of the film on the first through hole better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell, but also make the space occupied by the anti-corrosion layer smaller, so that the film can be adapted to more battery cells of different sizes.

[0023] In some embodiments of the present application, 100 μm ≤ W2 ≤ 3 mm.

[0024] In the above technical scheme, when W2≥100μm, the path of the electrolyte from the second area to the first edge can be further made longer, thereby further reducing the possibility of the electrolyte corroding the sealing surface between the film and the first wall, so that the sealing effect of the film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell; when W2≤3mm, the space occupied by the anti-corrosion layer can be smaller, and the film can be adapted to more battery cells of different sizes; therefore, when 100μm≤W2≤3mm, it can not only further make the sealing effect of the film on the first through hole better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell, but also make the space occupied by the anti-corrosion layer smaller, so that the film can be adapted to more battery cells of different sizes.

[0025] In some embodiments of the present application, the adhesive film is connected to the outer surface of the first wall to form a sealing surface.

[0026] In the above technical solution, the adhesive film is connected to the outer surface of the first wall to form a sealing surface, which can facilitate the assembly of the adhesive film and the housing.

[0027] In some embodiments of the present application, the adhesive film is connected to the outer surface of the first wall to form a first sub-sealing surface, and the adhesive film is connected to the hole wall of the first through hole to form a second sub-sealing surface. The first sub-sealing surface and the second sub-sealing surface constitute a sealing surface.

[0028] In the above technical solution, the first sub-sealing surface is formed by connecting the adhesive film to the outer surface of the first wall, and the second sub-sealing surface is formed by connecting the adhesive film to the hole wall of the first through hole. The first sub-sealing surface and the second sub-sealing surface constitute a sealing surface, which can make the sealing area between the adhesive film and the first wall larger, and the sealing effect between the adhesive film and the first wall better, thereby reducing the possibility of electrolyte leakage and helping to improve the safety of the battery cell.

[0029] In some embodiments of the present application, the adhesive film covers the first through hole.

[0030] In the above technical solution, by making the adhesive film cover the first through hole, the adhesive film itself can cover and seal the first through hole, thereby making the overall structure of the battery cell simple and easy to prepare, and helping to reduce the preparation cost of the battery cell.

[0031] In some embodiments of the present application, the battery cell includes a first metal sheet, and the first metal sheet is disposed on a side of the adhesive film facing away from the first wall.

[0032] In the above technical solution, by arranging the first metal sheet on the side of the adhesive film facing away from the first wall, the possibility of water vapor outside the battery cell penetrating into the battery cell through the adhesive film can be reduced, thereby achieving a better sealing effect.

[0033] In some embodiments of the present application, the adhesive film is provided with a second through hole, the first metal sheet has a second surface exposed by the second through hole, and the anti-corrosion layer covers the hole wall and the second surface of the second through hole.

[0034] In the above technical solution, by providing the adhesive film with a second through hole, when the adhesive film melts, a pressure relief path can be formed between the adhesive film and the first wall, and between the adhesive film and the first metal sheet, thereby increasing the number of pressure relief channels and making the pressure relief sensitivity higher; by making the anti-corrosion layer cover the hole wall and the second surface of the second through hole, so that the anti-corrosion layer can cover the edge of the connecting surface between the adhesive film and the first metal sheet, the possibility of the electrolyte inside the shell corroding the connecting surface between the adhesive film and the first metal sheet can be reduced, so that the sealing effect of the adhesive film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell.

[0035] In some embodiments of the present application, the outer diameter of the adhesive film is greater than the outer diameter of the first metal sheet, and the inner diameter of the adhesive film is smaller than the diameter of the first through hole.

[0036] In the above technical solution, by making the outer diameter of the adhesive film larger than the outer diameter of the first metal sheet, the connection area between the first metal sheet and the adhesive film can be made larger, which facilitates the assembly of the first metal sheet and the adhesive film; by making the inner diameter of the adhesive film smaller than the diameter of the first through hole, the adhesive film can cover the first through hole conveniently, so that the sealing effect of the adhesive film on the first through hole is better, which is beneficial to improve the safety of the battery cell and extend the service life of the battery cell.

[0037] In some embodiments of the present application, a protective layer is disposed on the side of the first metal sheet facing away from the adhesive film.

[0038] In the above technical solution, by providing a protective layer on the side of the first metal sheet facing away from the adhesive film, the possibility of oxidation of the first metal sheet can be reduced, and the possibility of other components piercing the first metal sheet and the adhesive film can be reduced, so that the sealing effect of the first through hole is better.

[0039] In some embodiments of the present application, the adhesive film, the first metal sheet, and the protective layer are hot pressed into a composite member, and the thickness of the composite member is H2, satisfying 0.03 mm ≤ H2 ≤ 1 mm.

[0040] In the above technical solution, by hot pressing the adhesive film, the first metal sheet and the protective layer into a composite part, the force can be better transmitted to the composite part when the first wall is subjected to force, so that the composite part and the first wall are deformed together, thereby reducing the possibility of the composite part and the first wall peeling off and leaking; and the integration of the composite part can make the composite part more flexible, and when high temperature and high pressure are formed inside the battery cell, it is easier to deform to open the first through hole for pressure relief.

[0041] When the thickness H2 of the composite component is greater than or equal to 0.03mm, the strength and flexibility of the composite component can be improved, and the sealing performance of the first through hole can be better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell; when the thickness H2 of the composite component is less than or equal to 1mm, the space occupied by the composite component can be smaller, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H2 of the composite component satisfies 0.03mm≤H2≤1mm, the strength and flexibility of the composite component can be improved, and the sealing performance of the first through hole can be better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell, and the space occupied by the composite component can be smaller, which is beneficial to improving the energy density of the battery cell.

[0042] In some embodiments of the present application, the thickness of the adhesive film is H3, satisfying 0.01mm≤H3≤0.5mm; the thickness of the first metal sheet is H4, satisfying 0.01mm≤H4≤0.25mm; the thickness of the protective layer is H5, satisfying 0.01mm≤H5≤0.25mm.

[0043] In the above technical scheme, when the thickness H3 of the film is greater than or equal to 0.01mm, the adhesion of the film can be stronger, the water permeability is lower, and it is not easy to be damaged, so that the sealing effect of the film on the first through hole is better; when the thickness H3 of the film is less than or equal to 0.5mm, the space occupied by the film can be smaller, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H3 of the film satisfies 0.01mm≤H3≤0.5mm, the adhesion of the film can be stronger, the water permeability is lower, and it is not easy to be damaged, so that the sealing effect of the film on the first through hole is better, and the space occupied by the film can be smaller, which is beneficial to improving the energy density of the battery cell.

[0044] When the thickness H4 of the first metal sheet is greater than or equal to 0.01mm, the strength of the first metal sheet can be higher and the water permeability can be lower, so that the sealing effect of the first through hole is better; when the thickness H4 of the first metal sheet is less than or equal to 0.25mm, the space occupied by the first metal sheet can be smaller, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H4 of the first metal sheet satisfies 0.01mm≤H4≤0.25mm, the strength of the first metal sheet can be higher and the water permeability can be lower, so that the sealing effect of the first through hole is better, and the space occupied by the first metal sheet can be smaller, which is beneficial to improving the energy density of the battery cell.

[0045] When the thickness H5 of the protective layer is greater than or equal to 0.01mm, the protective layer can better protect the first metal sheet, reduce the possibility of oxidation of the first metal sheet, reduce the possibility of other components piercing the first metal sheet and the adhesive film, and achieve better sealing effect on the first through hole; when the thickness H5 of the protective layer is less than or equal to 0.25mm, the space occupied by the protective layer can be smaller, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H5 of the protective layer satisfies 0.01mm≤H5≤0.25mm, the protective layer can better protect the first metal sheet, reduce the possibility of oxidation of the first metal sheet, reduce the possibility of other components piercing the first metal sheet and the adhesive film, and achieve better sealing effect on the first through hole, and the space occupied by the protective layer can be smaller, which is beneficial to improving the energy density of the battery cell.

[0046] In some embodiments of the present application, 0.02 mm ≤ H3 ≤ 0.3 mm, 0.01 mm ≤ H4 ≤ 0.15 mm, and 0.01 mm ≤ H5 ≤ 0.15 mm.

[0047] In the above technical scheme, when the thickness of the film is greater than or equal to 0.02mm, the adhesion of the film can be further made stronger, the water permeability is lower, and it is not easy to be damaged, so that the sealing effect of the film on the first through hole is better; when the thickness of the film is less than or equal to 0.3mm, the space occupied by the film can be further made smaller, which is beneficial to improve the energy density of the battery cell; therefore, when the thickness H3 of the film satisfies 0.02mm≤H3≤0.3mm, it can not only further make the adhesion of the film stronger, the water permeability is lower, and it is not easy to be damaged, so that the sealing effect of the film on the first through hole is better, but also can further make the space occupied by the film smaller, which is beneficial to improve the energy density of the battery cell.

