Battery cell and electrical device

Abstract

To provide a battery cell that can improve reliability of pressure release of the battery cell and improve a space utilization rate of the electrical device, and an electrical device.SOLUTION: A battery cell includes: a case provided with a first through hole; and a pressure relief mechanism including an adhesive film and covering the first through hole. In the pressure relief mechanism, a pressure relief passage communicating an inside and an outside of the case is formed by the adhesive film being melted by heat.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This application claims priority to Chinese Patent Application No. 202211736844.3, filed on December 31, 2022, for invention entitled "Battery Cell and Electrical Device," the entire contents of which are incorporated herein by reference.

[0002] This application relates to the field of battery technology, and more particularly to battery cells and electrical devices. [Background technology]

[0003] With the rapid development of new energy technologies, batteries are now widely used in electronic devices, electric vehicles, electric motorcycles, power tools, etc. Demands for battery quality, safety, miniaturization, etc. are also increasing.

[0004] Currently, to improve safety, steel-cased battery cells have laser-cut grooves on the case cover, which allow pressure to be released if the air pressure inside the battery cell becomes too high. The electrical device to which the steel-cased battery cell is installed must have a large pressure release space pre-installed to accommodate the cut grooves, which increases the space occupied by the entire electrical device. Furthermore, the thermal sensitivity of the cut grooves is poor, which reduces the reliability of pressure release and affects the safety of the battery cell. Furthermore, laser-cutting the grooves also increases the manufacturing costs of the battery cell. Summary of the Invention

[0005] The present invention provides a battery cell and an electric device, which can improve the reliability of pressure release of the battery cell and the space utilization rate of the electric device.

[0006] The present invention is realized by the following technical solutions.

[0007] In a first aspect, an embodiment of the present application provides a battery cell, the battery cell comprising: a case provided with a first through hole; and a pressure release mechanism including an adhesive film covering the first through hole, the adhesive film melting with heat to form a pressure release passage connecting the inside and outside of the case.

[0008] In the above technical solution, a pressure release mechanism is installed which includes an adhesive film and covers the first through-hole of the case. The adhesive film can be melted by heat to form a pressure release passage connecting the inside and outside of the case. The pressure release mechanism has good thermal sensitivity, which increases the reliability of pressure release and improves the safety of the battery cell. Furthermore, compared with the pressure release structure using a groove, this embodiment does not require a large space to be set up in advance, which makes the structure of the electrical device more compact and reduces the manufacturing cost of the pressure release mechanism.

[0009] In some embodiments, the first through hole is a liquid injection hole.

[0010] In the above technical solution, the liquid injection hole can be reused as the first through-hole for pressure release, which can further simplify the manufacturing process of the battery cell and reduce the manufacturing cost of the battery cell.

[0011] In some embodiments, the case includes a bottom wall and a plurality of side walls surrounding the bottom wall, the battery cell further includes a battery pole, and the battery pole and the first through-hole are provided in the same side wall.

[0012] In the above technical solution, when attaching a battery cell to an electrical device, it is necessary to set up a space in advance for the battery pole to electrically connect with other components of the electrical device. Therefore, by arranging the battery pole and the first through hole on the same side wall, it is not necessary to set up a separate space in advance for the first through hole to realize pressure release, which can further save space in the electrical device and make the structure of the electrical device more compact.

[0013] In some embodiments, the adhesive film is attached to the case, and the width of the attached portion between the adhesive film and the case is W, satisfying 0.2 mm≦W≦2 mm.

[0014] In the above technical solution, by setting the width W of the bonding portion between the adhesive film and the case to 0.2 mm to 2 mm, the length of the pressure release path in the event of thermal runaway of the battery cell can be shortened, the pressure release sensitivity of the battery cell can be increased, and the reliability of the sealing of the adhesive film to the first through-hole can be increased. If W is small (e.g., less than 0.2 mm), the reliability of the sealing of the adhesive film to the first through-hole will be reduced, and if W is large (e.g., greater than 2 mm), the length of the pressure release path will be long, and the pressure release sensitivity of the battery cell will be reduced.

[0015] In some embodiments, 0.3 mm≦W≦1 mm.

[0016] In the above technical solution, by setting the width W of the bonding part between the adhesive film and the case to 0.3 mm to 1 mm, the length of the pressure release path in the event of thermal runaway of the battery cell can be shortened, and the pressure release sensitivity of the battery cell can be increased.

[0017] In some embodiments, the pressure release mechanism further includes a first metal sheet, the first metal sheet being provided on the opposite side of the adhesive film from the case.

[0018] In the above technical solution, by providing a first metal sheet on the opposite side of the adhesive film from the case, the water permeable area of ​​the adhesive film can be reduced, and the sealing effect can be improved.

[0019] In some embodiments, the first metal sheet is configured in a circular shape and the adhesive film is configured in a circular shape.

[0020] In the above technical proposal, by configuring the first metal sheet in a circular shape, it is possible to facilitate the assembly of the first metal sheet and the adhesive film, and by configuring the adhesive film in a circular shape, it is possible to further improve the sealing effect.

[0021] In some embodiments, the first metal sheet is circular and the adhesive film is annular, which facilitates assembly of the first metal sheet and the adhesive film, and which increases the number of pressure release passages and improves the pressure release effect.

[0022] In some embodiments, the first through hole is circular, the diameter of the first metal sheet is equal to or smaller than the outer diameter of the adhesive film, and the diameter of the first metal sheet is larger than the diameter of the first through hole.

[0023] In the above technical solution, by setting the diameter of the first metal sheet to be equal to or smaller than the outer diameter of the adhesive film, the assembly of the first metal sheet and the adhesive film can be made easier; by setting the diameter of the first metal sheet to be larger than the diameter of the first through hole, the first metal sheet can completely cover the first through hole, resulting in a higher sealing effect.

[0024] In some embodiments, the pressure release mechanism further includes a second metal sheet, the second metal sheet being disposed between the adhesive film and the case, the second metal sheet being welded to the case, and the second metal sheet having a second through hole.

[0025] In the above technical solution, by installing a second metal sheet and welding it to the case, the connection between the pressure relief mechanism and the case can be made more stable, and the sealing effect can be improved.

[0026] In some embodiments, the adhesive film includes a first adhesive layer and a second adhesive layer, the first adhesive layer is laminated with the second adhesive layer, the second adhesive layer is located on the opposite side of the first adhesive layer from the case, and the melting point of the first adhesive layer is lower than the melting point of the second adhesive layer.

[0027] In the above technical solution, a first adhesive layer and a second adhesive layer are provided, and the melting point of the first adhesive layer is lower than that of the second adhesive layer. Therefore, when the adhesive film is activated at high temperature, the first adhesive layer melts and bonds to the case, while the second adhesive layer does not melt. This avoids the impact of over-melting of the adhesive film on the attachment of the adhesive film and also reduces the amount of adhesive overflow.

[0028] In some embodiments, the melting point of the first adhesive layer satisfies 100°C≦T1≦130°C, where T1 is the melting point of the first adhesive layer.

