Battery cell, battery, power consumption device, and method for manufacturing a battery cell

Abstract

The present application provides a battery cell, including a case having an opening, a cover plate covering the opening of the case, and a ventilation membrane, the cover plate and / or the case having at least one through-hole communicating the inside and outside of the battery cell, and the ventilation membrane connected to the inside of the cover plate and / or the case and covering the at least one through-hole. The battery cell of the present application can exhaust gas inside the battery and prevent gas from accumulating inside the case, improving the performance of the electrode assembly, extending the life of the secondary battery, and ensuring the safety performance of the battery cell.

Description

Technical Field

[0001] The present application relates to the field of batteries, and more specifically, to battery cells, batteries, power-consuming devices, and methods for manufacturing the battery cells.

Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automotive industry. Electric vehicles, due to their energy conservation and environmental protection advantages, have become an important part of the sustainable development of the automotive industry. For electric vehicles, battery technology is an important factor related to their development.

[0003] Batteries, such as lithium-ion batteries, are widely applied to electronic devices such as mobile phones and notebook computers due to advantages such as high energy density and environmental friendliness. In recent years, in order to address environmental problems, gasoline price problems, energy storage problems, etc., the application of lithium-ion batteries has rapidly expanded to hybrid vehicles, steamships, energy storage systems, etc.

Summary of the Invention

Problems to be Solved by the Invention

[0004] A battery generally includes a plurality of battery cells. A battery cell includes a case, an electrode assembly and an electrolyte solution accommodated in the case, and a cover assembly connected to the case. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator separating the positive electrode plate and the negative electrode plate. To avoid leakage of the electrolyte solution, the cover assembly generally seals the case. However, gas is generated during the charge and discharge process of the electrode assembly, and as the gas accumulates, the pressure inside the case continuously increases, which easily causes the risk of deformation of the battery and deterioration of the performance of the electrode assembly.

Means for Solving the Problems

[0005] In view of the above problems, the present application provides a battery cell, a battery, a power consumption device, and a method for manufacturing the battery cell. It is possible to discharge the gas inside the battery, avoid the accumulation of gas inside the case, improve the performance of the electrode assembly, extend the life of the secondary battery, and ensure the safety performance of the battery cell.

[0006] According to a first aspect, the present application provides a battery cell, which includes a case having an opening, a cover plate covering the opening of the case, and a ventilation film. The cover plate and / or the case has at least one through hole, the through hole communicates the inside and the outside of the battery cell, the ventilation film is connected inside the cover plate and / or the case, and covers the at least one through hole. In this way, the gas inside the battery cell can be discharged from the battery cell through the ventilation film, thereby reducing the risk of the battery cell expanding or exploding. The ventilation film can also prevent the leakage of the electrolyte solution inside the battery cell and the entry of external liquid into the battery cell. At the same time, since the ventilation film is connected inside the cover plate or the case, when the internal air pressure of the battery cell increases, the ventilation On the film By applying an outward pressure, the edge of the ventilation film becomes more tightly connected to the cover plate or the case, and the ventilation film becomes more difficult to separate from the cover plate or the case.

[0007] In some embodiments, the at least one through hole includes a receiving segment and an extending segment in a direction perpendicular to the plane of the cover plate or the case. The average pore diameter of the receiving segment is larger than the pore diameter of the extending segment. The receiving segment is closer to the inside of the battery cell than the extending segment, and further includes a backing material. At least a part of the backing material is received in the receiving segment. In this way, when the ventilation film tends to deform outward under the action of the internal air pressure of the battery cell, the inner wall of the through hole further increases the supporting force for the ventilation film by providing additional supporting force to the backing material, making the ventilation film more difficult to deform.

[0008] In some embodiments, the backing material is a hydrophobic breathable material, the air permeability of which is greater than that of the breathable membrane, and / or the melting point thereof is greater than that of the breathable membrane. Thus, the gas inside the battery cell passing through the breathable membrane can be smoothly discharged from the backing material, ensuring the safety performance of the battery cell. And when the temperature of the battery cell reaches the melting point of the breathable membrane, the breathable membrane deforms and flows. Since the melting point of the backing material is greater than that of the breathable membrane, it can play a role in supporting and fixing the breathable membrane material, and can reduce the flow and deformation of the breathable membrane.

[0009] In some embodiments, the interior of the cover plate and / or the case has grooves, the grooves are arranged surrounding the at least one through hole, and at least a part of the breathable membrane is accommodated in the grooves. Thus, it is possible to reduce the internal space of the battery cell occupied by the breathable membrane, reduce the overall thickness of the cover plate or the case, and ensure that the gas inside the battery cell is discharged outside the battery cell through the breathable membrane at least partially accommodated in the grooves.

[0010] In some embodiments, the minimum distance along the plane of the cover plate or the case from the edge of the breathable membrane to the edge inside the cover plate and / or the case of the at least one through hole is 1.5 millimeters or more. Thus, it can be ensured that the breathable membrane and the cover plate or the case can still maintain the connection state when the internal air pressure of the battery cell increases, and the degree of deformation of the breathable membrane is within an acceptable range.

[0011] In some embodiments, when there are a plurality of through holes, the plurality of through holes are arranged adjacent to each other in the plane of the cover plate or the case. Thus, while meeting the requirement of the exhaust volume of the battery cell, the interval part between the plurality of through holes can play a higher supporting role for the breathable membrane, and on the premise of covering the plurality of through holes, the area of the breathable membrane can be reduced as much as possible.

[0012] In some embodiments, the ventilation membrane is connected to the inside of the cover assembly and / or the case by a thermal lamination or adhesive method. In this way, since the connection method between the ventilation membrane and the cover plate or the case is simplified and the use of an additional connection structure is avoided, the manufacturing process is simplified and the manufacturing cost is reduced.

[0013] According to a second aspect, the present application provides a battery including the battery cell in the above embodiment.

[0014] According to a third aspect, the present application provides a power consumption device, which includes the battery in the above embodiment, and the battery is for providing electrical energy.

[0015] According to a fourth aspect, the present application provides a method for manufacturing a battery cell, the method including providing a cover plate, a case having an opening, and a ventilation membrane; covering the opening of the case with the cover plate; installing at least one through hole for communicating the battery cell with the outside on the cover plate and / or the case; and connecting the ventilation membrane to the inside of the cover plate and / or the case and covering the at least one through hole. In this way, the gas inside the battery cell can be discharged from the battery cell through the ventilation membrane, thereby reducing the risk of the battery cell expanding or exploding, and the ventilation membrane can also prevent the leakage of the electrolyte solution inside the battery cell and the entry of external liquid into the battery cell. At the same time, since the ventilation membrane is connected to the inside of the cover plate or the case, when the internal air pressure of the battery cell increases, by applying an outward pressure, the edge of the ventilation membrane becomes more tightly connected to the cover plate or the case, and the ventilation membrane becomes more difficult to separate from the cover plate or the case. On the film By applying an outward pressure, the edge of the ventilation membrane becomes more tightly connected to the cover plate or the case, and the ventilation membrane becomes more difficult to separate from the cover plate or the case.

[0016] In some embodiments, the at least one through hole is arranged to include a receiving segment and an extending segment in a direction perpendicular to the cover plate or the case plane. The average pore diameter of the receiving segment is larger than the pore diameter of the extending segment. The receiving segment is closer to the inside of the battery cell relative to the extending segment, provides a backing material, and at least a part of the backing material is received within the receiving segment. In this way, when the ventilation film tends to deform outwardly under the action of the internal air pressure of the battery cell, the inner wall of the through hole further increases the supporting force for the ventilation film by providing additional supporting force to the backing material, making it more difficult for the ventilation film to deform further.