[0048] When the thickness of the first metal sheet is greater than or equal to 0.01mm, the strength of the first metal sheet can be higher and the water permeability can be lower, so that the sealing effect of the first through hole is better; when the thickness of the first metal sheet is less than or equal to 0.15mm, the space occupied by the first metal sheet can be further reduced, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H4 of the first metal sheet satisfies 0.01mm≤H4≤0.15mm, the strength of the first metal sheet can be higher and the water permeability can be lower, so that the sealing effect of the first through hole is better, and the space occupied by the first metal sheet can be further reduced, which is beneficial to improving the energy density of the battery cell.

[0049] When the thickness of the protective layer is greater than or equal to 0.01mm, the protective layer can better protect the first metal sheet, reduce the possibility of oxidation of the first metal sheet, reduce the possibility of other components piercing the first metal sheet and the adhesive film, and achieve better sealing effect on the first through hole; when the thickness of the protective layer is less than or equal to 0.15mm, the space occupied by the protective layer can be further reduced, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H5 of the protective layer satisfies 0.01mm≤H5≤0.15mm, the protective layer can better protect the first metal sheet, reduce the possibility of oxidation of the first metal sheet, reduce the possibility of other components piercing the first metal sheet and the adhesive film, and achieve better sealing effect on the first through hole, and can further reduce the space occupied by the protective layer, which is beneficial to improving the energy density of the battery cell.

[0050] In some embodiments of the present application, the first wall includes a wall body and a second metal sheet, the wall body is provided with a third through hole, the second metal sheet covers the third through hole and is welded to the wall body, and the first through hole is provided in the second metal sheet.

[0051] In the above technical solution, by setting a second metal sheet, the second metal sheet covers the third through hole and is welded to the wall body, so that the connection between the second metal sheet and the wall body can be stabilized, and the second metal sheet, the adhesive film and the anti-corrosion layer can form standard parts to be assembled with the outer shells of different types of battery cells, which can improve the preparation efficiency of the battery cells.

[0052] In some embodiments of the present application, the second metal sheet is circular, and the radius of the second metal sheet is R; along the radial direction of the second metal sheet, the width of the overlapping portion of the anti-corrosion layer and the second metal sheet is W1, satisfying 5%≤W1 / R≤100%.

[0053] In the above technical solution, since the first through hole is arranged on the second metal sheet, that is, the adhesive film is connected to the second metal sheet to form a sealing surface, by making the width of the overlapping part of the anti-corrosion layer and the second metal sheet along the radial direction of the second metal sheet W1, satisfying 5%≤W1 / R≤100%, the path of the electrolyte through the overlapping part of the anti-corrosion layer and the second metal sheet to the first edge of the sealing surface can be longer, thereby further reducing the possibility of the electrolyte causing corrosion to the sealing surface of the adhesive film and the second metal sheet, so that the sealing effect of the adhesive film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell.

[0054] In some embodiments of the present application, the thickness of the second metal sheet is H6, satisfying 0.02 mm ≤ H6 ≤ 0.5 mm.

[0055] In the above technical solution, when the thickness H6 of the second metal sheet is greater than or equal to 0.02 mm, the strength of the second metal sheet can be increased and the connection with the wall body can be more stable; when the thickness H6 of the second metal sheet is less than or equal to 0.5 mm, the space occupied by the second metal sheet is smaller, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H6 of the second metal sheet satisfies 0.02 mm≤H6≤0.5 mm, the strength of the second metal sheet can be increased and the connection with the wall body can be more stable, and the space occupied by the second metal sheet can be smaller, which is beneficial to improving the energy density of the battery cell.

[0056] In some embodiments of the present application, 0.02 mm ≤ H6 ≤ 0.3 mm.

[0057] In the above technical solution, when the thickness H6 of the second metal sheet is greater than or equal to 0.02mm, the strength of the second metal sheet can be increased and the connection with the wall body can be more stable; when the thickness H6 of the second metal sheet is less than or equal to 0.3mm, the space occupied by the second metal sheet can be further reduced, which is beneficial to improving the energy density of the battery cell; therefore, when the thickness H6 of the second metal sheet satisfies 0.02mm≤H6≤0.3mm, the strength of the second metal sheet can be increased and the connection with the wall body can be more stable, and the space occupied by the second metal sheet can be further reduced, which is beneficial to improving the energy density of the battery cell.

[0058] In some embodiments of the present application, along the thickness direction of the first wall, the width of the overlapping portion between the projection of the adhesive film and the projection of the first wall is W3, satisfying 0.1 mm≤W3≤3 mm.

[0059] In the above technical solution, when the width W3 of the overlapping part between the projection of the adhesive film and the projection of the first wall is greater than or equal to 0.1 mm, the adhesive film and the first wall can have a larger bonding area, a higher bonding strength, and a smaller possibility of the adhesive film detaching from the first wall. The adhesive film has a better sealing effect on the first through hole, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell. When the width W3 of the overlapping part between the projection of the adhesive film and the projection of the first wall is less than or equal to 3 mm, the space occupied by the adhesive film is smaller, which is beneficial to improving the energy density of the battery cell, and the adhesive film can be suitable for the outer shell. The smaller the size of the battery cell, the wider the application range of the film; therefore, when the width W3 of the overlapping part between the projection of the film and the projection of the first wall satisfies 0.1mm≤W3≤3mm, the bonding strength between the film and the first wall can be higher, the possibility of the film detaching from the first wall is lower, and the sealing effect of the film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell. The space occupied by the film is smaller, which is beneficial to improving the energy density of the battery cell. The film can be suitable for battery cells with smaller shell sizes, which makes the application range of the film wider.

[0060] In some embodiments of the present application, 0.2 mm ≤ W3 ≤ 1.5 mm.

[0061] In the above technical solution, when the width W3 of the overlapping part between the projection of the adhesive film and the projection of the first wall is greater than or equal to 0.2 mm, the bonding area between the adhesive film and the first wall can be further increased, the bonding strength can be higher, the possibility of the adhesive film detaching from the first wall is smaller, and the sealing effect of the adhesive film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell; when the width W3 of the overlapping part between the projection of the adhesive film and the projection of the first wall is less than or equal to 1.5 mm, the space occupied by the adhesive film can be further reduced, which is beneficial to improving the energy density of the battery cell, and the adhesive film can be suitable for the outer shell. The smaller the size of the battery cell, the wider the application range of the film; therefore, when the width W3 of the overlapping part between the projection of the film and the projection of the first wall satisfies 0.2mm≤W3≤1.5mm, the bonding strength between the film and the first wall can be further increased, the possibility of the film detaching from the first wall is reduced, and the sealing effect of the film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell. The space occupied by the film is further reduced, which is beneficial to improving the energy density of the battery cell. The film can be suitable for battery cells with smaller shell sizes, which makes the film have a wider application range.

[0062] In some embodiments of the present application, the housing includes a shell and a shell cover, the shell has an opening, and the shell cover is arranged on the opening. The shell includes a bottom wall and a plurality of side walls arranged around the bottom wall, the bottom wall and the shell cover are arranged opposite to each other along the thickness direction of the battery cell, and the first wall is one of the plurality of side walls. The battery cell includes an electrode terminal, and the electrode terminal is arranged on the first wall.

[0063] In the above technical solution, by arranging the first through hole and the electrode terminal on the first wall, when the battery cell is depressurized, the internal space and external space reserved for the electrode terminal can be used, thereby saving the internal space of the battery cell and the space of the electrical equipment equipped with the battery cell, making the structure of the electrical equipment more compact and the cost of preparing the battery cell depressurization lower.

[0064] In a second aspect, the present application provides a pressure relief mechanism, which includes a second metal sheet, an adhesive film, and an anti-corrosion layer. The second metal sheet is provided with a first through hole, and the second metal sheet has a third surface and a fourth surface opposite to each other along its thickness direction. The adhesive film is provided on the third surface, and the adhesive film is used to seal the first through hole. The adhesive film is connected to the second metal sheet to form a sealing surface. When viewed from the fourth surface toward the third surface, the adhesive film has a first surface facing away from the fourth surface, and the first surface has a first edge. The anti-corrosion layer is provided on the fourth surface and covers the first edge, and the first edge is the outer contour of the first surface. The pressure relief mechanism is used for pressure relief of the battery cell.

[0065] In the above technical solution, by setting the adhesive film on the third surface, the adhesive film is used to seal the first through hole, so that the adhesive film can be heated and melted to form a pressure relief channel, the thermal sensitivity of the pressure relief of the battery cell can be better, the reliability of the pressure relief can be higher, the safety of the battery cell can be improved, and compared with the notched groove pressure relief structure, this embodiment does not need to reserve a large space, the structure of the electrical equipment can be more compact, and the cost of preparing the battery cell is lower. By connecting the adhesive film with the second metal sheet to form a sealing surface, when viewed from the fourth surface toward the third surface, the adhesive film has a first surface away from the fourth surface, and the first surface has a first edge. The anti-corrosion layer is set on the fourth surface and covers the first edge, and the first edge is the outer contour of the first surface, so that the anti-corrosion layer can prevent the electrolyte of the battery cell from corroding the sealing surface of the adhesive film and the second metal sheet, so that the sealing effect of the adhesive film on the first through hole is better, which is beneficial to improving the safety of the battery cell and extending the service life of the battery cell; and the anti-corrosion layer can form a seal with the fourth surface, so that the sealing area of ​​the adhesive film and the anti-corrosion layer to the first through hole is larger, and the sealing effect is better.

