Battery devices and electrical equipment

Abstract

This application discloses a battery device and an electrical appliance. The battery device comprises a battery cell assembly, including multiple battery cells, each equipped with a pressure relief mechanism. A housing has a pressure relief hole communicating with a receiving space. At least a portion of the pressure relief hole corresponds to the pressure relief mechanism to release substances released by the battery cells via the mechanism. A protective layer is connected to the housing and covers the pressure relief hole. The protective layer is located outside the receiving space and has a weak area. At least a portion of the weak area corresponds to the pressure relief hole. The weak area can partially or completely detach under the pressure generated by the substances released by the pressure relief mechanism, forming a channel communicating with the pressure relief hole on the protective layer. The orthographic projection of the pressure relief hole onto the protective layer falls within the area of ​​the weak area, and the area of ​​the weak area is larger than the area of ​​the orthographic projection of the pressure relief hole onto the protective layer. The technical solution of this application can improve the sealing performance of the battery device, thereby enhancing the operational stability of the battery device.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to a battery device and an electrical appliance. Background Technology

[0002] With the development of new energy technologies, batteries are being used more and more widely, such as in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, and power tools.

[0003] During battery operation or in the event of thermal runaway, gas is generated. The increased gas volume leads to a rise in internal temperature and pressure, triggering the battery's pressure relief mechanism to release the hot substances. Weaknesses in the battery's design can reduce the battery's sealing performance, thus requiring improvements to address these issues. Summary of the Invention

[0004] In view of the above problems, this application provides a battery device and an electrical device that can improve the sealing performance of the battery device to enhance the stability of the battery device operation.

[0005] In a first aspect, this application provides a battery device, including a battery cell assembly, a housing, and a protective layer. The battery cell assembly includes multiple battery cells, each equipped with a pressure relief mechanism. The housing has a receiving space, in which the battery cell assembly is disposed. The housing has a pressure relief hole communicating with the receiving space, at least a portion of which corresponds to the pressure relief mechanism to release substances released by the battery cells via the mechanism. The protective layer is connected to the housing and covers the pressure relief hole, located outside the receiving space, and has a weak area. At least a portion of the weak area corresponds to the pressure relief hole, and the weak area can be partially or completely detached under pressure from the substances released by the pressure relief mechanism to form a channel communicating with the pressure relief hole on the protective layer. The orthographic projection of the pressure relief hole onto the protective layer falls within the area of ​​the weak area, and the area of ​​the weak area is larger than the area of ​​the orthographic projection of the pressure relief hole onto the protective layer.

[0006] In the technical solution of this application embodiment, the pressure relief mechanism installed in the battery cell can open when the internal pressure or temperature of the battery cell reaches a threshold, releasing the high-temperature and high-pressure substances inside, reducing the risk of battery cell explosion or combustion, improving the safety performance of the battery cell during operation, and reducing damage to surrounding personnel or equipment. The housing is used to house the battery cell, providing a stable environment and reducing damage to the battery cell from external moisture and impurities. A pressure relief hole is provided on the housing, opposite to the pressure relief mechanism, to promptly discharge the substances released from the pressure relief mechanism, thereby reducing damage to surrounding battery cells from the high-temperature and high-pressure substances released by the pressure relief mechanism. For example, high-temperature and high-pressure substances can melt the insulating layer on the surface of the battery cell, leading to faults such as leakage and short circuits. The pressure relief hole can reduce the occurrence of such faults. Furthermore, a protective layer is provided to improve the sealing performance at the pressure relief hole and enhance the stability of the battery cell during normal operation. Specifically, the projection of the pressure relief hole onto the protective layer falls within the weak area, and the area of ​​the weak area is larger than the area of ​​the projection of the pressure relief hole onto the protective layer. This ensures that the edge of the weak area is offset from the pressure relief hole in the thickness direction of the protective layer, and there is a certain distance between the edge of the weak area and the edge of the pressure relief hole. Therefore, the weak area can completely cover the pressure relief hole and form a sealed connection with it, reducing the risk of external moisture or impurities entering the enclosure through the pressure relief hole. Furthermore, when the pressure relief mechanism is activated, the high-temperature and high-pressure substances can exert a certain impact force on the weak area of ​​the protective layer, causing it to partially or completely detach, forming a channel on the protective layer that connects to the pressure relief hole, thus facilitating the release of pressure. Moreover, the area of ​​the weak area is larger than the area of ​​the pressure relief hole, reducing the impact of high-temperature and high-pressure substances on the non-weak areas of the protective layer, improving the connection stability between the protective layer and the enclosure in the non-weak areas, reducing the risk of the protective layer peeling off from the enclosure when the pressure relief mechanism is activated, and improving the sealing performance of the protective layer.

[0007] In some embodiments, the protective layer includes a main body and thinning sections, the thickness of the main body being greater than the thickness of the thinning sections, and the weak area being formed by the thinning sections enclosing a ring-shaped path. In the above structure, by providing multiple thinning sections, the weak area can crack along the ring-shaped path when it detaches, thus improving the accuracy of the crack location in the weak area.

[0008] In some embodiments, the weak area is formed by locally thinning the protective layer. The structure described above can be obtained by thinning a predetermined area of ​​the protective layer, which facilitates molding and improves manufacturing efficiency.

[0009] In some embodiments, the weak zone is formed by a plurality of spaced-apart through holes along an annular path. This structure increases the rate of cracking in the weak zone and reduces the risk of pressure relief hole blockage.

[0010] In some embodiments, the battery cell assembly includes a plurality of battery cells arranged sequentially along a first direction. A plurality of weak regions are spaced apart along the first direction in the protective layer and are corresponding one-to-one with the pressure relief mechanism of each battery cell. In the above structure, the pressure relief holes and weak regions are respectively corresponding to the pressure relief mechanisms of the plurality of battery cells, improving the efficiency of releasing high-temperature, high-pressure substances.

[0011] In some embodiments, the thickness H of the protective layer satisfies 0.2mm ≤ H ≤ 1.0mm. In the above structure, by setting an appropriate thickness of the protective layer, the sealing performance at the pressure relief hole is improved, while the risk of the weak area failing to detach smoothly is reduced.

[0012] In some embodiments, the minimum distance A between the orthographic projection of the pressure relief hole on the protective layer and the edge of the protective layer satisfies: 20mm ≤ A ≤ 50mm. In the above structure, the protective layer has a certain width of connection with the housing along the first direction, which can improve the connection stability between the protective layer and the housing.

