Battery monomer, battery device and electric equipment

Abstract

The invention relates to the technical field of batteries, in particular to a battery monomer, a battery device and electric equipment. The battery monomer comprises a shell, a battery cell and an insulating film, a containing cavity is formed in the shell, the battery cell is arranged in the containing cavity, the insulating film is arranged between the shell and the battery cell, and the insulating film has extensibility and is configured to be capable of deforming in the direction towards the battery cell. According to the battery monomer provided by the invention, after the external penetrating object penetrates into the battery core, if the external penetrating object is a conductive part, the insulating film can extend under the extrusion of the conductive part and coat at least part of the conductive part, so that conductive connection between the conductive part and the battery core is reduced, a short circuit phenomenon in the battery monomer is reduced, and the potential safety hazard is further reduced; and the safety performance of the battery monomer is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, and electrical equipment. Background Technology

[0002] Lithium-ion batteries are widely used in various electrical devices due to their high energy density, high power density, good cycle performance, no memory effect, and environmental friendliness. However, with the large-scale application of lithium-ion batteries, battery safety issues have become increasingly prominent. Under abnormal conditions such as impact, compression, or puncture, lithium-ion batteries can experience internal short circuits, leading to thermal runaway and accidents such as fires and explosions.

[0003] When a battery cell is pierced by a conductive component such as a steel needle, the conductive component can easily become electrically connected to the cell, leading to an internal short circuit and subsequent thermal runaway, which greatly reduces the safety performance of lithium-ion batteries. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the purpose of this application is to provide a battery cell, battery device and electrical equipment that can effectively solve the problem of short circuits occurring inside the battery cell after a conductive component penetrates into it.

[0005] The first aspect of this application discloses a battery cell, the battery cell comprising:

[0006] The shell has an internal cavity for receiving the contents;

[0007] The battery cell is housed within the receiving cavity;

[0008] An insulating film is disposed between the housing and the battery cell, wherein the insulating film is extensible and configured to deform in the direction toward the battery cell.

[0009] According to the battery cell of this application, by providing an insulating film between the casing and the cell, when an external piercing object is inserted into the cell, if the external piercing object is a conductive element, due to the extensibility of the insulating film, the insulating film can extend under the pressure of the conductive element and cover at least part of the outside of the conductive element, and together with the conductive element, pierce into the inside of the cell, thereby reducing the conductive connection between the conductive element and the cell, reducing the occurrence of short circuits inside the battery cell, thereby reducing safety hazards and improving the safety performance of the battery cell.

[0010] In some embodiments of this application, the elongation of the insulating film is greater than or equal to 20%.

[0011] By setting the elongation rate of the insulating film to be greater than or equal to 20%, the extensibility of the insulating film can be improved. When an external piercing object is inserted into the battery cell, the insulating film has sufficient extensibility to extend under the pressure of the external piercing object and cover the outside of the external piercing object, reducing the breakage of the insulating film under the pressure of the external piercing object, thereby increasing the area of ​​the insulating film covering the external piercing object.

[0012] In some embodiments of this application, the tensile strength of the insulating film is greater than or equal to 1 GPa.

[0013] By setting the strength of the insulating film to be greater than or equal to 1GP, the strength of the insulating film can be improved, the puncture of the insulating film by external objects can be reduced, and the area of ​​the insulating film covering the external objects can be increased.

[0014] In some embodiments of this application, the tensile modulus of the insulating film is greater than or equal to 1 GPa.

[0015] By setting the tensile modulus of the insulating film to be greater than or equal to 1GP, the tensile modulus of the insulating film can be increased, reducing the likelihood of the insulating film breaking under the pressure of external piercings, thereby increasing the area of ​​the insulating film covering the external piercings.

[0016] In some embodiments of this application, the resistivity of the insulating film is greater than or equal to 10. 9 Ω.cm.

[0017] By ensuring the resistivity of the insulating film is greater than or equal to 10 9 Setting the Ω.cm value can increase the resistivity of the insulating film, thereby reducing the conductive connection between the positive and negative active materials through the insulating film.

[0018] In some embodiments of this application, the thickness D of the insulating film is from 5 μm to 2 mm along the arrangement direction of the housing, the insulating film and the battery cell.