[0066] In a third aspect, the present application provides an electrical device, including a battery cell as described above, and the battery cell is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can also be obtained based on these drawings.

[0068] Figure 1 A schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application;

[0069] Figure 2 An exploded schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0070] Figure 3 A schematic cross-sectional view of a partial structure of a battery cell provided in some embodiments of the present application;

[0071] Figure 4 for Figure 3 A partial enlarged structural diagram of the battery cell;

[0072] Figure 5 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0073] Figure 6 An exploded schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0074] Figure 7 A schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0075] Figure 8 A schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0076] Fig. 9 A schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0077] Fig.10 A schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0078] Fig.11 An exploded schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0079] Fig.12 A schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0080] Fig.13 A schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application;

[0081] Fig.14 A partially enlarged schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application.

[0082] Icons: 10-battery cell; 100-housing; 101-first through hole; 102-third through hole; 110-first wall; 111-inner surface of the first wall; 112-outer surface of the first wall; 113-wall body; 114-second metal sheet; 115-third surface; 116-fourth surface; 120-housing; 121-bottom wall; 122-side wall; 130-shell cover; 200-composite part; 201-second through hole; 210-adhesive film; 211-sealing surface; 2111-first sub-sealing surface; 2112-second sub-sealing surface; 2113-third sub-sealing surface; 212-first surface; 220-first metal sheet; 230-protective layer; 300-anti-corrosion layer; 301-fourth through hole; 400-electrode terminal; X-thickness direction of the first wall; Y-thickness direction of the battery cell; Z-first direction. DETAILED DESCRIPTION

[0083] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of this application.

[0084] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0085] The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0086] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0087] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0088] With the development of the new energy industry, batteries are gradually developing in the direction of high energy density and high power density. At present, for steel shell batteries, pressure relief mechanisms can be prepared by laser grooving and film sealing. Among them, the film sealing method has good thermal sensitivity and can make the pressure relief reliability higher, but the electrolyte inside the battery cell will cause corrosion to the sealing interface between the film and the metal parts, causing the sealing of the film to deteriorate or even fail, which in turn leads to the risk of leakage in the battery cell, affecting the safety and service life of the battery cell.

[0089] In order to improve the safety of a battery cell, the present application provides a battery cell, which includes a shell, a film and an anti-corrosion layer. The shell includes a first wall, and the first wall is provided with a first through hole. The film is used to seal the first through hole, and the film is connected to the first wall to form a sealing surface. The film has a first surface facing the inside of the shell, and the first surface has a first edge. The anti-corrosion layer is arranged on the inner surface and the first surface of the first wall, and covers the first edge, and the first edge is the outer contour of the first surface. Among them, the film can be melted by heat to form a pressure relief channel connecting the inside and outside of the shell.

[0090] In the battery cell of this structure, the shell includes a first wall, the first wall is provided with a first through hole, the adhesive film is used to seal the first through hole, the adhesive film can be melted by heat to form a pressure relief channel connecting the inside and outside of the shell, the thermal sensitivity of the pressure relief of the battery cell is good, the reliability of the pressure relief is high, the safety of the battery cell can be improved, and compared with the notched groove pressure relief structure, this embodiment does not need to reserve a large space, the structure of the electrical equipment can be more compact, and the cost of preparing the battery cell is lower. By connecting the adhesive film with the first wall to form a sealing surface, the adhesive film has a first surface facing the inside of the shell, the first surface has a first edge, the anti-corrosion layer is provided on the inner surface of the first wall and the first surface, and covers the first edge, the first edge is the outer contour of the first surface, the possibility of the electrolyte inside the shell causing corrosion to the sealing surface of the adhesive film and the first wall can be reduced, so that the sealing effect of the adhesive film on the first through hole is better, which is conducive to improving the safety of the battery cell and extending the service life of the battery cell; and the anti-corrosion layer can form a seal with the first surface, so that the sealing area of ​​the adhesive film and the anti-corrosion layer to the first through hole is larger, and the sealing effect is better.

[0091] The battery cell provided in the embodiment of the present application can be a secondary battery or a primary battery, for example, a lithium ion battery, a sodium ion battery or a magnesium ion battery, etc., which is not limited in the embodiment of the present application. The electrochemical device can be cylindrical, flat, rectangular or other shapes, etc., which is not limited in the embodiment of the present application.

[0092] The embodiments of the present application provide an electrical device that uses a battery cell as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, and the like.

[0093] See also Figures 1 to 6 , Figure 1 A schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application; Figure 2 An exploded schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0094] Figure 3 A schematic cross-sectional view of a partial structure of a battery cell provided in some embodiments of the present application; Figure 4 for Figure 3 A partial enlarged structural diagram of the battery cell; Figure 5 A schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application; Figure 6 An exploded schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application.

[0095] The embodiment of the present application provides a battery cell 10, which includes a shell 100, a film 210 and an anti-corrosion layer 300. The shell 100 includes a first wall 110, and the first wall 110 is provided with a first through hole 101. The film 210 is used to seal the first through hole 101, and the film 210 is connected to the first wall 110 to form a sealing surface 211. The film 210 has a first surface 212 facing the inside of the shell 100, and the first surface 212 has a first edge. The anti-corrosion layer 300 is arranged on the inner surface 111 of the first wall and the first surface 212, and covers the first edge, and the first edge is the outer contour of the first surface 212. Among them, the film 210 can be melted by heat to form a pressure relief channel connecting the inside and outside of the shell 100.

[0096] By making the shell 100 include a first wall 110, the first wall 110 is provided with a first through hole 101, and the adhesive film 210 is used to seal the first through hole 101, the adhesive film 210 can be melted by heat to form a pressure relief channel connecting the inside and the outside of the shell 100, so that the thermal sensitivity of the pressure relief of the battery cell 10 is better, the reliability of the pressure relief is higher, and the safety of the battery cell 10 can be improved. Compared with the notched groove pressure relief structure, this embodiment does not need to reserve a large space, can make the structure of the electrical equipment more compact, and the cost of preparing the battery cell 10 is lower. The sealing surface 211 is formed by connecting the adhesive film 210 with the first wall 110. The adhesive film 210 has a first surface 212 facing the inside of the shell 100. The first surface 212 has a first edge. The anti-corrosion layer 300 is arranged on the inner surface 111 of the first wall and the first surface 212, and covers the first edge. The first edge is the outer contour of the first surface 212. This can reduce the possibility of the electrolyte inside the shell 100 corroding the sealing surface 211 between the adhesive film 210 and the first wall 110, so that the sealing effect of the adhesive film 210 on the first through hole 101 is better, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10; and a seal can be formed between the anti-corrosion layer 300 and the first surface 212, so that the sealing surface 211 area of ​​the adhesive film 210 and the anti-corrosion layer 300 on the first through hole 101 is larger, and the sealing effect is better.

[0097] In some embodiments, the shell 100 can be made of a material with higher strength, such as metal materials such as steel, aluminum alloy, etc., so that the shell 100 has a higher force-bearing performance, and thus the shell 100 is not easily deformed or damaged due to force or environmental changes, thereby making the reliability of the battery cell 10 higher.

[0098] In other embodiments, the housing 100 may also be made of non-metallic materials with relatively high strength, such as carbon fiber, hard plastic, etc.

[0099] In some embodiments, the battery cell 10 is in the shape of a rectangular parallelepiped with rounded top corners, so as to better fit into a rounded battery compartment in an electrical device.

[0100] In other embodiments, the top corners of the battery cell 10 may also be arranged in a square angle.

[0101] See also Figure 6 In some embodiments, the thickness of the anti-corrosion layer 300 is H1, which satisfies 10 nm ≤ H1 ≤ 2 mm. For example, H1 can be 10 nm, 100 nm, 1 mm, or 2 mm.

[0102] The thickness of the anti-corrosion layer 300 is the thickness of the overlapping portion of the anti-corrosion layer 300 and the first wall 110 .

[0103] When the thickness H1 of the anti-corrosion layer 300 is greater than or equal to 10 nm, the anti-corrosion layer 300 can have a better anti-corrosion effect on the electrolyte, and the adhesive film 210 can have a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10, and can also make the sealing effect between the anti-corrosion layer 300 and the first surface 212 better; when the thickness H1 of the anti-corrosion layer 300 is less than or equal to 2 mm, the space occupied by the anti-corrosion layer 300 can be smaller, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10. 0 energy density; therefore, when the thickness H1 of the anti-corrosion layer 300 satisfies 10nm≤H1≤2mm, it can not only make the anti-corrosion effect of the anti-corrosion layer 300 on the electrolyte better, but also make the sealing effect of the adhesive film 210 on the first through hole 101 better, which is beneficial to improve the safety of the battery cell 10 and extend the service life of the battery cell 10, and can make the sealing effect between the anti-corrosion layer 300 and the first surface 212 better, but also make the space occupied by the anti-corrosion layer 300 smaller, which is beneficial to improve the energy density of the battery cell 10.

[0104] In some embodiments, 10 nm ≤ H1 ≤ 0.1 mm. For example, H1 may be 10 nm, 100 nm, 0.01 mm, or 0.1 mm.