[0029] In the above technical solution, the melting point of the first adhesive layer is set to 100°C to 130°C, so that the first adhesive layer can melt and form a pressure release passage when the battery cell experiences thermal runaway. If T1 is small (e.g., less than 100°C), the first adhesive layer may melt before the battery cell 10 experiences thermal runaway, reducing the reliability of sealing the adhesive film to the first through-hole. If T1 is large (e.g., greater than 130°C), the first adhesive layer is less likely to melt when the battery cell experiences thermal runaway, reducing the battery cell's sensitivity to pressure release.

[0030] In some embodiments, 110°C < T1 < 125°C.

[0031] In the above technical solution, the melting point of the first adhesive layer is set to 110°C to 125°C, so that the thermal runaway situation of the battery cell can be more reliably controlled.

[0032] In some embodiments, the melting point of the second adhesive layer satisfies 140°C≦T2≦190°C, where T2 is the melting point of the second adhesive layer.

[0033] In the above technical solution, the melting point of the second adhesive layer is set to 140°C to 190°C, so that the second adhesive layer does not melt when the first adhesive layer melts. If T2 is small (e.g., less than 140°C), the first and second adhesive layers may melt and mix simultaneously when the adhesive film is activated at high temperature, making it difficult to attach the adhesive film. If T2 is large (e.g., greater than 190°C), the second adhesive layer will not melt easily even if the battery cell experiences excessive thermal runaway, reducing the battery cell's sensitivity to pressure release.

[0034] In some embodiments, 150°C < T2 < 170°C.

[0035] In the above technical solution, the melting point of the second adhesive layer is set to 150 to 170°C, so that the thermal runaway situation of the battery cell can be more reliably controlled.

[0036] In some embodiments, the adhesive film further includes a third adhesive layer, the third adhesive layer being located between the second adhesive layer and the first metal sheet, and the melting point of the third adhesive layer being lower than the melting point of the second adhesive layer.

[0037] In the above technical solution, a third adhesive layer is provided, and the melting point of the third adhesive layer is set lower than that of the second adhesive layer. Therefore, when the adhesive film is activated at high temperature, the third adhesive layer melts and bonds to the first metal sheet, while the second adhesive layer does not melt. This avoids the impact of over-melting of the adhesive film on the attachment of the first metal sheet, and also reduces the amount of adhesive overflow.

[0038] In some embodiments, the melting point of the third adhesive layer satisfies 100°C≦T3≦130°C, where T3 is the melting point of the third adhesive layer.

[0039] In the above technical solution, by setting the melting point of the third adhesive layer to 100°C to 130°C, the third adhesive layer can melt and form a pressure release passage when the battery cell experiences thermal runaway. If T1 is small (e.g., less than 100°C), the third adhesive layer may melt before the battery cell experiences thermal runaway, reducing the reliability of sealing the adhesive film to the first through-hole. If T1 is large (e.g., greater than 130°C), the third adhesive layer will be less likely to melt when the battery cell experiences thermal runaway, reducing the battery cell's sensitivity to pressure release.

[0040] In some embodiments, 110°C < T3 < 125°C.

[0041] In the above technical solution, the melting point of the third adhesive layer is set to 110°C to 125°C, so that the thermal runaway of the battery cell can be more reliably controlled.

[0042] In some embodiments, the adhesive film has a thickness H that satisfies 0.05 mm≦H≦1 mm.

[0043] In the above technical solution, by setting the thickness of the adhesive film to 0.05mm to 1mm, the adhesive film will be less likely to break, less likely to permeate water, and will have a high pressure release effect. If H is small (e.g., less than 0.05mm), the adhesive film will be easily broken and its water permeability will be too high. If H is large (e.g., greater than 1mm), the adhesive film will be less likely to melt in the event of thermal runaway of the battery cell, and the pressure release sensitivity of the battery cell will be low.

[0044] In some embodiments, 0.1 mm≦H≦0.3 mm.

[0045] In the above technical solution, the thickness of the adhesive film is set to 0.1mm to 0.3mm, which further makes the adhesive film less susceptible to breakage, less permeable to water, and more effective in releasing pressure.

[0046] In some embodiments, the ratio of the thickness of the first adhesive layer, the second adhesive layer, and the third adhesive layer is 1:0.5:1 to 1:3:1.

[0047] In the above technical solution, the thickness ratio of the first adhesive layer, the second adhesive layer, and the third adhesive layer is set to 1:0.5:1 to 1:3:1, so that the second adhesive layer can provide effective support while minimizing the impact on the pressure release effect of the adhesive film. If the second adhesive layer is thin (e.g., less than 0.5 times the thickness of the first adhesive layer), the second adhesive layer cannot provide effective support, making it difficult for the adhesive device to support the second adhesive layer to prevent the adhesive film from displacing during the melting process of the first adhesive layer, and the second adhesive layer is likely to be damaged. If the second adhesive layer is thick (e.g., more than three times the thickness of the first adhesive layer), it may affect the melting of the first adhesive layer and further affect the pressure release sensitivity of the battery cell.

[0048] In some embodiments, the first through hole has a circular shape, and the diameter of the first through hole is defined as D, and the diameter satisfies 0.5 mm≦D≦2 mm.

[0049] In the above technical solution, by setting the diameter of the first through-hole to 0.5mm to 2mm, the first through-hole can provide a pressure release passage with a large cross-sectional area in the event of thermal runaway of the battery cell, and facilitate the installation of a pressure release mechanism. If D is small (e.g., less than 0.5mm), the adhesive film will melt when thermal runaway of the battery cell occurs, forming a pressure release passage with a small cross-sectional area, which may prevent the gas inside the case from being released in a timely manner, reducing the safety of pressure release of the battery cell. If D is large (e.g., greater than 2mm), a pressure release mechanism with a large area is required to cover the first through-hole, making it difficult to install the pressure release mechanism.

[0050] In some embodiments, 0.9 mm≦D≦1.6 mm.

[0051] In the above technical solution, by setting the diameter of the first through hole to 0.9 mm to 1.6 mm, the first through hole can provide a pressure release passage with a large cross-sectional area when the battery cell experiences thermal runaway, and can facilitate the installation of a pressure release mechanism.

[0052] In a second aspect, an embodiment of the present application provides an electric device, the electric device including the battery cell described above, the battery cell being used to supply electric energy. [Brief explanation of the drawings]

[0053] In order to more clearly explain the technical solutions of the embodiments of the present application, the drawings necessary for the embodiments of the present application will be briefly described below. Note that the drawings described below only illustrate some examples of the present application, and should not be considered as limiting the scope. Those skilled in the art can derive other drawings based on these drawings without any creative efforts.