[0017] In some embodiments, the backing material is a hydrophobic breathable material, the air permeability of which is larger than the air permeability of the ventilation film, and / or the melting point thereof is higher than the melting point of the ventilation film. In this way, the gas inside the battery cell passing through the ventilation film can be smoothly discharged from the backing material, ensuring the safety performance of the battery cell. And when the temperature of the battery cell reaches the melting point of the ventilation film, the ventilation film deforms and flows. Since the melting point of the backing material is higher than the melting point of the ventilation film, it can play a role in supporting and fixing the ventilation film material, and can reduce the flow and deformation of the ventilation film.

[0018] In some embodiments, a groove is provided inside the cover plate and / or the case. The groove is arranged surrounding the at least one through hole, and at least a part of the ventilation film is received within the groove. In this way, the internal space of the battery cell occupied by the ventilation film can be reduced, the overall thickness of the cover plate or the case can be decreased, and it can be ensured that the gas inside the battery cell is discharged outside the battery cell through the ventilation film at least a part of which is received in the groove.

[0019] In some embodiments, the minimum distance along the plane of the cover plate or the case from the edge of the ventilation film to the edge inside the cover plate and / or the case of the through hole is set to be 1.5 millimeters or more. In this way, even when the internal air pressure of the battery cell increases, the ventilation film and the cover plate or the case can still maintain the connection state, and it can be ensured that the degree of deformation of the ventilation film is within an acceptable range.

[0020] In some embodiments, when there are a plurality of through holes, the plurality of through holes are installed to be arranged adjacent to each other on the plane of the cover plate and / or the case. In this way, while meeting the requirement of the exhaust volume of the battery cell, the interval portion between the plurality of through holes plays a higher supporting role for the ventilation film, and on the premise of covering the plurality of through holes, the area of the ventilation film can be reduced as much as possible.

[0021] In some embodiments, the ventilation film is connected to the inside of the cover plate and / or the case by a thermal composite or an adhesive method.

[0022] The above description is only an overview of the technical solution of this application. In order to more clearly understand the technical means of this application, be able to implement it based on the content of the specification, and make the above and other objects, features and advantages of this application more clearly understood and easier to understand, the following specific embodiments of this application are given.

Brief Description of the Drawings

[0023] By reading the following detailed description of the preferred embodiments, various other advantages and beneficial points will become clear to those skilled in the art. The drawings are only used to illustrate the purpose of the preferred embodiments and are not considered to limit this application. And throughout the drawings, the same parts are represented by the same reference numerals. In the drawings,

[0024]

Figure 1A

Figure 1B

Figure 1C

Figure 1D

Figure 1E

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Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

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Figure 14A

Figure 14B

Figure 14C

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Embodiments for Carrying Out the Invention

[0025] Hereinafter, embodiments of the technical solution of the present application will be described in detail with reference to the drawings. The following embodiments are for more clearly explaining the technical solution of the present application, and are only examples, and do not limit the protection scope of the present application thereby.

[0026] Unless otherwise defined, all technical and scientific terms used in the text have the same meaning as commonly understood by those skilled in the art. The terms used in this specification are only used to explain specific embodiments, and are not intended to limit the present application. The terms "including", "having" and any variations thereof in the description of the specification and claims of the present application and the above description of the drawings are intended to cover non-exclusive "including".

[0027] In the description of the embodiments of the present application, terms such as "first", "second", etc. are only used for the purpose of distinguishing different objects, and are not understood to explicitly or implicitly indicate relative importance, or the number of technical features of the object, a specific order or a primary-secondary relationship. In the description of the embodiments of the present application, unless specifically limited, "a plurality" means two or more.

[0028] When referring to "embodiment" in the text, it means that the specific features, structures or characteristics described in combination with the embodiment may be included in at least one embodiment of the present application. The phrase described at each place in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art can explicitly and implicitly understand that the embodiments described in this specification can be combined with other embodiments.

[0029] In the description of the embodiments of this application, the term "and / or" is only used to describe the relationship of related objects and indicates that three relationships may exist. For example, A and / or B may represent three cases: A alone, a combination of A and B, and B alone. Also, the character " / " in the text generally represents that the related objects before and after are in an "or" relationship.

[0030] In the description of the embodiments of this application, the term "plurality" refers to two or more (including two). Similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of sheets" refers to two or more sheets (including two sheets).

[0031] In the description of the embodiments of this application, the orientation or positional relationship indicated by technical terms such as "center", "vertical direction", "horizontal direction", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial direction", "radial direction", "circumferential direction", etc. is based on the orientation or positional relationship shown in the drawings and is for the convenience of description or simplification of the description of the embodiments of this application. It does not indicate or imply that the mentioned device or element must have a specific orientation and be structured and operated in a specific orientation, and should not be understood as limiting the embodiments of this application.

[0032] In the description of the embodiments of this application, unless specifically defined and limited, technical terms such as "mount", "connect", "connect to", "fix", etc. should be understood in a broad sense. For example, it may be fixedly connected, detachably connected, integrated, mechanically connected, electrically connected, directly connected, indirectly connected through an intermediate medium, or the internal communication between the two elements or the interaction relationship between the two elements. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific situation.

[0033] At present, from the perspective of the development of the market situation, the application of batteries is expanding more and more. Batteries are not only applied to energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in many fields such as electric bicycles, electric motorcycles, electric vehicles and other electric transportation tools, military equipment, aviation, and space flight. With the continuous expansion of the battery application field, the demand in its market is also constantly expanding.

[0034] Since the capacity or power of a single battery cell is small, it is often necessary to arrange a plurality of battery cells to form a battery for use. As the cycle life of the battery increases, a phenomenon of gas generation occurs in the chemical system inside the battery cell, and thereby the air pressure inside the battery cell continuously rises. Therefore, in order to discharge the gas in the case, it is necessary to install an exhaust structure on the battery cell. When thermal runaway occurs in the battery cell, the air pressure inside the battery cell rises sharply, and when a predetermined temperature and pressure are reached, the pressure relief mechanism operates to release the air pressure inside the battery cell and can also take away some of the heat, thereby slowing down the speed of thermal runaway occurrence.

[0035] Figures 1A to 1E show schematic structural diagrams of a battery cell and its cover assembly. Referring to Figures 1A and 1B, the battery cell includes a case 2, an electrode assembly 3, and a cover assembly 1. The cover assembly 1 includes a cover plate 11 and electrode terminals 17. The cover plate 11 is fixed to the opening of the case 2 to confine the electrode assembly 3 and the electrolyte in the accommodation cavity of the case 2. The electrode terminals 17 are installed on the cover plate 11 and include a negative electrode terminal and a positive electrode terminal. Between both electrode terminals 17 and the corresponding tabs, they are electrically connected by an adapter piece 4. A liquid injection hole 5 is installed on the cover plate 11, and the electrolyte is injected into the accommodation cavity of the case 2 through the liquid injection hole 5. An explosion-proof hole 111 is installed on the cover plate 11, and an explosion-proof sheet 12 covers the explosion-proof hole 111. The cover assembly 1 further includes an insulating plate 16 to insulate the cover plate 11 and the electrode assembly 3.

[0036] FIG. 1B is an exploded view of the cover assembly of the battery cell, FIG. 1C is a front view of the cover assembly, FIG. 1D is a cross-sectional view taken along line A-A of FIG. 1C, and FIG. 1E is an enlarged view of portion B in FIG. 1D.

