Battery cell and electrical device

Abstract

The present application provides a battery cell and an electrical device. The battery cell comprises a casing and a pressure relief mechanism, the casing has a first wall, and the first wall is provided with a first through hole; the pressure relief mechanism comprises an adhesive film and a first metal sheet; the adhesive film covers the first through hole, and the adhesive film can melt upon heating to form a pressure relief channel communicating an interior and an exterior of the casing; the first metal sheet is provided on the side of the adhesive film facing away from the first wall; and the thickness of the first wall is H1, and the thickness of the first metal sheet is H2, which satisfy H2≤1.5*H1. In this way, the pressure relief mechanism has good thermal sensitivity and thus has high pressure relief reliability; and moreover, when the casing of the battery cell deforms under stress, the first metal sheet also deforms accordingly, thereby reducing the possibility of the adhesive film detaching from the casing and / or the first metal sheet, thus reducing the risk of electrolyte leakage of the battery cell and improving the safety of the battery cell.

Description

Battery cell and electric device Cross-reference to related applications

[0001] This application claims priority to Chinese Patent Application CN202410840432.7, filed on June 26, 2024, entitled "Battery cell and electric device", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a battery cell and an electric device. BACKGROUND

[0003] With the rapid development of new energy technology, batteries have been widely used in electronic devices, electric vehicles, electric two-wheel vehicles, electric tools and other fields. The quality, safety and miniaturization of batteries are also increasingly demanding.

[0004] At present, the pressure relief mechanism of the battery cell can include a glue film and a metal sheet. The glue film seals the through hole on the shell of the battery cell, and the metal sheet is arranged on the side of the glue film away from the shell. This pressure relief structure can improve the reliability of the pressure relief of the battery cell, improve the safety of the battery cell, and can reduce the preparation cost of the battery cell compared with the notch groove pressure relief. However, when the shell of the battery cell is deformed under stress, the side wall where the through hole is located tilts towards the inside of the battery cell, and the metal sheet of the pressure relief mechanism does not deform, which will cause the glue film to separate from the shell and / or the metal sheet, resulting in battery leakage and affecting the safety of the battery cell. SUMMARY

[0005] The present application provides a battery cell and an electric device, which can improve the safety of the battery cell.

[0006] In a first aspect, the present application provides a battery cell, which includes a shell and a pressure relief mechanism. The shell has a first wall body, and the first wall body is provided with a first through hole. The pressure relief mechanism includes a glue film and a first metal sheet. The glue film covers the first through hole, and the glue film can be melted by heat to form a pressure relief channel communicating the inside and the outside of the shell. The first metal sheet is arranged on the side of the glue film away from the first wall body. The thickness of the first wall body is H1, the thickness of the first metal sheet is H2, and H2≤1.5*H1 is satisfied.

[0007] In the technical solution, the pressure relief mechanism includes the adhesive film, the adhesive film covers 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 heat sensitivity of the pressure relief mechanism is good, the reliability of the pressure relief is high, the safety of the battery cell can be improved, compared with the notch groove pressure relief structure, the embodiment does not need to reserve a large space, the structure of the electric device can be more compact, and the cost of manufacturing the pressure relief mechanism is lower; the pressure relief structure includes the first metal sheet, the first metal sheet is arranged on the side of the adhesive film away from the first wall body, the water penetration area of the adhesive film can be reduced, and the sealing effect of the pressure relief mechanism is better; the thickness H1 of the first wall body and the thickness H2 of the first metal sheet satisfy H2≤1.5*H1, when the shell of the battery cell is deformed under stress, the first metal sheet can also be deformed, the possibility of the adhesive film separating from the shell and / or the first metal sheet can be reduced, and the risk of battery cell liquid leakage can be reduced, and the safety of the battery cell is improved.

[0008] In some embodiments of the present application, 0.01mm≤H2≤0.25mm.

[0009] In the technical solution, when H2 is greater than or equal to 0.01mm, the first metal sheet can have a better blocking effect on water vapor, the water penetration amount of the adhesive film can be reduced, and the sealing effect of the pressure relief mechanism is better; when H2 is less than or equal to 0.25mm, when the shell of the battery cell is deformed under stress, the first metal sheet is easy to deform with the shell, thereby the possibility of the adhesive film separating from the shell and / or the first metal sheet can be reduced, the risk of battery cell liquid leakage can be reduced, and the safety of the battery cell is improved; therefore, when 0.01mm≤H2≤0.25mm, the first metal sheet can have a better blocking effect on water vapor, the water penetration amount of the adhesive film can be reduced, and the sealing effect of the pressure relief mechanism is better, and when the shell of the battery cell is deformed under stress, the first metal sheet is easy to deform with the shell, thereby the possibility of the adhesive film separating from the shell and / or the first metal sheet can be reduced, the risk of battery cell liquid leakage can be reduced, and the safety of the battery cell is improved.

[0010] In some embodiments of the present application, 0.01mm≤H2≤0.15mm.

[0011] In the technical solution, when H2 is greater than or equal to 0.01 mm, the first metal sheet can better block water vapor, and the water permeation of the adhesive film can be reduced, so that the sealing effect of the pressure relief mechanism is better; when H2 is less than or equal to 0.15 mm, when the shell of the battery cell is deformed under stress, the first metal sheet is more likely to deform with the shell, so that the possibility of the adhesive film separating from the shell and / or the first metal sheet can be further reduced, the risk of liquid leakage of the battery cell can be further reduced, and the safety of the battery cell is further improved; therefore, when 0.01 mm≤H2≤0.15 mm, the first metal sheet can better block water vapor, the water permeation of the adhesive film can be reduced, so that the sealing effect of the pressure relief mechanism is better, and when the shell of the battery cell is deformed under stress, the first metal sheet is more likely to deform with the shell, so that the possibility of the adhesive film separating from the shell and / or the first metal sheet can be further reduced, the risk of liquid leakage of the battery cell can be further reduced, and the safety of the battery cell is further improved.

[0012] In some embodiments of the present application, the melting point of the adhesive film is T, which satisfies 100℃≤T≤130℃.

[0013] In the technical solution, when T is greater than or equal to 100℃, when the battery cell does not occur thermal runaway, the adhesive film is not easy to melt, so that the sealing effect of the pressure relief mechanism on the first through hole is better; when T is less than or equal to 130℃, when the battery cell occurs thermal runaway, the adhesive film can melt to form a pressure relief channel connecting the inside and outside of the shell, so that the thermal sensitivity of the pressure relief mechanism is better, the reliability of pressure relief is higher, and the safety of the battery cell can be improved; therefore, when 100℃≤T≤130℃, when the battery cell does not occur thermal runaway, the adhesive film is not easy to melt, so that the sealing effect of the pressure relief mechanism on the first through hole is better, and when the battery cell occurs thermal runaway, the adhesive film can melt to form a pressure relief channel connecting the inside and outside of the shell, so that the thermal sensitivity of the pressure relief mechanism is better, the reliability of pressure relief is higher, the safety of the battery cell can be improved, and the pressure relief mechanism can control the situation of battery cell thermal runaway more accurately.

