Battery device and electric equipment

Abstract

The invention discloses a battery device and electric equipment, a battery monomer assembly of the battery device comprises a plurality of battery monomers, and each battery monomer is provided with a pressure relief mechanism. A pressure relief hole communicated with the accommodating space is formed in the box body, and at least part of the pressure relief hole corresponds to the pressure relief mechanism so as to release substances released by the battery monomers through the pressure relief mechanism. The protection layer is connected to the box body and covers the pressure relief hole, the protection layer is located outside the containing space, a weak area is arranged on the protection layer, at least part of the weak area corresponds to the pressure relief hole, and the weak area can be partially or completely separated under the pressure effect generated by substances released by the pressure relief mechanism, so that a channel communicating with the pressure relief hole is formed in the protection layer; the orthographic projection of the pressure relief hole on the protective layer falls into the range of the weak area, and the area of the weak area is larger than that of the orthographic projection of the pressure relief hole on the protective layer. According to the technical scheme, the sealing performance of the battery device can be improved, so that the operation stability of the battery device is improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery device and an electrical device. Background Art

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

[0003] During battery operation or when thermal runaway occurs, gases are generated. The increased volume of these gases causes the internal temperature and pressure of the battery to rise, triggering the battery's pressure relief mechanism to release the hot material. Weak features in the battery can compromise the sealing performance of the battery assembly, necessitating improvements to address these issues. Summary of the Invention

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

[0005] In a first aspect, the present application provides a battery device comprising a battery cell assembly, a housing and a protective layer. The battery cell assembly comprises a plurality of battery cells, and the battery cells are provided with a pressure relief mechanism. The housing has a storage space, and the battery cell assembly is arranged in the storage space. The housing is provided with a pressure relief hole connected to the storage space, and at least a portion of the pressure relief hole is arranged corresponding to the pressure relief mechanism to release substances released by the battery cells via the pressure relief mechanism. The protective layer is connected to the housing and covers the pressure relief hole. The protective layer is located outside the storage space, and a weak area is provided on the protective layer. At least a portion of the weak area is arranged corresponding to the pressure relief hole, and the weak area can be partially or completely detached under the action of the pressure generated by the substance released by the pressure relief mechanism to form a channel on the protective layer that is connected to the pressure relief hole. 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.

[0006] In the technical solution of the embodiment of the present application, the pressure relief mechanism provided in the battery cell can be opened when the pressure or temperature inside the battery cell reaches a threshold value, and release the high-temperature and high-pressure substances inside, thereby reducing the risk of explosion or combustion of the battery cell, improving the safety performance of the battery cell operation process, and reducing damage to surrounding personnel or equipment. The box is used to accommodate the battery cell, provide a stable environment for the battery cell, and reduce the damage to the battery cell caused by external moisture and impurities. A pressure relief hole is provided on the box, opposite to the pressure relief mechanism, which can discharge the substances released from the pressure relief mechanism in a timely manner to reduce the damage to the surrounding battery cells caused by the high-temperature and high-pressure substances released by the pressure relief mechanism. For example, high-temperature and high-pressure substances will melt the insulating layer on the surface of the battery cell, causing the battery cell to leak, short-circuit and other faults. The provision of the pressure relief hole can reduce the occurrence of the above-mentioned faults. Furthermore, in order to improve the sealing performance at the pressure relief hole and enhance the stability of the battery cell during normal operation, a protective layer is provided. The orthographic projection of the pressure relief hole on the protective layer falls within the range of the weak zone, and the area of ​​the weak zone is larger than the orthographic projection of the pressure relief hole on the protective layer, so that the edge of the weak zone and the pressure relief hole are staggered in the thickness direction of the protective layer. The edge of the weak zone of the protective layer is at a certain distance from the edge of the pressure relief hole. Therefore, the weak zone can completely cover the pressure relief hole and be sealed with the pressure relief hole, thereby reducing the risk of external moisture or impurities entering the interior of the box through the pressure relief hole. In addition, after the pressure relief mechanism is opened, the high-temperature and high-pressure material in the weak zone on the protective layer can exert a certain impact force on the weak zone, causing the weak zone to partially or completely detach, forming a channel connected to the pressure relief hole on the protective layer, thereby smoothly releasing from the pressure relief hole. In addition, the area of ​​the weak zone is larger than the area of ​​the pressure relief hole, which reduces the impact of the high-temperature and high-pressure material on the non-weak zone of the protective layer, improves the connection stability between the protective layer and the box in the non-weak zone, reduces the risk of the protective layer peeling off from the box when the pressure relief mechanism is opened, and improves the sealing performance of the protective layer.