[0019] By setting D to 5μm to 2mm, the thickness of the insulating film can be increased while reducing the space occupied by the insulating film inside the casing. This reduces the likelihood of external objects puncturing the insulating film, thereby increasing the area of ​​the insulating film covering the external objects. Simultaneously, after the insulating film penetrates the cell along with the external object, it reduces the excessive compression margin of the cell caused by the insulating film.

[0020] In some embodiments of this application, the insulating film includes a first film layer, which includes at least one of PVC material, PE material and PTFE material.

[0021] PVC, PE, or PTFE are high-elongation and high-strength polymers, respectively. By forming the first film layer with at least one of PVC, PE, and PTFE, the strength of the first film layer can be improved, the puncture of the first film layer by external objects can be reduced, and the elongation of the first film layer can be increased. This allows the first film layer to cover the outside of the external object during the process of the external object penetrating the battery cell, and to penetrate into the battery cell together with the external object.

[0022] In some embodiments of this application, the insulating film further includes a second film layer disposed on the side of the first film layer away from the battery cell, and the second film layer includes at least one of aramid material and ultra-high molecular weight polyethylene material.

[0023] Aramid material and ultra-high molecular weight polyethylene material are both high-strength and high-tensile-modulus polymers. By forming a second film layer from at least one of the aramid material and ultra-high molecular weight polyethylene material, and placing the second film layer on the side of the first film layer away from the battery cell, the second film layer is squeezed after an external piercing object penetrates the casing. Since the second film layer has high strength and high tensile modulus, it can effectively reduce the external piercing object from puncturing the second film layer. Thus, the external piercing object can squeeze the first film layer through the second film layer, thereby reducing the external piercing object from puncturing the first film layer.

[0024] In some embodiments of this application, the insulating film is adhered to the outer surface of the battery cell; and / or, the insulating film is adhered to the inner wall surface of the receiving cavity.

[0025] Depending on the actual installation requirements, the insulating film can be selectively applied to the outer surface of the battery cell, or applied to the inner wall of the receiving cavity, or the outer surface of the battery cell and the inner wall of the receiving cavity can be respectively covered with insulating film.

[0026] In some embodiments of this application, the battery cell includes a positive electrode sheet, a separator, and a negative electrode sheet stacked together. The positive electrode sheet is provided with a positive active material, the negative electrode sheet is provided with a negative active material, and the separator is configured to isolate the positive active material and the negative active material.

[0027] By setting up positive and negative electrode plates, the positive active material can be placed on the positive electrode plate and the negative active material can be placed on the negative electrode plate. A separator is provided between the positive and negative electrode plates, thereby isolating the positive and negative active materials through the separator and reducing the conductive connection between the positive and negative active materials.

[0028] In some embodiments of this application, an insulating film is disposed between the casing and the battery cell along the stacking direction of the positive and negative electrode plates.

[0029] By placing the insulating film between the casing and the cell along the stacking direction of the positive and negative electrode plates, when an external object is inserted into the cell along the stacking direction of the positive and negative electrode plates, if the external object is a conductive element, the insulating film can extend under the pressure of the conductive element and cover the outside of the conductive element, and be inserted into the inside of the cell together with the conductive element. This reduces the conductive connection between the positive and negative active materials in the cell through the conductive element, reduces the occurrence of short circuits inside the battery cell, thereby reducing safety hazards and improving the safety performance of the battery cell.

[0030] A second aspect of this application provides a battery device comprising any of the aforementioned battery cells.

[0031] A third aspect of this application provides an electrical device that includes the battery device described in any of the above.

[0032] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0033] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0034] Figure 1 This is a structural schematic diagram of a vehicle provided in one embodiment of this application;

[0035] Figure 2 This is a schematic diagram of the structure of a battery device provided in one embodiment of this application;

[0036] Figure 3 This is a schematic diagram of the structure of a battery cell assembly provided in one embodiment of this application;

[0037] Figure 4 This is an exploded structural diagram of a battery cell provided in one embodiment of this application;

[0038] Figure 5 This is a top view of a battery cell provided in one embodiment of this application;

[0039] Figure 6 yes Figure 5 A schematic diagram of the AA cross-sectional structure of one embodiment of a battery cell;

[0040] Figure 7This is a schematic diagram of the structure after the conductive element is inserted into the battery cell according to one embodiment of this application;

[0041] Figure 8 yes Figure 7 Schematic diagram of the BB cross-sectional structure in the middle;

[0042] Figure 9 yes Figure 8 A schematic diagram showing the relative positions of the conductive components and the insulating film.