[0014] In some embodiments of the present application, the thickness of the adhesive film is H3, which satisfies 0.01mm≤H3≤0.5mm.

[0015] In the technical solution, when the thickness of the adhesive film is greater than or equal to 0.01 mm, the adhesive film is not easy to be damaged, the water permeation is small, and the sealing effect of the pressure relief mechanism on the first through hole is better; when the thickness of the adhesive film is less than or equal to 0.5 mm, the adhesive film is easy to melt when the battery cell is in thermal runaway, and the pressure relief sensitivity of the pressure relief mechanism is high; therefore, when 0.01 mm≤H3≤0.5 mm, the adhesive film is not easy to be damaged, the water permeation is small, and the sealing effect of the pressure relief mechanism on the first through hole is better, and the adhesive film is easy to melt when the battery cell is in thermal runaway, and the pressure relief sensitivity of the pressure relief mechanism is high.

[0016] In some embodiments of the present application, 0.02 mm≤H3≤0.3 mm.

[0017] In the technical solution, when the thickness of the adhesive film is greater than or equal to 0.02 mm, the adhesive film is not easy to be damaged, the water permeation is small, and the sealing effect of the pressure relief mechanism on the first through hole is better; when the thickness of the adhesive film is less than or equal to 0.3 mm, the adhesive film is easy to melt when the battery cell is in thermal runaway, and the pressure relief sensitivity of the pressure relief mechanism is high; therefore, when 0.02 mm≤H3≤0.3 mm, the adhesive film is not easy to be damaged, the water permeation is small, and the sealing effect of the pressure relief mechanism on the first through hole is better, and the adhesive film is easy to melt when the battery cell is in thermal runaway, and the pressure relief sensitivity of the pressure relief mechanism is high.

[0018] In some embodiments of the present application, the pressure relief mechanism comprises a protective layer, the protective layer is arranged on the side of the first metal sheet away from the adhesive film, and the first metal sheet is connected with the adhesive film and the protective layer.

[0019] In the technical solution, by arranging the protective layer on the pressure relief mechanism, the protective layer is arranged on the side of the first metal sheet away from the adhesive film, and the first metal sheet is connected with the adhesive film and the protective layer, so that the thickness of the pressure relief mechanism is larger, the pressure relief mechanism is not easy to be damaged by force, thereby reducing the possibility of battery cell liquid leakage and improving the safety of the battery cell.

[0020] In some embodiments of the present application, the thickness of the protective layer is H4, and 0.01 mm≤H4≤0.25 mm.

[0021] In the technical solution, when H4 is greater than or equal to 0.01 mm, the protective layer has a good protection effect on the adhesive film and the first metal sheet, and the pressure relief mechanism is not easily damaged by force, thereby reducing the possibility of leakage of the battery cell and improving the safety of the battery cell; when H4 is less than or equal to 0.25 mm, the protective layer occupies a small space, which is conducive to improving the energy density of the battery cell and reducing the possibility of interference between the pressure relief mechanism and external equipment; therefore, when 0.01 mm≤H4≤0.25 mm, the protective layer has a good protection effect on the adhesive film and the first metal sheet, and the pressure relief mechanism is not easily damaged by force, thereby reducing the possibility of leakage of the battery cell and improving the safety of the battery cell, and the protective layer occupies a small space, which is conducive to improving the energy density of the battery cell and reducing the possibility of interference between the pressure relief mechanism and external equipment.

[0022] In some embodiments of the present application, 0.01 mm≤H4≤0.15 mm.

[0023] In the technical solution, when H4 is greater than or equal to 0.01 mm, the protective layer has a good protection effect on the adhesive film and the first metal sheet, and the pressure relief mechanism is not easily damaged by force, thereby reducing the possibility of leakage of the battery cell and improving the safety of the battery cell; when H4 is less than or equal to 0.15 mm, the protective layer further occupies a small space, which is conducive to improving the energy density of the battery cell and further reducing the possibility of interference between the pressure relief mechanism and external equipment; therefore, when 0.01 mm≤H4≤0.15 mm, the protective layer has a good protection effect on the adhesive film and the first metal sheet, and the pressure relief mechanism is not easily damaged by force, thereby reducing the possibility of leakage of the battery cell and improving the safety of the battery cell, and the protective layer further occupies a small space, which is conducive to improving the energy density of the battery cell and further reducing the possibility of interference between the pressure relief mechanism and external equipment.

[0024] In some embodiments of the present application, the thicknesses of the adhesive film, the first metal sheet and the protective layer are T, and 0.03 mm≤T≤1 mm.

[0025] In the technical solution, when T is greater than or equal to 0.03 mm, the pressure relief mechanism has a good sealing effect on the first through hole; when T is less than or equal to 1 mm, the pressure relief mechanism occupies a small space, which is conducive to improving the energy density of the battery cell and further reducing the possibility of interference between the pressure relief mechanism and external equipment; therefore, when 0.03 mm≤T≤1 mm, the pressure relief mechanism has a good sealing effect on the first through hole, and the pressure relief mechanism occupies a small space, which is conducive to improving the energy density of the battery cell and further reducing the possibility of interference between the pressure relief mechanism and external equipment.

[0026] In some embodiments of the present application, the pressure relief mechanism comprises a second metal sheet, the second metal sheet is arranged between the adhesive film and the first wall body, the second metal sheet is welded to the first wall body, and the second metal sheet is provided with a second through hole in communication with the first through hole.

[0027] In the above technical solution, by arranging the second metal sheet on the pressure relief mechanism, the second metal sheet is arranged between the adhesive film and the first wall body, and the second metal sheet is welded to the first wall body, so that the connection between the pressure relief mechanism and the shell is more stable, and the sealing effect of the pressure relief mechanism on the first through hole is better.

[0028] In some embodiments of the present application, the thickness of the second metal sheet is H5, and H5≤2*H1 is satisfied.

[0029] In the above technical solution, by satisfying H5≤2*H1 for the thickness H2 of the first metal sheet and the thickness H5 of the second metal sheet, when the shell of the battery cell is deformed under stress, the first metal sheet can also be deformed, which can reduce the possibility of the adhesive film separating from the shell and / or the first metal sheet, thereby reducing the risk of battery cell leakage and improving the safety of the battery cell.

[0030] In some embodiments of the present application, the thickness of the second metal sheet is H5, and 0.02mm≤H5≤0.5mm is satisfied.

[0031] In the above technical solution, when H5 is greater than or equal to 0.02mm, the connection between the pressure relief mechanism and the shell is more stable, and the sealing effect of the pressure relief mechanism on the first through hole is better; when H5 is less than or equal to 0.5mm, the space occupied by the second metal sheet is small, which is conducive to improving the energy density of the battery cell and reducing the possibility of interference between the pressure relief mechanism and external equipment; therefore, when 0.02mm≤H5≤0.5mm, the connection between the pressure relief mechanism and the shell is more stable, the sealing effect of the pressure relief mechanism on the first through hole is better, the space occupied by the second metal sheet is small, which is conducive to improving the energy density of the battery cell, and the possibility of interference between the pressure relief mechanism and external equipment is reduced.