[0037] As shown in FIGS. 1A to 1E, the cover assembly 1 includes a cover plate 11, a ventilation film 13, a sealing component 14, and a ring-shaped metal pressing piece 15. Here, the cover plate 11 has ventilation holes 112, the ventilation holes 112 penetrate through the cover plate 11, the ventilation film 13 seals the ventilation holes 112, the ventilation film 13 has the functions of moisture prevention and ventilation, and by diffusing the gas inside the battery cell to the outside, the internal pressure of the battery cell can be relieved, and by preventing the entry of external liquid into the battery cell, the sealing performance of the battery cell can be ensured. The sealing component 14 surrounds the ventilation holes 112 and is installed between the ventilation film 13 and the cover plate 11 to seal the gap between the ventilation film 13 and the cover plate 11. The ring-shaped metal pressing piece 15 has a through hole 151 penetrating in its thickness direction, which is crimped to the ventilation film 13 and welded and fixed to the cover plate 11 to fix the ventilation film 13 to the cover plate 11.

[0038] With the above structure, the gas inside the battery cell can be discharged from the ventilation holes 112 through the ventilation film 13, thereby realizing the effect of relieving the pressure inside the battery cell.

[0039] According to the discovery of the invention, in the above prior art solution, the ventilation film 13 and the cover plate 11 are connected by the ring-shaped metal pressing piece 15 and the sealing part 14, and the airtightness between the ventilation film 13, the ring-shaped metal pressing piece 15 and the cover plate 11 is low. As time increases, the sealing part 14 deteriorates. When the internal pressure continues to increase, the ventilation film 13 deforms. All of the above reasons cause an increase in the gap between the cover plate 11 and the ventilation film 13. And the ventilation film 13 does not have a support, and deformation is likely to occur during the use process, which also causes an increase in the gap between the cover plate 11 and the ventilation film 13. On the other hand, since welding fixation is required between the ring-shaped metal pressing piece 15 and the cover plate 11, there is a risk of falling off of particulate matter or metal chips.

[0040] In order to solve the defects existing in the above prior art, as a result of intensive research, the inventor designed a battery cell, and installed one or more through-holes connecting the inside and outside of the battery cell as ventilation holes in the cover plate, and connected the ventilation film to the inside of the cover plate by a thermal composite or adhesive method, and covered the through-holes. By such an installation method of the ventilation film, the connection structure between the ventilation film and the cover plate is simplified, and risks such as slag scattering due to welding are avoided. When there are a plurality of the ventilation holes, the plurality of ventilation holes may be arranged adjacent to each other, while ensuring the ventilation volume, increasing the supporting force on the ventilation film, and reducing the area of the ventilation film as much as possible. Also, a backing material may be accommodated in the ventilation holes, and the ventilation force of the backing material is stronger than that of the ventilation film, and the melting point is higher than that of the ventilation film, thereby ensuring the ventilation volume and further increasing the supporting force on the ventilation film. According to further findings of the inventor, the ventilation film and the cover plate are combined by a thermal composite or adhesive method, and by this simplified method, it is no longer necessary to install a single connection structure on the cover plate to fix the ventilation film. Therefore, in addition to installing the ventilation holes in the cover plate, the ventilation holes may be installed at any position of the case of the battery cell. In this case, the installation method of the ventilation holes and the backing material, and the connection method between the ventilation film and the case may be the same as the above method of installing the ventilation holes in the cover plate and the method of connecting the ventilation film and the cover plate.

[0041] The battery cell disclosed in the embodiments of the present application may be used in power-consuming devices such as vehicles, ships, or aircraft, but is not limited thereto. The battery cell, battery, etc. disclosed in the present application can be used to constitute the power supply system of the power-consuming device. In this way, it helps to discharge the gas inside the battery cell, avoid the accumulation of gas inside the case, improve the performance of the electrode assembly, extend the life of the battery cell, and ensure the safety performance of the battery cell.

[0042] Embodiments of the present application provide a power-consuming device that uses a battery as a power source. The power-consuming device may be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery-powered vehicle, an electric vehicle, a steamship, an aircraft, etc. Here, the electric toy may include a stationary or mobile electric toy, such as a game console, an electric vehicle toy, an electric steamship toy, an electric airplane toy, etc., and the aircraft may include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0043] For the sake of easy explanation, the following embodiments will be described by taking the power-consuming device of an embodiment of the present application as the vehicle 200 as an example.

[0044] Referring to FIG. 2, FIG. 2 is a schematic structural diagram of a vehicle 200 according to an embodiment of the present application. The vehicle 200 may be a fuel-powered vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle, etc. A battery 201 is installed inside the vehicle 200, and the battery 201 can be installed at the bottom, front, or rear of the vehicle 200. The battery 201 can be used to supply power to the vehicle 200. For example, the battery 201 can be used as the operating power source of the vehicle 200. The vehicle 200 may further include a controller 202 and a motor 203. The controller 202 is for controlling the battery 201 to supply power to the motor 203, for example, for starting the vehicle 200, navigation, and power required for operation during driving.

[0045] In some embodiments of the present application, the battery 201 can not only be used as the operating power source of the vehicle 200, but also be used as the driving power source of the vehicle 200 to provide driving power to the vehicle 200 instead of, or partly instead of, fuel oil or natural gas.

[0046] Referring to FIG. 3, FIG. 3 is a schematic structural decomposition diagram of the battery 201 according to the embodiment of the present application. The battery 201 includes a housing 302 and a plurality of battery modules 301, and the plurality of battery modules 301 are accommodated in the housing 302. Here, the housing 302 is for providing an accommodation space for the plurality of battery modules 301, and the housing 302 can adopt a plurality of types of structures. In some embodiments, the housing 302 may include a first portion 3021 and a second portion 3022. The first portion 3021 and the second portion 3022 are covered, and the first portion 3021 and the second portion 3022 jointly define an accommodation space for accommodating the plurality of battery modules 301. The second portion 3022 may have a hollow structure with one end being open, and the first portion 3021 may have a plate-like structure. By covering the first portion 3021 on the opening side of the second portion 3022, the first portion 3021 and the second portion 3022 jointly define an accommodation space. The first portion 3021 and the second portion 3022 may both have a hollow structure with one side being open, and the opening side of the first portion 3021 is covered by the opening side of the second portion 3022. Of course, the housing 302 formed by the first portion 3021 and the second portion 3022 may have various shapes, such as a cylinder or a cuboid, etc.

[0047] To meet various power demands, the battery module 301 may include one or more battery cells 40. After configuring the battery module 301 by connecting a plurality of battery cells 40 in series, parallel, or series-parallel, a battery may be configured by connecting a plurality of battery modules 301 in series, parallel, or series-parallel. Series-parallel connection refers to a combination of series connection and parallel connection. Exemplarily, the battery 20 may include a plurality of battery cells 40, where the plurality of battery cells 40 may be connected in series, parallel, or series-parallel to each other. The plurality of battery cells 40 may be directly installed in the housing. That is, the battery 201 may be directly constituted from the plurality of battery cells 40, or the battery 201 may be constituted from the battery module 301 after configuring the battery module 301. Here, each battery cell 40 may be a secondary battery or a primary battery, and may be, but is not limited to, a lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery. The battery cell 40 may exhibit a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes.

[0048] Referring to FIG. 4, FIG. 4 is a schematic exploded view of the battery cell 40 according to an embodiment of the present application. The battery cell 40 refers to the minimum unit constituting the battery. As shown in FIG. 4, the battery cell 40 includes a cover plate 41, a case 42, an electrode assembly 43, and other functional components.