[0043] Figure 10 This is a schematic diagram of the structure of the insulating film provided in one embodiment of this application;

[0044] Figure 11 This is a schematic diagram of the structure of an insulating film provided in another embodiment of this application;

[0045] Figure 12 yes Figure 5 A schematic diagram of the AA cross-sectional structure of another embodiment of the battery cell.

[0046] The reference numerals in the detailed embodiments are as follows:

[0047] 1. Vehicles;

[0048] 10. Battery assembly; 11. Controller; 12. Motor;

[0049] 20. Battery cell assembly; 21. Battery cell; 211. Casing; 212. End cap; 213. Cell; 2131. Positive electrode; 2132. Separator; 2133. Negative electrode; 214. Electrode terminal; 215. Receiving cavity;

[0050] 30. Box; 301. First box; 302. Second box;

[0051] 40. Insulating film; 41. First film layer; 42. Second film layer;

[0052] 2. Conductive components. Detailed Implementation

[0053] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0054] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application shall have the ordinary meaning as understood by those skilled in the art to which the embodiments of this application pertain.

[0055] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and other terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0056] Furthermore, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined.

[0057] In the description of the embodiments of this application, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0058] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace, among other fields.

[0060] Lithium-ion batteries are widely used in various electrical devices due to their high energy density, high power density, good cycle performance, no memory effect, and environmental friendliness. However, with the large-scale application of lithium-ion batteries, battery safety issues have become increasingly prominent. Under abnormal conditions such as impact, compression, or puncture, lithium-ion batteries can experience internal short circuits, leading to thermal runaway and accidents such as fires and explosions.

[0061] When a battery cell is pierced by a conductive component such as a steel needle, the conductive component can easily become electrically connected to the cell, leading to an internal short circuit and subsequent thermal runaway, which greatly reduces the safety performance of lithium-ion batteries.

[0062] Based on the above considerations, in order to solve the problem of short circuits occurring inside battery cells when conductive parts are inserted into them, this application proposes a battery cell, a battery device including the battery cell, and an electrical device including the battery device. According to the battery cell, battery device, and electrical device of this application, when an external object is inserted into the battery cell, if the external object is a conductive part, the conductive connection between the conductive part and the battery cell can be reduced, the occurrence of short circuits inside the battery cell can be reduced, thereby reducing safety hazards and improving the safety performance of the battery cell.

[0063] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0064] In some implementations, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0065] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0066] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0067] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0068] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0069] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0070] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0071] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0072] The technical solutions described in this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0073] Figure 1 This is a structural schematic diagram of vehicle 1 provided for some embodiments of this application. For example... Figure 1 As shown, vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 10 is installed inside vehicle 1, and the battery device 10 can be located at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1; for example, the battery device 10 can serve as the operating power source for vehicle 1. Vehicle 1 may also include a controller 11 and a motor 12. The controller 11 is used to control the battery device 10 to supply power to the motor 12, for example, to meet the power needs of vehicle 1 during starting, navigation, and driving.

[0074] In some embodiments of this application, the battery device 10 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0075] Figure 2 This is a schematic diagram of the structure of a battery device 10 according to an embodiment of this application. Figure 3 This is a schematic diagram of the structure of a battery cell assembly 20 according to one embodiment of this application. (In conjunction with...) Figure 2 and Figure 3As shown, to meet different power demands, the battery device 10 may include multiple battery cells 21, where each battery cell 21 is the smallest unit constituting the battery device 10. Multiple battery cells 21 can be connected in series and / or in parallel via electrode terminals for various applications. Furthermore, the multiple battery cells 21 can be connected in series, in parallel, or in a mixed configuration, where a mixed configuration refers to a combination of series and parallel connections.

[0076] Combination Figure 2 and Figure 3 As shown, the battery device 10 may include multiple battery cell assemblies 20 and a battery housing 30, with the multiple battery cell assemblies 20 housed inside the battery housing 30. The battery housing 30 is used to house the battery cells 21 or battery cell assemblies 20 to reduce the impact of liquids or other foreign objects on the charging or discharging of the battery cells 21. The battery housing 30 may be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of simple three-dimensional structures such as cuboids, cylinders, or spheres. The battery housing 30 may be made of alloy materials such as aluminum alloy or iron alloy, polymer materials such as polycarbonate or polyisocyanurate foam, or composite materials such as glass fiber and epoxy resin.