[0032] In some embodiments of the present application, 0.02mm≤H5≤0.3mm is satisfied.

[0033] In the technical solution, when H5 is greater than or equal to 0.02 mm, the connection between the pressure relief mechanism and the shell is more stable, and the sealing effect of the pressure relief mechanism on the first through hole is better; when H5 is less than or equal to 0.3 mm, the second metal sheet occupies less space, which is conducive to further improving the energy density of the battery cell, and the possibility of interference between the pressure relief mechanism and external equipment is further reduced; therefore, when 0.02 mm≤H5≤0.3 mm, the connection between the pressure relief mechanism and the shell is more stable, the sealing effect of the pressure relief mechanism on the first through hole is better, the second metal sheet occupies less space, which is conducive to further improving the energy density of the battery cell, and the possibility of interference between the pressure relief mechanism and external equipment is further reduced.

[0034] In some embodiments of the present application, the adhesive film is attached to the second metal sheet, and the width of the part where the adhesive film is attached to the second metal sheet is W, which satisfies 0.1 mm≤W≤3 mm.

[0035] In the technical solution, when W is greater than or equal to 0.1 mm, the attachment area of the adhesive film to the second metal sheet is larger, which further makes the connection between the adhesive film and the second metal sheet more tight, and the sealing reliability of the pressure relief mechanism on the first through hole is higher; when W is less than or equal to 3 mm, the pressure relief path of the gas inside the battery cell is shorter, and the pressure relief sensitivity of the pressure relief mechanism is higher; therefore, when 0.1 mm≤W≤3 mm, the connection between the adhesive film and the second metal sheet is more tight, the sealing reliability of the pressure relief mechanism on the first through hole is higher, the pressure relief path of the gas inside the battery cell is shorter, and the pressure relief sensitivity of the pressure relief mechanism is higher.

[0036] In some embodiments of the present application, 0.2 mm≤W≤1.5 mm.

[0037] In the technical solution, when W is greater than or equal to 0.2 mm, the attachment area of the adhesive film to the second metal sheet is further larger, which further makes the connection between the adhesive film and the second metal sheet more tight, and the sealing reliability of the pressure relief mechanism on the first through hole is higher; when W is less than or equal to 1.5 mm, the pressure relief path of the gas inside the battery cell is further shorter, and the pressure relief sensitivity of the pressure relief mechanism is higher; therefore, when 0.2 mm≤W≤1.5 mm, the connection between the adhesive film and the second metal sheet is further more tight, the sealing reliability of the pressure relief mechanism on the first through hole is higher, the pressure relief path of the gas inside the battery cell is further shorter, and the pressure relief sensitivity of the pressure relief mechanism is higher.

[0038] In some embodiments of the present application, the battery cell comprises a pole, and the pole is arranged on the first wall body.

[0039] In the technical solution, when the battery cell is installed in the electric device, space is reserved for the pole to be electrically connected with other components of the electric device, and the pole and the first through hole are arranged on the same side wall, so that space is saved for the first through hole to release pressure, and the structure of the electric device is more compact.

[0040] In a second aspect, the embodiments of the present application provide an electric device, comprising the battery cell as described above, and the battery cell is used to provide electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. Other related drawings can also be obtained by those skilled in the art according to these drawings.

[0042] Fig. 1 is a perspective structural schematic view of a battery cell provided by some embodiments of the present application;

[0043] Fig. 2 is an exploded schematic view of a partial structure of the battery cell provided by some embodiments of the present application;

[0044] Fig. 3 is a structural schematic view of the battery cell from one perspective provided by some embodiments of the present application;

[0045] Fig. 4 is a cross-sectional structural schematic view of the battery cell shown in Fig. 3 along A-A;

[0046] Fig. 5 is a partially enlarged structural schematic view of the battery cell shown in Fig. 4 at B;

[0047] Fig. 6 is an exploded schematic view of a partial structure of a battery cell provided by another embodiments of the present application;

[0048] Fig. 7 is a structural schematic view of the battery cell from one perspective provided by another embodiments of the present application;

[0049] Fig. 8 is a cross-sectional structural schematic view of the battery cell shown in Fig. 7 along C-C;

[0050] Fig. 9 is a partially enlarged structural schematic view of the battery cell shown in Fig. 8 at D.

[0051] Fig. 10 is a structural schematic view of the battery cell shown in Fig. 9 along D-D;

[0052] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art belong to the scope of protection of the present application.

[0053] Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "comprise" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0054] The terms "first", "second", and the like in the specification and claims of the present application or the above description of drawings are used to distinguish different objects, rather than to describe a specific order or primary and secondary relationship.

[0055] In the present application, referring to "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily all refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments.

[0056] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, detailed description of the same components is 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 and should not constitute any limitation on the present application.

[0057] In the present application, each battery cell can be a secondary battery or a primary battery; for example, the battery cell can be a lithium ion battery, a sodium ion battery or a magnesium ion battery, etc., and the embodiments of the present application are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc., and the embodiments of the present application are not limited thereto.

[0058] The battery cell includes a shell and an electrode assembly, the electrode assembly is arranged in the shell, and the electrode assembly can be in a wound structure or a stacked structure, and the embodiments of the present application are not limited thereto.

[0059] For a general steel shell battery, a notch groove is formed on the shell by laser engraving to play a role in pressure relief. However, in order to make the gas in the battery inside smoothly discharged after the notch groove breaks, a valve space corresponding to the notch groove needs to be reserved in the electric device, which will affect the space utilization in the electric device. Moreover, the notch groove mainly relies on the pressure of the battery inside to break, and the thermal sensitivity is poor, the pass rate of the thermal box test is low, which affects the safety of the battery, and the laser engraving also increases the preparation cost of the battery. Therefore, by setting a pressure relief mechanism including a glue film and a metal sheet, the glue film seals the through hole on the shell of the battery, and can melt to form a pressure relief channel connecting the inside and outside of the shell when heated, and the thermal sensitivity is good. The metal sheet is arranged on the side of the glue film away from the shell, which can reduce the penetration of water vapor into the shell. However, when the shell of the battery is deformed under stress, the side wall where the through hole is located will generally tilt towards the inside of the battery, and the metal sheet of the pressure relief mechanism has high rigidity and is not easy to deform, which will cause the glue film to separate from the shell and / or the metal sheet, thereby causing the battery to leak and affecting the safety of the battery.