[0013] In some embodiments, the minimum distance B between the orthographic projection of the pressure relief hole on the protective layer and the edge of the weak area satisfies: 1mm ≤ B ≤ 10mm. In the above structure, the edge of the weak area extends beyond the edge of the pressure relief hole by a certain distance, which can improve the sealing performance between the protective layer and the pressure relief hole.

[0014] In some embodiments, the release pressure threshold of the weak zone is less than the opening pressure threshold of the pressure relief mechanism. In the above structure, by setting an appropriate width of the through hole, the connection stability between the protective layer and the housing can be improved while ensuring that the weak zone breaks smoothly, so as to release the high-temperature and high-pressure material in a timely manner.

[0015] In some embodiments, the minimum width D of the through hole satisfies 0.4mm≤D≤0.8mm. By setting an appropriate width for the through hole, the connection stability between the protective layer and the housing can be improved while ensuring that the weak area can be easily broken to release high-temperature and high-pressure substances in a timely manner.

[0016] In some embodiments, an insulating layer is provided on the side of the housing facing the receiving space. The insulating layer is located between the battery cell assembly and the housing, and is used to insulate the battery cells from the housing. A drain hole, communicating with the pressure relief hole, is provided on the insulating layer at the position corresponding to the pressure relief hole. In the above structure, by providing an insulating layer, the risk of a short circuit due to contact between some fragments of the pressure relief mechanism and the housing after the pressure relief mechanism is opened is reduced.

[0017] In some embodiments, the insulating layer includes at least a first portion covering the wall of the pressure relief orifice; the insulating layer also includes a second portion covering the surface of the housing facing the pressure relief mechanism, the first portion and the second portion being connected and integrally formed. In the above structure, the risk of a short circuit occurring due to contact between some fragments of the pressure relief mechanism and the wall of the pressure relief orifice after the pressure relief mechanism is opened is reduced. By providing the insulating layer, the risk of a short circuit occurring due to contact between some fragments of the pressure relief mechanism and the housing caused by the conductivity of high-temperature and high-pressure materials after the pressure relief mechanism is opened is reduced.

[0018] Secondly, this application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0019] In some embodiments, the protective layer of the battery device is disposed facing outwards towards the electrical device. Distributing the protective layer outwards facilitates the discharge of substances released from the battery cells, reducing damage to the electrical device from high-temperature, high-pressure substances.

[0020] 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

[0021] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0022] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0023] Figure 2 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0024] Figure 3 This is a partial structural schematic diagram of a battery device provided in some embodiments of this application;

[0025] Figure 4 This is a schematic diagram of the structure of the protective layer and the housing provided in some embodiments of this application;

[0026] Figure 5 for Figure 3 A magnified structural diagram of section E in the middle;

[0027] Figure 6 This is a schematic diagram of the structure of the protective layer provided in other embodiments of this application;

[0028] Figure 7 for Figure 6 Schematic diagram of the structure of the FF section;

[0029] Figure 8 This is a schematic diagram of the structure of the protective layer provided in other embodiments of this application;

[0030] Figure 9 for Figure 8 Schematic diagram of the GG section;

[0031] Figure 10 This is a schematic diagram of the structure of the protective layer provided in other embodiments of this application;

[0032] Figure 11 This is a schematic diagram of the structure of the protective layer provided in other embodiments of this application;

[0033] Figure 12 This is a schematic diagram of the structure of the insulating layer provided in some embodiments of this application.

[0034] Detailed Explanation of Reference Numerals

[0035] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing section; 5b. Second housing section; 5c. Receiving space; 501. Pressure relief hole; 6. Battery cell; 7. Protective layer; 701. Weak area; 702. Thinning section; 703. Through hole; 704. Thinning sheet; 705. Main body; 706. Straight section; 707. Bending section; 8. Insulating layer; 801. Drain hole; 802. First part; 803. Second part; X, First direction; Y, Second direction. Detailed Implementation

[0036] 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.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0038] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0041] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0042] 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," and "circumferential" indicate the orientation or positional relationship 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.

[0043] In the description of the embodiments of this application, unless otherwise expressly specified and limited, 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.

[0044] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0045] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering. For example, if the angle between two directions is 85°-95°, the two directions can be considered perpendicular; if the angle between two directions is 0°-5°, the two directions can be considered parallel.

[0046] In this application, "multiple" means two or more (including two).

[0047] In the embodiments of this application, the battery cell can be a secondary battery, which refers to a type of battery that can be used again after the battery cell has been discharged by recharging to activate the active materials.

[0048] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0049] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the positive and negative electrodes. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0050] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0051] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0052] In some embodiments, the housing includes an end cap and a housing, the housing having an opening, and the end cap covering the opening. The housing may have one or more openings. The end cap may also have one or more.

[0053] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0054] Battery packs typically consist of multiple stacked battery cells to improve compactness and maximize the utilization of internal space. When a battery cell experiences thermal runaway, the pressure relief mechanism activates and releases the high-temperature, high-pressure material inside. This material then moves within the pack, potentially damaging adjacent, normally functioning battery cells. For example, the high-temperature, high-pressure material might melt the insulation layer of an adjacent battery cell, causing a short circuit between the battery cell and the pack. Therefore, pressure relief vents are necessary to release the high-temperature, high-pressure material. However, the presence of these vents reduces the pack's sealing performance, necessitating structural improvements.