[0077] In some embodiments, the housing 30 may include a first housing 301 and a second housing 302, which overlap each other, and together define a space for accommodating the battery cell 21. The second housing 302 may be a hollow structure with one end open, and the first housing 301 may be a plate-like structure, with the first housing 301 covering the open side of the second housing 302 so that the first housing 301 and the second housing 302 together define a space for accommodating the battery cell 21; alternatively, the first housing 301 and the second housing 302 may both be hollow structures with one side open, with the open side of the first housing 301 covering the open side of the second housing 302.

[0078] The battery cell assembly 20 may include multiple battery cells 21. These battery cells 21 may be connected in series, parallel, or a combination thereof to form the battery cell assembly 20. The multiple battery cell assemblies 20 may then be connected in series, parallel, or a combination thereof to form the battery device 10. The battery cell 21 may be cylindrical, flat, cuboid, or other shapes, and this application does not limit this. Battery cells 21 are generally classified into three types according to their packaging method: cylindrical battery cells, cuboid battery cells, and pouch battery cells, and this application does not limit this either. However, for the sake of brevity, the following embodiments will use a cuboid lithium-ion battery cell 21 as an example for explanation.

[0079] Figure 4This is an exploded structural diagram of a battery cell 21 provided for some embodiments of this application. The battery cell 21 refers to the smallest unit constituting the battery device 10. For example... Figure 4 The battery cell 21 includes a casing 211, an end cap 212, and a cell 213.

[0080] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 21 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 212 is not easily deformed under pressure and impact, giving battery cell 21 higher structural strength and improved safety performance. Functional components such as electrode terminals 214 can be provided on end cap 212. Electrode terminals 214 can be used for electrical connection with battery cell 213 to output or input electrical energy to battery cell 21. In some embodiments, end cap 212 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 21 reaches a threshold. In some embodiments, an insulating element may be provided on the inner side of the end cap 212. The insulating element can be used to isolate the electrical connection components inside the housing 211 from the end cap 212 to reduce the risk of short circuit. For example, the insulating element may be made of plastic, rubber, etc.

[0081] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 21. This internal environment can accommodate the battery cell 213, electrolyte (not shown in the figure), and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form the internal environment of the battery cell 21. Alternatively, the end cap 212 and the housing 211 can be integrated. Specifically, the end cap 212 and the housing 211 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 211, the end cap 212 closes the housing 211. The housing 211 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the battery cell 213. The housing 211 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0082] Cell 213 is the component in the battery cell 21 where the electrochemical reaction occurs. The casing 211 may contain one or more cells 213. Cell 213 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of cell 213, while the portions of the positive and negative electrode sheets without active material each constitute a tab (not shown in the figure). The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals 214 to form a current loop.

[0083] Combination Figures 5 to 9 As shown, the first aspect of this application proposes a battery cell 21. In some embodiments of this application, the battery cell 21 includes a housing 211, a cell 213 and an insulating film 40. The housing 211 has a receiving cavity 215 formed inside, the cell 213 is disposed in the receiving cavity 215, and the insulating film 40 is disposed between the housing 211 and the cell 213. The insulating film 40 is extensible and is configured to be deformable in the direction toward the cell 213.

[0084] For ease of description, this application will only use an external insert as an example of a conductive element 2.

[0085] Specifically, one end of the casing 211 has an opening communicating with the receiving cavity 215, through which the battery cell 213 can be placed. The battery cell 21 also includes an end cap 212, which is connected to the casing 211 and used to seal the opening of the casing 211, thereby protecting the battery cell 213 within the receiving cavity 215. The battery cell 213 has positive and negative active materials, which can be disposed on different electrode plates, or in different electrolyte cavities; the specific method is not limited here.

[0086] An insulating film 40 is disposed within the receiving cavity 215 and between the housing 211 and the battery cell 213. The insulating film 40 is a thin film with good electrical insulation properties. This film has a high resistivity and can effectively prevent electrostatic discharge interference between electronic components, protecting the components for safe and stable operation.

[0087] During the process of the conductive element 2 passing through the housing 211 and penetrating the cell 213, the conductive element 2 first comes into contact with and compresses the insulating film 40. Under the compression of the conductive element 2, the insulating film 40 can extend and cover at least part of the outside of the conductive element 2, and together with the conductive element 2, it penetrates into the inside of the cell 213. This reduces the conductive connection between the positive and negative active materials in the cell 213 through the conductive element 2, reduces the occurrence of short circuits inside the battery cell 21, thereby reducing safety hazards and improving the safety performance of the battery cell 21.