[0054] [Figure 1] FIG. 1 is a plan view schematic diagram of a portion of the structure of an electrical device provided by some embodiments of the present application. [Figure 2] FIG. 2 is a schematic diagram of the three-dimensional structure of a battery cell provided by some embodiments of the present application. [Figure 3] FIG. 3 is an exploded structural schematic diagram of a battery cell provided by some embodiments of the present application. [Figure 4] FIG. 4 is a cross-sectional schematic diagram of a portion of a battery cell structure provided by some embodiments of the present application. [Figure 5] FIG. 5 is a schematic front view of the structure of an adhesive film provided by some embodiments of the present application. [Figure 6] FIG. 6 is a schematic exploded structural view of a battery cell provided by some embodiments of the present application. [Figure 7] FIG. 7 is a schematic exploded structural view of a battery cell provided by some embodiments of the present application. [Figure 8]FIG. 8 is a schematic diagram of a three-dimensional structure of a battery cell provided by some embodiments of the present application. [Figure 9] FIG. 9 is an exploded structural schematic diagram of a battery cell provided by some embodiments of the present application. [Figure 10] FIG. 10 is a schematic planar structural view of a first insulating member provided according to some embodiments of the present application. [Figure 11] FIG. 11 is a front structural schematic view of a first insulating member provided according to some embodiments of the present application. [Figure 12] FIG. 12 is a front structural schematic diagram of a battery cell provided by some embodiments of the present application. [Figure 13] FIG. 13 is a schematic diagram of the bottom structure of a battery cell provided by some embodiments of the present application. [Figure 14] FIG. 14 is a schematic cross-sectional view taken along the X1-X1 direction in FIG. [Figure 15] FIG. 15 is a schematic cross-sectional view taken along the line X2-X2 in FIG. [Figure 16] FIG. 16 is a cross-sectional schematic diagram of a portion of a battery cell structure provided by some embodiments of the present application. [Figure 17] FIG. 17 is a cross-sectional schematic diagram of a portion of a battery cell structure provided by some embodiments of the present application. [Figure 18] FIG. 18 is an exploded schematic view of a battery cell provided by some embodiments of the present application. [Figure 19] FIG. 19 is a cross-sectional schematic diagram of a portion of a battery cell structure provided by some embodiments of the present application.

[0055] Explanation of symbols: 10: battery cell, 100: case, 101: first through-hole, 110: bottom wall, 121: first side wall, 122: second side wall, 123: third side wall, 124: fourth side wall, 200: case cover, 300: pressure release mechanism, 310: adhesive film, 311: first adhesive layer, 312: second adhesive layer, 313: third adhesive layer, 320: first metal sheet, 330: adhesive film, 340: second metal sheet, 400: battery pole, 500: case, 501: first through-hole, 502 : Second through hole, 510: Bottom wall, 520: First side wall, 610: Battery pole, 620: First insulating member, 621: Groove, 622: Third through hole, 630: Adapter, 631: Fourth through hole, 640: Second insulating member, 641: Fifth through hole, 710: Adhesive film, 720: Adhesive film, 721: First adhesive portion, 722: Second adhesive portion, 730: Adhesive film, 731: First adhesive portion, 732: Second adhesive portion, 733: Third adhesive portion, 740: Metal sheet, 20: Housing. DETAILED DESCRIPTION OF THE INVENTION

[0056] In order to clarify the objectives, technical solutions and advantages of the present invention, the technical solutions of the embodiments of the present invention will be described in detail below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all the embodiments. Those skilled in the art will understand that all other embodiments obtained based on the embodiments of the present invention are within the protection scope of the present invention.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Terms used in the present specification are for the purpose of describing specific embodiments only and are not intended to limit the present specification. The terms "comprise," "have," and any variations thereof in the present specification and claims, as well as the above-mentioned drawings, are intended to cover a non-exclusive inclusion. The terms "first," "second," etc. in the present specification and claims or the above-mentioned drawings are used to distinguish between different objects, but are not intended to describe a particular order or primary-secondary relationship.

[0058] In the description of this application, it should be explained that unless otherwise specified and limited, the terms "mount," "connect," and "attach" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application according to specific circumstances.

[0059] In this application, the term "and / or" is only used to describe the associative relationship of related objects, and indicates that three types of relationships can exist, for example, A and / or B can indicate three situations: A exists alone, A and B exist simultaneously, and B exists alone. Also, in this specification, the character " / " generally indicates that the related objects before and after it are in an "or" relationship.

[0060] In the embodiments of the present application, the same reference numerals refer to the same elements, and for the sake of brevity, detailed descriptions of the same elements in different embodiments will be omitted. It should be understood that the dimensions, such as thickness, length, and width, of the various elements in the embodiments of the present application shown in the drawings, and the overall dimensions, such as thickness, length, and width, of the combined device, are merely illustrative and do not constitute limitations on the present application.

[0061] In the present application, each battery cell may be a secondary battery or a primary battery, for example, a lithium ion battery, a sodium ion battery, a magnesium ion battery, etc., and is not limited to the embodiments of the present application. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shape, and is not limited to the embodiments of the present application.

[0062] The electrode assembly may have a wound structure or a stacked structure, and is not limited to the embodiments of the present application.

[0063] The inventors discovered the following: For typical steel-cased battery cells, the grooves are typically formed by laser-cutting grooves into the case cover. When the internal pressure of the battery cell becomes too high, the grooves burst to form a pressure release passage, allowing the gas inside the battery cell to escape and prevent explosion, thereby improving the safety of the battery cell. However, to ensure smooth release of the gas inside the battery cell after the grooves burst, a pressure release space must typically be pre-installed in the electrical device at the location corresponding to the grooves. Furthermore, because the case cover is the side with the largest area of ​​the battery cell housing and the grooves are long, the pre-installed space between the case cover and other components occupies a large amount of space inside the electrical device. Furthermore, the grooves rupture primarily due to the internal pressure of the battery cell, have poor thermal sensitivity, and a low pass rate in hot box tests, affecting the safety of the battery cell. Furthermore, laser-cutting the grooves also increases the manufacturing costs of the battery cell.

[0064] Based on the above considerations, in order to solve the problems of battery cells currently using notched grooves to release pressure, which occupy a large space, reduce the safety of the battery cell's pressure release, and increase manufacturing costs, the inventors conducted extensive research and designed the following battery cell. The battery cell includes a case and a pressure release mechanism, where the case is provided with a first through-hole, which covers the first through-hole and includes an adhesive film that melts when heated to form a pressure release passage connecting the inside and outside of the case. The pressure release mechanism has good thermal sensitivity, which increases the reliability of pressure release and improves the safety of the battery cell. Furthermore, compared to pressure release structures using notched grooves, the size of the first through-hole in this embodiment is smaller, which eliminates the need for a large space in advance, allowing the structure of the electrical device to be more compact, and the manufacturing costs of the pressure release mechanism are lower.

[0065] The embodiments of the present application provide an electric device that uses a battery cell as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric vehicle, a steamship, a spacecraft, etc. Illustratively, in FIG. 1 , FIG. 1 is a plan view schematic diagram of a part of the structure of an electric device provided by some embodiments of the present application, in which a battery cell 10 has a rectangular parallelepiped structure and is housed in a housing 20.