[0105] When the thickness H1 of the anti-corrosion layer 300 is greater than or equal to 10 nm, the anti-corrosion effect of the anti-corrosion layer 300 on the electrolyte can be better, and the sealing effect of the adhesive film 210 on the first through hole 101 can be better, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10, and can make the sealing effect between the anti-corrosion layer 300 and the first surface 212 better; when the thickness H1 of the anti-corrosion layer 300 is less than or equal to 0.1 mm, the space occupied by the anti-corrosion layer 300 can be further reduced, which is beneficial to improving the battery cell 1 0 energy density; therefore, when the thickness H1 of the anti-corrosion layer 300 satisfies 10nm≤H1≤0.1mm, it can not only make the anti-corrosion effect of the anti-corrosion layer 300 on the electrolyte better, but also make the sealing effect of the adhesive film 210 on the first through hole 101 better, which is beneficial to improve the safety of the battery cell 10 and extend the service life of the battery cell 10, and can make the sealing effect between the anti-corrosion layer 300 and the first surface 212 better, but also can further make the space occupied by the anti-corrosion layer 300 smaller, which is beneficial to improve the energy density of the battery cell 10.

[0106] In some embodiments, the material of the anti-corrosion layer 300 includes at least one of ceramic, polypropylene, fluoride, polyvinylidene fluoride, carbon-based materials, titanium, and nickel-based materials.

[0107] By making the material of the anti-corrosion layer 300 include at least one of ceramic, polypropylene, fluoride, polyvinylidene fluoride, carbon-based materials, titanium, and nickel-based materials, the anti-corrosion layer 300 can have a better corrosion resistance against the electrolyte, and the adhesive film 210 can have a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10.

[0108] In some embodiments, the material of the adhesive film 210 includes a high molecular polymer, such as polypropylene (PP).

[0109] In some embodiments, the melting point of the adhesive film 210 is T1, which satisfies 100° C. ≤ T1 ≤ 130° C. For example, T1 may be 100° C., 110° C., 120° C., or 130° C., etc.

[0110] When the melting point T1 of the adhesive film 210 is greater than or equal to 100°C, the possibility of the adhesive film 210 melting and failing when the battery cell 10 does not produce thermal runaway can be reduced, thereby improving the sealing reliability of the adhesive film 210 to the first through hole 101 and improving the safety of the battery cell 10; when the melting point T1 of the adhesive film 210 is less than or equal to 130°C, the adhesive film 210 can melt when the battery cell 10 has thermal runaway so as to quickly open the first through hole 101, thereby making the battery cell 10 more sensitive to pressure relief; therefore, when the melting point T1 of the adhesive film 210 satisfies 100°C≤T1≤130°C, it can not only improve the sealing reliability of the adhesive film 210 to the first through hole 101 and improve the safety of the battery cell 10, but also make the battery cell 10 more sensitive to pressure relief.

[0111] In some embodiments, the melting point of the anti-corrosion layer 300 is T2, which satisfies 90° C. ≤ T2 ≤ 130° C. For example, T2 may be 90° C., 100° C., 110° C., 120° C., or 130° C.

[0112] When the melting point T2 of the anti-corrosion layer 300 is greater than or equal to 90°C, the possibility of the anti-corrosion layer 300 melting and failing when the battery cell 10 does not produce thermal runaway can be reduced, thereby improving the reliability of the anti-corrosion layer 300 in resisting corrosion of the electrolyte, which is beneficial to extending the service life of the battery cell 10; when the melting point T2 of the anti-corrosion layer 300 is less than or equal to 130°C, the anti-corrosion layer 300 can melt when the battery cell 10 has thermal runaway so as to quickly open the first through hole 101, thereby making the battery cell 10 more sensitive to pressure relief; therefore, when the melting point T2 of the anti-corrosion layer 300 satisfies 90°C≤T2≤130°C, it can not only improve the reliability of the anti-corrosion layer 300 in resisting corrosion of the electrolyte, which is beneficial to extending the service life of the battery cell 10, but also make the battery cell 10 more sensitive to pressure relief. The melting points of the adhesive film 210 and the anti-corrosion layer 300 are close, so that when the battery cell 10 thermally runs away, both the adhesive film 210 and the anti-corrosion layer 300 can melt, thereby facilitating the rapid opening of the first through hole 101 and making the pressure relief sensitivity of the battery cell 10 higher.

[0113] In some embodiments, the melting point T2 of the anti-corrosion layer 300 is lower than the melting point T1 of the adhesive film 210 .

[0114] By making the melting point T2 of the anti-corrosion layer 300 lower than the melting point T1 of the adhesive film 210 , the anti-corrosion layer 300 can be melted first when the battery cell 10 needs to release pressure, thereby achieving a better pressure release effect.

[0115] See also Figure 2 In some embodiments, the adhesive film 210 may be arranged in a circular shape, the first through hole 101 may be arranged in a circular shape, and the anti-corrosion layer 300 may be arranged in a circular shape.

[0116] By setting the adhesive film 210 into a circle, the adhesive film 210 can be assembled in the circular first through hole 101, and when the center of the adhesive film 210 is collinear with the center of the first through hole 101, the contact surface between the adhesive film 210 and the first wall 110 is evenly distributed, the sealing effect is better, and the installation of the adhesive film 210 is facilitated.

[0117] See also Figure 5 In some embodiments, the area of ​​the inner surface 111 of the first wall covered by the anti-corrosion layer 300 is the first area, and along the radial direction of the first through hole 101, the width of the first area is W1, which satisfies 10μm≤W1≤3mm. For example, W1 can be 10μm, 100μm, 1mm, 2mm or 3mm.

[0118] When W1≥10μm, the path of the electrolyte from the first area to the first edge can be longer, thereby further reducing the possibility of the electrolyte corroding the sealing surface 211 of the adhesive film 210 and the first wall 110, so that the adhesive film 210 has a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10; when W1≤3mm, the space occupied by the anti-corrosion layer 300 can be smaller, and the adhesive film 210 can be adapted to more battery cells 10 of different sizes; therefore, when 10μm≤W1≤3mm, the sealing effect of the adhesive film 210 on the first through hole 101 can be better, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10, and the space occupied by the anti-corrosion layer 300 can be smaller, so that the adhesive film 210 can be adapted to more battery cells 10 of different sizes.

[0119] In some embodiments, 100 μm≤W1≤3 mm. For example, W1 may be 100 μm, 500 μm, 1.2 mm, 2.5 mm, or 3 mm.

[0120] When W1≥100μm, the path of the electrolyte from the first area to the first edge can be further lengthened, thereby further reducing the possibility of the electrolyte corroding the sealing surface 211 of the adhesive film 210 and the first wall 110, so that the adhesive film 210 has a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10; when W1≤3mm, the space occupied by the anti-corrosion layer 300 can be smaller, so that the adhesive film 210 can be adapted to more battery cells 10 of different sizes; therefore, when 100μm≤W1≤3mm, it can not only further improve the sealing effect of the adhesive film 210 on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10, but also can make the space occupied by the anti-corrosion layer 300 smaller, so that the adhesive film 210 can be adapted to more battery cells 10 of different sizes.

[0121] In some embodiments, the area of ​​the first surface 212 covered by the anti-corrosion layer 300 is the second area, and along the radial direction of the first through hole 101, the width of the second area is W2, which satisfies 10 μm≤W2≤3 mm. For example, W2 can be 10 μm, 100 μm, 1 mm, 2 mm or 3 mm.

[0122] When W2≥10μm, the path of the electrolyte from the second area to the first edge can be longer, thereby further reducing the possibility of the electrolyte corroding the sealing surface 211 of the adhesive film 210 and the first wall 110, so that the adhesive film 210 has a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10; when W2≤3mm, the space occupied by the anti-corrosion layer 300 can be smaller, and the adhesive film 210 can be adapted to more battery cells 10 of different sizes; therefore, when 10μm≤W2≤3mm, the sealing effect of the adhesive film 210 on the first through hole 101 can be better, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10, and the space occupied by the anti-corrosion layer 300 can be smaller, so that the adhesive film 210 can be adapted to more battery cells 10 of different sizes.

[0123] In some embodiments, 100 μm≤W2≤3 mm. For example, W2 may be 100 μm, 500 μm, 1.3 mm, 2.1 mm, or 3 mm.

[0124] When W2≥100μm, the path of the electrolyte from the second area to the first edge can be further lengthened, thereby further reducing the possibility of the electrolyte corroding the sealing surface 211 of the adhesive film 210 and the first wall 110, so that the adhesive film 210 has a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10; when W2≤3mm, the space occupied by the anti-corrosion layer 300 can be smaller, so that the adhesive film 210 can be adapted to more battery cells 10 of different sizes; therefore, when 100μm≤W2≤3mm, it can not only further improve the sealing effect of the adhesive film 210 on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10, but also can make the space occupied by the anti-corrosion layer 300 smaller, so that the adhesive film 210 can be adapted to more battery cells 10 of different sizes.

[0125] See also Figure 5 In some embodiments, the anti-corrosion layer 300 covers the first surface 212. This can further reduce the possibility that the electrolyte inside the housing 100 will corrode the sealing surface 211 between the adhesive film 210 and the first wall 110, so that the adhesive film 210 has a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10.

[0126] See also Figure 7 , Figure 7 Schematic diagram of partial structure of battery cells provided in other embodiments of the present application.