[0060] Based on the above considerations, in order to improve the safety of the battery, the application provides a battery, which includes a shell and a pressure relief mechanism, the shell has a first wall body, and the first wall body is provided with a first through hole; the pressure relief mechanism includes a glue film and a first metal sheet, the glue film covers the first through hole, and the glue film can melt to form a pressure relief channel connecting the inside and outside of the shell when heated, and the first metal sheet is arranged on the side of the glue film away from the first wall body; wherein the thickness of the first wall body is H1, the thickness of the first metal sheet is H2, and H2≤1.5*H1 is satisfied. By making the pressure relief mechanism include a glue film, the glue film covers the first through hole, and the glue film can melt to form a pressure relief channel connecting the inside and outside of the shell when heated, the thermal sensitivity of the pressure relief mechanism is good, the reliability of pressure relief is high, the safety of the battery can be improved, and compared with the notch groove pressure relief structure, a large space does not need to be reserved, the structure of the electric device can be more compact, and the cost of preparing the pressure relief mechanism is lower; by making the pressure relief structure include a first metal sheet, the first metal sheet is arranged on the side of the glue film away from the first wall body, the water penetration area of the glue film can be reduced, and the sealing effect of the pressure relief mechanism is better; by making the thickness H1 of the first wall body and the thickness H2 of the first metal sheet satisfy H2≤1.5*H1, when the shell of the battery is deformed under stress, the first metal sheet can also be deformed, the possibility of the glue film separating from the shell and / or the first metal sheet can be reduced, thereby the risk of battery leakage can be reduced, and the safety of the battery can be improved.

[0061] The application embodiment provides a power utilization device using a battery as a power source, which can be but is not limited to a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, etc.

[0062] Please refer to FIG. 1 to FIG. 5, FIG. 1 is a perspective structural schematic diagram of an electric core provided by some embodiments of the present application; FIG. 2 is an exploded schematic diagram of a partial structure of the electric core provided by some embodiments of the present application; FIG. 3 is a structural schematic diagram of the electric core from one perspective provided by some embodiments of the present application; FIG. 4 is a cross-sectional structural schematic diagram of the electric core shown in FIG. 3 along A-A; and FIG. 5 is a local enlarged structural schematic diagram of B of the electric core shown in FIG. 4.

[0063] Some embodiments of the present application provide an electric core 10, which comprises a shell 100 and a pressure relief mechanism 200, the shell 100 has a first wall body 110, the first wall body 110 is provided with a first through hole 111; the pressure relief mechanism 200 comprises a glue film 210 and a first metal sheet 220, the glue film 210 covers the first through hole 111, the glue film 210 can be melted by heat to form a pressure relief channel communicating the inside and the outside of the shell 100, and the first metal sheet 220 is arranged on a side of the glue film 210 away from the first wall body 110; wherein the thickness of the first wall body 110 is H1, the thickness of the first metal sheet 220 is H2, and H2≤1.5*H1 is satisfied. For example, H2 can be 1.5*H1, 1.2*H1 or H1, etc.

[0064] By making the pressure relief mechanism 200 comprise the glue film 210, the glue film 210 covers the first through hole 111, and the glue film 210 can be melted by heat to form a pressure relief channel communicating the inside and the outside of the shell 100, the heat sensitivity of the pressure relief mechanism 200 is better, the reliability of pressure relief is higher, the safety of the electric core 10 can be improved, and compared with the notch groove pressure relief structure, this embodiment does not need to reserve a large space, can make the structure of the electric device more compact, and the cost of preparing the pressure relief mechanism 200 is lower; by making the pressure relief mechanism comprise the first metal sheet 220, the first metal sheet 220 is arranged on a side of the glue film 210 away from the first wall body 110, the water penetration area of the glue film 210 can be reduced, and the sealing effect of the pressure relief mechanism 200 is better; by making the thickness H1 of the first wall body 110 and the thickness H2 of the first metal sheet 220 satisfy H2≤1.5*H1, when the shell 100 of the electric core 10 is deformed under stress, the first metal sheet 220 can also be deformed, the possibility of the glue film 210 separating from the shell and / or the first metal sheet 220 can be reduced, thereby the risk of liquid leakage of the electric core 10 can be reduced, and the safety of the electric core 10 can be improved.

[0065] In some embodiments, the first through hole 111 can be a liquid injection hole, and electrolyte is injected into the inside of the electric core 10 via the first through hole 111.

[0066] Multiplexing the liquid injection hole as the first through hole 111 for pressure relief can further simplify the preparation process of the electric core 10, reduce the punching step, and reduce the preparation cost of the electric core 10.

[0067] In other embodiments, the first through hole 111 can also be another through hole formed in the shell 100.

[0068] In some embodiments, the shell 100 includes a shell body 120 and a shell cover 130, the shell body 120 includes a bottom wall 121 and a plurality of side walls surrounding the bottom wall, the bottom wall 121 is the largest wall of the shell body 120, and the first wall 110 is one of the side walls.

[0069] In some embodiments, the shell body 120 is a hollow structure with one open end, and the shell cover 130 can be a plate-shaped structure, which covers the open end of the shell body 120, so that the shell body 120 and the shell cover 130 together define a containing space, and the electrode assembly is arranged in the containing space.

[0070] In other embodiments, the shell body 120 and the shell cover 130 can also be hollow structures with one open end, and the open end of the shell cover 130 covers the open end of the shell body 120.

[0071] In some embodiments, the shell 100 is a cuboid.

[0072] In other embodiments, the shell 100 can also be a cylinder.

[0073] In some embodiments, the shell 100 can be made of aluminum, aluminum alloy or other metal materials, so that the shell 100 has high stress performance.

[0074] In other embodiments, the shell 100 can also be made of carbon fiber, hard plastic or other non-metallic materials with high strength.

[0075] In some embodiments, 0.01mm≤H2≤0.25mm. For example, H2 can be 0.01mm, 0.1mm or 0.25mm, etc.

[0076] When H2 is greater than or equal to 0.01 mm, the first metal sheet 220 can have a better blocking effect on water vapor, and the amount of water permeation of the adhesive film 210 can be reduced, so that the sealing effect of the pressure relief mechanism 200 is better. When H2 is less than or equal to 0.25 mm, when the shell 100 of the battery cell 10 is deformed under stress, the first metal sheet 220 is easily deformed with the shell 100, so that the possibility of the adhesive film 210 separating from the shell and / or the first metal sheet 220 can be reduced, so that the risk of liquid leakage of the battery cell 10 can be reduced, and the safety of the battery cell 10 can be improved. Therefore, when 0.01 mm≤H2≤0.25 mm, the first metal sheet 220 can have a better blocking effect on water vapor, and the amount of water permeation of the adhesive film 210 can be reduced, so that the sealing effect of the pressure relief mechanism 200 is better, and when the shell 100 of the battery cell 10 is deformed under stress, the first metal sheet 220 is easily deformed with the shell 100, so that the possibility of the adhesive film 210 separating from the shell and / or the first metal sheet 220 can be reduced, so that the risk of liquid leakage of the battery cell 10 can be reduced, and the safety of the battery cell 10 can be improved.

[0077] In some embodiments, 0.01 mm≤H2≤0.15 mm. For example, H2 can be 0.01 mm, 0.08 mm, or 0.15 mm, etc.