[0066] 2 and 3, FIG. 2 is a schematic diagram of the three-dimensional structure of a battery cell provided according to some embodiments of the present application, and FIG. 3 is a schematic diagram of the exploded structure of a battery cell provided according to some embodiments of the present application. The battery cell 10 includes a case 100, a case cover 200, an electrode assembly (not shown), and an electrolyte (not shown). The case cover 200 is provided to cover the case 100 to form a storage space for the electrode assembly and the electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell operates mainly through the movement of metal ions between the positive electrode sheet and the negative electrode sheet.

[0067] According to some embodiments of the present application, with reference to FIGS. 1 to 3 , the embodiments of the present application provide a battery cell 10, which includes a case 100 and a pressure release mechanism 300, wherein the case 100 has a first through-hole 101, and the pressure release mechanism 300 covers the first through-hole 101, and the pressure release mechanism 300 includes an adhesive film 310, which can be melted by heat to form a pressure release passage connecting the inside and outside of the case 100.

[0068] By installing the pressure release mechanism 300, which includes an adhesive film 310 and covers the first through-hole 101 of the case 100, the adhesive film 310 can be melted by heat to form a pressure release passage connecting the inside and outside of the case 100. The pressure release mechanism 300 has good thermal sensitivity, which increases the reliability of pressure release and improves the safety of the battery cell 10. Furthermore, compared to a pressure release structure using an engraved groove, the size of the first through-hole 101 in this embodiment is smaller, eliminating the need to pre-install a large space and allowing the structure of the electrical device to be more compact. Furthermore, manufacturing the pressure release mechanism 300 only requires processes such as drilling and melting the adhesive, which is less expensive than laser groove engraving.

[0069] In some embodiments, the first through-hole 101 is a liquid injection hole, and an electrolyte can be injected into the battery cell 10 through the first through-hole 101.

[0070] By reusing the liquid injection hole as the first through hole 101 for pressure release, the manufacturing process of the battery cell 10 can be further simplified, the number of hole drilling steps can be reduced, and the manufacturing cost of the battery cell 10 can be reduced.

[0071] In another embodiment, the first through-hole 101 may be another through-hole formed in the case 100 .

[0072] In some embodiments, the case 100 includes a bottom wall 110 and a plurality of side walls surrounding the bottom wall 110, and the plurality of side walls may include a first side wall 121, a second side wall 122, a third side wall 123, and a fourth side wall 124 connected in sequence, and the battery cell 10 further includes a battery pole 400, and the battery pole 400 and the first through hole 101 may be provided in the same side wall (e.g., the first side wall 121).

[0073] When the battery cell 10 is assembled into an electrical device, it is necessary to provide space in advance for the battery pole 400 to be electrically connected to other components of the electrical device so that the electrode assembly inside the case 100 can be electrically connected to other components. However, by providing the battery pole 400 and the first through-hole 101 on the same side wall, there is no need to provide a separate space in advance for the first through-hole 101 to release pressure. Furthermore, the first side wall 121 can have the smallest area of ​​the multiple walls of the case 100, and the required spacing space can be reduced, thereby further saving space in the electrical device and making the structure of the electrical device more compact.

[0074] 4, which is a cross-sectional schematic diagram of a portion of the structure of a battery cell provided by some embodiments of the present application. In some embodiments, the adhesive film 310 is attached to the case 100, and the width of the attached portion between the adhesive film 310 and the case 100 is W, which satisfies 0.2 mm≦W≦2 mm.

[0075] By attaching the adhesive film 310 to the case 100, the adhesive film 310 can seal the first through-hole 101, and by setting the width W of the attached portion of the adhesive film 310 and the case 100 to 0.2 mm to 2 mm, the length of the pressure release path in the event of thermal runaway of the battery cell 10 can be shortened, the pressure release sensitivity of the battery cell 10 can be increased, and the reliability of the sealing of the adhesive film 310 into the first through-hole 101 can be increased. If W is small (for example, less than 0.2 mm), the reliability of the sealing of the adhesive film 310 into the first through-hole 101 will be reduced, and if W is large (for example, greater than 2 mm), the length of the pressure release path will be increased and the pressure release sensitivity of the battery cell will be reduced.

[0076] Preferably, 0.3 mm≦W≦1 mm, which can shorten the length of the pressure release path when the battery cell 10 experiences thermal runaway, and make the battery cell 10 more sensitive to pressure release.

[0077] In some embodiments, the pressure release mechanism 300 may further include a first metal sheet, and the first metal sheet 320 and the adhesive film 310 are laminated along the opening direction of the first through hole 101 (i.e., the thickness direction of the first side wall 121), and the first metal sheet 320 is arranged on the opposite side of the adhesive film 310 from the case 100.

[0078] The adhesive film 310 is a water-permeable polymer, and if moisture enters the inside of the case 100 through the adhesive film 310, it will have a negative effect on the electrode assembly and electrolyte. Therefore, by providing a first metal sheet 320 on the opposite side of the adhesive film 310 from the case 100, the water-permeable area of ​​the adhesive film 310 can be reduced, thereby improving the sealing effect.

[0079] In some embodiments, adhesive film 310 can be made of polypropylene, which has good toughness and chemical resistance.

[0080] In some embodiments, the first metal sheet 320 can be made of materials such as aluminum, nickel, stainless steel, etc., which are rust-resistant and have a long service life.

[0081] In some embodiments, the first metal sheet 320 may be configured in a circular shape, the adhesive film 310 may be configured in a circular shape, and the first through-hole 101 may be configured in a circular shape.

[0082] By configuring the first metal sheet 320 in a circular shape, there is no need to adjust the assembly direction, making it easier to assemble the first metal sheet 320 and the adhesive film 310.By configuring the adhesive film 310 in a circular shape, the adhesive film 310 can be assembled into the circular first through hole 101.If the center of the adhesive film 310 and the center of the first through hole 101 are concentric, the bonding surface between the adhesive film 310 and the case 100 will be evenly distributed, further improving the sealing effect and making it easier to attach the adhesive film 310.

[0083] 5, which is a schematic front view of an adhesive film provided in some embodiments of the present application. In some embodiments, the first metal sheet 320 may be circular, and the adhesive film 330 may be annular.

[0084] By configuring the adhesive film 330 in a circular ring shape, pressure release passages can be formed between the adhesive film 330 and the case 100, and between the adhesive film 330 and the first metal sheet 320, and the number of pressure release passages can be increased, thereby further improving the pressure release effect.

[0085] Referring back to Figures 1 to 3, in some embodiments, the first through hole 101 is configured in a circular shape, the diameter of the first metal sheet 320 is less than or equal to the outer diameter of the adhesive film 310, and the diameter of the first metal sheet 320 is greater than the diameter of the first through hole 101.

[0086] By setting the diameter of the first metal sheet 320 to be equal to or smaller than the outer diameter of the adhesive film 310, the assembly of the first metal sheet 320 and the adhesive film 310 can be made easier, and by setting the diameter of the first metal sheet 320 to be larger than the diameter of the first through hole 101, the first metal sheet 320 can completely cover the first through hole 101, resulting in a higher sealing effect and an excellent water vapor blocking effect.