[0007] In some embodiments, the protective layer includes a main portion and thinned sections. The main portion is thicker than the thinned sections, and the weak zone is formed by the thinned sections arranged along an annular path. In this structure, the provision of multiple thinned sections allows the weak zone to crack along the annular path when detached, thereby improving the positional accuracy of the cracking of the weak zone.

[0008] In some embodiments, the weak area is formed by thinning the local thickness of the protective layer. The above structure can be obtained by thinning the 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 through holes arranged at intervals and enclosed along an annular path. In the above structure, the cracking speed of the weak zone is increased and the risk of the pressure relief hole being blocked is reduced.

[0010] In some embodiments, a battery cell assembly includes multiple battery cells arranged sequentially along a first direction. Multiple weak areas are spaced apart along the first direction on the protective layer and are provided one-to-one with the pressure relief mechanism of each battery cell. In this structure, the pressure relief holes and weak areas are provided in correspondence with the pressure relief mechanisms of the multiple battery cells, thereby improving the efficiency of releasing high-temperature and high-pressure materials.

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

[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: 20 mm ≤ A ≤ 50 mm. In the above structure, the protective layer has a certain width of connection with the box along the first direction, which can improve the stability of the connection between the protective layer and the box.

[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 zone satisfies the following: 1 mm ≤ B ≤ 10 mm. In the above structure, the edge of the weak zone extends a certain distance beyond the edge of the pressure relief hole, which can improve the sealing performance between the protective layer and the pressure relief hole.

[0014] In some embodiments, the pressure threshold for the weak zone to break away is less than the pressure threshold for the pressure relief mechanism to open. In the above structure, 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 zone ruptures smoothly, allowing for the timely release of high-temperature, high-pressure materials.

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

[0016] In some embodiments, an insulating layer is provided on the side of the housing facing the storage space. The insulating layer is located between the battery cell assembly and the housing to insulate the battery cells from the housing. A drain hole connected to the pressure relief hole is provided in the insulating layer at a position corresponding to the pressure relief hole. In this structure, the provision of the insulating layer reduces the risk of a short circuit between the residual components of the pressure relief mechanism and the housing after activation.

[0017] In some embodiments, 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. This structure reduces the risk of short circuits caused by overlapping of fragments of the pressure relief mechanism with the wall of the pressure relief hole after the pressure relief mechanism is opened. The provision of the insulating layer reduces the risk of short circuits caused by overlapping of fragments of the pressure relief mechanism with the housing due to electrical conduction of high-temperature, high-pressure materials after the pressure relief mechanism is opened.

[0018] In a second aspect, the present application provides an electrical device, which includes the battery device in the above embodiment, and the battery device is used to provide electrical energy.

[0019] In some embodiments, the protective layer of the battery device is disposed toward the outside of the electrical device. Disposing the protective layer toward the outside can facilitate the discharge of substances released from the battery cells, thereby reducing damage to the electrical device caused by high-temperature and high-pressure substances.

[0020] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0022] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application; Figure 2 A schematic structural diagram of a battery device provided in some embodiments of the present application; Figure 3 A schematic diagram of a portion of the structure of a battery device provided in some embodiments of the present application; Figure 4 A schematic diagram of the structure of the protective layer and the box body provided in some embodiments of the present application; Figure 5 for Figure 3 Schematic diagram of the enlarged structure of part E; Figure 6 Schematic diagram of the structure of the protective layer provided in other embodiments of the present application; Figure 7 for Figure 6 Schematic diagram of the structure of the FF section; Figure 8 Schematic diagram of the structure of the protective layer provided in other embodiments of the present application; Figure 9 for Figure 8Schematic diagram of the structure of the GG section; Figure 10 Schematic diagram of the structure of the protective layer provided in other embodiments of the present application; Figure 11 Schematic diagram of the structure of the protective layer provided in other embodiments of the present application; Figure 12 A schematic structural diagram of the insulating layer provided in some embodiments of the present application.

[0023] DETAILED DESCRIPTION OF THE REFERENCE NUMERALS 1. Vehicle; 2. Battery device; 3. Controller; 4. Motor; 5. Housing; 5a. First housing portion; 5b. Second housing portion; 5c. Accommodation space; 501. Pressure relief hole; 6. Battery cell; 7. Protective layer; 701. Weakened area; 702. Thinning section; 703. Through hole; 704. Thinning sheet; 705. Main body; 706. Straight section; 707. Bent section; 8. Insulating layer; 801. Drain hole; 802. First portion; 803. Second portion; X, first direction; Y, second direction. DETAILED DESCRIPTION

[0024] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0026] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0027] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0029] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0030] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0031] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0032] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0033] In the embodiments of this application, "parallel" includes not only absolute parallelism but also approximately parallelism as commonly understood in engineering practice. Similarly, "perpendicular" also includes not only absolute perpendicularity but also approximately perpendicularity as commonly understood in engineering practice. For example, if the angle between two directions is 85°-95°, they are considered perpendicular; if the angle between two directions is 0°-5°, they are considered parallel.