[0078] When H2 is greater than or equal to 0.01 mm, the first metal sheet 220 can have a better blocking effect on water vapor, and the amount of water permeation of the adhesive film 210 can be reduced, so that the sealing effect of the pressure relief mechanism 200 is better. When H2 is less than or equal to 0.15 mm, when the shell 100 of the battery cell 10 is deformed under stress, the first metal sheet 220 is more easily deformed with the shell 100, so that the possibility of the adhesive film 210 separating from the shell and / or the first metal sheet 220 can be further reduced, so that the risk of liquid leakage of the battery cell 10 can be further reduced, and the safety of the battery cell 10 can be further improved. Therefore, when 0.01 mm≤H2≤0.15 mm, the first metal sheet 220 can have a better blocking effect on water vapor, and the amount of water permeation of the adhesive film 210 can be reduced, so that the sealing effect of the pressure relief mechanism 200 is better, and when the shell 100 of the battery cell 10 is deformed under stress, the first metal sheet 220 is more easily deformed with the shell 100, so that the possibility of the adhesive film 210 separating from the shell and / or the first metal sheet 220 can be further reduced, so that the risk of liquid leakage of the battery cell 10 can be further reduced, and the safety of the battery cell 10 can be further improved.

[0079] In some embodiments, the first metal sheet 220 can be made of steel, aluminum, nickel, silver, copper, or an alloy material, so that the first metal sheet 220 is not easily rusted and has a long service life.

[0080] In some embodiments, the melting point of the adhesive film 210 is T, satisfying 100℃≤T≤130℃. For example, T can be 100℃, 115℃, or 130℃, etc.

[0081] When T is greater than or equal to 100℃, the adhesive film 210 is not easy to melt when the battery cell 10 does not occur thermal runaway, so that the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better; when T is less than or equal to 130℃, the adhesive film 210 can melt to form a pressure relief channel connecting the inside and outside of the shell 100 when the battery cell 10 occurs thermal runaway, so that the thermal sensitivity of the pressure relief mechanism 200 is better, the reliability of pressure relief is higher, and the safety of the battery cell 10 can be improved; therefore, when 100℃≤T≤130℃, the adhesive film 210 is not easy to melt when the battery cell 10 does not occur thermal runaway, so that the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better, and the adhesive film 210 can melt to form a pressure relief channel connecting the inside and outside of the shell 100 when the battery cell 10 occurs thermal runaway, so that the thermal sensitivity of the pressure relief mechanism 200 is better, the reliability of pressure relief is higher, the safety of the battery cell 10 can be improved, and the pressure relief mechanism 200 controls the situation of the battery cell 10 thermal runaway more accurately.

[0082] In some embodiments, the thickness of the adhesive film 210 is H3, satisfying 0.01mm≤H3≤0.5mm. For example, H3 can be 0.01mm, 0.2mm, or 0.5mm, etc.

[0083] When the thickness of the adhesive film 210 is greater than or equal to 0.01mm, the adhesive film 210 is not easy to break, and the water permeation amount is small, so that the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better; when the thickness of the adhesive film 210 is less than or equal to 0.5mm, the adhesive film 210 is easy to melt when the battery cell 10 occurs thermal runaway, so that the pressure relief sensitivity of the pressure relief mechanism 200 is higher; therefore, when 0.01mm≤H3≤0.5mm, the adhesive film 210 is not easy to break, and the water permeation amount is small, so that the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better, and the adhesive film 210 is easy to melt when the battery cell 10 occurs thermal runaway, so that the pressure relief sensitivity of the pressure relief mechanism 200 is higher.

[0084] In some embodiments, 0.02mm≤H3≤0.3mm. For example, H3 can be 0.02mm, 0.12mm, or 0.3mm, etc.

[0085] When the thickness of the adhesive film 210 is greater than or equal to 0.02 mm, the adhesive film 210 is less likely to be damaged, and the water permeation amount is small, and the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better. When the thickness of the adhesive film 210 is less than or equal to 0.3 mm, the adhesive film 210 is easy to melt when the battery cell 10 is in thermal runaway, and the pressure relief sensitivity of the pressure relief mechanism 200 is high. Therefore, when 0.02 mm≤H3≤0.3 mm, the adhesive film 210 is less likely to be damaged, the water permeation amount is small, and the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better, and the adhesive film 210 is easy to melt when the battery cell 10 is in thermal runaway, and the pressure relief sensitivity of the pressure relief mechanism 200 is high.

[0086] In some embodiments, the adhesive film 210 can be made of a high polymer, such as polypropylene (PP), polyethylene (PE), polyimide (PI), etc.

[0087] Since the adhesive film 210 is a high polymer and has water permeability, water entering the inside of the shell 100 through the adhesive film 210 will have an adverse effect on the electrode assembly and the electrolyte. By arranging the first metal sheet 220 on the side of the adhesive film 210 away from the shell 100, the water permeation area of the adhesive film 210 is reduced, and the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better.

[0088] In some embodiments, the adhesive film 210 includes a layer of high polymer.

[0089] In other embodiments, the adhesive film 210 can also include multiple layers of high polymer, such as the adhesive film 210 including a first adhesive layer and a second adhesive layer (not shown in the figure), the second adhesive layer being located on the side of the first adhesive layer away from the first wall body 110, the melting point of the second adhesive layer being greater than that of the first adhesive layer, so that when the first adhesive layer melts, the second adhesive layer does not melt, the thermal sensitivity of the battery cell 10 is high, and the installation of the adhesive film 210 is facilitated. For example, the adhesive film 210 includes a first adhesive layer, a second adhesive layer, and a third adhesive layer (not shown in the figure), the second adhesive layer being located on the side of the first adhesive layer away from the first wall body 110, the third adhesive layer being located on the side between the second adhesive layer and the first metal sheet 220, the melting point of the second adhesive layer being greater than that of the first adhesive layer, and the melting point of the second adhesive layer being greater than that of the third adhesive layer, so that when the adhesive film 210 is activated by high temperature, the third adhesive layer can melt to adhere to the first metal sheet 220, while the second adhesive layer does not melt, which can avoid excessive melting of the adhesive film 210 affecting the installation of the first metal sheet 220, and can also reduce the amount of adhesive overflow.

[0090] In some embodiments, the adhesive film 210 and the first metal sheet 220 are circular. The first metal sheet 220 can be conveniently assembled with the adhesive film 210 without adjusting the assembly direction. By setting the adhesive film 210 to be circular, the adhesive film 210 can be assembled in the first through hole 111, and the center of the adhesive film 210 is collinear with the center of the first through hole 111, so that the adhesive film 210 is uniformly distributed on the surface of the shell 100, the sealing effect is better, and the installation of the adhesive film 210 is facilitated.

[0091] In other embodiments, the first metal sheet 220 can be circular, and the adhesive film 210 can also be circular. By setting the adhesive film 210 to be circular, the adhesive film 210 and the shell 100, and the adhesive film 210 and the first metal sheet 220 can form pressure relief channels, thereby increasing the number of pressure relief channels and improving the pressure relief effect.