[0055] In view of this, this application provides a battery device with a pressure relief mechanism installed in the battery cell. This mechanism can open when the internal pressure or temperature of the battery cell reaches a threshold, releasing the high-temperature and high-pressure substances inside. This reduces the risk of the battery cell exploding or burning, improves the safety performance of the battery cell during operation, and reduces damage to surrounding personnel or equipment. The housing is used to contain the battery cell, providing a stable environment and reducing damage from external moisture and impurities. A pressure relief hole is provided on the housing, opposite the pressure relief mechanism, to promptly discharge the high-temperature and high-pressure substances released through the mechanism, thereby reducing damage to surrounding battery cells. For example, high-temperature and high-pressure substances can melt the insulating layer on the surface of the battery cell, leading to faults such as leakage and short circuits. The pressure relief hole reduces the occurrence of such faults. Furthermore, a protective layer is provided to improve the sealing performance at the pressure relief hole and enhance the stability of the battery cell during normal operation. Specifically, the projection of the pressure relief hole onto the protective layer falls within the weak area, and the area of ​​the weak area is larger than the area of ​​the projection of the pressure relief hole onto the protective layer. This ensures that the edge of the weak area is offset from the pressure relief hole in the thickness direction of the protective layer, meaning there is a certain distance between the edge of the weak area and the edge of the pressure relief hole. Therefore, the weak area can completely cover the pressure relief hole and form a sealed connection with the enclosure, reducing the risk of external moisture or impurities entering the enclosure through the pressure relief hole. Furthermore, when the pressure relief mechanism is activated, the high-temperature, high-pressure material can exert a certain impact force on the weak area of ​​the protective layer, causing it to partially or completely detach, forming a channel in the protective layer that connects to the pressure relief hole, allowing for smooth release from the hole. Moreover, the area of ​​the weak area is larger than the area of ​​the pressure relief hole, reducing the impact of high-temperature, high-pressure material on the non-weak areas of the protective layer, improving the connection stability between the protective layer and the enclosure in the non-weak areas, reducing the risk of the protective layer peeling off from the enclosure when the pressure relief mechanism is activated, and improving the sealing performance of the protective layer.

[0056] 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.

[0057] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0058] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0059] 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.

[0060] 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.

[0061] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0062] 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.

[0063] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0064] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, 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.

[0065] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0066] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0067] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0068] As shown in Figure 1, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0069] Vehicle 1 may also include controller 3 and motor 4. Controller 3 is used to control battery device 2 to supply power to motor 4, for example, for the power needs of vehicle 1 during start-up, navigation and driving.

[0070] In some embodiments of this application, the battery device 2 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.

[0071] Figure 2 This is a schematic diagram of a battery explosion provided for some embodiments of this application. For example... Figure 2 As shown, the battery device 2 includes a housing 5 and battery cells 6, with the battery cells 6 housed within the housing 5. The battery cell 6 can be the smallest unit constituting the battery device 2.

[0072] The housing 5 is used to house the battery cell 6, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, and together define a housing space 5c for housing the battery cell 6. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b can be various shapes, such as cylinders, cuboids, etc.

[0073] In the battery device 2, multiple battery cells 6 can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel.

[0074] Multiple battery cells 6 can be directly connected in series, parallel, or in a mixed manner, and then the whole composed of multiple battery cells 6 can be housed in the housing 5; of course, multiple battery cells 6 can also be connected in series, parallel, or in a mixed manner to form a battery module, and multiple battery modules can then be connected in series, parallel, or in a mixed manner to form a whole, and housed in the housing 5.

[0075] Please refer to the reference. Figures 2 to 5 , Figure 2 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application. Figure 3 This is a partial structural schematic diagram of a battery device provided in some embodiments of this application. Figure 4 This is a schematic diagram of the structure of the protective layer and the housing provided in some embodiments of this application. Figure 5 for Figure 3 A magnified structural diagram of section E in the middle.

[0076] As shown in the figure, this application embodiment provides a battery device 2, including a battery cell assembly, a housing 5, and a protective layer 7. The battery cell assembly includes multiple battery cells 6, and each battery cell 6 is provided with a pressure relief mechanism. The housing 5 has a receiving space 5c, in which the battery cell assembly is disposed. The housing 5 has a pressure relief hole 501 communicating with the receiving space 5c, at least a portion of which corresponds to the pressure relief mechanism to release the substance released by the battery cells 6 via the pressure relief mechanism. The protective layer 7 is connected to the housing 5 and covers the pressure relief hole 501, and is located outside the receiving space 5c. The protective layer 7 has a weak area 701, at least a portion of which corresponds to the pressure relief hole 501. The weak area 701 can be partially or completely detached under the pressure generated by the substance released by the pressure relief mechanism, thereby forming a channel in the protective layer 7 communicating with the pressure relief hole 501. The orthographic projection of the pressure relief hole 501 onto the protective layer 7 falls within the range of the weak area 701, and the area of ​​the weak area 701 is greater than the area of ​​the orthographic projection of the pressure relief hole 501 onto the protective layer 7.

[0077] The pressure relief mechanism installed in the battery cell 6 can open when the pressure or temperature inside the battery cell 6 reaches a threshold, releasing the high-temperature and high-pressure substances inside and reducing the risk of explosion or combustion of the battery cell 6. For example, the housing 5 includes a first wall, which can be the bottom wall of the housing 5. The battery cell 6 includes a second wall, and the pressure relief mechanism is located on the second wall, which is opposite to the first wall. Specifically, the second wall has a pressure relief hole, and the pressure relief mechanism covers the pressure relief hole and is sealed to the second wall. When thermal runaway occurs in the battery cell 6, the pressure relief mechanism opens to release the high-temperature and high-pressure substances inside the battery cell 6.

[0078] The housing 5 houses the individual battery cells 6, providing them with a stable environment and reducing damage from external moisture and impurities. A pressure relief hole 501 is provided on the housing 5, corresponding to the pressure relief mechanism. This ensures that substances released from the pressure relief mechanism of the battery cells 6 can be discharged through the pressure relief hole 501, preventing disorderly diffusion of substances within the housing 5 and reducing damage to other components inside. For example, high-temperature, high-pressure substances can melt the insulating layer 8 on the surface of the battery cells 6, leading to leakage, short circuits, and other faults. The pressure relief hole 501 reduces the probability of such faults occurring.

[0079] The protective layer 7 reduces the risk of external moisture or impurities entering the housing 5 through the pressure relief hole 501. Optionally, the protective layer 7 has certain high-temperature resistance and corrosion resistance. When one pressure relief hole 501 is opened, the protective layer 7 can withstand the erosion of high-temperature and high-pressure substances, maintain its structural stability, and ensure its sealing performance to other pressure relief holes 501.

[0080] Optionally, the release pressure threshold of the weak zone 701 is less than the opening pressure threshold of the pressure relief mechanism. For example, the opening pressure threshold of the pressure relief mechanism is 1.5-2.0 MPa; the rupture pressure threshold of the weak zone 701 is 0.8-1.2 MPa.

[0081] After the high-temperature and high-pressure material is released through the pressure relief mechanism, its pressure energy level has appropriately decayed. The optimized weak zone 701 only needs to withstand the decayed medium pressure, so a lower rupture pressure threshold can be set. This pressure gradient design ensures pressure relief reliability while avoiding increased costs caused by over-design.