[0034] The term "plurality" used in this application refers to two or more (including two).

[0035] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a type of battery that can be continuously used by activating active materials by charging the battery cell after discharge.

[0036] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0037] A battery cell typically includes an electrode assembly. This assembly consists of a positive electrode, a negative electrode, and a separator, which is positioned between the positive and negative electrodes. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing the active ions to pass through.

[0038] In some embodiments, a battery cell may include an outer shell. This outer shell may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film. In some embodiments, the outer shell may be sealed or non-sealed. For example, in a non-sealed outer shell, the outer shell protects the electrode assembly and includes a sealing bag between the outer shell and the electrode assembly, which encapsulates the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating member or an aluminum-plastic film. In a sealed outer shell, the outer shell encapsulates the electrode assembly, electrolyte, and other components.

[0039] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in this application.

[0040] In some embodiments, the housing includes an end cap and a shell, wherein the shell has an opening and the end cap covers the opening. The shell may have one or more openings. One or more end caps may also be provided.

[0041] In some embodiments, the housing is provided with at least one electrode terminal, which is electrically connected to the tab. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via a current collecting member. The electrode terminal may be provided on an end cap or on the housing.

[0042] A battery device usually includes multiple stacked battery cells to improve the compactness of the battery cell arrangement and improve the utilization rate of the internal space of the battery box. When a battery cell experiences thermal runaway, the pressure relief mechanism is activated and discharges the high-temperature and high-pressure substances inside it. The high-temperature and high-pressure substances will move around in the box and easily damage the adjacent normally operating battery cells. For example, the high-temperature and high-pressure substances may melt the insulating layer on the surface of the adjacent battery cells, thereby causing a short circuit between the battery cells and the box. Therefore, a pressure relief hole needs to be provided on the box to discharge the high-temperature and high-pressure substances. The presence of the pressure relief hole will reduce the sealing performance of the box, so the above structure needs to be improved.

[0043] In view of this, the present application provides a battery device, in which a pressure relief mechanism is provided in the battery cell, which can be opened when the pressure or temperature inside the battery cell reaches a threshold value, and release the high-temperature and high-pressure substances inside, thereby reducing the risk of explosion or combustion of the battery cell, improving the safety performance of the battery cell operation process, and reducing damage to surrounding personnel or equipment. The box is used to accommodate the battery cell, provide a stable environment for the battery cell, and reduce the damage to the battery cell caused by external moisture and impurities. A pressure relief hole is provided on the box, opposite to the pressure relief mechanism, which can discharge the high-temperature and high-pressure substances released by the pressure relief mechanism in time to reduce the damage of the high-temperature and high-pressure substances to the surrounding battery cells. For example, the high-temperature and high-pressure substances will melt the insulating layer on the surface of the battery cell, causing the battery cell to leak, short-circuit and other faults. The provision of the pressure relief hole can reduce the occurrence of the above-mentioned faults. Furthermore, in order to improve the sealing performance at the pressure relief hole and improve the stability of the battery cell during normal operation, a protective layer is provided. Among them, the positive 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 positive projection of the pressure relief hole on the protective layer, so that the edge of the weak area and the pressure relief hole are staggered in the thickness direction of the protective layer, that is, the edge of the weak area of ​​the protective layer is at a certain distance from the edge of the pressure relief hole. Therefore, the weak area can completely cover the pressure relief hole and be sealed with the box body, thereby reducing the risk of external moisture or impurities entering the interior of the box body through the pressure relief hole. In addition, after the pressure relief mechanism is opened, the high-temperature and high-pressure material in the weak area of ​​the protective layer can exert a certain impact force on the weak area, causing the weak area to partially or completely detach, forming a channel connected to the pressure relief hole on the protective layer, thereby smoothly releasing from the pressure relief hole. In addition, the area of ​​the weak area is larger than the area of ​​the pressure relief hole, which reduces the impact of the high-temperature and high-pressure material on the non-weak area of ​​the protective layer, improves the connection stability between the protective layer and the box body in the non-weak area, reduces the risk of the protective layer peeling off from the box body when the pressure relief mechanism is opened, and improves the sealing performance of the protective layer.

[0044] The battery device mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0045] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0046] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells with a cable tie.