[0127] In other embodiments, the anti-corrosion layer 300 covers a portion of the first surface 212. The anti-corrosion layer 300 is provided with a fourth through hole 301, and the fourth through hole 301 is connected to the inside of the battery cell 10. When high temperature and high pressure are formed inside the battery cell 10, the pressure is directly released through the fourth through hole 301, further improving the reliability of the pressure release of the battery cell 10.

[0128] See also Figure 5 In some embodiments, the adhesive film 210 is connected to the outer surface 112 of the first wall to form a first sub-sealing surface 2111, and the adhesive film 210 is connected to the hole wall of the first through hole 101 to form a second sub-sealing surface 2112. The first sub-sealing surface 2111 and the second sub-sealing surface 2112 constitute a sealing surface 211.

[0129] By connecting the adhesive film 210 with the outer surface 112 of the first wall to form a first sub-sealing surface 2111, and connecting the adhesive film 210 with the hole wall of the first through hole 101 to form a second sub-sealing surface 2112, the first sub-sealing surface 2111 and the second sub-sealing surface 2112 form a sealing surface 211, which can make the sealing surface 211 of the adhesive film 210 and the first wall 110 larger, and the sealing effect of the adhesive film 210 and the first wall 110 is better, thereby reducing the possibility of electrolyte leakage, which is beneficial to improving the safety of the battery cell 10.

[0130] See also Figure 8 , Figure 8 Schematic diagram of partial structure of battery cells provided in other embodiments of the present application.

[0131] In some other embodiments, the adhesive film 210 is connected to the outer surface 112 of the first wall to form a sealing surface 211 .

[0132] By connecting the adhesive film 210 and the outer surface 112 of the first wall to form a sealing surface 211 , the assembly of the adhesive film 210 and the housing 100 can be facilitated.

[0133] See also Fig. 9 , Fig. 9 Schematic diagram of partial structure of battery cells provided in other embodiments of the present application.

[0134] In other embodiments, the adhesive film 210 is connected to the outer surface 112 of the first wall to form a first sub-sealing surface 2111, the adhesive film 210 is connected to the hole wall of the first through hole 101 to form a second sub-sealing surface 2112, the adhesive film 210 is connected to the inner surface 111 of the first wall to form a third sub-sealing surface 2113, and the first sub-sealing surface 2111, the second sub-sealing surface 2112 and the third sub-sealing surface 2113 constitute the sealing surface 211. The sealing surface 211 of the adhesive film 210 and the first wall 110 can be made larger, the sealing effect of the adhesive film 210 and the first wall 110 is better, the possibility of electrolyte leakage is reduced, and the safety of the battery cell 10 is improved.

[0135] See also Figure 5 , Figure 7 and Figure 8 In some embodiments, the adhesive film 210 covers the first through hole 101 .

[0136] By making the adhesive film 210 cover the first through hole 101 , the adhesive film 210 itself can cover and seal the first through hole 101 , thereby making the overall structure of the battery cell 10 simple and easy to prepare, and helping to reduce the preparation cost of the battery cell 10 .

[0137] In some embodiments, the battery cell 10 includes a first metal sheet 220 , and the first metal sheet 220 is disposed on a side of the adhesive film 210 facing away from the first wall 110 .

[0138] By arranging the first metal sheet 220 on the side of the adhesive film 210 facing away from the first wall 110 , the possibility of water vapor outside the battery cell 10 penetrating into the battery cell 10 through the adhesive film 210 can be reduced, thereby achieving a better sealing effect.

[0139] In some embodiments, the material of the first metal sheet 220 includes at least one of steel, aluminum, nickel, silver, copper, and alloy materials, so that the first metal sheet 220 has a higher strength and a better water-proof effect.

[0140] In some embodiments, the first metal sheet 220 is arranged in a circular shape, and the adhesive film 210 is arranged in a circular shape, so that the first metal sheet 220 does not need to adjust the assembly direction, and the first metal sheet 220 and the adhesive film 210 can be easily assembled.

[0141] See also Fig.10 and Fig.11 , Fig.10 A schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application; Fig.11 An exploded schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application.

[0142] In some embodiments, the adhesive film 210 is provided with a second through hole 201 , the first metal sheet 220 has a second surface exposed by the second through hole 201 , and the anti-corrosion layer 300 covers the hole wall and the second surface of the second through hole 201 .

[0143] By providing the adhesive film 210 with the second through hole 201, when the adhesive film 210 melts, a pressure relief path can be formed between the adhesive film 210 and the first wall 110, and between the adhesive film 210 and the first metal sheet 220, so that the number of pressure relief channels can be increased, and the pressure relief sensitivity is higher; by making the anti-corrosion layer 300 cover the hole wall and the second surface of the second through hole 201, so that the anti-corrosion layer 300 can cover the edge of the connecting surface between the adhesive film 210 and the first metal sheet 220, the possibility of the electrolyte inside the shell 100 corroding the connecting surface between the adhesive film 210 and the first metal sheet 220 can be reduced, so that the sealing effect of the adhesive film 210 on the first through hole 101 is better, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10.

[0144] In some embodiments, the outer diameter of the adhesive film 210 is greater than the outer diameter of the first metal sheet 220 , and the inner diameter of the adhesive film 210 is smaller than the diameter of the first through hole 101 .

[0145] By making the outer diameter of the adhesive film 210 larger than the outer diameter of the first metal sheet 220, the connection area between the first metal sheet 220 and the adhesive film 210 can be made larger, which facilitates the assembly of the first metal sheet 220 and the adhesive film 210; by making the inner diameter of the adhesive film 210 smaller than the diameter of the first through hole 101, it is convenient for the adhesive film 210 to cover the first through hole 101, so that the sealing effect of the adhesive film 210 on the first through hole 101 is better, which is beneficial to improve the safety of the battery cell 10 and extend the service life of the battery cell 10.

[0146] See also Figures 5 to 11 In some embodiments, a protective layer 230 is disposed on the side of the first metal sheet 220 facing away from the adhesive film 210 .

[0147] By providing a protective layer 230 on the side of the first metal sheet 220 facing away from the adhesive film 210 , the possibility of oxidation of the first metal sheet 220 and the possibility of other components piercing the first metal sheet 220 and the adhesive film 210 can be reduced, thereby improving the sealing effect of the first through hole 101 .

[0148] In some embodiments, the material of the protective layer 230 includes a high molecular polymer, such as at least one of polyethylene terephthalate (PET), polyamide (PA), polypropylene (PP), polyethylene (PE), polyimide (PI), polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PU), polycarbonate (PC), and polyetheretherketone (PEEK) materials.

[0149] In some embodiments, the adhesive film 210 , the first metal sheet 220 , and the protective layer 230 are hot pressed into a composite part 200 .

[0150] By hot pressing the adhesive film 210, the first metal sheet 220, and the protective layer 230 into the composite part 200, the first wall 110 can be better transferred to the composite part 200 when the force is applied, so that the composite part 200 and the first wall 110 are deformed together, reducing the possibility of the composite part 200 and the first wall 110 peeling off and leaking; and the integration of the composite part 200 can make the composite part 200 more flexible, and when high temperature and high pressure are formed inside the battery cell 10, it is easier to deform to open the first through hole 101 for pressure relief.

[0151] See also Figure 6 In some embodiments, the thickness of the composite member 200 is H2, which satisfies 0.03 mm ≤ H2 ≤ 1 mm. For example, H2 may be 0.03 mm, 0.05 mm, 0.08 mm, 0.1 mm, 0.5 mm, 1 mm, etc.

[0152] The thickness of the composite member 200 is the thickness of the overlapping portion of the composite member 200 and the first wall 110 .

[0153] When the thickness H2 of the composite component 200 is greater than or equal to 0.03 mm, the strength and flexibility of the composite component 200 can be improved, and the sealing performance of the first through hole 101 can be better, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10; when the thickness H2 of the composite component 200 is less than or equal to 1 mm, the space occupied by the composite component 200 can be smaller, which is beneficial to improving the energy density of the battery cell 10; therefore, when the thickness H2 of the composite component 200 satisfies 0.03 mm ≤ H2 ≤ 1 mm, the strength and flexibility of the composite component 200 can be improved, and the sealing performance of the first through hole 101 can be better, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10, and the space occupied by the composite component 200 can be smaller, which is beneficial to improving the energy density of the battery cell 10.

[0154] In some embodiments, the thickness of the adhesive film 210 is H3, which satisfies 0.01 mm≤H3≤0.5 mm. For example, H3 may be 0.01 mm, 0.05 mm, 0.1 mm, 0.3 mm, or 0.5 mm.

[0155] The thickness of the adhesive film 210 is the thickness of the overlapping portion of the adhesive film 210 and the first wall 110 .

[0156] When the thickness H3 of the adhesive film 210 is greater than or equal to 0.01 mm, the adhesive film 210 can have a stronger adhesive force, lower water permeability, and is not easily damaged, so that the adhesive film 210 has a better sealing effect on the first through hole 101; when the thickness H3 of the adhesive film 210 is less than or equal to 0.5 mm, the space occupied by the adhesive film 210 is smaller, which is beneficial to improving the energy density of the battery cell 10; therefore, when the thickness H3 of the adhesive film 210 satisfies 0.01 mm≤H3≤0.5 mm, the adhesive film 210 can have a stronger adhesive force, lower water permeability, and is not easily damaged, so that the adhesive film 210 has a better sealing effect on the first through hole 101, and the space occupied by the adhesive film 210 is smaller, which is beneficial to improving the energy density of the battery cell 10.