[0087] 6 and 7, Fig. 6 is a schematic view of an exploded structure of a battery cell provided by some embodiments of the present application, and Fig. 7 is a schematic view of an exploded structure of a battery cell provided by some embodiments of the present application. In some embodiments, the pressure release mechanism 300 further includes a second metal sheet 340, which is disposed between the adhesive film 310 and the case 100, and which is welded to the case 100. The second metal sheet 340 may have a second through-hole 341.

[0088] Because the liquid injection hole is reused as the first through-hole 101, electrolyte may remain in the liquid injection hole after the battery cell 10 is filled with liquid. The electrolyte may affect the adhesiveness of the adhesive film 310, preventing the adhesive film 310 and the case 100 from being firmly attached to each other. By providing the second metal sheet 340 and welding it to the case 100, the connection between the pressure release mechanism 300 and the case 100 can be made more stable, resulting in a more effective sealing.

[0089] In some embodiments, the pressure release mechanism 300 can be constructed by first bonding the adhesive film 310 to the first metal sheet 320 and the second metal sheet 340, respectively, and then welding and connecting the pressure release mechanism 300 to the case 100, thereby simplifying the manufacturing process.

[0090] In another embodiment, first, the first metal sheet 320, the adhesive film 310, and the second metal sheet 340 are laminated, and then, when the second metal sheet 340 is welded to the case 100, the adhesive film 310 is melted at the high welding temperature, thereby simultaneously bonding the adhesive film 310 to the first metal sheet 320 and the second metal sheet 340.

[0091] In some embodiments, the second metal sheet 340 is configured in a circular ring shape.

[0092] By configuring the second metal sheet 340 in an annular shape, a pressure release passage with a large area can be formed within the second metal sheet 340, and the pressure release effect can be further improved.

[0093] Referring to FIG. 4, in some embodiments, the adhesive film 310 may include a first adhesive layer 311 and a second adhesive layer 312, the first adhesive layer 311 and the second adhesive layer 312 being laminated along the opening direction of the first through hole 101, the second adhesive layer 312 being located on the opposite side of the first adhesive layer 311 relative to the case 100, and the melting point of the first adhesive layer 311 being lower than the melting point of the second adhesive layer 312.

[0094] By providing a first adhesive layer 311 and a second adhesive layer 312 and making the melting point of the first adhesive layer 311 lower than the melting point of the second adhesive layer 312, when the adhesive film 310 is activated at high temperature, the first adhesive layer 311 melts and bonds to the first metal sheet 320, while the second adhesive layer 312 does not melt, thereby avoiding the impact of over-melting of the adhesive film 310 on the attachment of the first metal sheet 320 and reducing the amount of adhesive overflow.

[0095] In some embodiments, the melting point of the first adhesive layer 311 may satisfy the relationship 100°C≦T1≦130°C, where T1 is the melting point of the first adhesive layer 311.

[0096] By setting the melting point of the first adhesive layer 311 to 100°C to 130°C, the first adhesive layer 311 can melt and form a pressure release path in the event of thermal runaway of the battery cell 10. If T1 is small (e.g., less than 100°C), the first adhesive layer 311 may melt before the battery cell 10 experiences thermal runaway, reducing the reliability of sealing the adhesive film 310 to the first through-hole 101. If T1 is large (e.g., greater than 130°C), the first adhesive layer 311 is less likely to melt in the event of thermal runaway of the battery cell 10, reducing the sensitivity of the battery cell 10 to pressure release.

[0097] Preferably, 110°C≦T1≦125°C, so that the thermal runaway situation of the battery cell 10 can be controlled more reliably.

[0098] In some embodiments, the melting point of the second adhesive layer 312 satisfies 140°C≦T2≦190°C, where T2 is the melting point of the second adhesive layer 312.

[0099] By setting the melting point of the second adhesive layer 312 to 140°C to 190°C, the second adhesive layer 312 can be prevented from melting when the first adhesive layer 311 melts. If T2 is small (e.g., less than 140°C), the first adhesive layer 311 and the second adhesive layer 312 may melt and mix together at the same time when the adhesive film 310 is activated at high temperature, which may make it difficult to attach the adhesive film 310. If T2 is large (e.g., greater than 190°C), the second adhesive layer 312 will not melt easily even if the battery cell 10 experiences excessive thermal runaway, and the battery cell 10 will be less susceptible to pressure release.

[0100] Preferably, 150°C≦T2≦170°C, so that the thermal runaway situation of the battery cell 10 can be controlled more reliably.

[0101] In some embodiments, the adhesive film 310 further includes a third adhesive layer 313, which is located between the second adhesive layer 312 and the first metal sheet 320, and the melting point of the third adhesive layer 313 is lower than the melting point of the second adhesive layer 312.

[0102] By providing a third adhesive layer 313 and making the melting point of the third adhesive layer 313 lower than the melting point of the second adhesive layer 312, when the adhesive film 310 is activated at high temperature, the third adhesive layer 313 melts and bonds to the first metal sheet 320, while the second adhesive layer 312 does not melt, thereby avoiding the impact of over-melting of the adhesive film 310 on the attachment of the first metal sheet 320 and reducing the amount of adhesive overflow.

[0103] In some embodiments, the melting point of the third adhesive layer 313 satisfies 100°C≦T3≦130°C, where T3 is the melting point of the third adhesive layer 313.

[0104] By setting the melting point of the third adhesive layer 313 to 100°C to 130°C, the third adhesive layer 313 can melt and form a pressure release path in the event of thermal runaway of the battery cell 10. If T3 is small (e.g., less than 100°C), the third adhesive layer 313 may melt before the battery cell 10 experiences thermal runaway, reducing the reliability of sealing the adhesive film 310 to the first through-hole 101. If T3 is large (e.g., greater than 130°C), the third adhesive layer 313 is less likely to melt in the event of thermal runaway of the battery cell 10, reducing the sensitivity of the battery cell 10 to pressure release.

[0105] Preferably, 110°C≦T3≦125°C, so that the thermal runaway situation of the battery cell 10 can be controlled more reliably.

[0106] In some embodiments, the thickness of the adhesive film 310 is H, and satisfies 0.05 mm≦H≦1 mm.

[0107] By setting the thickness of the adhesive film 310 to 0.05 mm to 1 mm, the adhesive film 310 is less likely to break, less likely to permeate water, and has a high pressure release effect. If H is small (e.g., less than 0.05 mm), the adhesive film 310 is easily broken and has too high water permeability, while if H is large (e.g., greater than 1 mm), the adhesive film 310 is less likely to melt when the battery cell 10 experiences thermal runaway, and the battery cell 10 is less sensitive to pressure release.

[0108] Preferably, 0.1 mm≦H≦0.3 mm, which further makes the adhesive film 310 less susceptible to damage, less permeable to water, and more effective in releasing pressure, thereby more reliably controlling the thermal runaway situation of the battery cell 10.