[0047] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0048] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0049] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0050] As an example, the box body may include a first box body and a second box body. The first box body and the second box body are buckled together to form a closed space inside the box body to accommodate the battery cell assembly.

[0051] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0052] The technical solutions described in the embodiments of the present application are applicable to various electrical devices that use battery cells, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0053] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0054] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0055] Figure 1 A schematic structural diagram of a vehicle provided for some embodiments of the present application.

[0056] As shown in FIG1 , a battery device 2 is provided inside a vehicle 1 , and the battery device 2 can be provided at the bottom, head, or tail 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 an operating power source for the vehicle 1 .

[0057] The vehicle 1 may further include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, to meet the power requirements of starting, navigating, and driving the vehicle 1.

[0058] In some embodiments of the present application, the battery device 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0059] Figure 2 Schematic diagram of the explosion of the battery provided in some embodiments of the present application. Figure 2 As shown, the battery device 2 includes a housing 5 and a battery cell 6, and the battery cell 6 is accommodated in the housing 5. The battery cell 6 may be the smallest unit constituting the battery device 2.

[0060] The housing 5 is used to house the battery cells 6 and can have various structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b. The first housing portion 5a and the second housing portion 5b overlap each other and together define a storage space 5c for the battery cells 6. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Alternatively, both the first housing portion 5a and the second housing portion 5b can be hollow structures with one end open, and the open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0061] In the battery device 2 , the multiple battery cells 6 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 6 are connected in both series and in parallel.

[0062] Multiple battery cells 6 can be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 6 can be accommodated in the box 5; of course, multiple battery cells 6 can also be first connected in series, in parallel, or in a mixed connection to form a battery module, and then multiple battery modules can be connected in series, in parallel, or in a mixed connection to form a whole and accommodated in the box 5.

[0063] Please refer to Figures 2 to 5 , Figure 2 This is a schematic diagram of the structure of a battery device provided in some embodiments of the present application. Figure 3 A schematic diagram of a portion of the structure of a battery device provided in some embodiments of the present application. Figure 4 This is a schematic diagram of the structure of the protective layer and the box body provided in some embodiments of the present application. Figure 5 for Figure 3 Schematic diagram of the enlarged structure of part E.

[0064] As shown in the figure, an embodiment of the present application provides a battery device 2, including a battery cell assembly, a casing 5 and a protective layer 7. The battery cell assembly includes a plurality of battery cells 6, and the battery cells 6 are provided with a pressure relief mechanism. The casing 5 has a accommodating space 5c, and the battery cell assembly is arranged in the accommodating space 5c. The casing 5 is provided with a pressure relief hole 501 connected to the accommodating space 5c, and at least a portion of the pressure relief hole 501 is arranged corresponding to the pressure relief mechanism to release the substance released by the battery cell 6 through the pressure relief mechanism. The protective layer 7 is connected to the casing 5 and covers the pressure relief hole 501. The protective layer 7 is located outside the accommodating space 5c. A weak area 701 is provided on the protective layer 7, and at least a portion of the weak area 701 is arranged corresponding to the pressure relief hole 501. The weak area 701 can be partially or completely detached under the action of the pressure generated by the substance released by the pressure relief mechanism to form a channel on the protective layer 7 that is connected to the pressure relief hole 501. The orthographic projection of the pressure relief hole 501 on the protective layer 7 falls within the range 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 on the protective layer 7 .

[0065] The pressure relief mechanism provided in the battery cell 6 can be opened when the pressure or temperature inside the battery cell 6 reaches a threshold value, and release the high-temperature and high-pressure substances inside, thereby reducing the risk of explosion or combustion of the battery cell 6. Exemplarily, the box body 5 includes a first wall, which can be the bottom wall of the box body 5. The battery cell 6 includes a second wall, and the pressure relief mechanism is provided on the second wall, and the second wall is arranged opposite to the first wall. Specifically, a pressure relief hole is provided on the second wall, and the pressure relief mechanism covers the pressure relief hole and is sealed with 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.

[0066] The housing 5 is used to accommodate the battery cells 6, providing a stable environment for the battery cells 6 and reducing damage to the battery cells 6 from external moisture and impurities. A pressure relief hole 501 is provided on the housing 5. The housing 5 is provided with a pressure relief hole 501 corresponding to the pressure relief mechanism, ensuring that the substances released from the pressure relief mechanism of the battery cells 6 can be discharged through the pressure relief hole 501, avoiding disorderly diffusion of the substances within the housing 5 and reducing damage to other components inside the housing 5. For example, high-temperature and high-pressure substances can melt the insulating layer 8 on the surface of the battery cells 6, causing the battery cells 6 to suffer from leakage, short circuit and other faults. The provision of the pressure relief hole 501 can reduce the probability of the above-mentioned faults.