[0157] In some embodiments, the thickness of the first metal sheet 220 is H4, which satisfies 0.01 mm≤H4≤0.25 mm. For example, H4 may be 0.01 mm, 0.05 mm, 0.1 mm, or 0.25 mm.

[0158] When the thickness H4 of the first metal sheet 220 is greater than or equal to 0.01mm, the strength of the first metal sheet 220 can be higher and the water permeability can be lower, so that the sealing effect of the first through hole 101 is better; when the thickness H4 of the first metal sheet 220 is less than or equal to 0.25mm, the space occupied by the first metal sheet 220 can be smaller, which is beneficial to improving the energy density of the battery cell 10; therefore, when the thickness H4 of the first metal sheet 220 satisfies 0.01mm≤H4≤0.25mm, the strength of the first metal sheet 220 can be higher and the water permeability can be lower, so that the sealing effect of the first through hole 101 is better, and the space occupied by the first metal sheet 220 can be smaller, which is beneficial to improving the energy density of the battery cell 10.

[0159] In some embodiments, the thickness of the protective layer 230 is H5, which satisfies 0.01 mm≤H5≤0.25 mm. For example, H5 can be 0.01 mm, 0.05 mm, 0.1 mm, or 0.25 mm.

[0160] When the thickness H5 of the protective layer 230 is greater than or equal to 0.01 mm, the protective layer 230 can better protect the first metal sheet 220, reduce the possibility of oxidation of the first metal sheet 220, and reduce the possibility of other components piercing the first metal sheet 220 and the adhesive film 210, so that the sealing effect of the first through hole 101 is better; when the thickness H5 of the protective layer 230 is less than or equal to 0.25 mm, the space occupied by the protective layer 230 is smaller, which is beneficial to improving the energy density of the battery cell 10; therefore, when the thickness H5 of the protective layer 230 satisfies 0.01 mm≤H5≤0.25 mm, the protective layer 230 can better protect the first metal sheet 220, reduce the possibility of oxidation of the first metal sheet 220, and reduce the possibility of other components piercing the first metal sheet 220 and the adhesive film 210, so that the sealing effect of the first through hole 101 is better, and the space occupied by the protective layer 230 is smaller, which is beneficial to improving the energy density of the battery cell 10.

[0161] In some embodiments, 0.02 mm ≤ H3 ≤ 0.3 mm. For example, H3 may be 0.02 mm, 0.05 mm, 0.1 mm, 0.2 mm, or 0.3 mm.

[0162] When the thickness of the adhesive film 210 is greater than or equal to 0.02 mm, the adhesive force of the adhesive film 210 can be further made stronger, the water permeability is lower, and it is not easy to be damaged, so that the sealing effect of the adhesive film 210 on the first through hole 101 is better; when the thickness of the adhesive film 210 is less than or equal to 0.3 mm, the space occupied by the adhesive film 210 can be further made smaller, which is beneficial to improving the energy density of the battery cell 10; therefore, when the thickness H3 of the adhesive film 210 satisfies 0.02 mm≤H3≤0.3 mm, it can not only further make the adhesive force of the adhesive film 210 stronger, the water permeability is lower, and it is not easy to be damaged, so that the sealing effect of the adhesive film 210 on the first through hole 101 is better, but also can further make the space occupied by the adhesive film 210 smaller, which is beneficial to improving the energy density of the battery cell 10.

[0163] In some embodiments, 0.01 mm ≤ H4 ≤ 0.15 mm. For example, H4 may be 0.01 mm, 0.05 mm, 0.1 mm, or 0.15 mm.

[0164] When the thickness of the first metal sheet 220 is greater than or equal to 0.01mm, the strength of the first metal sheet 220 can be higher and the water permeability can be lower, so that the sealing effect of the first through hole 101 is better; when the thickness of the first metal sheet 220 is less than or equal to 0.15mm, the space occupied by the first metal sheet 220 can be further reduced, which is beneficial to improving the energy density of the battery cell 10; therefore, when the thickness H4 of the first metal sheet 220 satisfies 0.01mm≤H4≤0.15mm, the strength of the first metal sheet 220 can be higher and the water permeability can be lower, so that the sealing effect of the first through hole 101 is better, and the space occupied by the first metal sheet 220 can be further reduced, which is beneficial to improving the energy density of the battery cell 10.

[0165] In some embodiments, 0.01 mm ≤ H5 ≤ 0.15 mm. For example, H5 may be 0.01 mm, 0.05 mm, 0.1 mm, or 0.15 mm.

[0166] When the thickness of the protective layer 230 is greater than or equal to 0.01 mm, the protective layer 230 can better protect the first metal sheet 220, reduce the possibility of oxidation of the first metal sheet 220, and reduce the possibility of other components piercing the first metal sheet 220 and the adhesive film 210, so that the sealing effect of the first through hole 101 is better; when the thickness of the protective layer 230 is less than or equal to 0.15 mm, it can further make the space occupied by the protective layer 230 smaller, which is beneficial to improve the energy density of the battery cell 10; therefore, when the thickness H5 of the protective layer 230 satisfies 0.01 mm≤H5≤0.15 mm, it can not only make the protective layer 230 better protect the first metal sheet 220, reduce the possibility of oxidation of the first metal sheet 220, reduce the possibility of other components piercing the first metal sheet 220 and the adhesive film 210, so that the sealing effect of the first through hole 101 is better, but also can further make the space occupied by the protective layer 230 smaller, which is beneficial to improve the energy density of the battery cell 10.

[0167] See also Fig.12 , Fig.12 Schematic diagram of partial structure of battery cells provided in other embodiments of the present application.

[0168] In other embodiments, the first through hole 101 may be covered and sealed by the adhesive film 210 , so that the structure of the battery cell 10 is simpler, which is beneficial to improving the preparation efficiency of the battery cell 10 and reducing the preparation cost of the battery cell 10 .

[0169] See also Fig.13 , Fig.13 Schematic diagram of partial structure of battery cells provided in other embodiments of the present application.

[0170] In other embodiments, the first through hole 101 may be covered and sealed by the adhesive film 210 and the first metal sheet 220 , so that the structure of the battery cell 10 is simple, which is beneficial to improving the preparation efficiency of the battery cell 10 and reducing the preparation cost of the battery cell 10 .

[0171] See also Figures 2 to 6 In some embodiments, the first wall 110 includes a wall body 113 and a second metal sheet 114 , the wall body 113 is provided with a third through hole 102 , the second metal sheet 114 covers the third through hole 102 and is welded to the wall body 113 , and the first through hole 101 is provided in the second metal sheet 114 .

[0172] By setting the second metal sheet 114, the second metal sheet 114 covers the third through hole 102 and is welded to the wall body 113, the connection between the second metal sheet 114 and the wall body 113 can be stabilized, and the second metal sheet 114, the adhesive film 210, and the anti-corrosion layer 300 can form a standard part to be assembled with the casing 100 of different models of battery cells 10, which can improve the preparation efficiency of the battery cells 10.

[0173] In some embodiments, the third through hole 102 is a liquid injection hole for injecting electrolyte into the interior of the housing 100 through the liquid injection hole so that the electrolyte can infiltrate the electrode assembly disposed inside the housing 100 .

[0174] By reusing the injection hole as the third through hole 102 for pressure relief, the preparation process of the battery cell 10 can be further simplified and the preparation cost of the battery cell 10 can be reduced.

[0175] In some embodiments, the material of the second metal sheet 114 includes at least one of aluminum, nickel, and stainless steel, so that the second metal sheet 114 has a higher strength.

[0176] In some embodiments, the material of the second metal sheet 114 is the same as that of the wall body 113 , which can facilitate welding of the second metal sheet 114 and the wall body 113 .

[0177] In some embodiments, the second metal sheet 114 is circular, and the radius of the second metal sheet 114 is R; along the radial direction of the second metal sheet 114, the width of the overlapping portion of the anti-corrosion layer 300 and the second metal sheet 114 is W1, satisfying 5%≤W1 / R≤100%.

[0178] Since the first through hole 101 is arranged on the second metal sheet 114, that is, the adhesive film 210 is connected to the second metal sheet 114 to form the sealing surface 211, by making the width of the overlapping part of the anti-corrosion layer 300 and the second metal sheet 114 along the radial direction of the second metal sheet 114 W1, and satisfying 5%≤W1 / R≤100%, the path of the electrolyte through the overlapping part of the anti-corrosion layer 300 and the second metal sheet 114 to the first edge of the sealing surface 211 can be longer, thereby further reducing the possibility of the electrolyte corroding the sealing surface 211 of the adhesive film 210 and the second metal sheet 114, so that the adhesive film 210 has a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10.

[0179] In some embodiments, the thickness of the second metal sheet 114 is H6, which satisfies 0.02 mm≤H6≤0.5 mm. For example, H6 may be 0.02 mm, 0.05 mm, 0.1 mm, 0.2 mm, or 0.5 mm.