[0092] In some embodiments, the first through hole 111 is circular, the diameter of the first metal sheet 220 is less than or equal to the outer diameter of the adhesive film 210, and the diameter of the first metal sheet 220 is greater than the diameter of the first through hole 111. By setting the diameter of the first metal sheet 220 to be less than or equal to the outer diameter of the adhesive film 210, the first metal sheet 220 can be conveniently assembled with the adhesive film 210. By setting the diameter of the first metal sheet 220 to be greater than the diameter of the first through hole 111, the first metal sheet 220 can completely cover the first through hole 111, so that the sealing effect is better and the water vapor shielding effect is better.

[0093] In some embodiments, the pressure relief mechanism 200 includes a protective layer 230, the protective layer 230 is arranged on the side of the first metal sheet 220 away from the adhesive film 210, and the adhesive film 210 is connected with the first metal sheet 220 and the protective layer 230.

[0094] By setting the protective layer 230 on the pressure relief mechanism 200, the protective layer 230 is arranged on the side of the first metal sheet 220 away from the adhesive film 210, and the adhesive film 210 is connected with the first metal sheet 220 and the protective layer 230. The thickness of the pressure relief mechanism 200 is greater, and the pressure relief mechanism 200 is not easily damaged by force, thereby reducing the possibility of liquid leakage of the battery cell 10 and improving the safety of the battery cell 10.

[0095] In some embodiments, the thickness of the protective layer 230 is H4, which satisfies 0.01mm≤H4≤0.25mm. For example, H4 can be 0.01mm, 0.11mm or 0.25mm, etc.

[0096] When H4 is greater than or equal to 0.01 mm, the protective layer 230 can have a better protection effect on the adhesive film 210 and the first metal sheet 220, and the pressure relief mechanism 200 is not easy to be damaged by force, thereby reducing the possibility of liquid leakage of the battery cell 10 and improving the safety of the battery cell 10. When H4 is less than or equal to 0.25 mm, the protective layer 230 occupies a smaller space, which is conducive to improving the energy density of the battery cell 10 and reducing the possibility of interference between the pressure relief mechanism 200 and external equipment. Therefore, when 0.01 mm≤H4≤0.25 mm, the protective layer 230 can have a better protection effect on the adhesive film 210 and the first metal sheet 220, and the pressure relief mechanism 200 is not easy to be damaged by force, thereby reducing the possibility of liquid leakage of the battery cell 10 and improving the safety of the battery cell 10, and the protective layer 230 occupies a smaller space, which is conducive to improving the energy density of the battery cell 10 and reducing the possibility of interference between the pressure relief mechanism 200 and external equipment.

[0097] In some embodiments, 0.01 mm≤H4≤0.15 mm. For example, H4 can be 0.01 mm, 0.07 mm, or 0.15 mm, etc.

[0098] When H4 is greater than or equal to 0.01 mm, the protective layer 230 can have a better protection effect on the adhesive film 210 and the first metal sheet 220, and the pressure relief mechanism 200 is not easy to be damaged by force, thereby reducing the possibility of liquid leakage of the battery cell 10 and improving the safety of the battery cell 10. When H4 is less than or equal to 0.15 mm, the protective layer 230 can further occupy a smaller space, which is conducive to improving the energy density of the battery cell 10 and further reducing the possibility of interference between the pressure relief mechanism 200 and external equipment. Therefore, when 0.01 mm≤H4≤0.15 mm, the protective layer 230 can have a better protection effect on the adhesive film 210 and the first metal sheet 220, and the pressure relief mechanism 200 is not easy to be damaged by force, thereby reducing the possibility of liquid leakage of the battery cell 10 and improving the safety of the battery cell 10, and the protective layer 230 can further occupy a smaller space, which is conducive to improving the energy density of the battery cell 10 and further reducing the possibility of interference between the pressure relief mechanism 200 and external equipment.

[0099] In some embodiments, the protective layer 230 can be made of a high molecular polymer, such as polyethylene terephthalate (PET), polyamide (PA), polypropylene (PP), polyethylene (PE), polyimide (PI), polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PU), polycarbonate (PC), polyether ether ketone (PEEK), etc. The protective layer 230 can be more resistant to high temperatures, can slow down the oxidation speed of the first metal sheet 220, and reduce the possibility of foreign objects puncturing the pressure relief mechanism 200.

[0100] In some embodiments, the protective layer 230 is arranged in a circular shape, and the first metal sheet 220 and the protective layer 230 can be assembled without adjusting the assembly direction.

[0101] In some embodiments, the diameter of the protective layer 230 is less than or equal to the diameter of the first metal sheet 220. The protective layer 230 can be connected to the first metal sheet 220, and the protective layer 230 is not easily separated from the first metal sheet 220.

[0102] In some embodiments, the thicknesses of the adhesive film 210, the first metal sheet 220, and the protective layer 230 are T, and 0.03 mm≤T≤1 mm is satisfied. For example, T can be 0.03 mm, 0.5 mm, or 1 mm, etc.

[0103] When T is greater than or equal to 0.03 mm, the pressure relief mechanism 200 can have a better sealing effect on the first through hole 111. When T is less than or equal to 1 mm, the pressure relief mechanism 200 occupies a smaller space, which is beneficial to improve the energy density of the battery cell 10, and can further reduce the possibility of interference between the pressure relief mechanism 200 and external equipment. Therefore, when 0.03 mm≤T≤1 mm, the pressure relief mechanism 200 can have a better sealing effect on the first through hole 111, and the pressure relief mechanism 200 occupies a smaller space, which is beneficial to improve the energy density of the battery cell 10, and can further reduce the possibility of interference between the pressure relief mechanism 200 and external equipment.

[0104] In some embodiments, the adhesive film 210 and the first metal sheet 220 can be bonded by an adhesive layer, and the first metal sheet 220 and the protective layer 230 can be bonded by an adhesive layer.

[0105] In other embodiments, the adhesive film 210, the first metal sheet 220, and the protective layer 230 can be formed into one body by hot pressing.

[0106] Please refer to FIGS. 6-9. FIG. 6 is an exploded schematic view of a partial structure of a battery cell according to some embodiments of the present application; FIG. 7 is a schematic view of a structure of a battery cell according to some embodiments of the present application from one perspective; FIG. 8 is a schematic view of a cross-sectional structure of the battery cell shown in FIG. 7 along line C-C; and FIG. 9 is a schematic view of a partially enlarged structure of the battery cell at D shown in FIG. 8.

[0107] In some embodiments, the pressure relief mechanism 200 includes a second metal sheet 240, the second metal sheet 240 is arranged between the adhesive film 210 and the first wall body 110, the second metal sheet 240 is welded to the first wall body 110, and the second metal sheet 240 is provided with a second through hole 241, the second through hole 241 is in communication with the first through hole 111.

[0108] By arranging the second metal sheet 240 on the pressure relief mechanism 200, the second metal sheet 240 is arranged between the adhesive film 210 and the first wall body 110, and the second metal sheet 240 is welded to the first wall body 110, which can make the connection between the pressure relief mechanism 200 and the shell 100 more stable, and the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better. Since the first through hole 111 is reused as the liquid injection hole, after the liquid injection is completed, there may be residual electrolyte at the liquid injection hole, which can affect the adhesion of the adhesive film 210, so that the adhesive film 210 is not firmly attached to the shell 100. By arranging the second metal sheet 240 to be welded to the shell 100, the connection between the pressure relief mechanism 200 and the shell 100 can be more stable, and the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is further improved.