[0088] The insulating film 40 covering at least part of the conductive element 2 includes the following two situations: the conductive element 2 does not puncture the insulating film 40 during the process of piercing the battery cell 213, and the insulating film 40 completely covers the outside of the structure in which the conductive element 2 pierces the battery cell 213; or the conductive element 2 punctures the insulating film 40 during the process of piercing the battery cell 213, and the insulating film 40 only covers the outside of the structure in which the conductive element 2 pierces the battery cell 213, and the piercing end of the conductive element 2 is not covered by the insulating film 40.

[0089] Combination Figures 5 to 9 As shown, in some embodiments of this application, the elongation of the insulating film 40 is greater than or equal to 20%.

[0090] Specifically, the elongation of the insulating film 40 can be 20%...50%...100% or even higher.

[0091] Elongation is the percentage of the total deformation ΔL of the gauge length after the specimen breaks under tension, relative to the original gauge length L: δ = ΔL / L × 100%. Elongation δ is an indicator describing the plastic properties of a material. Elongation can be measured on a tensile testing machine according to the relevant provisions of GB / T228—2010 "Metallic materials, tensile testing—Part 1: Test at room temperature".

[0092] By setting the elongation rate of the insulating film 40 to be greater than or equal to 20%, the elongation of the insulating film 40 can be improved. When the conductive element 2 is inserted into the battery cell, the insulating film 40 has sufficient elongation to extend under the pressure of the conductive element 2 and cover the outside of the conductive element 2, reducing the breakage of the insulating film 40 under the pressure of the conductive element 2, thereby increasing the area of ​​the insulating film 40 covering the conductive element 2.

[0093] Combination Figures 5 to 9 As shown, in some embodiments of this application, the tensile strength of the insulating film 40 is greater than or equal to 1 GPa.

[0094] Specifically, the tensile strength of the insulating film 40 can be 1GPa…2GPa…5GPa or even higher.

[0095] Tensile strength refers to the maximum stress a material can withstand before it breaks. Tensile strength can be measured on a universal testing machine according to the relevant provisions of GB / T228—2010 "Metallic materials, tensile testing—Part 1: Test method at room temperature".

[0096] By setting the strength of the insulating film 40 to be greater than or equal to 1GP, the strength of the insulating film 40 can be improved, the number of times the conductive element 2 punctures the insulating film 40 can be reduced, and the area of ​​the insulating film 40 covering the conductive element 2 can be increased.

[0097] Combination Figures 5 to 9 As shown, in some embodiments of this application, the tensile modulus of the insulating film is greater than or equal to 1 GPa.

[0098] Specifically, the tensile modulus of the insulating film 40 can be 1 GPa…2 GPa…5 GPa or even larger.

[0099] Tensile modulus refers to the elasticity of a material under tension. Its value is the ratio of the force required to stretch the material by a unit length along its central axis to its cross-sectional area. Tensile modulus reflects the stiffness of a material, that is, how easily it resists deformation. Tensile modulus can be measured on a universal testing machine according to the relevant provisions of GB / T228—2010 "Metallic materials, tensile testing—Part 1: Test at room temperature".

[0100] By setting the tensile modulus of the insulating film 40 to be greater than or equal to 1GP, the tensile modulus of the insulating film 40 can be increased, reducing the breakage of the insulating film 40 under the extrusion state of the conductive element 2, thereby increasing the area of ​​the insulating film 40 covering the conductive element 2.

[0101] Combination Figures 5 to 9 As shown, in some embodiments of this application, the resistivity of the insulating film 40 is greater than or equal to 10. 9 Ω.cm.

[0102] Specifically, the resistivity of insulating film 40 can be 10. 9 Ω.cm…10 10 Ω.cm…10 11 Ω.cm or even larger values.

[0103] Resistivity is a physical quantity used to represent the electrical resistance of various materials. The higher the resistivity, the greater the resistance to electric current.

[0104] By ensuring the resistivity of insulating film 40 is greater than or equal to 10... 9 The Ω.cm setting can increase the resistivity of the insulating film 40, thereby reducing the conductive connection between the positive and negative active materials through the insulating film 40.

[0105] Combination Figures 5 to 9As shown, in some embodiments of this application, the thickness D of the insulating film 40 is 5 μm to 2 mm along the arrangement direction of the housing 322, the insulating film 5, and the battery cell 213.