[0109] In some embodiments, the ratio of the thickness of the first adhesive layer 311, the second adhesive layer 312, and the third adhesive layer 313 is between 1:0.5:1 and 1:3:1.

[0110] By setting the thickness ratio of the first adhesive layer 311, the second adhesive layer 312, and the third adhesive layer 313 to 1:0.5:1 to 1:3:1, the second adhesive layer 312 can provide effective support while minimizing the impact on the pressure release effect of the adhesive film 310. If the second adhesive layer 312 is thin (e.g., less than 0.5 times the thickness of the first adhesive layer 311), the second adhesive layer 312 cannot provide effective support, making it difficult for the adhesive device (not shown) to support the second adhesive layer 312 to prevent the adhesive film 310 from displacing during the melting process of the first adhesive layer 311, and the second adhesive layer 312 is likely to be damaged. If the second adhesive layer 312 is thick (e.g., more than three times the thickness of the first adhesive layer), this may affect the melting of the first adhesive layer 311 and further affect the pressure release sensitivity of the battery cell 10.

[0111] In some embodiments, the first through-hole 101 is circular, and the diameter of the first through-hole 101 is D, which satisfies 0.5 mm≦D≦2 mm.

[0112] By setting the diameter of the first through-holes 101 to 0.5 mm to 2 mm, the first through-holes 101 can provide a pressure release passage with a large cross-sectional area in the event of thermal runaway of the battery cells 10, and facilitate installation of the pressure release mechanism 300. If D is small (e.g., less than 0.5 mm), the adhesive film 310 will melt in the event of thermal runaway of the battery cells 10, forming a pressure release passage with a small cross-sectional area, which may prevent the gas inside the case 100 from being released in a timely manner, reducing the safety of pressure release of the battery cells 10. If D is large (e.g., greater than 2 mm), a pressure release mechanism 300 with a large area is required to cover the first through-holes 101, and installation of the pressure release mechanism 300 will be difficult because the adhesive film 310 is a flexible material with weak supporting strength.

[0113] Preferably, 0.9 mm≦D≦1.6 mm, so that in the event of thermal runaway of the battery cell, the first through-hole 101 can further provide a pressure release passage with a large cross-sectional area and facilitate the installation of the pressure release mechanism 300.

[0114] 8 and 9, Fig. 8 is a schematic diagram of a three-dimensional structure of a battery cell provided according to some embodiments of the present application, and Fig. 9 is a schematic diagram of an exploded structure of a battery cell provided according to some embodiments of the present application. The battery cell 10 includes a case 500, a battery pole 610, and a pressure release mechanism, where the case 500 has a bottom wall 510 and a plurality of side walls surrounding the bottom wall 510, a first side wall 520 of the plurality of side walls has a first through-hole 501 and a second through-hole 502, the battery pole 610 is disposed through the first through-hole 501, and the pressure release mechanism is disposed to cover the second through-hole 502, where the pressure release mechanism includes an adhesive film 710 that can melt when the temperature of the battery cell 10 reaches a threshold value so that the pressure inside the case 100 is released through the second through-hole 502.

[0115] The pressure release mechanism includes an adhesive film 710 and covers the second through-hole 502 of the case 500. When the temperature of the battery cell 10 reaches a threshold, the adhesive film 710 melts, allowing the pressure inside the case 500 to be released through the second through-hole 502. This improves the thermal sensitivity of the pressure release mechanism, increases the reliability of pressure release, and improves the safety of the battery cell 10. The second through-hole 502 and the first through-hole 501 for attaching the battery pole 610 are both located on the first side wall 520, allowing the pressure release mechanism to utilize the space previously reserved for the battery pole 610, saving space in the electrical device to which the battery cell 10 is attached, making the structure of the electrical device more compact, and reducing the manufacturing costs of the pressure release mechanism.

[0116] In some embodiments, the battery cell 10 further includes a first insulating member 620, which is located inside the first side wall 520 and is connected to the battery pole 610, and which has a passage in the first insulating member 620 that connects the internal space of the case 500 with the pressure release mechanism.

[0117] By providing a passage in the first insulating member 620 that connects the internal space of the case 500 to the pressure release mechanism, the second through-hole 502 is less likely to be blocked during the pressure release process, the pressure release effect is improved, and the safety of pressure release from the battery cell is increased.

[0118] In some embodiments, the passage is a groove 621 provided on the side of the first insulating member 620 facing the first side wall 520, and at least one end of the groove 621 extends to the edge of the first insulating member 620.

[0119] By providing the passage as a groove 621 on the side facing the first side wall 520 of the first insulating member 620, the distance between the second through hole 502 and the passage can be made shorter, the possibility of the passage being blocked is further reduced, the pressure release effect is improved, and the safety of pressure release of the battery cell is increased.

[0120] In some embodiments, the passage extends through the first insulating member 620 along the width of the first insulating member 620 .

[0121] This allows air on both sides of the bottom wall 510 in the thickness direction to flow through passages along the width direction of the first insulating member 620 to the second through-hole 502, making the air flow faster during the pressure release process.In addition, pressure can be released even if either side of the first insulating member 620 in the width direction of the first insulating member 620 is blocked, thereby increasing the reliability of pressure release in the battery cell 10.

[0122] 10, which is a schematic planar structural view of a first insulating member provided in some embodiments of the present application. In some embodiments, the depth A of the passage in the opening direction of the second through-hole 502 (i.e., the thickness direction of the first side wall 520) satisfies 0.05 mm≦A≦0.5 mm.

[0123] By setting the depth A of the passage in the opening direction of the second through-hole 502 to 0.05 mm to 0.5 mm, the first insulating member 620 does not occupy excessive space inside the case 500, and the cross-sectional area of ​​the passage is increased, thereby accelerating the speed of pressure release. If A is small (e.g., less than 0.05 mm), the cross-sectional area of ​​the passage is small and prone to clogging, and the pressure release speed is too slow, affecting the safety of pressure release. If A is large (e.g., greater than 0.5 mm), the size of the first insulating member 620 is too large, occupying excessive space inside the case 500 and compressing the installation space for other components inside the case 500.

[0124] Preferably, 0.1 mm≦A≦0.2 mm, so that the space inside the case 500 is not excessively occupied and the cross-sectional area of ​​the passage can be increased.

[0125] 11 and 12, Fig. 11 is a schematic front view of a first insulating member according to some embodiments of the present application, and Fig. 12 is a schematic front view of a battery cell according to some embodiments of the present application. In some embodiments, when the diameter of the second through hole 502 in the spacing direction between the first through hole 501 and the second through hole 502 is B and the width of the passage in the spacing direction between the first through hole 501 and the second through hole 502 is C, the relationship 0.8 × B≦C is satisfied.

[0126] By setting C to 0.8×B or more, the communication area between the passage and the second through-hole 502 becomes large, and the pressure release speed becomes fast. If C is small (for example, less than 0.8×B), the communication area between the passage and the second through-hole 502 becomes small, making it prone to clogging, and the pressure release speed is too slow, which affects the safety of pressure release.