[0067] The provision of protective layer 7 can reduce the risk of external moisture or impurities entering the interior of the housing 5 through the pressure relief holes 501. Optionally, protective layer 7 has certain high-temperature and corrosion resistance properties. When a pressure relief hole 501 is opened, protective layer 7 can withstand the erosion of high-temperature and high-pressure substances, maintain its structural stability, and ensure its sealing performance for other pressure relief holes 501.

[0068] Optionally, the separation pressure threshold of the weak area 701 is lower 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, and the rupture pressure threshold of the weak area 701 is 0.8-1.2 MPa.

[0069] After the high-temperature, 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 the cost increase caused by overdesign.

[0070] Optionally, the protective layer 7 can be bonded to the surface of the box body 5 using polyimide film, polyester film, mica paper, etc. Alternatively, epoxy resin, ceramic silicone rubber, tetrafluoroethylene, etc. can be coated on the surface of the box body 5 and cured to form.

[0071] A weak area 701 is also provided on the protective layer 7 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 is connected to the pressure relief hole 501, thereby smoothly releasing from the pressure relief hole 501.

[0072] 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 larger than the area of ​​the orthographic projection of the pressure relief hole 501 on the protective layer 7 .

[0073] The above structure allows the edge of the weak area 701 and the pressure relief hole 501 to be staggered in the thickness direction of the protective layer 7, that is, the edge of the weak area 701 of the protective layer 7 is at 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 interior of the box body 5 through the pressure relief hole 501.

[0074] Because the orthographic projection of the pressure relief hole 501 falls completely within the weak zone 701, when the pressure relief mechanism is activated, the substance can directly and quickly act on the weak zone 701, causing it to rupture. This design reduces the risk of substance diffusion between the protective layer 7 and the housing 5, improving pressure relief efficiency and reducing the risk of substance breaking through 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 zone 701, the possibility of substance causing unnecessary damage to other parts of the battery device 2 is reduced.

[0075] Furthermore, the area of ​​weak area 701 is larger than that of pressure relief hole 501, reducing the impact of high-temperature, high-pressure materials on the non-weak areas of protective layer 7. This improves the stability of the connection between protective layer 7 and housing 5 in these non-weak areas, reduces the risk of protective layer 7 peeling off from housing 5 when the pressure relief mechanism is activated, and improves the sealing performance of protective layer 7. The design of weak area 701 ensures that protective layer 7 remains intact under normal conditions, effectively preventing external foreign matter and moisture from entering the interior of battery device 2. Furthermore, when pressure relief is required, weak area 701 can be quickly ruptured, without affecting the pressure relief function. This design enhances the reliability and adaptability of protective layer 7.

[0076] In the above structure, the weak area 701 is larger, and after the pressure relief mechanism is opened, the weak area 701 of the protective layer 7 can be broken through more smoothly, thereby improving the efficiency of releasing high-temperature substances and improving the sealing performance of the protective layer 7.

[0077] like Figure 5 As shown, in some embodiments of the present 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 along a circular path.

[0078] Optionally, by adjusting the width, length, and spacing of the thinned sections 702, the overall strength of the weak area 701 can be adjusted, thereby enabling the setting of a rupture pressure. This helps ensure that when the battery device 2 reaches a specific pressure threshold, the weak area 701 will rupture in time, achieving safe pressure relief.

[0079] The above structure allows the weak areas 701 to be evenly distributed on the annular path. When the pressure relief mechanism is activated, high-temperature and high-pressure materials can evenly pass through the ruptured weak areas 701, avoiding problems of excessive local pressure or uneven release, and improving the uniformity and stability of pressure relief.

[0080] Under normal conditions, the spacing between the thinned sections 702 and the remainder of the protective layer 7 together maintain the overall structural strength of the protective layer 7, ensuring that the battery device 2 will not accidentally rupture due to external impact or vibration during normal use. This design not only ensures the protective function of the protective layer 7 but also provides reliable pressure relief when needed. This structure allows the weak area 701 to rupture along a circular path, improving the positional accuracy of the rupture of the weak area 701.

[0081] Optionally, there are multiple thinning sections 702, which are spaced apart along the annular path. Optionally, the thinning sections 702 are closed annular sections continuously arranged along the annular path. The number of thinning sections 702 can be selected based on the thickness of the protective layer 7 and the preset pressure.

[0082] like Figure 6 as well as Figure 7 As shown, in some embodiments of the present application, the weak area 701 is formed by local thinning of the protective layer 7 .