[0049] The cover plate 41 refers to a component that isolates the internal environment of the battery cell 40 from the external environment by covering the opening position of the case 42. The shape of the cover plate 41 may be adapted to the shape of the case 42 so as to fit with the case 42, but is not limited thereto. Optionally, the cover plate 41 may be made of a material having a certain hardness and strength, whereby the cover plate 41 is less likely to deform when subjected to pressing or collision, providing the battery cell 40 with higher structural strength and enhancing the safety performance. A through hole 411 for discharging the gas inside the battery cell 40 is provided in the cover plate 41. The explosion-proof hole 412 is for quickly discharging the gas inside the battery cell when thermal runaway of the battery cell 40 occurs and the internal air pressure rises rapidly. The electrolyte is injected into the accommodation cavity of the case 42 through the liquid injection hole 413. Functional components such as electrode terminals may be installed on the cover plate 41. The electrode terminal may be used for electrical connection with the electrode assembly 43 to input and output the electrical energy of the battery cell 40. The material of the cover plate 41 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, or other materials having a certain hardness and strength, and is not particularly limited in the embodiments of the present application. In some embodiments, an insulating member (not shown) may be further installed inside the cover plate 41, and the insulating member may be used for isolating the electrical connection components in the case 42 from the cover plate 41 so as to reduce the risk of short circuit. Exemplarily, the insulating member may be plastic, rubber, or the like.

[0050] Case 42 is an assembly for forming the internal environment of battery cell 40 in accordance with cover plate 41, where the formed internal environment can be used to accommodate electrode assembly 43, electrolyte, and other components. Case 42 and cover plate 41 may be independent components, or an opening may be provided on case 42 and cover plate 41 may be placed over the opening to form the internal environment of battery cell 40. This is not the only way, and cover plate 41 and case 42 may be integrated. Specifically, cover plate 41 and case 42 may form a common connection surface before other components are placed into the case. When it is necessary to package the interior of case 42, cover plate 41 may be placed over case 42. Case 42 may have various shapes and dimensions, such as a cuboid shape, a cylindrical shape, a hexagonal prism shape, etc. Specifically, the shape of case 42 may be determined based on the specific shape and dimensions of electrode assembly 43. The material of case 42 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, or other materials with a certain hardness and strength. In the embodiments of the present application, it is not particularly limited in this regard.

[0051] Electrode assembly 43 is the component in battery cell 40 where an electrochemical reaction occurs. One or more electrode assemblies 43 may be included in case 42. Electrode assembly 43 is mainly formed by winding or laminating a positive electrode plate and a negative electrode plate. Generally, a separator is provided between the positive electrode plate and the negative electrode plate. The portions of the positive electrode plate and the negative electrode plate having active material constitute the main body of the electrode assembly, and the portions of the positive electrode plate and the negative electrode plate without active material respectively constitute tabs. The positive tab and the negative tab may both be located at one end of the main body, or may be located at both ends of the main body respectively. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs are connected to the electrode terminals to form an electric current circuit.

[0052] This application provides a battery cell 40. The battery cell 40 includes a cover plate 41, a case 42, and a ventilation film 44. The case 42 has an opening, and the cover plate 41 covers the opening of the case 42. At least one through hole 411 is provided on the cover plate 41 and / or the case 42. And The through hole 411 communicates the battery cell with the outside. The ventilation film 44 is connected inside the cover plate 41 and / or the case 42 and covers the at least one through hole 411.

[0053] This application provides a battery cell 40. The battery cell 40 includes a cover plate 41, a case 42, and a ventilation film 44. The case 42 has an opening, and the cover plate 41 covers the opening of the case 42. At least one through hole 411 is provided on the cover plate 41 and / or the case 42, and the through hole 411 communicates the battery cell with the outside. The ventilation film 44 is connected inside the cover plate 41 and / or the case 42 and covers the at least one through hole 411.

[0054] In FIGS. 4 to 7, illustratively, at least one through hole 411 is provided on the cover plate 41. However, the at least one through hole 411 may be provided at any position on each side plate or bottom plate of the case 42. The installation method and positional relationship between the through hole 411 and the case 42 are the same as the installation method and positional relationship between the through hole 411 and the cover plate 41 shown in FIG. 7. And in FIGS. 4 to 7, illustratively, the through hole 411 is shown as a plurality of through holes 411 with a fixed aperture.

[0055] As shown in the figure, the case 42 is filled with an electrolyte, and at least one electrode assembly 43 is disposed in the case 42. As can be understood by those skilled in the art, the battery cell further includes other components not shown in the drawings.

[0056] The through-hole 411 penetrates the cover plate 41 or the case 42. The number of through-holes 411 is one or more, and it is sufficient if the minimum area of the through-hole 411 in the plane of the cover plate 41 or the case 42 can meet the requirement of the exhaust volume of the battery cell. The aperture diameter of the through-hole 411 may be fixed or variable. When the aperture diameter of the through-hole 411 is a fixed aperture diameter and there is only one through-hole 411, the minimum area of the through-hole 411 in the plane of the cover plate 41 or the case 42 is the aperture area of the through-hole 411 in the plane of the cover plate 41 or the case 42. When the aperture diameter of the through-hole 411 is a fixed aperture diameter and there are multiple through-holes 411, the minimum area of the through-hole 411 in the plane of the cover plate 41 or the case 42 is the sum of the aperture areas of the multiple through-holes 411 in the plane of the cover plate 41 or the case 42. When the aperture diameter of the through-hole 411 is a variable aperture diameter and there is only one through-hole 411, the minimum area of the through-hole 411 in the plane of the cover plate 41 or the case 42 is the smaller one of the aperture area of the through-hole 411 on the inner surface of the plane of the cover plate 41 or the case 42 and the aperture area on the outer surface. When the aperture diameter of the through-hole 411 is a variable aperture diameter and there are multiple through-holes 411, the minimum area of the through-hole 411 in the plane of the cover plate 41 or the case 42 is the smaller one of the sum of the aperture areas of the multiple through-holes 411 on the inner surface of the plane of the cover plate 41 or the case 42 and the sum of the aperture areas on the outer surface.

[0057] In this example, the plane of the cover plate 41 refers to a certain plane of the cover plate 41, the plane of the case 42 refers to the four side surfaces or one bottom surface of the case where the through-hole 411 is installed, the inner surface of the plane of the cover plate 41 or the case 42 refers to the surface of the cover plate 41 or the case 42 that is inside the battery cell 40, and the outer surface of the plane of the cover plate 41 or the case 42 refers to the surface of the cover plate 41 or the case 42 that is outside the battery cell 40.

[0058] Optionally, the ventilation film 44 is made of a polymer material having ventilation properties (for example, one or a combination of two or more of PP, PE, and PU), and can block liquids. The ventilation film 44 is connected inside the cover plate 41 and / or the case 42 and covers the at least one through hole 411.

[0059] By the above installation, the ventilation film 44 can discharge the gas inside the battery cell 40 from the battery cell 40, thereby reducing the risk of the battery cell 40 expanding or exploding, and can also prevent the leakage of the electrolyte solution inside the battery cell 40 and the entry of external liquid into the battery cell 40. At the same time, by connecting the ventilation film 44 inside the cover plate 41 or the case 42, when the internal air pressure of the battery cell 40 increases, an outward pressure is applied to the ventilation film 44, so that the edge of the ventilation film 44 is more tightly connected to the cover plate 41 or the case 42, and the ventilation film 44 is less likely to separate from the cover plate 41 or the case 42. And as the number of the through holes 411 increases, the supporting force on the ventilation film 44 by the interval portions 412 between the plurality of through holes 411 on the cover plate 41 or the case 42 also increases, so that the ventilation film 44 is less likely to be deformed.