[0082] Alternatively, the protective layer 7 can be bonded to the surface of the enclosure 5 using materials such as polyimide film, polyester film, and mica paper. Alternatively, materials such as epoxy resin, ceramicized silicone rubber, or tetrafluoroethylene can be coated onto the surface of the enclosure 5 and cured.

[0083] The protective layer 7 is also provided with a weak area 701 at the position corresponding to the pressure relief hole 501. After the pressure relief mechanism is opened, the high temperature and high pressure material can cause the weak area 701 to rupture, forming a channel on the protective layer 7 that communicates with the pressure relief hole 501, so that it can be released smoothly from the pressure relief hole 501.

[0084] like Figure 4 As shown, the orthographic projection of the pressure relief hole 501 on the protective layer 7 falls within the range of the corresponding weak area 701, and the area of ​​the weak area 701 is greater than the area of ​​the orthographic projection of the pressure relief hole 501 on the protective layer 7.

[0085] The above structure allows the edge of the weak area 701 to be offset from the pressure relief hole 501 in the thickness direction of the protective layer 7. That is, the edge of the weak area 701 of the protective layer 7 is a certain distance from the edge of the pressure relief hole 501. Therefore, the weak area 701 can completely cover the pressure relief hole 501 and form a sealed connection with the box body 5, thereby reducing the risk of external moisture or impurities entering the box body 5 through the pressure relief hole 501.

[0086] Because the orthographic projection of the pressure relief hole 501 falls entirely within the weak area 701, when the pressure relief mechanism is activated, the material can directly and rapidly act on the weak area 701, causing it to rupture. This design reduces the risk of material spreading between the protective layer 7 and the housing 5, improves pressure relief efficiency, and reduces the risk of material breaching the connection between the protective layer 7 and the housing 5 and spreading to the unruptured pressure relief mechanism. By designing the orthographic projection of the pressure relief hole 501 within the weak area 701, it helps to reduce the possibility of material causing unnecessary damage to other parts of the battery device 2.

[0087] Furthermore, the area of ​​the weak zone 701 is larger than that of the pressure relief hole 501, reducing the impact of high-temperature and high-pressure substances on the non-weak zones of the protective layer 7, improving the connection stability between the protective layer 7 and the housing 5 in the non-weak zones, reducing the risk of the protective layer 7 peeling off from the housing 5 when the pressure relief mechanism is opened, and improving the sealing performance of the protective layer 7. The design of the weak zone 701 ensures that the protective layer 7 remains intact under normal conditions, effectively preventing external foreign objects and moisture from entering the battery device 2. At the same time, when pressure relief is required, the weak zone 701 can rupture quickly without affecting the pressure relief function. This design enhances the reliability and adaptability of the protective layer 7.

[0088] In the above structure, the weak area 701 is relatively large. After the pressure relief mechanism is opened, it can more easily break through the weak area 701 of the protective layer 7, which improves the efficiency of releasing high-temperature substances and improves the sealing performance of the protective layer 7.

[0089] like Figure 5 As shown, in some embodiments of this application, the protective layer 7 includes a main body 705 and a thinning section 702. The thickness of the main body 705 is greater than the thickness of the thinning section 702, and the weak area 701 is formed by the thinning section 702 surrounding a ring path.

[0090] Optionally, by adjusting the width, length, and spacing of the thinning sections 702, the overall strength of the weak area 701 can be adjusted, thereby setting the rupture pressure. This helps ensure that the weak area 701 can rupture in time when the battery device 2 reaches a specific pressure threshold, achieving safe pressure relief.

[0091] The above structure ensures that the weak zone 701 is evenly distributed along the annular path. When the pressure relief mechanism is activated, the high-temperature and high-pressure material can pass evenly through the ruptured weak zone 701, avoiding the problem of excessive local pressure or uneven release, and improving the uniformity and stability of pressure relief.

[0092] Under normal conditions, the spacing between the thinned sections 702 and the rest of the protective layer 7 together maintain the overall structural strength of the protective layer 7, ensuring that the battery device 2 will not break unexpectedly due to external impact or vibration during normal use. This design not only guarantees the protective function of the protective layer 7 but also achieves reliable pressure relief when needed. In the above structure, when the weak area 701 breaks, it can crack along a ring path, improving the accuracy of the crack location of the weak area 701.

[0093] Optionally, there are multiple thinning sections 702, which are spaced apart along an annular path. Optionally, the thinning sections 702 are closed annular sections continuously arranged along the annular path. The selection can be based on the thickness of the protective layer 7 and the preset pressure.

[0094] like Figure 6 as well as Figure 7 As shown, in some embodiments of this application, the weak area 701 is formed by localized thinning of the protective layer 7.

[0095] For example, the area corresponding to the pressure relief hole 501 and the surrounding area of ​​the protective layer 7 are thinned to form a thinning sheet 704. By precisely controlling the thickness of the thinning sheet 704, the rupture pressure of the weak area 701 can be set. For instance, if the weak area 701 is set to rupture when the internal pressure of the battery reaches 1.5 MPa, the thickness of the thinning sheet 704 can be adjusted to a suitable value through experiments and calculations, so that the thinning sheet 704 can reliably rupture under this pressure. This precise control helps ensure that the battery device 2 can operate safely and reliably under various operating conditions.

[0096] The thinned sheet 704, formed by localized thickness reduction, gives the fracture in the weak area 701 a clear starting point and propagation path. Compared to the protective layer 7, which has a uniform overall thickness but is more fragile, this design can more accurately control the location and manner of fracture, reduce the risk of irregular fractures or localized excessive fractures, and improve the controllability of the pressure relief process.

[0097] Under normal operating conditions of the battery cell 6, the protective layer 7, except for the weak area 701, maintains normal thickness and strength, which can provide sufficient protection for the battery device 2, prevent external foreign objects, moisture and other substances from entering the battery device 2, and ensure the safety and stability of the battery device 2.

[0098] When the internal pressure of the battery is too high, the thinner sheet 704, due to its thinness and low strength, can quickly rupture, creating a channel in the weak area 701 that connects to the pressure relief hole 501. This rapid response characteristic can release the high-pressure substances inside the battery in a timely manner, reduce the internal pressure of the battery, prevent dangerous situations such as battery explosion or fire, and ensure the safety of the battery device 2.