[0083] For example, the protective layer 7 is thinned in the area corresponding to the pressure relief hole 501 and the surrounding area 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 example, 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 an appropriate value through experimentation and calculation to ensure that the thinning sheet 704 reliably ruptures at this pressure. This precise control helps ensure that the battery device 2 can operate safely and reliably under various operating conditions.

[0084] The thinning sheet 704, formed by the localized thinning, ensures that the rupture of the weak zone 701 has a clear starting point and propagation path. Compared to a protective layer 7 with uniform overall thickness but a more fragile material, this design allows for more precise control of the location and mode of rupture, reducing the risk of irregular or localized excessive rupture and improving the controllability of the pressure relief process.

[0085] When the battery cell 6 is in normal working condition, the protective layer 7 maintains normal thickness and strength except for the weak area 701, which can provide sufficient protection for the battery device 2, prevent external foreign matter, moisture, etc. from entering the interior of the battery device 2, and ensure the safety and stability of the battery device 2.

[0086] When the internal pressure of the battery is too high, the thinning sheet 704, due to its thinness and low strength, can quickly rupture, allowing the weak area 701 to form a channel connected to the pressure relief hole 501. This rapid response characteristic can promptly release the high-pressure material inside the battery, 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.

[0087] Furthermore, compared to using special materials or complex structures to implement the weak area 701, the method of forming the thinning plate 704 by localized thinning is less expensive. It does not require additional special materials or complex processing techniques and equipment, thus reducing the manufacturing cost of the battery device 2.

[0088] The above structure can be obtained by thinning a preset area of ​​the protective layer 7, which facilitates molding and improves manufacturing efficiency.

[0089] like Figure 8 as well as Figure 9 As shown, in some embodiments of the present application, the weak area 701 is formed by a plurality of through holes 703 arranged at intervals and enclosed along an annular path.

[0090] The aperture size of through-hole 703 is one of the key factors affecting the rupture pressure of weak zone 701. By precisely designing and controlling the aperture size of through-hole 703, the rupture pressure threshold of weak zone 701 can be accurately set. For example, in experiments, the aperture size can be varied to test the rupture behavior of protective layer 7 under pressure at different aperture sizes, thereby finding the optimal aperture size that meets specific battery safety requirements. This precise control ensures that the battery device 2 maintains structural integrity within its normal operating range and provides timely pressure relief in the event of abnormally high pressure.

[0091] The spacing between through-holes 703 also affects the overall strength and rupture characteristics of the weak zone 701. A smaller hole spacing makes the protective layer 7 more fragile in the area of ​​through-holes 703, thereby reducing the rupture pressure. A larger hole spacing, on the other hand, increases the strength of the weak zone 701 and the rupture pressure. By properly adjusting the hole spacing, the rupture pressure of the weak zone 701 can be further fine-tuned to match the actual battery operating conditions.

[0092] The above structure increases the cracking speed of the weak area 701 and reduces the risk of the pressure relief hole 501 being blocked.

[0093] In some embodiments, the through hole 703 is not connected to the pressure relief hole to improve the sealing performance of the battery device 2 .

[0094] Please refer to Figure 3 In some embodiments of the present application, the battery cell assembly includes a plurality of battery cells 6 sequentially arranged along a first direction X. A plurality of weak areas 701 are spaced apart along the first direction X on the protective layer 7 and are arranged one-to-one corresponding to the pressure relief mechanisms of the plurality of battery cells 6 .

[0095] Each weak area 701 corresponds to a pressure relief mechanism. This precise correspondence ensures that when abnormally high pressure is present in a battery cell 6, only the corresponding weak area 701 ruptures and releases pressure, avoiding the problem of excessive or insufficient pressure relief caused by the simultaneous rupture of multiple weak areas 701. This precise pressure relief mechanism effectively reduces the risk of battery pack explosion or fire, thereby improving battery pack safety.

[0096] Since the weak area 701 corresponds closely to the pressure relief mechanism, when the internal pressure of the battery cell 6 increases, the weak area 701 can be quickly broken and form a channel connected to the pressure relief mechanism, thereby achieving rapid pressure relief.

[0097] In the above structure, the pressure relief holes 501 and the weak areas 701 are respectively provided corresponding to the pressure relief mechanisms of the plurality of battery cells 6 , thereby improving the efficiency of releasing high-temperature and high-pressure substances.

[0098] like Figure 9As shown, in some embodiments of the present application, the thickness H of the protective layer 7 satisfies 0.2 mm ≤ H ≤ 1.0 mm. Exemplarily, the thickness H of the protective layer 7 is 0.2 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm or 1.2 mm.