[0180] When the thickness H6 of the second metal sheet 114 is greater than or equal to 0.02 mm, the strength of the second metal sheet 114 can be increased, and the connection with the wall body 113 can be more stable; when the thickness H6 of the second metal sheet 114 is less than or equal to 0.5 mm, the space occupied by the second metal sheet 114 is smaller, which is beneficial to improving the energy density of the battery cell 10; therefore, when the thickness H6 of the second metal sheet 114 satisfies 0.02 mm≤H6≤0.5 mm, the strength of the second metal sheet 114 can be increased, the connection with the wall body 113 can be more stable, and the space occupied by the second metal sheet 114 can be smaller, which is beneficial to improving the energy density of the battery cell 10.

[0181] In some embodiments, 0.02 mm ≤ H6 ≤ 0.3 mm. For example, H6 may be 0.02 mm, 0.06 mm, 0.15 mm, 0.25 mm, or 0.3 mm.

[0182] When the thickness H6 of the second metal sheet 114 is greater than or equal to 0.02 mm, the strength of the second metal sheet 114 can be increased and the connection with the wall body 113 can be more stable; when the thickness H6 of the second metal sheet 114 is less than or equal to 0.3 mm, the space occupied by the second metal sheet 114 can be further reduced, which is beneficial to improving the energy density of the battery cell 10; therefore, when the thickness H6 of the second metal sheet 114 satisfies 0.02 mm≤H6≤0.3 mm, the strength of the second metal sheet 114 can be increased and the connection with the wall body 113 can be more stable, and the space occupied by the second metal sheet 114 can be further reduced, which is beneficial to improving the energy density of the battery cell 10.

[0183] See also Fig.14 , Fig.14A partially enlarged schematic diagram of a partial structure of a battery cell provided in some other embodiments of the present application.

[0184] In other embodiments, the first wall 110 is a wall of the housing 100, and the first through hole 101 is directly disposed on the first wall 110. This can make the overall structure of the battery cell 10 simpler, and the pressure relief structure composed of the adhesive film 210 and the anti-corrosion layer 300 occupies less space, which is beneficial to improving the energy density of the battery cell 10.

[0185] See also Figure 5 In some embodiments, along the thickness direction X of the first wall, the width of the overlapping portion of the projection of the adhesive film 210 and the projection of the first wall 110 is W3, which satisfies 0.1mm≤W3≤3mm. For example, W3 can be 0.1mm, 0.2mm, 1mm, 2mm or 3mm.

[0186] When the width W3 of the overlapping portion between the projection of the adhesive film 210 and the projection of the first wall 110 is greater than or equal to 0.1 mm, the adhesive film 210 and the first wall 110 can have a larger bonding area, a higher bonding strength, and a smaller possibility of the adhesive film 210 detaching from the first wall 110. The adhesive film 210 has a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10. When the width W3 of the overlapping portion between the projection of the adhesive film 210 and the projection of the first wall 110 is less than or equal to 3 mm, the space occupied by the adhesive film 210 is smaller, which is beneficial to improving the energy density of the battery cell 10, and the adhesive film 210 can be suitable for batteries with a smaller shell 100. 10, so that the application range of the adhesive film 210 is wider; therefore, when the width W3 of the overlapping part of the projection of the adhesive film 210 and the projection of the first wall 110 satisfies 0.1mm≤W3≤3mm, the bonding strength between the adhesive film 210 and the first wall 110 can be higher, the possibility of the adhesive film 210 detaching from the first wall 110 is smaller, and the sealing effect of the adhesive film 210 on the first through hole 101 is better, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10. The space occupied by the adhesive film 210 is smaller, which is beneficial to improving the energy density of the battery cell 10. The adhesive film 210 can be applied to the battery cell 10 with a smaller shell 100, so that the application range of the adhesive film 210 is wider.

[0187] In some embodiments, 0.2 mm ≤ W3 ≤ 1.5 mm. For example, W3 may be 0.2 mm, 0.5 mm, 0.8 mm, 1.2 mm, or 1.5 mm.

[0188] When the width W3 of the overlapping portion between the projection of the adhesive film 210 and the projection of the first wall 110 is greater than or equal to 0.2 mm, the adhesive area between the adhesive film 210 and the first wall 110 can be further increased, the adhesive strength can be higher, the possibility of the adhesive film 210 being separated from the first wall 110 is smaller, and the sealing effect of the adhesive film 210 on the first through hole 101 is better, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10; when the width W3 of the overlapping portion between the projection of the adhesive film 210 and the projection of the first wall 110 is less than or equal to 1.5 mm, the space occupied by the adhesive film 210 can be further reduced, which is beneficial to improving the energy density of the battery cell 10, and the adhesive film 210 can be suitable for batteries with smaller shells 100. 10, so that the application range of the adhesive film 210 is wider; therefore, when the width W3 of the overlapping part of the projection of the adhesive film 210 and the projection of the first wall 110 satisfies 0.2mm≤W3≤1.5mm, it can not only further make the bonding strength between the adhesive film 210 and the first wall 110 higher, the possibility of the adhesive film 210 detaching from the first wall 110 is smaller, and the sealing effect of the adhesive film 210 on the first through hole 101 is better, which is beneficial to improve the safety of the battery cell 10 and extend the service life of the battery cell 10, but also can further make the space occupied by the adhesive film 210 smaller, which is beneficial to improve the energy density of the battery cell 10, and the adhesive film 210 can be applied to the battery cell 10 with a smaller shell 100, so that the application range of the adhesive film 210 is wider.

[0189] See also Figure 6 In some embodiments, the thickness of the first metal sheet 220 is H4, and the thickness of the second metal sheet 114 is H6, satisfying H4≤1.5*H6. For example, H4 can be 1.5*H6, 1.2*H6 or H6, etc. When the second metal sheet 114 is subjected to force, the first metal sheet 220 can be deformed together with the first metal sheet 220, thereby reducing the possibility of the adhesive film 210 peeling off from the first wall 110 and leaking liquid.

[0190] See also Figure 2 In some embodiments, the housing 100 includes a shell 120 and a shell cover 130, the shell 120 has an opening 103, and the shell cover 130 is covered on the opening 103. The shell 120 includes a bottom wall 121 and a plurality of side walls 122 surrounding the bottom wall 121, the bottom wall 121 and the shell cover 130 are arranged opposite to each other along the thickness direction Y of the battery cell, and the first wall 110 is one of the plurality of side walls 122.

[0191] In some embodiments, the bottom wall 121 and the side wall 122 are integrally formed, which can make the overall structure of the shell 120 stable and prevent gaps or separation between the bottom wall 121 and the side wall 122 due to force or environmental changes, and the shell 120 has better sealing performance.

[0192] In other embodiments, the bottom wall 121 and the side wall 122 may also be separately prepared and formed, and then fixedly connected by welding or bonding.

[0193] In some embodiments, the shell 120 and the shell cover 130 can be welded, which can ensure that the connection between the shell 120 and the shell cover 130 is stable, the sealing of the battery cell 10 is better, and the battery cell 10 is not prone to gaps or separation between the shell 120 and the shell cover 130 due to force or environmental changes, and the reliability of the battery cell 10 is higher.

[0194] In other embodiments, the housing 120 and the housing cover 130 may also be connected by adhesive bonding.

[0195] In some embodiments, the battery cell 10 includes an electrode terminal 400 disposed on the first wall 110. The electrode terminal 400 and the first through hole 101 are spaced apart along the first direction Z. The thickness direction X of the first wall, the thickness direction Y of the battery cell, and the first direction Z are perpendicular to each other.

[0196] By arranging both the first through hole 101 and the electrode terminal 400 on the first wall 110, when the battery cell 10 is depressurized, the internal space and external space reserved for the electrode terminal 400 can be used, thereby saving the internal space of the battery cell 10 and the space of the electrical equipment in which the battery cell 10 is installed, making the structure of the electrical equipment more compact and the cost of preparing the depressurization of the battery cell 10 lower.

[0197] See also Figure 3 In some embodiments, the thickness D of the battery cell 10 is less than 4.5 mm. For example, the thickness D of the battery cell 10 may be 4.4 mm, 4 mm, or 3 mm.

[0198] Since a seal is formed between the anti-corrosion layer 300 and the first surface 212, the sealing surface 211 between the adhesive film 210 and the first wall 110 can be set smaller, that is, the size of the first wall 110 where the adhesive film 210 is located can be set smaller, thereby making the thickness of the battery cell 10 less than 4.5 mm, so that the battery cell 10 has a wider range of applications.

[0199] In some embodiments, the battery cell 10 further includes an electrode assembly and an electrolyte, and the housing 100 is used to accommodate the electrode assembly and the electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The electrochemical device mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode collector, and the part of the positive electrode collector not coated with the positive electrode active material layer is used as a positive electrode ear to realize the input or output of the electric energy of the positive electrode sheet through the positive electrode ear. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary material or lithium manganese oxide. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode collector, and the part of the negative electrode collector not coated with the negative electrode active material layer is used as a negative electrode ear to realize the input or output of the electric energy of the negative electrode sheet through the negative electrode ear. The negative electrode current collector may be made of copper, and the negative electrode active material may be made of carbon material or silicon material, etc. The material of the separator may be made of polypropylene (PP) or polyethylene (PE), etc. The electrolyte may include an organic solvent, an electrolyte lithium salt, etc.