[0099] Furthermore, compared to using special materials or complex structures to achieve the weak area 701, the method of forming a thinner sheet 704 by locally reducing the thickness is less expensive. It does not require additional special materials, nor does it require complex processing techniques and equipment, thus reducing the manufacturing cost of the battery device 2.

[0100] The above structure can be obtained by thinning the pre-defined area of ​​the protective layer 7, which facilitates molding and improves manufacturing efficiency.

[0101] like Figure 8 as well as Figure 9 As shown, in some embodiments of this application, the weak area 701 is formed by a plurality of spaced through holes 703 enclosing a ring path.

[0102] The aperture size of the through-hole 703 is one of the key factors affecting the rupture pressure of the weak zone 701. By precisely designing and controlling the aperture of the through-hole 703, the rupture pressure threshold of the weak zone 701 can be accurately set. For example, in experiments, the rupture of the protective layer 7 under pressure can be tested by changing the aperture size, thereby finding the optimal aperture size that meets the specific battery safety requirements. This precise control ensures that the battery device 2 maintains structural integrity within its normal operating range, while timely pressure relief under abnormally high pressure conditions.

[0103] The spacing between the through holes 703 also affects the overall strength and fracture characteristics of the weak area 701. A smaller hole spacing makes the structure of the protective layer 7 in the through hole 703 area more fragile, thus reducing the fracture pressure; while a larger hole spacing makes the strength of the weak area 701 relatively higher, and the fracture pressure increases accordingly. By reasonably adjusting the hole spacing, the fracture pressure of the weak area 701 can be further fine-tuned to match the actual operating conditions of the battery.

[0104] The aforementioned structure increases the cracking speed of the weak zone 701 and reduces the risk of blockage of the pressure relief hole 501.

[0105] In some embodiments, the through hole 703 is not connected to the pressure relief hole to improve the sealing of the battery device 2.

[0106] Please refer to Figure 3 In some embodiments of this application, the battery cell assembly includes a plurality of battery cells 6 arranged sequentially along a first direction X. A plurality of weak areas 701 are arranged at intervals along the first direction X in the protective layer 7, and are arranged one-to-one with the pressure relief mechanisms of the plurality of battery cells 6.

[0107] Each weak point 701 corresponds one-to-one with a pressure relief mechanism. This precise correspondence ensures that when an abnormally high voltage occurs in a single battery cell 6, only the corresponding weak point 701 will rupture and release pressure, avoiding the problem of excessive or insufficient pressure relief caused by the simultaneous rupture of multiple weak points 701. This precise pressure relief mechanism can effectively reduce the risk of battery pack explosion or fire, improving the safety of the battery pack.

[0108] Since the weak area 701 is closely connected to the pressure relief mechanism, when the internal pressure of the battery cell 6 increases, the weak area 701 can quickly rupture and form a channel connected to the pressure relief mechanism, thereby achieving rapid pressure relief.

[0109] In the above structure, the pressure relief hole 501 and the weak area 701 are respectively set with the pressure relief mechanism of multiple battery cells 6, which improves the efficiency of releasing high temperature and high pressure materials.

[0110] like Figure 9 As shown, in some embodiments of this application, the thickness H of the protective layer 7 satisfies 0.2mm ≤ H ≤ 1.0mm. For example, the thickness H of the protective layer 7 is: 0.2mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm or 1.2mm.

[0111] In the battery assembly 2, the thickness H of the protective layer 7 is limited to between 0.2 mm and 1.0 mm. A protective layer 7 with a thickness of not less than 0.2 mm provides basic protection for the individual battery cells 6 inside the housing 5, effectively preventing the intrusion of external foreign objects, moisture, etc., and protecting the internal structure of the battery assembly 2 from damage. Setting the thickness of the protective layer 7 to be less than or equal to 1.0 mm helps save materials and reduces the space occupied by the protective layer 7.

[0112] In the above structure, by setting an appropriate thickness of the protective layer 7, the sealing performance at the pressure relief hole 501 is improved, while the risk of the weak area 701 failing to detach smoothly is reduced.

[0113] like Figure 4 As shown, in some embodiments of this application, the minimum distance A between the orthographic projection of the pressure relief hole 501 on the protective layer 7 and the edge of the protective layer 7 satisfies: 20mm ≤ A ≤ 50mm. For example, A is 20mm, 25mm, 30mm, 35mm, 40mm, or 50mm.

[0114] The minimum distance A between the pressure relief hole 501 and the edge of the protective layer 7 is not less than 20mm. This helps reduce the risk of cracking or damage to the edge of the protective layer 7 due to excessive proximity, thus ensuring the safety and reliability of the pressure relief process. The limitation of a distance A not exceeding 50mm prevents the size of the pressure relief hole 501 from being too small, which helps improve pressure relief efficiency.

[0115] An appropriate distance A helps maintain the structural strength of the protective layer 7, avoiding stress concentration or structural weakness caused by improper positioning of the pressure relief hole 501, thereby improving the overall stability of the battery device 2. During battery use, it may be subjected to external forces such as vibration and impact. A reasonable distance C design ensures that the protective layer 7 remains intact when subjected to these external forces, preventing the pressure relief hole 501 from prematurely breaking or being damaged due to external forces.

[0116] In the above structure, the protective layer 7 has a certain width of connection with the housing 5 along the first direction X, which can improve the connection stability between the protective layer 7 and the housing 5.

[0117] like Figure 4 As shown, in some embodiments of this application, the minimum distance B between the orthogonal projection of the pressure relief hole 501 on the protective layer 7 and the edge of the weak area 701 satisfies: 1mm ≤ B ≤ 10mm. For example, B is: 1mm, 2mm, 5mm, 6mm, 8mm, or 10mm.

[0118] A distance of B of not less than 1 mm ensures a safe distance between the pressure relief hole 501 and the edge of the weak area 701, reducing the risk of substances discharged from the pressure relief hole 501 entering the space between the protective layer 7 and the housing 5 due to excessive proximity. A distance of B of not more than 10 mm ensures that the pressure relief efficiency is not reduced due to excessive distance between the pressure relief hole 501 and the weak area 701. In the event of a rupture in the weak area 701, the pressure relief hole 501 can quickly form an effective pressure relief channel, promptly discharging high-pressure substances from inside the battery cell 6.