[0060] Figs. 8 to 10 show an example of a through hole 411 with variable pore diameter in some embodiments of the present invention. In Figs. 8 to 10, the through hole 411 includes a receiving segment 4112 and an extending segment 4111 in a direction perpendicular to the plane of the cover plate 41 or the case 42. The receiving segment 4112 is closer to the inside of the battery cell 40 than the extending segment 4111. The average pore diameter of the receiving segment 4112 is larger than the average pore diameter of the extending segment 4111. The battery cell 40 further includes a backing material 45, and at least a part of the backing material 45 is received in the receiving segment 4112.

[0061] The space from the accommodation segment 4112 to the extension segment 4111 may decrease step by step one by one (as shown in FIGS. 8 and 9), or may decrease gradually little by little (as shown in FIG. 10). In FIGS. 8 and 9, only one staircase is exemplarily shown, but it may be arranged in a manner of more staircases. And the accommodation segment 4112 and the extension segment 4111 are exemplarily defined only for the changing pore diameters, but there may be a clear boundary point between the accommodation segment 4112 and the extension segment 4111 (as shown in FIGS. 8 and 9), or there may be no clear boundary point (as shown in FIG. 10). If there is no clear boundary point, an appropriate location in the through hole may be selected as the boundary point between the accommodation segment 4112 and the extension segment 4111.

[0062] When the through hole is as shown in FIGS. 8 and 9, the pore diameters of both the accommodation segment 4112 and the extension segment 4111 are fixed, and the average pore diameter is the pore diameter of each of the accommodation segment 4112 and the extension segment 4111. When the through hole is as shown in FIG. 10, the section from the boundary point to the opening of the through hole 411 outside the battery cell 40 is the extension segment 4111, and its average pore diameter is the average value of the pore diameters at each position in this section. The section from the boundary point to the opening of the through hole 411 inside the battery cell 40 is the accommodation segment 4112, and its average pore diameter is the average value of the pore diameters at each position in this section. Thereby, the average pore diameter of the portion of the through hole 411 closer to the inside of the battery cell 40, that is, the accommodation segment 4112, is larger than the average pore diameter of the portion closer to the outside of the battery cell 40, that is, the extension segment 4111. As can be understood, when there are a plurality of through holes 411, each through hole 411 may have a fixed pore diameter, a variable pore diameter, or a combination of through holes 411 with a fixed pore diameter and various variable pore diameters.

[0063] In some embodiments, the through-hole 411 further includes a backing material 45. In the drawings of the present application, the backing material 45 is shown with a dot background. As shown in FIG. 8, the backing material 45 is filled only in the accommodation segment 4112. As shown in FIG. 9, the backing material 45 is filled in the accommodation segment 4112 and the extension segment 4111. As shown in FIG. 10, the backing material 45 is filled in the through-hole 411 with a gradually changing pore diameter. As can be understood, when there are a plurality of through-holes 411, the backing material 45 may be filled in a part of the space of some of the through-holes, or may be filled in all of the space of all of the through-holes.

[0064] Each through-hole 411 may have a fixed pore diameter, a variable pore diameter, or a combination of through-holes 411 with a fixed pore diameter and various variable pore diameters.

[0065] According to the installation method of the through-hole 411, when the ventilation film 44 tends to deform outward under the action of the internal air pressure of the battery cell 40, the inner wall of the through-hole 411 with an exemplary shape according to FIGS. 8 to 10 provides additional support force to the backing material 45, further increasing the support force for the ventilation film 44 and making the ventilation film 44 less likely to deform.

[0066] According to some embodiments of the present application, optionally, the backing material 45 is a hydrophobic breathable material, and its ventilation volume is larger than that of the ventilation film 44, and / or its melting point is higher than that of the ventilation film 44.

[0067] The backing material 45 adopts a hydrophobic breathable material. While meeting the support requirements for the ventilation film 44, it ensures that the gas passing through the ventilation film 44 can smoothly pass through the backing material 45, and can also ensure the ventilation effect of the ventilation film 44. At the same time, it blocks external liquids and the like, avoiding the entry of external liquids into the battery cell 40 and affecting the battery cell 40, and can also avoid the leakage of the electrolyte inside the battery cell 40.

[0068] In some alternative embodiments, the melting point of the backing material 45 is greater than the melting point of the breathable film 44, and optionally, the difference between the melting point of the backing material 45 and the melting point of the breathable film 44 is 10 °C or more.

[0069] The breathable film 44 is a material that realizes the ventilation effect of the battery cell, and the gas permeating through the breathable film 44 needs to be smoothly discharged from the backing material 45 to the outside of the battery cell 40. Therefore, it is necessary that the ventilation amount of the backing material 45 is greater than the ventilation amount of the breathable film 44. In this way, the gas inside the battery cell 40 passing through the breathable film 44 can be smoothly discharged from the backing material 45, and the safety performance of the battery cell 40 can be ensured.

[0070] Since the melting point of the backing material 45 is higher than the melting point of the breathable film 44, when the temperature of the battery cell 40 reaches the melting point of the breathable film 44, the breathable film 44 deforms and flows. Because the melting point of the backing material 45 is higher than the melting point of the breathable film 44, at this time, the material of the backing material 45 has not reached its melting point, and it can play a role of supporting and fixing the material of the breathable film 44, and reduce the flow and deformation of the breathable film 44.

[0071] According to some embodiments of the present application, referring to FIGS. 11 to 13, FIGS. 11 and 12 take the installation of a plurality of through holes 411 as an example, and FIG. 13 takes the installation of one through hole 411 as an example, showing a schematic diagram of installing a groove 46 inside the cover plate 41 or the case 42. Optionally, the inside of the cover plate 41 and / or the case 42 has a groove 46, the groove 46 is installed surrounding the at least one through hole 411, and at least a part of the breathable film 44 is accommodated in the groove.

[0072] The groove 46 is installed inside the cover plate 41 or the case 42, surrounds the at least one through hole 411, and is for accommodating at least a part of the breathable film 44 therein, whereby a part of the breathable film 44 is accommodated in the groove 46 and at the same time can cover the at least one through hole 411.

[0073] By providing the groove 46, the internal space of the battery cell 40 occupied by the ventilation film 44 is reduced, the overall thickness of the cover plate 41 or the case 42 is decreased, and it can be ensured that at least part of the gas inside the battery cell 40 is discharged outside the battery cell 40 through the ventilation film accommodated in the groove 46 at least partially.

[0074] Referring to FIGS. 7 to 13, according to some embodiments of the present application, optionally, the minimum distance D0 along the plane of the cover plate 41 or the case 42 from the edge of the ventilation film 44 to the edge inside the cover plate 41 and / or the case 42 of the at least one through hole 411 is 1.5 millimeters or more.

[0075] When there are a plurality of through holes 411, the minimum distance D0 is the minimum distance along the plane of the cover plate 41 or the case 42 from the edge inside the cover plate 41 or the case 42 of the through hole 411 closest to the edge of the ventilation film 44 among the plurality of through holes 411 to the edge of the ventilation film 44, as shown in FIGS. 7, 11, and 12 for example. When there is one through hole 411, the D0 is the minimum distance along the plane of the cover plate 41 or the case 42 from the edge inside the cover plate 41 or the case 42 of the through hole 411 to the edge of the ventilation film 44, as shown in FIGS. 8 to 10 and 13 for example.