[0200] In some embodiments, the electrode assembly may be a laminated structure formed by stacking a negative electrode sheet, a separator, and a positive electrode sheet.

[0201] In other embodiments, the electrode assembly may also be a wound structure formed by winding a negative electrode sheet, a separator and a positive electrode sheet.

[0202] See also Figure 5 and Figure 6 The embodiment of the present application provides a pressure relief mechanism, which includes a second metal sheet 114, a film 210 and an anti-corrosion layer 300. The second metal sheet 114 is provided with a first through hole 101. The second metal sheet 114 has a third surface 115 and a fourth surface 116 that are opposite to each other along its thickness direction. The film 210 is provided on the third surface 115. The film 210 is used to seal the first through hole 101. The film 210 is connected to the second metal sheet 114 to form a sealing surface 211. When viewed from the fourth surface 116 toward the third surface 115, the film 210 has a first surface 212 that is away from the fourth surface 116. The first surface 212 has a first edge. The anti-corrosion layer 300 is provided on the fourth surface 116 and covers the first edge. The first edge is the outer contour of the first surface 212. The pressure relief mechanism is used to relieve pressure on the battery cell 10.

[0203] By setting the adhesive film 210 on the third surface 115, the adhesive film 210 is used to seal the first through hole 101, so that the adhesive film 210 can be melted by heat to form a pressure relief channel, so that the thermal sensitivity of the pressure relief of the battery cell 10 is better, the reliability of the pressure relief is higher, and the safety of the battery cell 10 is improved. Compared with the notched groove pressure relief structure, this embodiment does not need to reserve a large space, which can make the structure of the electrical equipment more compact and the cost of preparing the battery cell 10 is lower. By connecting the adhesive film 210 and the second metal sheet 114 to form a sealing surface 211, the adhesive film 210 has a first edge when viewed from the fourth surface 116 toward the third surface 115. The anti-corrosion layer 300 is arranged on the fourth surface 116 and covers the first edge, so that the anti-corrosion layer 300 can prevent the electrolyte of the battery cell 10 from corroding the sealing surface 211 of the adhesive film 210 and the second metal sheet 114, so that the adhesive film 210 has a better sealing effect on the first through hole 101, which is beneficial to improving the safety of the battery cell 10 and extending the service life of the battery cell 10; and a seal can be formed between the anti-corrosion layer 300 and the fourth surface 116, so that the sealing surface 211 of the adhesive film 210 and the anti-corrosion layer 300 to the first through hole 101 is larger and the sealing effect is better.

[0204] An embodiment of the present application provides an electrical device, including a battery cell 10 according to any of the above solutions, and the battery cell 10 is used to provide electrical energy to the electrical device.

[0205] The electrical equipment may be any of the aforementioned devices or equipment using the battery cell 10 .

[0206] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0207] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: The housing comprises a first wall, wherein the first wall is provided with a first through hole; An adhesive film, used for sealing the first through hole, the adhesive film being connected to the first wall to form a sealing surface; The adhesive film has a first surface facing the interior of the housing, and the first surface has a first edge; an anti-corrosion layer, disposed on the inner surface of the first wall and the first surface, and covering the first edge, the first edge being the outer contour of the first surface; The adhesive film can be melted by heat to form a pressure relief channel connecting the inside and outside of the shell.

2. The battery cell according to claim 1, characterized in that: The thickness of the anti-corrosion layer is H1, satisfying 10nm≤H1≤2mm.

3. The battery cell according to claim 2, characterized in that: 10nm≤H1≤0.1mm.

4. The battery cell according to claim 1, characterized in that: The material of the anti-corrosion layer includes at least one of ceramic, polypropylene, fluoride, polyvinylidene fluoride, carbon-based material, titanium, and nickel-based material.

5. The battery cell according to claim 1, characterized in that: The melting point of the adhesive film is T1, which satisfies 100°C≤T1≤130°C; The melting point of the anti-corrosion layer is T2, which satisfies 90°C≤T2≤130°C.

6. The battery cell according to claim 5, characterized in that: The melting point T2 of the anti-corrosion layer is lower than the melting point T1 of the adhesive film.

7. The battery cell according to claim 1, characterized in that: The area of ​​the inner surface of the first wall covered by the anti-corrosion layer is the first area. Along the radial direction of the first through hole, the width of the first area is W1, which satisfies 10 μm≤W1≤3 mm.

8. The battery cell according to claim 7, characterized in that: 100μm≤W1≤3mm.

9. The battery cell according to claim 1, characterized in that: The area of ​​the first surface covered by the anti-corrosion layer is the second area. Along the radial direction of the first through hole, the width of the second area is W2, satisfying 10 μm≤W2≤3 mm.

10. The battery cell according to claim 9, characterized in that: 100μm≤W2≤3mm.

11. The battery cell according to claim 1, characterized in that: The adhesive film is connected to the outer surface of the first wall to form the sealing surface.

12. The battery cell according to claim 1, characterized in that: The adhesive film is connected to the outer surface of the first wall to form a first sub-sealing surface, and the adhesive film is connected to the hole wall of the first through hole to form a second sub-sealing surface. The first sub-sealing surface and the second sub-sealing surface constitute the sealing surface.

13. The battery cell according to claim 1, characterized in that: The adhesive film covers the first through hole.

14. The battery cell according to claim 1, characterized in that: The battery core includes a first metal sheet, and the first metal sheet is arranged on a side of the adhesive film facing away from the first wall.

15. The battery cell according to claim 14, characterized in that: The adhesive film is provided with a second through hole, the first metal sheet has a second surface exposed by the second through hole, and the anti-corrosion layer covers the hole wall of the second through hole and the second surface.

16. The battery cell according to claim 15, characterized in that: The outer diameter of the adhesive film is greater than the outer diameter of the first metal sheet, and the inner diameter of the adhesive film is smaller than the diameter of the first through hole.

17. The battery cell according to claim 14, characterized in that: A protective layer is disposed on the side of the first metal sheet facing away from the adhesive film.

18. The battery cell according to claim 17, characterized in that: The adhesive film, the first metal sheet, and the protective layer are hot-pressed into a composite component, and the thickness of the composite component is H2, satisfying 0.03 mm ≤ H2 ≤ 1 mm.

19. The battery cell according to claim 17, characterized in that: The thickness of the adhesive film is H3, satisfying 0.01mm≤H3≤0.5mm; The thickness of the first metal sheet is H4, satisfying 0.01 mm ≤ H4 ≤ 0.25 mm; The thickness of the protective layer is H5, satisfying 0.01 mm ≤ H5 ≤ 0.25 mm.

20. The battery cell according to claim 19, characterized in that: 0.02mm≤H3≤0.3mm; 0.01mm≤H4≤0.15mm; 0.01mm≤H5≤0.15mm.

21. The battery cell according to claim 1, characterized in that: The first wall includes a wall body and a second metal sheet. The wall body is provided with a third through hole. The second metal sheet covers the third through hole and is welded to the wall body. The first through hole is provided in the second metal sheet.

22. The battery cell according to claim 21, characterized in that: The second metal sheet is circular, and the radius of the second metal sheet is R; Along the radial direction of the second metal sheet, the width of the overlapping portion between the anti-corrosion layer and the second metal sheet is W1, satisfying 5%≤W1 / R≤100%.

23. The battery cell according to claim 21, characterized in that: The thickness of the second metal sheet is H6, satisfying 0.02 mm ≤ H6 ≤ 0.5 mm.

24. The battery cell according to claim 23, characterized in that: 0.02mm≤H6≤0.3mm.

25. The battery cell according to claim 1, characterized in that: Along the thickness direction of the first wall, the width of the overlapping portion between the projection of the adhesive film and the projection of the first wall is W3, satisfying 0.1 mm≤W3≤3 mm.

26. The battery cell according to claim 25, characterized in that: 0.2mm≤W3≤1.5mm.

27. The battery cell according to claim 1, characterized in that: The housing comprises a shell and a shell cover, the shell has an opening, and the shell cover is arranged on the opening; The shell comprises a bottom wall and a plurality of side walls surrounding the bottom wall, the bottom wall and the shell cover are arranged opposite to each other along the thickness direction of the battery core, and the first wall is one of the plurality of side walls; The battery cell includes an electrode terminal, and the electrode terminal is disposed on the first wall.

28. A pressure relief mechanism, characterized in that: The pressure relief mechanism comprises: A second metal sheet, provided with a first through hole, wherein the second metal sheet has a third surface and a fourth surface opposite to each other along a thickness direction thereof; An adhesive film is disposed on the third surface, the adhesive film is used to seal the first through hole, the adhesive film is connected with the second metal sheet to form a sealing surface, and when viewed from the fourth surface toward the third surface, the adhesive film has a first surface facing away from the fourth surface, and the first surface has a first edge; an anti-corrosion layer, disposed on the fourth surface and covering the first edge, wherein the first edge is an outer contour of the first surface; The pressure relief mechanism is used for releasing pressure from the battery cell.

29. An electrical equipment, characterized in that: The battery cell comprises a battery cell as described in any one of claims 1 to 27, wherein the battery cell is used to provide electrical energy.

Images