[0119] A well-designed distance B utilizes the fracture characteristics of the weak area 701, allowing it to fracture preferentially under a preset pressure, with pressure relief achieved through the pressure relief hole 501. This design helps ensure that the weak area 701 functions reliably when needed, improving the safety of the battery device 2. By controlling the distance B, the risk of accidental fracture of the weak area 701 due to external factors (such as vibration, impact, etc.) can be reduced, thereby improving the stability and reliability of the battery device 2.

[0120] In the above structure, the edge of the weak area 701 extends beyond the edge of the pressure relief hole 501 by a certain distance, which can improve the sealing performance between the protective layer 7 and the pressure relief hole 501.

[0121] like Figure 10 As shown, in some embodiments of this application, the weak region 701 includes a straight section 706 and a bent section 707. The straight section 706 extends along a second direction Y, and two straight sections 706 are arranged parallel to each other along a first direction X, with the second direction Y perpendicular to the first direction X. The bent section 707 connects the two straight sections 706, and the middle portion of the bent section 707 bends towards the opposite ends in a direction away from the straight section 706.

[0122] The straight section 706 primarily bears tensile or compressive stress along the second direction Y when under stress, while the bending design of the bent section 707 causes stress concentration and dispersion at the bend. When the internal pressure of the battery increases, the middle part of the bent section 707, due to its bending, will bear greater stress first, making it more prone to rupture. This optimized stress distribution allows the weak area 701 to rupture accurately under a preset pressure, improving the reliability and accuracy of pressure relief. When the internal pressure of the battery reaches the preset value, the middle part of the bent section 707 will rupture rapidly, forming a channel communicating with the pressure relief hole 501, allowing the high-pressure material inside the battery to be released quickly. This rapid pressure relief capability helps reduce the risk of battery explosion or fire, improving the safety performance of the battery device 2.

[0123] Furthermore, the aforementioned structure forms a racetrack-shaped annular region, consistent with the shape of the pressure relief hole 501. This racetrack-shaped annular region, matching the shape of the pressure relief hole 501, allows for the formation of a channel that mates with the pressure relief hole 501 when the weak area 701 ruptures. This shape matching reduces obstruction and detours during the release process, enabling high-pressure materials inside the battery to be discharged more directly and quickly through the pressure relief hole 501, improving pressure relief efficiency and reducing the risk of damage to the normally operating battery cells 6 caused by high-temperature, high-pressure materials.

[0124] In the above structure, the shape of the weak area 701 matches the shape of the pressure relief mechanism and the pressure relief hole 501, which improves the efficiency of releasing high-temperature and high-pressure substances.

[0125] like Figure 11 As shown, in some embodiments of this application, the minimum width D of the through hole 703 along the second direction Y satisfies 0.4mm≤D≤0.8mm.

[0126] For example, in the straight section 706, the thinning section 702 is a structure that penetrates the protective layer 7, equivalent to a through hole 703. The width D1 of the thinning section 702 satisfies 0.4mm ≤ D1 ≤ 0.8mm. In the bent section 707, 702 is a structure that penetrates the protective layer 7, equivalent to a through hole 703. The width D2 of the thinning section 702 satisfies 0.4mm ≤ D2 ≤ 0.8mm. For example, D1 is: 0.4mm, 0.5mm, 0.6mm, 0.7mm, or 0.8mm. D2 is: 0.4mm, 0.5mm, 0.6mm, 0.7mm, or 0.8mm.

[0127] A minimum width of 0.4 mm reduces the risk that the through-hole 703 will not rupture under the preset pressure. An excessively narrow thinning section 702 may lead to excessively high rupture pressure or uneven rupture, affecting the pressure relief effect. An maximum width of 0.8 mm prevents the thinning section 702 from being too wide, which could result in insufficient strength of the protective layer 7, leading to accidental rupture or structural failure under normal operating conditions.

[0128] Optionally, the straight section 706 and the bent section 707 may have the same width range. This structure simplifies the design and manufacturing process while ensuring consistent pressure relief performance.

[0129] In the above structure, by setting an appropriate width for the through hole 703, the connection stability between the protective layer 7 and the housing 5 can be improved, while ensuring that the weak area 701 can be broken smoothly so as to release the high-temperature and high-pressure material in a timely manner.

[0130] like Figure 12 As shown, in some embodiments of this application, the side of the housing 5 facing the accommodating space 5c is also provided with an insulating layer 8. The insulating layer 8 is located between the battery cell assembly and the housing 5. The insulating layer 8 is used to insulate the battery cell 6 from the housing 5. The insulating layer 8 is provided with a drain hole 801 at the position corresponding to the pressure relief hole 501.

[0131] The protective layer 7 is located on the side of the housing 5 away from the receiving space 5c. Its main function is to act as a protective barrier for the battery cell assembly, preventing external impacts and foreign object intrusion, and releasing internal high-pressure gas through the pressure relief hole 501 in the event of thermal runaway of the battery cell 6. The insulating layer 8 is located on the side of the housing 5 facing the receiving space 5c, directly contacting the battery cell 6, and is used to achieve electrical insulation between the battery cell 6 and the housing 5 to prevent short circuits or leakage. The insulating layer 8 has a vent hole 801 at the position corresponding to the pressure relief hole 501 to ensure unobstructed pressure relief channels.

[0132] When the internal pressure of a single battery cell 6 is too high, the high-pressure gas can be quickly discharged through the corresponding pressure relief hole 501 and vent hole 801 to prevent the battery from exploding or catching fire.

[0133] In the above structure, by setting the insulation layer 8, the risk of short circuit caused by the overlap between some of the residual parts of the pressure relief mechanism and the housing 5 after the pressure relief mechanism is opened is reduced.

[0134] In some embodiments of this application, the insulating layer 8 includes at least a first portion 802 covering the wall of the pressure relief hole 501.

[0135] If the pressure relief hole 501 is not insulated, high-pressure gas carrying conductive materials (such as electrolyte or metal particles) may come into contact with the housing 5, leading to a short circuit or leakage. The first part 802 of the insulating layer 8 covers the hole wall, effectively isolating conductive materials from the housing 5. In the event of battery thermal runaway, high-pressure gas may carry high-temperature materials; therefore, the insulating layer 8 must be resistant to high temperatures and chemical corrosion to ensure insulation remains intact even under extreme conditions. The remaining parts of the insulating layer 8 cover the contact surface between the housing 5 and the battery cell 6, forming a continuous insulating barrier to prevent safety hazards caused by localized insulation failure.