[0106] Specifically, the size of D can be any value in the range of 5μm…50μm…100μm…1mm…2mm.

[0107] By setting D to 5μm to 2mm, the thickness of the insulating film 40 can be increased while reducing the space occupied by the insulating film 40 within the housing 211. This reduces the likelihood of the conductive element 2 puncturing the insulating film, thereby increasing the area covered by the insulating film 40 on the conductive element 2. Simultaneously, after the insulating film 40 penetrates the cell 213 along with the conductive element 2, the excessive compression of the cell 213 by the insulating film 40 can be reduced. The group margin is an important characteristic characterizing the space filling degree of the cell 213 in the battery cell 21; the group margin is approximately equal to the thickness of the cell 213 divided by the thickness of the receiving cavity 215.

[0108] Combination Figures 5 to 10 As shown, in some embodiments of this application, the insulating film 40 includes a first film layer 41, which includes at least one of PVC material, PE material and PTFE material.

[0109] Specifically, the insulating film 40 can be a single film layer formed of a polymer with high elongation and high strength, and the single film layer can be the first film layer 41.

[0110] PVC, PE, or PTFE are high-elongation and high-strength polymers, respectively. By forming the first film layer 41 with at least one of the PVC, PE, and PTFE materials, the strength of the first film layer 41 can be improved, the number of times the conductive element 2 punctures the first film layer 41 can be reduced, and the elongation of the first film layer 41 can be increased. This allows the first film layer 41 to cover the outside of the conductive element 2 during the process of the conductive element 2 piercing into the battery cell 213, and to be inserted into the battery cell 213 together with the conductive element 2.

[0111] Combination Figures 5 to 9 as well as Figure 11 As shown, in some embodiments of this application, the insulating film 40 further includes a second film layer 42, which is disposed on the side of the first film layer 41 away from the battery cell 213, and the second film layer 42 includes at least one of aramid material and ultra-high molecular weight polyethylene material.

[0112] Specifically, the insulating film 40 can be a double-layer film, including a first film layer 41 formed of a high-elongation, high-strength polymer, and a second film layer 42 formed of a high-strength, high-tensile-modulus polymer. The second film layer 42 has a higher strength and modulus than the first film layer 41, and is located on the side of the first film layer 41 away from the battery cell 213.

[0113] Aramid material and ultra-high molecular weight polyethylene material are high-strength and high-tensile-modulus polymers, respectively. By forming a second film layer 42 from at least one of the aramid material and ultra-high molecular weight polyethylene material, and placing the second film layer 42 on the side of the first film layer 41 away from the battery cell 213, the second film layer 42 is squeezed after the conductive element 2 pierces the housing 211. Since the second film layer 42 has high strength and high tensile modulus, it can effectively reduce the conductive element 2 from piercing the second film layer 42. Thus, the conductive element 2 can squeeze the first film layer 41 through the second film layer 42, thereby reducing the conductive element 2 from piercing the first film layer 41.

[0114] Combination Figures 5 to 9 as well as Figure 12 As shown, in some embodiments of this application, the insulating film 40 is attached to the outer surface of the battery cell 213; and / or, the insulating film 40 is attached to the inner wall surface of the receiving cavity 215.

[0115] Specifically, the insulating film 40 has a film-like structure. For ease of installation, the insulating film 40 can be attached to the outer surface of the battery cell 213 and / or to the inner wall of the receiving cavity 215. Optionally, an adhesive bonding method can be used.

[0116] like Figure 6 As shown, the insulating film 40 is adhered to the inner wall surface of the receiving cavity 215. Figure 12 As shown, the insulating film 40 is attached to the outer surface of the battery cell 213.

[0117] Depending on the actual installation requirements, the insulating film 40 can be selectively attached to the outer surface of the battery cell 213, or attached to the inner wall of the receiving cavity 215, or the insulating film 40 can be attached to both the outer surface of the battery cell 213 and the inner wall of the receiving cavity 215.

[0118] Combination Figures 5 to 9 As shown, in some embodiments of this application, the battery cell 213 includes a positive electrode 2131, a separator 2132 and a negative electrode 2133 stacked together. The positive electrode 2131 is provided with a positive active material, the negative electrode 2133 is provided with a negative active material, and the separator 2132 is configured to isolate the positive active material and the negative active material.