[0099] In battery device 2, the thickness H of protective layer 7 is limited to between 0.2 mm and 1.0 mm. A protective layer 7 with a thickness of at least 0.2 mm provides basic protection for the battery cells 6 within the housing 5, effectively blocking the intrusion of foreign matter, moisture, and the like, and protecting the internal structure of battery device 2 from damage. Setting the thickness of protective layer 7 to 1.0 mm or less helps conserve material and minimizes the space occupied by protective layer 7.

[0100] 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 be successfully separated is reduced.

[0101] like Figure 4 As shown, in some embodiments of the present 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: 20 mm ≤ A ≤ 50 mm. Exemplarily, A is: 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, or 50 mm.

[0102] The minimum distance A between pressure relief hole 501 and the edge of protective layer 7 is no less than 20 mm, which helps reduce the risk of edge rupture or damage to protective layer 7 due to excessive proximity, thereby ensuring the safety and reliability of the pressure relief process. The distance A is no greater than 50 mm, which prevents the size of pressure relief hole 501 from being too small, thereby improving pressure relief efficiency.

[0103] An appropriate distance A helps maintain the structural strength of the protective layer 7, preventing stress concentration or structural weakness caused by improperly positioned pressure relief holes 501, thereby improving the overall stability of the battery device 2. During use, the battery may be subject to external forces such as vibration and impact. A reasonable distance C ensures that the protective layer 7 remains intact despite these external forces, preventing premature rupture or damage to the pressure relief holes 501 due to these external forces.

[0104] In the above structure, the protective layer 7 has a connection with the box body 5 along the first direction X with a certain width, which can improve the connection stability between the protective layer 7 and the box body 5 .

[0105] like Figure 4As shown, in some embodiments of the present application, the minimum distance B between the orthographic projection of the pressure relief hole 501 on the protective layer 7 and the edge of the weak area 701 satisfies: 1mm≤B≤10mm. Exemplarily, B is: 1mm, 2mm, 5mm, 6mm, 8mm or 10mm.

[0106] Distance B is no less than 1mm, ensuring a safe distance between the pressure relief hole 501 and the edge of the weak area 701. This reduces the risk of material discharged from the pressure relief hole 501 entering the gap between the protective layer 7 and the housing 5 due to a close distance. Distance B is no greater than 10mm, ensuring that the pressure relief efficiency is not reduced due to excessive distance between the pressure relief hole 501 and the weak area 701. If the weak area 701 ruptures, the pressure relief hole 501 can quickly form an effective pressure relief channel, promptly discharging the high-pressure material inside the battery cell 6.

[0107] A reasonable design of distance B can leverage the rupture characteristics of weak area 701, causing it to rupture preferentially under a preset pressure, allowing pressure relief through pressure relief hole 501. This design helps ensure that weak area 701 can function reliably when needed, improving the safety of battery device 2. By controlling distance B, the risk of accidental rupture of weak area 701 due to external factors (such as vibration and impact) can be reduced, thereby improving the stability and reliability of battery device 2.

[0108] In the above structure, the edge of the weak area 701 exceeds 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.

[0109] like Figure 10 As shown, in some embodiments of the present application, the weak area 701 includes a straight section 706 and a bent section 707. The straight section 706 extends along the second direction Y, and the two straight sections 706 are arranged parallel and spaced apart along the first direction X, where the second direction Y is perpendicular to the first direction X. The bent section 707 is connected between the two straight sections 706, and the middle portion of the bent section 707 is bent away from the straight sections 706 at opposite ends.

[0110] When subjected to stress, the straight section 706 mainly bears tensile stress or compressive stress along the second direction Y, while the curved design of the bent section 707 causes the stress to be concentrated and dispersed at the bend. When the internal pressure of the battery increases, the middle part of the bent section 707 will first bear greater stress due to the bending, making it more likely to rupture. This optimization of stress distribution enables the weak area 701 to rupture accurately under a preset pressure, thereby improving the reliability and accuracy of pressure relief. When the internal pressure of the battery reaches a preset value, the middle part of the bent section 707 will rupture rapidly, forming a channel connected to the pressure relief hole 501, so that the high-pressure material inside the battery can be quickly released. This rapid pressure relief capability helps to reduce the risk of battery explosion or fire and improve the safety performance of the battery device 2.

[0111] Furthermore, the aforementioned structure forms a racetrack-shaped annular area that matches the shape of the pressure relief hole 501. This conformal shape allows for the formation of a channel that interfaces with the pressure relief hole 501 when the weak zone 701 ruptures. This shape matching reduces obstruction and detours during the release of material, allowing high-pressure material within the battery to be discharged more directly and quickly through the pressure relief hole 501. This improves pressure relief efficiency and reduces the risk of damage to the normally operating battery cell 6 from high-temperature, high-pressure material.