[0076] By simulating various internal pressure conditions of the battery cell 40 and performing tests for various minimum distances D0, when the minimum distance D0 is 1.5 millimeters or more, the ventilation film 44 and the cover plate 41 or the case 42 can still maintain a connected state, and the degree of deformation of the ventilation film 44 is within an acceptable range.

[0077] According to some embodiments of the present application, optionally, when having a plurality of through holes 411, the plurality of through holes 411 are arranged adjacent to each other in the plane of the cover plate 41 or the case 42.

[0078] Figures 14A - C exemplarily show a method in which a plurality of through - holes 411 are arranged adjacent to each other. As can be understood, the arrangement method of the plurality of through - holes 411 and the number of through - holes 411 are not limited to the three methods shown in Figures 14A - C. The plurality of through - holes 411 may be arranged adjacent to each other in other regular or irregular methods.

[0079] By arranging the plurality of through - holes 411 adjacent to each other, while meeting the requirement for the exhaust volume of the battery cell 40, the interval portion 412 between the plurality of through - holes 411 can play a higher supporting role for the ventilation film 44, and on the premise of covering the plurality of through - holes, the area of the ventilation film 44 can be reduced as much as possible.

[0080] According to some embodiments of the present application, optionally, the ventilation film 44 is connected to the inside of the cover plate 41 and / or the case 42 by a thermal composite and / or adhesion method.

[0081] By connecting the ventilation film 44 and the cover plate 41 or the case 42 by a thermal composite method, on the bonding surface between the ventilation film 44 and the cover plate 41 or the case 42, the functional groups of the ventilation film 44 and the functional groups of the cover plate 41, the case 42, or the backing material 45 are connected by chemical bonds, thereby obtaining a strong connection force. In some embodiments, the ventilation film 44 and the cover plate 41 or the case 42 may be connected by an adhesion method.

[0082] By the above - mentioned thermal composite or adhesion connection method, the connection method between the ventilation film 44 and the cover plate 41 or the case 42 is simplified, and the use of additional connection structures is avoided. Therefore, the manufacturing process is simplified and the manufacturing cost is reduced.

[0083] According to some embodiments of the present application, optionally, the present application further provides a battery including the battery cell 40 described in each of the above embodiments.

[0084] The battery may include one or more battery modules, and the plurality of battery modules can be configured into a battery by means of series connection, parallel connection, or series-parallel connection. The battery module may further include one or more of the above battery cells 40, and the plurality of battery cells can be configured into the above battery module by means of series connection, parallel connection, or series-parallel connection. Alternatively, the battery may directly include one or more of the above battery cells 40, and the plurality of battery cells can be configured into a battery by means of series connection, parallel connection, or series-parallel connection.

[0085] The battery may include a case for wrapping and sealing the battery module or battery cell therein, or may not include a case so that the battery module or battery cell is exposed. The case can be selected in various shapes according to specific requirements so as to adapt to the shape of the battery module or battery cell therein or to the arrangement of the power-consuming device using the battery.

[0086] Since the battery includes the battery cell 40 in the above embodiments, the gas inside the battery cell 40 can be discharged from the battery cell 40 in a timely manner, further reducing the safety risk of the battery by reducing the risk of the battery cell 40 expanding or exploding.

[0087] According to some embodiments of the present application, optionally, the present application further provides a power-consuming device including the battery described in the above embodiments, and the battery is for providing electrical energy to the power-consuming device.

[0088] The power-consuming device may be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery vehicle, an electric vehicle, a steamship, an aircraft, etc. Here, the electric toy may include a stationary or mobile electric toy, for example, a game console, an electric vehicle toy, an electric steamship toy, an electric airplane toy, etc., and the aircraft may include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0089] Since the power consumption device includes the battery cell 40 in each of the above embodiments, the gas inside the battery cell 40 can be discharged from the battery cell 40 in a timely manner, and by reducing the risk of the battery cell 40 expanding or exploding, the safety risk of the power consumption device is further reduced.

[0090] According to some embodiments of the present application, optionally, referring to FIG. 15, the present application further provides a method for manufacturing a battery cell, specifically including the following steps.

[0091] In S1501, a cover plate, a case having an opening, and a ventilation film are provided.

[0092] In S1502, the opening of the case is covered with the cover plate.

[0093] In S1503, at least one through hole for communicating the battery cell with the outside is provided in the cover plate and / or the case. The installation method and specific shape of the through hole are the same as the definitions in each of the above embodiments.

[0094] In S1504, the ventilation film is attached inside the cover plate and / or the case and covers the at least one through hole.

[0095] The types, materials, shapes, installation methods of the cover plate, case, ventilation film, and through hole, as well as the connection relationship between each part, are all the same as the definitions in each of the above embodiments.

[0096] The battery cell manufactured by the above method can reduce the risk of the battery cell 40 expanding or exploding, and can also prevent the leakage of the electrolyte solution inside the battery cell 40 and the entry of external liquid into the battery cell 40. At the same time, by connecting the ventilation film 44 inside the cover plate 41 or the case 42, when the internal air pressure of the battery cell 40 increases, an outward pressure is applied to the ventilation film 44, whereby the edge of the ventilation film 44 is more tightly connected to the cover plate 41 or the case 42, and the ventilation film 44 is less likely to be further separated from the cover plate 41 or the case 42. And as the number of the through holes 411 increases, the supporting force on the ventilation film 44 by the interval portion 412 between the plurality of through holes 411 on the cover plate 41 or the case 42 also increases, whereby the ventilation film 44 is less likely to be deformed further.

[0097] According to some embodiments of the present application, optionally, the at least one through hole 411 is installed to include a receiving segment 4112 and an extending segment 4111 in a direction perpendicular to the plane of the cover plate 41 or the case 42, the average pore diameter of the receiving segment 4112 is larger than the pore diameter of the extending segment 4111, and the receiving segment 4112 is closer to the inside of the battery cell 40 than the extending segment 411. A backing material 45 is provided, and at least a part of the backing material 45 is received in the receiving segment 4112.

[0098] The shapes, installation methods and positional relationships of the through hole 411, the receiving segment 4112, the extending segment 4111, and the backing material 45 are all the same as those in the above embodiments.

[0099] By the installation method of the through hole 411 above, when the ventilation film 44 tends to deform outward under the action of the internal air pressure of the battery cell 40, the inner wall of the through hole 411 with an exemplary shape according to FIGS. 8 to 10 provides a greater supporting force by the backing material 45, further increasing the supporting force on the ventilation film 44 and making the ventilation film 44 less likely to be deformed further.

[0100] According to some embodiments of the present application, optionally, the backing material 45 is a hydrophobic breathable material, the air permeability of which is greater than that of the breathable film 44, and / or the melting point thereof is greater than the melting point of the breathable film 44.

[0101] The backing material 45 employs a hydrophobic breathable material. While meeting the support requirements for the breathable film 44, it ensures that the gas passing through the breathable film 44 can smoothly pass through the backing material 45, can also ensure the ventilation effect of the breathable film 44, and blocks external liquids, etc., avoiding the entry of external liquids into the battery cell 40 and affecting the battery cell 40, and can also avoid the leakage of the electrolyte inside the battery cell 40.

[0102] In some alternative embodiments, the melting point of the backing material 45 is greater than the melting point of the breathable film 44. Optionally, the difference between the melting point of the backing material 45 and the melting point of the breathable film 44 is 10 °C or more.