[0127] Preferably, B≦C≦2×B, whereby the communication area between the passage and the second through-hole 502 can be further increased.

[0128] 9 and 13 to 15, Fig. 13 is a schematic diagram of a bottom structure of a battery cell provided according to some embodiments of the present application, Fig. 14 is a schematic diagram of a cross-sectional structure taken along the X1-X1 direction of Fig. 13, and Fig. 15 is a schematic diagram of a cross-sectional structure taken along the X2-X2 direction of Fig. 13. In some embodiments, the battery cell 10 further includes an electrode assembly (not shown) and an adapter 630, both of which are provided within the case 500. The adapter 630 is used to electrically connect the electrode assembly and the battery pole 610. A first insulating member 620 is located between the first side wall 520 and the adapter 630. A third through-hole 622 is provided in the first insulating member 620, and a fourth through-hole 631 is provided in the adapter 630. The battery pole 610 is provided to pass through the third through-hole 622 and the fourth through-hole 631 and is riveted to the adapter 630.

[0129] The battery pole 610 is installed to penetrate the first insulating member 620 and the adapter 630, and is riveted to the adapter 630, thereby making the connection between the battery pole 610 and the adapter 630 more stable, and the first insulating member 620 can play a role in insulatingly spacing the adapter 630 and the case 500.

[0130] In some embodiments, the battery cell 10 further includes a second insulating member 640, at least a portion of which is located outside the first side wall 520, a fifth through hole 641 is provided in the second insulating member 640, and the battery pole 610 is provided to pass through the fifth through hole 641.

[0131] The battery pole 610 is provided to penetrate the second insulating member 640, so that the second insulating member 640 can serve to electrically separate the battery pole 610 and the case 500.

[0132] In some embodiments, the melting point of the adhesive film 710 is T, and the melting point satisfies 100°C≦T≦190°C.

[0133] By setting the melting point T of the adhesive film 710 to 100°C to 190°C, the adhesive film 710 can melt and release the pressure inside the case 500 in the event of thermal runaway of the battery cell 10. If T is small (for example, less than 100°C), the adhesive film 710 may melt before the battery cell 10 experiences thermal runaway, reducing the reliability of sealing the adhesive film 710 in the second through-hole 502. If T is large (for example, greater than 190°C), the adhesive film 710 is less likely to melt in the event of thermal runaway of the battery cell, reducing the sensitivity of the battery cell 10 to pressure release.

[0134] Preferably, 100° C.≦T≦130° C., thereby more reliably controlling the thermal runaway situation of the battery cell 10.

[0135] In some embodiments, the thickness of the adhesive film 710 is H, and satisfies 0.05 mm≦H≦0.5 mm.

[0136] By setting the thickness H of the adhesive film 710 to 0.05 mm to 0.5 mm, the adhesive film 710 is less likely to break, less likely to pass water, and has a high pressure release effect. If H is small (e.g., less than 0.05 mm), the adhesive film 710 is more likely to break and has too high water permeability. If H is large (e.g., greater than 0.5 mm), the adhesive film 710 is less likely to melt in the event of thermal runaway of the battery cell 10, and the battery cell 10 is less sensitive to pressure release.

[0137] Preferably, 0.1 mm≦H≦0.3 mm, so that the thermal runaway situation of the battery cell 10 can be more reliably controlled.

[0138] In some embodiments, the second through-hole 502 may be circular, and the diameter of the second through-hole 502 is B, where B satisfies 0.5 mm≦B≦3 mm.

[0139] By setting the diameter B of the second through-hole 502 to 0.5 mm to 3 mm, the second through-hole 502 can provide a pressure release passage with a large cross-sectional area in the event of thermal runaway of the battery cell 10, and can facilitate the installation of a pressure release mechanism. If B is small (e.g., less than 0.5 mm), the adhesive film 710 will melt in the event of thermal runaway of the battery cell 10, forming a pressure release passage with a small cross-sectional area, which may prevent the gas inside the case 100 from being released in a timely manner, reducing the safety of pressure release of the battery cell 10. If B is large (e.g., greater than 3 mm), a pressure release mechanism 300 with a large area is required to cover the second through-hole 502, and the adhesive film 710 is a flexible material with poor supporting strength, making it difficult to install the pressure release mechanism.

[0140] Preferably, 0.9 mm≦B≦1.6 mm, which can further provide a pressure release passage with a large cross-sectional area and can facilitate the installation of a pressure release mechanism.

[0141] In some embodiments, the width of the bonded portion between the pressure release mechanism and the first side wall 520 is W, and satisfies 0.2 mm≦W≦2 mm.

[0142] By setting the width W of the bonding portion between the adhesive film 710 and the first side wall 520 to 0.2 mm to 2 mm, it is possible to shorten the length of the pressure release path in the event of thermal runaway of the battery cell 10, increase the pressure release sensitivity of the battery cell 10, and increase the reliability of sealing of the adhesive film 710 into the second through-hole 502. If W is small (for example, less than 0.2 mm), the reliability of sealing of the adhesive film 710 into the second through-hole 502 decreases, and if W is large (for example, greater than 2 mm), the length of the pressure release path increases, and the pressure release sensitivity of the battery cell 10 decreases.

[0143] Preferably, 0.3 mm≦W≦1 mm, which allows the length of the pressure release path in the event of thermal runaway of the battery cell 10 to be shorter and makes the battery cell 10 more sensitive to pressure release.

[0144] 16, which is a cross-sectional schematic diagram of a portion of a structure of a battery cell provided by some embodiments of the present application. In some embodiments, the adhesive film 720 includes a first adhesive portion 721 and a second adhesive portion 722 that are connected together, the first adhesive portion 721 being located outside the first side wall 520, and at least a portion of the second adhesive portion 722 being located within the second through-hole 502.

[0145] The adhesive film 720 consists of a first adhesive portion 721 and a second adhesive portion 722, and at least a portion of the second adhesive portion 722 is located within the second through hole 502, so that the first adhesive portion 721 can be attached to the case 500 and the second adhesive portion 722 can seal the second through hole 502, thereby improving the sealing effect on the second through hole 502.

[0146] 17, which is a cross-sectional schematic diagram of a portion of the structure of a battery cell provided by some embodiments of the present application. In some embodiments, the adhesive film 730 includes a first adhesive portion 731, a second adhesive portion 732, and a third adhesive portion 733, which are connected in order, where the first adhesive portion 731 is located on the outside of the first side wall 520, the second adhesive portion 732 is located in the second through-hole 502, and the third adhesive portion 733 is located on the inside of the first side wall 520.

[0147] The adhesive film 730 consists of three adhesive parts, and the third adhesive part 733 is located within the first side wall 520, which can better fix the adhesive film 730 to the case 500 and more reliably seal the second through-hole 502.