[0136] The first part 802 of the insulating layer 8 covers the hole wall, but a vent hole 801 must be left in the center of the hole wall to ensure unobstructed pressure relief channel. The diameter of the vent hole 801 is the same as that of the pressure relief hole 501 of the protective layer 7 to avoid obstruction of gas flow. The material of the insulating layer 8 must have sufficient flexibility and mechanical strength to prevent it from cracking or falling off due to the impact of high-pressure gas during pressure relief.

[0137] The above structure reduces the risk of a short circuit caused by some fragments of the pressure relief mechanism overlapping with the wall of the pressure relief hole 501 after the pressure relief mechanism is opened.

[0138] In some embodiments of this application, the insulating layer 8 further includes a second portion 803 covering the surface of the housing 5 facing the pressure relief mechanism, wherein the first portion 802 is connected to and integrally formed with the second portion 803.

[0139] The first part 802 covers the wall of the pressure relief hole 501, ensuring electrical insulation in the pressure relief channel area. The second part 803 covers the surface of the housing 5 facing the pressure relief mechanism, extending the protection range of the insulation layer 8. The first part 802 and the second part 803 are seamlessly connected, eliminating the splicing gaps that may exist in traditional separate insulation layers 8, preventing conductive materials (such as electrolytes and metal particles) from causing short circuits or leakage through the gaps. The continuous coverage of the insulation layer 8 from the wall of the pressure relief hole 501 to the surface of the housing 5 ensures the integrity of electrical insulation and improves the safety of the battery pack.

[0140] While covering the hole wall, the first part 802 of the insulating layer 8 must retain a vent hole 801 in the center to ensure unobstructed pressure relief channel. The diameter of the vent hole 801 is the same as that of the pressure relief hole 501 in the protective layer 7 to avoid obstruction of gas flow.

[0141] For example, the first part 802 and the second part 803 of the insulation layer 8 are formed in one step through processes such as die-cutting, injection molding, and spraying, reducing processing steps and manual intervention, and improving production efficiency. One-piece molding avoids the problem of difficult alignment of the separate insulation layers 8, ensuring that the pressure relief hole 501 and the pressure relief hole 801 of the protective layer 7 are aligned. In the event of battery thermal runaway, the one-piece insulation layer 8 can prevent short circuits caused by conductive materials and ensure unobstructed pressure relief channels, reducing the risk of explosion or fire. Through the synergistic design of local insulation and overall protection, the impact of a single battery cell 6 failure on other batteries is reduced, protecting the safety of the entire battery module.

[0142] In the above structure, by setting the insulation layer 8, the risk of short circuit caused by the contact between the residual parts of the pressure relief mechanism and the housing 5 due to the conductivity of the high temperature and high pressure material after the pressure relief mechanism is opened is reduced.

[0143] In some alternative embodiments, the battery device 2 includes a battery cell assembly, a housing 5, and a protective layer 7. The battery cell assembly includes multiple battery cells 6, each battery cell 6 having a pressure relief mechanism. The housing 5 has a receiving space 5c, in which the battery cell assembly is disposed. The housing 5 has a pressure relief hole 501 communicating with the receiving space 5c, at least a portion of which corresponds to the pressure relief mechanism to release substances released by the battery cells 6 via the pressure relief mechanism. The protective layer 7 is connected to the housing 5 and covers the pressure relief hole 501, and is located outside the receiving space 5c. The protective layer 7 has a weak area 701, at least a portion of which corresponds to the pressure relief hole 501. The weak area 701 can be partially or completely detached under the pressure generated by the substances released by the pressure relief mechanism, forming a channel in the protective layer 7 communicating with the pressure relief hole 501. The orthographic projection of the pressure relief hole 501 onto the protective layer 7 falls within the area of ​​the weak zone 701, and the area of ​​the weak zone 701 is larger than the area of ​​the orthographic projection of the pressure relief hole 501 onto the protective layer 7. The weak zone 701 is formed by multiple spaced through holes along a ring-shaped path. The protective layer 7 is located on the side of the housing 5 facing away from the receiving space 5c. An insulating layer 8 is also provided on the side of the housing 5 facing the receiving space 5c. The insulating layer 8 is used to insulate the battery cell 6 from the housing 5, and a drain hole 801 is provided on the insulating layer 8 corresponding to the position of the pressure relief hole 501.

[0144] This application also provides an electrical device including the battery device 2 described in the above embodiments, which provides electrical energy. The electrical device includes the battery device 2, which comprises multiple battery cells 6. Each battery cell 6 has a pressure relief mechanism that opens when the internal pressure or temperature reaches a threshold, releasing the high-temperature, high-pressure material inside, reducing the risk of explosion or combustion, improving the safety of the battery cell 6 during operation, and minimizing damage to surrounding personnel or equipment. A housing 5 houses the battery cells 6, providing a stable environment and reducing damage from external moisture and impurities. A pressure relief hole 501 is provided on the housing 5, opposite the pressure relief mechanism, to promptly discharge the material released by the mechanism, reducing damage to surrounding battery cells 6 from the high-temperature, high-pressure material. For example, the high-temperature, high-pressure material can melt the insulating layer 8 on the surface of the battery cell 6, causing leakage, short circuits, or other faults. The pressure relief hole 501 reduces the occurrence of such faults. Furthermore, to improve the sealing performance of the pressure relief hole 501 and reduce the stability of the battery cell 6 during normal operation, a protective layer 7 is provided to reduce the entry of external moisture or impurities into the housing 5 through the pressure relief hole 501. Additionally, a weak area 701 is provided on the protective layer 7 corresponding to the pressure relief hole 501. After the pressure relief mechanism is activated, the high temperature and pressure of the material can cause the weak area 701 to rupture, forming a channel on the protective layer 7 that connects to the pressure relief hole 501, thus allowing for smooth release from the pressure relief hole 501. The orthographic projection of the pressure relief hole 501 onto the protective layer 7 falls within the area of ​​the weak area 701, and the area of ​​the weak area 701 is larger than the area of ​​the orthographic projection of the pressure relief hole 501 onto the protective layer 7. The weak area 701 can completely cover the pressure relief hole 501 and seal it tightly to the housing 5, thereby reducing the risk of external moisture or impurities entering the housing 5 through the pressure relief hole. Furthermore, the area of ​​the weak zone 701 is larger than the area of ​​the pressure relief hole 501, which reduces the impact of high temperature and high pressure substances on the non-weak zone of the protective layer 7, improves the connection stability between the protective layer 7 and the housing 5 in the non-weak zone, reduces the risk of the protective layer 7 peeling off from the housing 5 when the pressure relief mechanism is opened, and improves the sealing performance of the protective layer 7.