[0103] The breathable film 44 is a material for realizing the ventilation effect of the battery cell. The gas passing through the breathable film 44 needs to be smoothly discharged from the backing material 45 to the outside of the battery cell 40. Therefore, it is necessary that the air permeability of the backing material 45 is greater than that of the breathable film 44. In this way, the gas inside the battery cell 40 passing through the breathable film 44 can be smoothly discharged from the backing material 45, and the safety performance of the battery cell 40 can be ensured.

[0104] Since the melting point of the backing material 45 is greater than the melting point of the breathable film 44, when the temperature of the battery cell 40 reaches the melting point of the breathable film 44, the breathable film 44 deforms and flows. Because the melting point of the backing material 45 is greater than the melting point of the breathable film 44, at this time, the material of the backing material 45 has not reached its melting point, and it can play a role in supporting and fixing the material of the breathable film 44, and can reduce the flow and deformation of the breathable film 44.

[0105] According to some embodiments of the present application, referring to FIGS. 11 to 13, FIGS. 11 and 12 take the installation of a plurality of through holes 411 as an example, and FIG. 13 takes the installation of one through hole 411 as an example, showing a schematic diagram of installing a groove 46 inside the cover plate 41 or the case 42. Optionally, the inside of the cover plate 41 and / or the case 42 has a groove 46, the groove 46 is installed surrounding the at least one through hole 411, and at least a part of the ventilation film 44 is accommodated in the groove.

[0106] The groove 46 is installed inside the cover plate 41 or the case 42 to surround the at least one through hole 411 and accommodate at least a part of the ventilation film 44 therein, so that part of the ventilation film 44 can be accommodated in the groove 46 and at the same time cover the at least one through hole 411.

[0107] By installing the groove 46, the internal space of the battery cell 40 occupied by the ventilation film 44 is reduced, the overall thickness of the cover plate 41 or the case 42 is decreased, and it can be ensured that the gas inside the battery cell 40 is discharged outside the battery cell 40 through the ventilation film at least partially accommodated in the groove 46.

[0108] Referring to FIGS. 7 to 13, according to some embodiments of the present application, optionally, the minimum distance D0 along the plane of the cover plate 41 or the case 42 from the edge of the ventilation film 44 to the edge inside the cover plate 41 and / or the case 42 of the at least one through hole 411 is 1.5 millimeters or more, and / or the peeling force between the ventilation film 44 and the cover plate 41 and / or the case 42 is 1 newton / millimeter or more.

[0109] When there are a plurality of through holes 411, D0 is the minimum distance along the plane of the cover plate 41 or the case 42 from the edge inside the cover plate 41 or the case 42 of the through hole 411 closest to the edge of the ventilation film 44 among the plurality of through holes 411 to the edge of the ventilation film 44, as shown in, for example, FIGS. 7, 11, and 12. When there is one through hole 411, D0 is the minimum distance along the plane of the cover plate 41 or the case 42 from the edge inside the cover plate 41 or the case 42 of the through hole 411 to the edge of the ventilation film 44, as shown in, for example, FIGS. 8 to 10 and 13.

[0110] By simulating the internal pressure conditions of various battery cells 40 and performing tests for various D0s, when the minimum distance D0 is 1.5 millimeters or more, the ventilation film 44 and the cover plate 41 or the case 42 can still maintain the connection state, and the degree of deformation of the ventilation film 44 is within an acceptable range.

[0111] According to some embodiments of the present application, optionally, when having a plurality of through holes 411, the plurality of through holes 411 are arranged adjacent to each other on the plane of the cover plate 41 or the case 42.

[0112] FIGS. 14A-C exemplarily show a manner in which a plurality of through holes 411 are arranged adjacent to each other. As can be understood, the arrangement manner of the plurality of through holes 411 and the number of through holes 411 are not limited to the three manners in FIGS. 14A-C, and the plurality of through holes 411 may be arranged adjacent to each other in other regular or irregular manners.

[0113] By arranging the plurality of through holes 411 adjacent to each other, while meeting the exhaust gas volume requirement of the battery cell 40, the interval portion 412 between the plurality of through holes 411 can play a higher supporting role for the ventilation film 44, and on the premise of covering the plurality of through holes, the area of the ventilation film 44 can be reduced as much as possible.

[0114] According to some embodiments of the present application, optionally, the ventilation film 44 is connected to the inside of the cover plate 41 and / or the case 42 by a thermal composite and / or adhesion method.

[0115] By connecting the ventilation film 44 and the cover plate 41 or the case 42 by a thermal composite method, on the bonding surface between the ventilation film 44 and the cover plate 41 or the case 42, the functional groups of the ventilation film 44 and the functional groups of the cover plate 41, the case 42, or the backing material 45 are connected by chemical bonds, thereby obtaining a strong connection force. In some embodiments, the ventilation film 44 and the cover plate 41 or the case 42 may be connected by an adhesion method.

[0116] Referring to FIGS. 4 to 7, specific embodiments when there are a plurality of through holes are exemplarily shown. Here, a battery cell 40 is provided, and the battery cell 40 includes a cover plate 41, a case 42, an electrode assembly 43, and a ventilation film 44. The Cover plate 41 includes a plurality of through holes 411 and a plurality of spaced portions 412 between the plurality of through holes 411. In FIGS. 6 and 7, Cover plate 41 and its plurality of spaced portions 412 are shown using a hatched background, the plurality of through holes 411 are shown using a white background, and the ventilation film 44 is shown using a black background. Here, five Through hole 411 are exemplarily shown.

[0117] Referring to FIGS. 4 to 7, specific embodiments when there are a plurality of through holes are exemplarily shown. Here, a battery cell 40 is provided, and the battery cell 40 includes a cover plate 41, a case 42, an electrode assembly 43, and a ventilation film 44. The cover body 41 includes a plurality of through holes 411 and a plurality of spaced portions 412 between the plurality of through holes 411. In FIGS. 6 and 7, the cover body 41 and its plurality of spaced portions 412 are shown using a hatched background, the plurality of through holes 411 are shown using a white background, and the ventilation film 44 is shown using a black background. Here, five ventilation holes 411 are exemplarily shown.

[0118] Here, the ventilation film 44 is connected to the inside of the cover plate 41 and / or the case 42 by means of thermal lamination and / or adhesion. By connecting the ventilation film 44 to the cover plate 41 or the case 42 by means of thermal lamination, the functional groups of the ventilation film 44 and the functional groups of the cover plate 41, the case 42, or the backing material 45 are connected by chemical bonds at the bonding surface between the ventilation film 44 and the cover plate 41 or the case 42, thereby obtaining a strong connection force. In some embodiments, the ventilation film 44 and the cover plate 41 or the case 42 may be connected by an adhesion method.

[0119] Referring to FIG. 7, from the edge of the ventilation film 44 to the plurality of through holes, the minimum distance D0 along the plane of the cover plate 41 or the case 42 of the edge of the through hole closest to the edge of the ventilation film 44 inside the cover plate 41 and / or the case 42 is 1.5 millimeters. By setting the minimum distance D0, when the internal air pressure of the battery cell 40 increases and a pressure is applied to the ventilation film towards the outside of the battery cell 40, the ventilation film 44 and the cover plate 41 or the case 42 can still maintain the connected state, and it is ensured that the degree of deformation of the ventilation film 44 is within an acceptable range.

[0120] Referring to FIG. 13, a specific embodiment when there is one through hole is exemplarily shown. In FIG. 13, only the specific structure of the position of the through hole is shown, and the parts other than the through hole, such as the cover plate, the case, and the electrode assembly, may be the same as those in other embodiments.