[0148] In some embodiments, the size of the third adhesive portion 733 in the thickness direction of the bottom wall 510 is larger than the size of the second adhesive portion 732 in the thickness direction of the bottom wall 510, which makes it less likely for the adhesive film 730 to come off and improves the reliability of sealing the second through hole 502.

[0149] 18 and 19, Fig. 18 is an exploded schematic view of a battery cell provided according to some embodiments of the present application, and Fig. 19 is a cross-sectional schematic view of a partial structure of a battery cell provided according to some embodiments of the present application. In some embodiments, the pressure release mechanism 700 includes an adhesive film 710 and a metal sheet 740 that are laminated along the opening direction of the second through-holes 502, and the metal sheet 740 is provided on the opposite side of the adhesive film 710 from the case 500.

[0150] Since the adhesive film 710 is water permeable, if moisture enters the inside of the case 500 through the adhesive film 710, it may have a negative effect on the electrode assembly and the electrolyte. By providing the first metal sheet 740 on the opposite side of the adhesive film 710 from the case 500, the water permeable area of ​​the adhesive film 710 can be reduced, thereby improving the sealing effect.

[0151] Referring to FIG. 1 , according to some embodiments of the present application, the present application further provides an electric device, which includes the battery cell 10 of any of the above aspects, and the battery cell 10 is used to supply electric energy to the electric device.

[0152] The electrical device may be any apparatus or device that uses any of the battery cells 10 described above.

[0153] It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other if they do not conflict.

[0154] The above embodiments are only used to explain the technical solution of the present application and are not intended to limit the present application, and those skilled in the art can make various modifications and variations to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. a case provided with a first through hole; a pressure release mechanism including an adhesive film covering the first through-hole, the adhesive film melting with heat to form a pressure release passage that communicates between the inside and outside of the case; The pressure release mechanism further includes a first metal sheet, the first metal sheet is provided on the opposite side of the adhesive film from the case, and a projection of the first metal sheet covers the first through hole in a direction perpendicular to the thickness direction of the first metal sheet.

2. The battery cell according to claim 1 , wherein the first through-hole is a liquid injection hole.

3. 2. The battery cell according to claim 1, wherein the case includes a bottom wall and a plurality of side walls surrounding the bottom wall, the battery cell further includes a battery pole, and the battery pole and the first through-hole are provided in the same side wall.

4. 2. The battery cell of claim 1, wherein the adhesive film is bonded to the case, and when a cross section of the adhesive film is observed in a direction perpendicular to the thickness direction of the adhesive film and passing through the center of the adhesive film, the bonding interface between the adhesive film and the case is divided into a first portion and a second portion, and the width of the first portion and / or the second portion is W, and the relationship 0.2 mm≦W≦2 mm is satisfied.

5. 5. The battery cell according to claim 4, wherein 0.3 mm≦W≦1 mm.

6. The battery cell according to claim 1 , wherein the first metal sheet is circular, and the adhesive film is circular or annular.

7. 2. The battery cell of claim 1, wherein the first through hole is circular, the diameter of the first metal sheet is equal to or smaller than the outer diameter of the adhesive film, and the diameter of the first metal sheet is larger than the diameter of the first through hole.

8. 2. The battery cell of claim 1, wherein the pressure release mechanism further includes a second metal sheet, the second metal sheet being disposed between the adhesive film and the case, the second metal sheet being welded to the case, and the second metal sheet having a second through-hole.

9. 2. The battery cell of claim 1, wherein the adhesive film includes a first adhesive layer and a second adhesive layer, the first adhesive layer and the second adhesive layer are laminated together, the second adhesive layer is located on the opposite side of the first adhesive layer from the case, and the melting point of the first adhesive layer is lower than the melting point of the second adhesive layer.

10. The battery cell according to claim 9 , wherein the melting point of the first adhesive layer is T1, and the melting point satisfies 100° C.≦T1≦130° C.

11. The battery cell according to claim 10, wherein 110°C≦T1≦125°C.

12. The battery cell according to claim 11 , wherein the melting point of the second adhesive layer is T2, and the melting point satisfies 140° C.≦T2≦190° C.

13. The battery cell according to claim 12, wherein 150°C≦T2≦170°C.

14. 14. The battery cell of claim 13, wherein the adhesive film further comprises a third adhesive layer, the third adhesive layer being located between the second adhesive layer and the first metal sheet, and the melting point of the third adhesive layer being lower than the melting point of the second adhesive layer.

15. The battery cell according to claim 14 , wherein the melting point of the third adhesive layer is T3, and the melting point satisfies 100° C.≦T3≦130° C.

16. 16. The battery cell according to claim 15, wherein 110°C≦T3≦125°C.

17. The battery cell according to claim 1 , wherein the thickness of the adhesive film is H and satisfies 0.05 mm≦H≦1 mm.

18. 18. The battery cell according to claim 17, wherein 0.1 mm≦H≦0.3 mm.

19. 15. The battery cell of claim 14, wherein a thickness ratio of the first adhesive layer to the second adhesive layer is in the range of 1:0.5 to 1:

3.

20. 20. The battery cell of claim 19, wherein a ratio of the thickness of the second adhesive layer to the thickness of the third adhesive layer is 0.5:1 to 3:

1.

21. The battery cell according to claim 1 , wherein the first through-hole is circular, and the diameter of the first through-hole is D, and the relationship 0.5 mm≦D≦2 mm is satisfied.

22. 22. The battery cell according to claim 21, wherein 0.9 mm≦D≦1.6 mm.

23. A pressure release mechanism used to release pressure from a battery cell, An adhesive film; a first metal sheet provided on one side of the adhesive film; a second metal sheet provided on the opposite side of the adhesive film from the first metal sheet, the second metal sheet having a second through hole formed therein.

24. 24. The pressure release mechanism of claim 23, wherein the adhesive film has a melting point of 100°C to 130°C.

25. 24. The pressure release mechanism of claim 23, wherein the adhesive film includes a first adhesive layer and a second adhesive layer, the first adhesive layer and the second adhesive layer are laminated together, the second adhesive layer is configured to be located on the opposite side of the first adhesive layer from the case of the battery cell, and the melting point of the first adhesive layer is lower than the melting point of the second adhesive layer.

26. 26. The pressure release mechanism of claim 25, wherein the adhesive film further includes a third adhesive layer, the third adhesive layer being located between the second adhesive layer and the first metal sheet, and the melting point of the third adhesive layer being lower than the melting point of the second adhesive layer.

27. The first adhesive layer, the second adhesive layer, and the third adhesive layer satisfy at least one of the following conditions: (1) The melting point of the first adhesive layer is T1, and the melting point satisfies 100°C≦T1≦130°C. (2) The melting point of the second adhesive layer is T2, and the melting point satisfies 140°C≦T2≦190°C. (3) The melting point of the third adhesive layer satisfies the condition 100° C.≦T3≦130° C., where T3 is the melting point of the third adhesive layer.

27. The pressure relief mechanism of claim 26.

28. An electric device comprising a battery cell according to any one of claims 1 to 22, characterized in that the battery cell is used to supply electric energy.

Images