[0145] In some embodiments of this application, the protective layer 7 of the battery device 2 is disposed facing the outside of the electrical device.

[0146] For example, the electrical equipment is a vehicle, and the battery unit 2 is located at the bottom of the vehicle body. The housing 5 includes a top wall and a bottom wall arranged opposite each other, and a pressure relief hole 501 is located on the bottom wall. The top wall is connected to the bottom of the vehicle body, and the bottom wall is located on the side of the top wall away from the vehicle body. The protective layer 7 is located on the outer side of the bottom of the vehicle body. When the pressure relief mechanism of the battery cell 6 is activated, high-temperature and high-pressure substances pass through the pressure relief hole and break through the weak area 701 of the protective layer 7, causing it to partially or completely detach and form a pressure relief through hole. The high-temperature and high-pressure substances are directly discharged to the ground through the pressure relief channel to reduce injury to the occupants of the vehicle and damage to the equipment inside the vehicle. Setting the protective layer 7 facing outwards facilitates the discharge of substances released from the battery cell 6, reducing the damage of high-temperature and high-pressure substances to the electrical equipment. Furthermore, the protective layer 7 is set to improve the sealing performance at the pressure relief hole 501 and improve the stability of the battery cell 6 during normal operation. In this design, the orthographic projection of the pressure relief hole 501 onto the protective layer 7 falls within the area of ​​the weak zone 701, and the area of ​​the weak zone 701 is larger than the area of ​​the orthographic projection of the pressure relief hole 501 onto the protective layer 7. This results in the edge of the weak zone 701 being offset from the pressure relief hole 501 in the thickness direction of the protective layer 7. In other words, there is a certain distance between the edge of the weak zone 701 and the edge of the pressure relief hole 501. Therefore, the weak zone 701 can completely cover the pressure relief hole 501 and be sealed to the housing 5, thereby reducing the risk of external moisture or impurities entering the housing 5 through the pressure relief hole. Furthermore, after the pressure relief mechanism is activated, the high-temperature and high-pressure material can exert a certain impact force on the weak zone 701, causing it to partially or completely detach, forming a channel on the protective layer 7 that communicates with the pressure relief hole, thus allowing for smooth release from the pressure relief hole. Furthermore, the area of ​​the weak zone 701 is larger than the area of ​​the pressure relief hole 501, which reduces the impact of high temperature and high pressure substances on the non-weak zone of the protective layer 7, improves the connection stability between the protective layer 7 and the housing 5 in the non-weak zone, reduces the risk of the protective layer 7 peeling off from the housing 5 when the pressure relief mechanism is opened, and improves the sealing performance of the protective layer 7.

[0147] 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 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 device, characterized in that, include: A battery cell assembly includes multiple battery cells, each battery cell being equipped with a pressure relief mechanism; The housing has a receiving space, in which the battery cell assembly is disposed. The housing is provided with a pressure relief hole communicating with the receiving space. At least a portion of the pressure relief hole is correspondingly disposed with the pressure relief mechanism to release the substance released by the battery cell through the pressure relief mechanism. A protective layer is connected to the housing and covers the pressure relief hole. The protective layer is located outside the accommodating space. The protective layer has a weak area, at least part of which corresponds to the pressure relief hole. The weak area can be partially or completely detached under the pressure generated by the substance released by the pressure relief mechanism to form a channel communicating with the pressure relief hole on the protective layer. The orthographic projection of the pressure relief hole on the protective layer falls within the range of the weak area, and the area of ​​the weak area is larger than the area of ​​the orthographic projection of the pressure relief hole on the protective layer. The weak area completely covers the pressure relief hole and is sealed to the housing.

2. The battery device according to claim 1, characterized in that, The protective layer includes a main body and a thinning section. The thickness of the main body is greater than the thickness of the thinning section, and the weak area is formed by the thinning section along a ring path.

3. The battery device according to claim 1, characterized in that, The weak area is formed by a localized reduction in the thickness of the protective layer.

4. The battery device according to claim 1, characterized in that, The weak zone is formed by multiple spaced through holes arranged along a ring path.

5. The battery device according to claim 2, characterized in that, The battery cell assembly includes multiple battery cells arranged sequentially along a first direction. Multiple weak zones are arranged at intervals along the first direction in the protective layer, and are configured one-to-one with the pressure relief mechanism of each battery cell.

6. The battery device according to any one of claims 1-5, characterized in that, The thickness H of the protective layer satisfies 0.2mm≤H≤1.0mm.

7. The battery device according to any one of claims 1-5, characterized in that, The minimum distance A between the orthographic projection of the pressure relief hole on the protective layer and the edge of the protective layer satisfies: 20mm≤A≤50mm.

8. The battery device according to any one of claims 1-5, characterized in that, The minimum distance B between the orthographic projection of the pressure relief hole on the protective layer and the edge of the weak area satisfies: 1mm≤B≤10mm.

9. The battery device according to any one of claims 1-5, characterized in that, The pressure threshold for the weak zone to disengage is less than the opening pressure threshold for the pressure relief mechanism.

10. The battery device according to claim 4, characterized in that, The minimum width D of the through hole satisfies 0.4mm≤D≤0.8mm.

11. The battery device according to claim 1 or 2, characterized in that, An insulating layer is provided on the side of the housing facing the accommodating space. The insulating layer is located between the battery cell assembly and the housing. The insulating layer is used to insulate the battery cell from the housing. The insulating layer has a drain hole corresponding to the pressure relief hole, which is connected to the pressure relief hole.

12. The battery device according to claim 11, characterized in that, The insulating layer includes at least a first portion covering the wall of the pressure relief hole; the insulating layer also includes a second portion covering the surface of the housing facing the pressure relief mechanism, the first portion and the second portion being connected and integrally formed.

13. An electrical appliance, characterized in that, The electrical equipment includes a battery device as described in any one of claims 1-12, the battery device being used to provide electrical energy.

14. The electrical equipment according to claim 13, characterized in that, The protective layer of the battery device is positioned facing outwards from the electrical equipment.

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