[0109] In some embodiments, the adhesive film 210, the first metal sheet 220, the protective layer 230, and the second metal sheet 240 can be first attached after being activated by high temperature to form the pressure relief mechanism 200, and then the pressure relief mechanism 200 and the shell 100 are welded, which can make the preparation process more simple.

[0110] In some embodiments, the adhesive film 210, the first metal sheet 220, the protective layer 230, and the second metal sheet 240 can be first attached after being activated by high temperature to form the pressure relief mechanism 200, and then the pressure relief mechanism 200 and the shell 100 are welded, which can make the preparation process more simple.

[0111] In some embodiments, the thickness of the second metal sheet 240 is H5, which satisfies H5≤2*H1. For example, H5 can be 2*H1 / 1.5*H1 or H1.

[0112] By arranging the thickness H2 of the first metal sheet 220 and the thickness H5 of the second metal sheet 240 to satisfy H1, when the shell 100 of the battery cell 10 is deformed under stress, the first metal sheet 220 can also be deformed, which can reduce the possibility of the adhesive film 210 separating from the shell and / or the first metal sheet 220, thereby reducing the risk of liquid leakage of the battery cell 10 and improving the safety of the battery cell 10.

[0113] In some embodiments, the thickness of the second metal sheet 240 is H5, which satisfies 0.02mm≤H5≤0.5mm. For example, H5 can be 0.02mm, 0.3mm, or 0.5mm, etc.

[0114] When H5 is greater than or equal to 0.02 mm, the connection between the pressure relief mechanism 200 and the shell 100 can be more stable, and the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better; when H5 is less than or equal to 0.5 mm, the second metal sheet 240 occupies a smaller space, which is conducive to improving the energy density of the battery cell 10, and can reduce the possibility of interference between the pressure relief mechanism 200 and external equipment; therefore, when 0.02 mm≤H5≤0.5 mm, the connection between the pressure relief mechanism 200 and the shell 100 can be more stable, the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better, and the second metal sheet 240 occupies a smaller space, which is conducive to improving the energy density of the battery cell 10, and can reduce the possibility of interference between the pressure relief mechanism 200 and external equipment.

[0115] In some embodiments, 0.02 mm≤H5≤0.3 mm. For example, H5 can be 0.02 mm, 0.25 mm, or 0.3 mm, etc.

[0116] When H5 is greater than or equal to 0.02 mm, the connection between the pressure relief mechanism 200 and the shell 100 can be more stable, and the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better; when H5 is less than or equal to 0.3 mm, the second metal sheet 240 occupies a smaller space, which is conducive to further improving the energy density of the battery cell 10, and can further reduce the possibility of interference between the pressure relief mechanism 200 and external equipment; therefore, when 0.02 mm≤H5≤0.3 mm, the connection between the pressure relief mechanism 200 and the shell 100 can be more stable, the sealing effect of the pressure relief mechanism 200 on the first through hole 111 is better, and the second metal sheet 240 occupies a smaller space, which is conducive to further improving the energy density of the battery cell 10, and can further reduce the possibility of interference between the pressure relief mechanism 200 and external equipment.

[0117] In some embodiments, the second metal sheet 240 can be made of aluminum, nickel, stainless steel, etc., so that the second metal sheet 240 is not prone to rust and has a long service life.

[0118] In some embodiments, the second metal sheet 240 is arranged in a circular ring shape, without the need to adjust the assembly direction, which can facilitate the assembly of the second metal sheet 240 and the first wall body 110.

[0119] In some embodiments, the adhesive film 210 is attached to the second metal sheet 240, and the width of the portion where the adhesive film 210 is attached to the second metal sheet 240 is W, which satisfies 0.1 mm≤W≤3 mm. For example, W can be 0.1 mm, 1.5 mm, or 3 mm, etc.

[0120] When W is greater than or equal to 0.1 mm, the bonding area of the adhesive film 210 and the second metal sheet 240 can be large, and thus the connection between the adhesive film 210 and the second metal sheet 240 is more secure, and the sealing reliability of the pressure relief mechanism 200 on the first through hole 111 is high. When W is less than or equal to 3 mm, the pressure relief path of the gas inside the battery cell 10 is short, and the pressure relief sensitivity of the pressure relief mechanism 200 is high. Therefore, when 0.1 mm≤W≤3 mm, the connection between the adhesive film 210 and the second metal sheet 240 is more secure, the sealing reliability of the pressure relief mechanism 200 on the first through hole 111 is high, and the pressure relief path of the gas inside the battery cell 10 is short, and the pressure relief sensitivity of the pressure relief mechanism 200 is high.

[0121] In some embodiments, 0.2 mm≤W≤1.5 mm. For example, W can be 0.2 mm, 0.8 mm, or 1.5 mm, etc.

[0122] When W is greater than or equal to 0.2 mm, the bonding area of the adhesive film 210 and the second metal sheet 240 can be large, and thus the connection between the adhesive film 210 and the second metal sheet 240 is more secure, and the sealing reliability of the pressure relief mechanism 200 on the first through hole 111 is higher. When W is less than or equal to 1.5 mm, the pressure relief path of the gas inside the battery cell 10 is short, and the pressure relief sensitivity of the pressure relief mechanism 200 is higher. Therefore, when 0.2 mm≤W≤1.5 mm, the connection between the adhesive film 210 and the second metal sheet 240 is more secure, the sealing reliability of the pressure relief mechanism 200 on the first through hole 111 is higher, and the pressure relief path of the gas inside the battery cell 10 is short, and the pressure relief sensitivity of the pressure relief mechanism 200 is higher.

[0123] In some embodiments, the outer diameter of the second metal sheet 240 is greater than or equal to the diameter of the adhesive film 210. The connection area between the second metal sheet 240 and the adhesive film 210 can be large, and the connection strength is high.

[0124] In some embodiments, the battery cell 10 includes a pole 300, and the pole 300 is arranged on the first wall body 110.

[0125] Since the battery cell 10 is installed in an electrical device, space needs to be reserved to facilitate electrical connection of the pole 300 with other components of the electrical device. Therefore, the pole 300 and the first through hole 111 are arranged on the same side wall, and no additional space needs to be reserved for the first through hole 111 to achieve pressure relief, which can further save space in the electrical device and make the structure of the electrical device more compact.

[0126] Referring to Table 1, Table 1 is the test results of the peeling rate and the weld back penetration rate of a plurality of embodiments and comparative examples provided by the embodiments of the present application. Among them, H1 is the thickness of the first wall body of the shell, H2 is the thickness of the first metal sheet of the pressure relief mechanism, and H5 is the thickness of the adapter sheet of the pressure relief mechanism.

[0127] Table 1 Test results of the peeling rate and the weld back penetration rate of the battery cell

[0128] In some embodiments, the test method of the peeling rate comprises:

[0129] (1) Charge the battery cell to a state of charge (SOC) of 50%.