[0121] In this embodiment, the through hole 411 may be divided into an extension segment 4111 and a receiving segment 4112. The extension segment 4111 is a cylinder with a hole diameter of L11 and a height of H11, and the receiving segment 4112 is a cylinder with a hole diameter of L12 and a height of H12. The receiving segment 4112 is closer to the inside of the battery cell 40 than the extension segment 4111, and the diameter of the receiving segment 4112 is larger than the diameter of the extension segment 4111.

[0122] The accommodating segment 4112 and the extending segment 4111 shown in FIG. 13 are two coaxial cylinders. As can be understood by those skilled in the art, when the accommodating segment 4112 and the extending segment 4111 are cylinders, their axes may or may not overlap, may or may not be parallel. As long as the through hole 41 formed by the accommodating segment 4112 and the extending segment 4111 can penetrate through the inside and outside of the battery cell 40. And the accommodating segment 4112 and the extending segment 4111 may have other regular or irregular shapes. When the accommodating segment 4112 and the extending segment 4111 have non-fixed pore diameters, it is only necessary to ensure that the average pore diameter of the accommodating segment 4112 is larger than the average pore diameter of the extending segment 4111.

[0123] Due to the installation method of the through hole 411, when the ventilation film 44 tends to deform outward under the action of the internal air pressure of the battery cell 40, due to the gradually decreasing pore diameter from the accommodating segment 4112 to the extending segment 4111, the hole wall can provide additional supporting force to the backing material 45, thereby further increasing the supporting force on the ventilation film 44 and making the ventilation film 44 less likely to deform. Of course, the gradually decreasing pore diameter from the accommodating segment 4112 to the extending segment 4111 little by little can also cause the above-mentioned additional supporting force.

[0124] As shown in FIG. 13, the accommodating segment 4112 and the extending segment 4111 are filled with a backing material 45. The backing material 45 is shown in a dot background in FIG. 13, and the material of the backing material 45 is the same as that in each of the above embodiments.

[0125] As shown in FIG. 13, the interior of the cover plate 41 further includes a groove 46. The illustrated groove 46 is a cylinder with a height of H46 and a hole diameter of L46. The groove 46 is installed surrounding the through hole 411, and the ventilation film 44 is accommodated therein. As can be understood by those skilled in the art, the groove 46 may have other regular or irregular shapes, as long as it is installed surrounding the through hole and at least a part of it can accommodate the ventilation film 44.

[0126] As can be understood by those skilled in the art, in the above embodiment, the specific form of installing the through hole 411 on Cover plate 41 can also be applied to the embodiment of installing the through hole 411 on each side surface or the bottom surface of the case 42.

[0127] As can be understood by those skilled in the art, in the above embodiment, the specific form of installing the through hole 411 on the top cover 41 can also be applied to the embodiment of installing the through hole 411 on each side surface or the bottom surface of the case 42.

[0128] Finally, it should be noted that the above-described embodiments are only used to explain the technical solutions of this application and do not limit them. Although this application has been described in detail with reference to the above-described embodiments, as can be understood by those skilled in the art, it is still possible to modify the technical solutions described in the above-described embodiments, or equivalently replace some or all of their technical features. These modifications or replacements do not deviate from the essence of the corresponding technical solutions from the scope of the technical solutions of each embodiment of this application and should be included in the scope of the claims and the specification of this application. In particular, as long as there is no structural contradiction, any of the technical features mentioned in each embodiment can be combined in any way. This application is not limited to the specific embodiments disclosed in this specification but includes all technical solutions included in the scope of the claims.

[0129] The reference numerals in the drawings in the specific embodiments are as follows.

Description of Reference Numerals

[0130] In FIGS. 1A to 1E battery cell 100 cover assembly 1 case 2 Electrode assembly 3 adapter piece 4 liquid injection hole 5 cover plate 11 explosion-proof hole 111 vent hole 112 explosion-proof sheet 12 vent film 13 sealing component 14 ring-shaped metal pressing piece 15 through hole 151 insulating plate 16 electrode terminal 17

[0131] In FIGS. 2 to 15 vehicle 200 battery 201 controller 202 motor 203 battery module 301 housing 302 first portion 3021 of housing 302 second portion 3022 of housing 302 battery cell 40 cover plate 41 through hole 411 extension segment 4111 accommodation segment 4112 isolation portion 412 explosion-proof hole 412 liquid injection hole 413 case 42 electrode assembly 43 vent film 44 backing material 45 groove 46

Claims

1. A battery cell comprising a case having an opening, a cover plate covering the opening of the case, and a ventilation film, wherein the cover plate and / or the case has at least one through hole, and the through hole communicates the inside and the outside of the battery cell, the ventilation film is connected inside the cover plate and / or the case and covers the at least one through hole, the at least one through hole includes a receiving segment and an extending segment in a direction perpendicular to the plane of the cover plate or the case, the average pore diameter of the receiving segment is larger than the average pore diameter of the extending segment, and the receiving segment is closer to the inside of the battery cell than the extending segment, further comprising a backing material, and at least a part of the backing material is received in the receiving segment, the backing material is a hydrophobic breathable material, the ventilation amount thereof is larger than the ventilation amount of the ventilation film, and / or the melting point thereof is higher than the melting point of the ventilation film, a battery cell.

2. The inside of the cover plate and / or the case has a groove, the groove is installed surrounding the at least one through hole, and at least a part of the ventilation film is received in the groove, the battery cell according to claim 1.

3. The minimum distance along the plane of the cover plate or the case from the edge of the ventilation film to the edge inside the cover plate and / or the case of the at least one through hole is 1.5 millimeters or more, the battery cell according to claim 2.

4. When having a plurality of through holes, the plurality of through holes are arranged adjacent to each other on the plane of the cover plate or the case, the battery cell according to claim 3.

5. The ventilation film is connected inside the cover plate and / or the case by a thermal composite or adhesion method, the battery cell according to claim 4.

6. A battery comprising the battery cell according to any one of claims 1 to 5.

7. An electric power consuming device comprising the battery according to claim 6, wherein the battery is for providing electric energy.

8. A method for manufacturing a battery cell, providing a cover plate, a case having an opening, and a ventilation film, covering the opening of the case with the cover plate, Providing at least one through-hole for communicating the battery cell with the outside in the cover plate and / or the case; Connecting the ventilation film inside the cover plate and / or the case and covering the at least one through-hole; Installing the at least one through-hole to include a receiving segment and an extending segment in a direction perpendicular to the plane of the cover plate or the case, wherein the average pore diameter of the receiving segment is larger than that of the extending segment, and the receiving segment is closer to the inside of the battery cell than the extending segment; Providing a backing material and accommodating at least a part of the backing material in the receiving segment; A method of manufacturing a battery cell, wherein the backing material is a hydrophobic breathable material, the air permeability thereof is larger than that of the ventilation film, and / or the melting point thereof is higher than that of the ventilation film.

9. Installing a groove inside the cover plate and / or the case, the groove being installed surrounding the at least one through-hole, and accommodating at least a part of the ventilation film in the groove. The method of manufacturing a battery cell according to Claim 8.

10. The method of manufacturing a battery cell according to Claim 9, wherein the minimum distance along the plane of the cover plate or the case from the edge of the ventilation film to the edge inside the cover plate and / or the case of the through-hole is set to be 1.5 millimeters or more.

11. The method of manufacturing a battery cell according to Claim 10, wherein when there are a plurality of through-holes, the plurality of through-holes are installed to be arranged adjacent to each other on the plane of the cover plate and / or the case.

12. The method of manufacturing a battery cell according to Claim 11, wherein the ventilation film is connected inside the cover plate and / or the case by a thermal composite or adhesive method.

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