[0119] Specifically, the battery cell 213 may include multiple positive electrode plates 2131 and multiple negative electrode plates 2133, which are alternately stacked in sequence, and a separator 2132 is provided between adjacent positive electrode plates 2131 and negative electrode plates 2133. Alternatively, the battery cell 213 may include at least one positive electrode plate 2131 and at least one negative electrode plate 2133, which are alternately stacked in sequence and then wound into shape, and a separator 2132 is provided between adjacent positive electrode plates 2131 and negative electrode plates 2133. Here, the positive electrode plate 2131, the negative electrode plate 2133, and the separator 2132 are all sheet-like structures, and the stacking arrangement means that the largest surfaces of the sheet-like structures are bonded together.

[0120] By setting a positive electrode 2131 and a negative electrode 2133, the positive active material can be placed on the positive electrode 2131 and the negative active material can be placed on the negative electrode 2133. A separator 2132 is provided between the positive electrode 2131 and the negative electrode 2133, thereby isolating the positive active material and the negative active material through the separator 2132 and reducing the conductive connection between the positive active material and the negative active material.

[0121] Combination Figures 5 to 9 As shown, in some embodiments of this application, along the stacking direction of the positive electrode 2131 and the negative electrode 2133, the insulating film 40 is disposed between the housing 211 and the battery cell 213.

[0122] Specifically, taking a square battery cell 21 as an example, the square battery cell 21 includes a length direction X, a width direction Y, and a height direction Z. An electrode terminal 214 is provided at one end in the height direction Z. Positive electrode plates 2131 and negative electrode plates 2133 are stacked along the width direction Y of the battery cell 21. When the conductive element 2 is inserted into the cell 213 in a direction parallel to the surface of the positive electrode plate 2131 or negative electrode plate 2133, that is, when the conductive element 2 is inserted into the cell 213 in a direction perpendicular to the width direction Y of the battery cell 21, if it is inserted between adjacent positive electrode plates 2131 and negative electrode plates 2133 along the length direction X or height direction Z of the battery cell 21, the conductive element 2 cannot simultaneously pass through both positive and negative electrode plates 2131. Therefore, the conductive connection between the positive and negative active materials through the conductive element 2 can be reduced. When the conductive element 2 is inserted into the cell 213 at an angle to the surface of the positive electrode 2131 or the negative electrode 2133, if the conductive element 2 passes through both the positive electrode 2131 and the negative electrode 2133 along the width direction Y of the battery cell 21, it can easily lead to conductive connection between the positive and negative active materials through the conductive element 2. Therefore, by placing the insulating film 40 between the casing 211 and the cell 213 along the stacking direction of the positive electrode 2131 and the negative electrode 2133, the conductive connection between the positive and negative active materials in the cell 213 through the conductive element 2 can be effectively reduced.

[0123] Optionally, when the battery cell 21 is a cylindrical battery cell, the insulating film 40 may be arranged around the outer peripheral surface of the cell 213 in the radial direction.

[0124] By placing the insulating film 40 between the housing 211 and the cell 213 along the stacking direction of the positive electrode 2131 and the negative electrode 2133, when the external conductive member 2 is inserted into the cell 213 along the stacking direction of the positive electrode 2131 and the negative electrode 2133, the insulating film 40 can extend under the pressure of the conductive member 2 and cover the outside of the conductive member 2, and be inserted into the inside of the cell 213 together with the conductive member 2. This reduces the conductive connection between the positive electrode active material and the negative electrode active material in the cell 213 through the conductive member 2, reduces the occurrence of short circuits inside the battery cell 21, thereby reducing safety hazards and improving the safety performance of the battery cell 21.

[0125] like Figure 2 As shown, a second aspect of this application provides a battery device 10, which includes a battery cell 21 as described above.

[0126] Specifically, the battery device 10 may include one or more battery cells 21, where a battery cell 21 is the smallest unit constituting the battery device 10. When there are multiple battery cells 21, they can be connected in series and / or in parallel via electrode terminals 214 for various applications. Multiple battery cells 21 can be connected in series, in parallel, or in a mixed configuration to form a battery cell assembly 20. Since the battery device 10 in this application has the same technical features as the battery cell 21 in any of the above embodiments and can achieve the same technical effects, it will not be described in detail here.

[0127] like Figure 1 As shown, a third aspect of this application provides an electrical device that includes the battery device 10 of any of the above claims.