[0130] (2) Drop the battery cell from a height of 1 meter for 18 times (one round), wherein 6 surfaces of the square battery cell are dropped downward respectively, 4 top corners of the battery cell are dropped downward respectively, 8 edges of the battery cell are dropped downward respectively, and two rounds of tests are performed.

[0131] (3) Drop the battery cell from a height of 75 mm for 5500 times.

[0132] (4) Measure the distance between the edge of the first metal sheet of the battery cell and the first wall body in the thickness direction of the first wall body. If the distance is greater than or equal to 0.05 mm, it is considered that there is peeling.

[0133] (5) The number of battery cells with peeling is A1, the total number of battery cells is A, and the peeling rate = A1 / A.

[0134] In some embodiments, the test method of the weld back penetration rate comprises:

[0135] (1) After welding the second metal sheet of the pressure relief mechanism with the first wall body, observe whether there is a trace of weld penetration on the side of the first wall body facing away from the pressure relief mechanism.

[0136] (2) Detect the circumference of the weld on the side of the second metal sheet facing away from the first wall body as L1, and the circumference of the weld on the side of the first wall body facing away from the pressure relief mechanism as L2. If L2 / L1>15%, it is considered that the weld penetrates back.

[0137] (3) The number of battery cells with weld back penetration is B1, the total number of battery cells is B, and the weld back penetration rate = B1 / B.

[0138] From the data in Table 1, the following conclusions can be drawn:

[0139] (1) According to the embodiments 1-3 and comparative examples 1-2, in the present application, H2 / H1≤1.5, which can make the peeling rate of the battery cell lower, and the battery cell is not prone to the problem of liquid leakage, and the weld back penetration rate of the battery cell is lower, further reducing the possibility of battery cell leakage. If H2 / H1 is greater than 1.5, the peeling rate of the battery cell will be higher, and the battery cell is prone to the problem of liquid leakage, which affects the safety of the battery cell.

[0140] With the increase of H2 / H1, the peeling rate of the battery cell will also increase.

[0141] (2) According to the embodiments 4-8, in the present application, 0.01mm≤H2≤0.25mm, which can make the peeling rate of the battery cell lower, and the battery cell is not prone to the problem of liquid leakage, and the weld back penetration rate of the battery cell is lower, further reducing the possibility of battery cell leakage. If H2 is greater than 0.25mm, the peeling rate of the battery cell will be higher, and the battery cell is prone to the problem of liquid leakage, which affects the safety of the battery cell.

[0142] In the present application, 0.01mm≤H2≤0.15mm, which can further reduce the peeling rate of the battery cell.

[0143] With the increase of H2, the peeling rate of the battery cell will also increase.

[0144] (3) According to the embodiments 9-12, in the present application, H5 / H1≤2, which can make the peeling rate of the battery cell lower, and the battery cell is not prone to the problem of liquid leakage, and the weld back penetration rate of the battery cell is lower, further reducing the possibility of battery cell leakage. If H5 / H1>2, the weld back penetration rate of the battery cell will be higher, and the battery cell will be welded through, and the possibility of battery cell leakage is larger.

[0145] With the increase of H5 / H1, the weld back penetration rate of the battery cell will also increase.

[0146] (4) According to the embodiments 13-17, in the present application, 0.02mm≤H5≤0.5mm, which can make the peeling rate of the battery cell lower, and the battery cell is not prone to the problem of liquid leakage, and the weld back penetration rate of the battery cell is lower. If H5 is greater than 0.5mm, the weld back penetration rate of the battery cell will be higher, and the battery cell will be welded through, and the possibility of battery cell leakage is larger.

[0147] In the present application, 0.02mm≤H5≤0.3mm, which can further reduce the weld back penetration rate of the battery cell.

[0148] With the increase of H5, the weld back penetration rate of the battery cell will also increase.

[0149] The present application also provides a power utilization device, which comprises the battery cell 10 of any one of the above schemes, and the battery cell 10 is used to provide electric energy for the power utilization device.

[0150] The electric device can be any of the devices or apparatuses of the aforementioned application battery cell 10.

[0151] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict.

[0152] The above only is the preferred embodiment of the present application, and is not used to limit the present application, and the present application can have various changes and changes for the person skilled in the art. 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. An electric cell, characterized by, include: The outer casing has a first wall, and the first wall is provided with a first through hole; The pressure relief mechanism includes a diaphragm and a first metal sheet. The diaphragm covers the first through hole and can be heated to melt to form a pressure relief channel connecting the inside and outside of the housing. The first metal sheet is disposed on the side of the diaphragm facing away from the first wall. The thickness of the first wall is H1, and the thickness of the first metal sheet is H2, satisfying H2≤1.5*H1.

2. The electric cell of claim 1, wherein, 0.01mm≤H2≤0.25mm.

3. The electric cell of claim 2, wherein, 0.01mm≤H2≤0.15mm.

4. The electric cell of claim 1, wherein, The melting point of the adhesive film is T, which satisfies the condition 100℃≤T≤130℃.

5. The electric cell of claim 1, wherein, The thickness of the adhesive film is H3, which satisfies 0.01mm≤H3≤0.5mm.

6. The electric cell of claim 5, wherein, 0.02mm≤H3≤0.3mm.

7. The electric cell of claim 1, wherein, The pressure relief mechanism includes a protective layer disposed on the side of the first metal sheet facing away from the adhesive film, and the first metal sheet is connected to the adhesive film and the protective layer.

8. The electric cell of claim 7, wherein, The thickness of the protective layer is H4, which satisfies 0.01mm≤H4≤0.25mm.

9. The electric cell of claim 8, wherein, 0.01mm≤H4≤0.15mm.

10. The electric cell of claim 7, wherein, The thickness of the adhesive film, the first metal sheet, and the protective layer is T, which satisfies 0.03mm≤T≤1mm.

11. The electric cell of claim 1, wherein, The pressure relief mechanism includes a second metal sheet, which is disposed between the adhesive film and the first wall. The second metal sheet is welded to the first wall and has a second through hole that communicates with the first through hole.

12. The electric cell of claim 11, wherein, The thickness of the second metal sheet is H5, which satisfies H5≤2*H1.

13. The electric cell of claim 11, wherein, The thickness of the second metal sheet is H5, which satisfies 0.02mm≤H5≤0.5mm.

14. The electric cell of claim 13, wherein, 0.02mm≤H5≤0.3mm.

15. The electric cell of claim 13, wherein, The adhesive film is bonded to the second metal sheet, and the width of the portion of the adhesive film bonded to the second metal sheet is W, which satisfies 0.1mm≤W≤3mm.

16. The electric cell of claim 15, wherein, 0.2mm≤W≤1.5mm.

17. The electrically charged cell of claim 1, wherein, The battery cell includes a terminal post, which is disposed on the first wall.

18. An electrical device, comprising: Includes a battery cell as described in any one of claims 1 to 17, the battery cell being used to provide electrical energy.

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