[0128] Since the electrical device in this application has the same technical features as the battery device 10 in any of the above embodiments and can achieve the same technical effect, it will not be described again here.

[0129] like Figure 1 As shown, in some embodiments of this application, the electrical device can be a vehicle 1, which includes a battery device 10 according to any of the above embodiments. The battery device 10 is used to provide electrical energy to the vehicle 1 and to drive the vehicle 1 to move.

[0130] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application.

[0131] Combination Figure 1 and Figure 2 As shown, this application proposes a vehicle 1, which includes a battery device 10, and the battery device 10 includes at least one battery cell 21.

[0132] Combination Figures 5 to 9 As shown, the battery cell 21 includes a casing 211, a cell 213, and an insulating film 40. A receiving cavity 215 is formed inside the casing 211, and the cell 213 is disposed within the receiving cavity 215. The insulating film 40 is disposed between the casing 211 and the cell 213. The insulating film 40 is extensible and configured to deform in the direction toward the cell 213. The insulating film 40 has an elongation greater than or equal to 20%, a tensile strength greater than or equal to 1 GPa, a tensile modulus greater than or equal to 1 GPa, and a resistivity greater than or equal to 10 Ω·cm. 9 Ω.cm. Along the arrangement direction of the housing 211, the insulating film 40 and the battery cell 213, the thickness dimension D of the insulating film 40 is 5μm to 2mm.

[0133] Combination Figures 5 to 9 as well as Figure 11 As shown, the battery cell 213 includes a positive electrode 2131, a separator 2132, and a negative electrode 2133 stacked together. The positive electrode 2131 is provided with a positive active material, and the negative electrode 2133 is provided with a negative active material. The separator 2132 is configured to isolate the positive and negative active materials. Along the stacking direction of the positive and negative electrode 2131 and the negative electrode 2133, an insulating film 40 is disposed between the housing 211 and the battery cell 213 and is attached to the inner wall of the receiving cavity 215. The insulating film 40 includes a first film layer 41, which includes at least one of PVC, PE, and PTFE materials. The insulating film 40 also includes a second film layer 42, which is disposed on the side of the first film layer 41 facing away from the battery cell 213. The second film layer 42 includes at least one of aramid and ultra-high molecular weight polyethylene materials.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: A housing, the interior of which is formed with a receiving cavity; A battery cell, wherein the battery cell is disposed within the receiving cavity; An insulating film is disposed between the housing and the battery cell, wherein the insulating film is extensible and configured to deform in a direction toward the battery cell.

2. The battery cell according to claim 1, characterized in that, The elongation of the insulating film is greater than or equal to 20%.

3. The battery cell according to claim 1 or 2, characterized in that, The tensile strength of the insulating film is greater than or equal to 1 GPa.

4. The battery cell according to any one of claims 1 to 3, characterized in that, The tensile modulus of the insulating film is greater than or equal to 1 GPa.

5. The battery cell according to any one of claims 1 to 3, characterized in that, The resistivity of the insulating film is greater than or equal to 10. 9 Ω.cm.

6. The battery cell according to any one of claims 1 to 3, characterized in that, Along the arrangement direction of the housing, the insulating film, and the battery cell, the thickness D of the insulating film is from 5 μm to 2 mm.

7. The battery cell according to any one of claims 1 to 3, characterized in that, The insulating film includes a first film layer, which includes at least one of PVC material, PE material and PTFE material.

8. The battery cell according to claim 7, characterized in that, The insulating film further includes a second film layer, which is disposed on the side of the first film layer away from the battery cell, and the second film layer includes at least one of aramid material and ultra-high molecular weight polyethylene material.

9. The battery cell according to any one of claims 1 to 8, characterized in that, The insulating film is adhered to the outer surface of the battery cell; and / or, the insulating film is adhered to the inner wall of the receiving cavity.

10. The battery cell according to any one of claims 1 to 8, characterized in that, The battery cell includes a positive electrode, a separator, and a negative electrode stacked together. The positive electrode has the positive active material, the negative electrode has the negative active material, and the separator is configured to isolate the positive active material and the negative active material.

11. The battery cell according to any one of claims 1 to 8, characterized in that, Along the stacking direction of the positive electrode and the negative electrode, the insulating film is disposed between the housing and the battery cell.

12. A battery device, characterized in that, Includes the battery cell according to any one of claims 1 to 11.

13. An electrical appliance, characterized in that, Includes the battery device according to claim 12.

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