[0112] 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, thereby improving the efficiency of releasing high-temperature and high-pressure substances.

[0113] like Figure 11 As shown, in some embodiments of the present application, the minimum width D of the through hole 703 along the second direction Y satisfies 0.4 mm ≤ D ≤ 0.8 mm.

[0114] Exemplarily, in straight section 706, thinned section 702 is a structure that penetrates protective layer 7, equivalent to through-hole 703. The width D1 of thinned section 702 satisfies 0.4 mm ≤ D1 ≤ 0.8 mm. In curved section 707, 702 is a structure that penetrates protective layer 7, equivalent to through-hole 703. The width D2 of thinned section 702 satisfies 0.4 mm ≤ D2 ≤ 0.8 mm. Exemplarily, D1 is 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, or 0.8 mm. D2 is 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, or 0.8 mm.

[0115] The lower limit of 0.4mm in width reduces the risk of through-hole 703 failing to rupture under the preset pressure. An excessively narrow thinning section 702 may result in excessively high rupture pressure or uneven rupture, affecting the pressure relief effect. The upper limit of 0.8mm in width prevents excessively wide thinning section 702 from causing insufficient strength of protective layer 7, leading to accidental rupture or structural failure under normal operating conditions.

[0116] Optionally, the straight section 706 and the bent section 707 have the same width range. The above structure simplifies the design and processing technology while ensuring the consistency of the pressure relief performance.

[0117] In the above structure, by setting a suitable width of the through hole 703, the connection stability between the protective layer 7 and the box body 5 can be improved while ensuring that the weak area 701 is broken smoothly to release the high-temperature and high-pressure material in time.

[0118] like Figure 12 As shown, in some embodiments of the present application, an insulating layer 8 is further provided on the side of the box body 5 facing the accommodating space 5c. The insulating layer 8 is located between the battery cell assembly and the box body 5. The insulating layer 8 is used to insulate the battery cell 6 from the box body 5. The insulating layer 8 is provided with a drain hole 801 at the position corresponding to the pressure relief hole 501.

[0119] The protective layer 7 is located on the side of the housing 5 facing away from the storage space 5c. Its main function is to serve as a protective barrier to the outside of the battery cell assembly, preventing external impact and foreign object intrusion. It also releases internal high-pressure gas through the pressure relief hole 501 when the battery cell 6 experiences thermal runaway. The insulating layer 8 is located on the side of the housing 5 facing the storage space 5c, directly contacting the battery cell 6. It 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 is provided with a drain hole 801 at the position corresponding to the pressure relief hole 501 to ensure that the pressure relief channel is unobstructed.

[0120] When the internal pressure of the battery cell 6 is too high, the high-pressure gas can be quickly discharged through the corresponding pressure relief holes 501 and the drain holes 801 to prevent the battery from exploding or catching fire.

[0121] In the above structure, by providing the insulating layer 8, the risk of short circuit caused by overlap between some of the debris of the pressure relief mechanism and the box body 5 after the pressure relief mechanism is opened is reduced.

[0122] In some embodiments of the present application, the insulating layer 8 includes at least a first portion 802 covering the hole wall of the pressure relief hole 501 .

[0123] If the walls of the pressure relief hole 501 are not insulated, high-pressure gas carrying conductive materials (such as electrolyte or metal particles) may come into contact with the casing 5, causing a short circuit or leakage. The first portion 802 of the insulating layer 8 covers the hole wall, effectively isolating the conductive material from the casing 5. During thermal runaway, the 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 even under extreme conditions. The remaining portion of the insulating layer 8 covers the contact surface between the casing 5 and the battery cells 6, forming a continuous insulation barrier to prevent safety hazards caused by localized insulation failure.

[0124] The first portion 802 of the insulating layer 8 covers the hole wall, but a drainage hole 801 must be retained in the center of the hole wall to ensure a clear pressure relief channel. The diameter of drainage hole 801 matches the pressure relief hole 501 in the protective layer 7 to prevent obstruction of gas flow. The insulating layer 8 material must have sufficient flexibility and mechanical strength to prevent cracking or disintegration due to the impact of high-pressure gas during pressure relief.

[0125] In the above structure, the risk of short circuit caused by overlap between some of the debris of the pressure relief mechanism and the hole wall of the pressure relief hole 501 after the pressure relief mechanism is opened is reduced.

[0126] In some embodiments of the present application, the insulating layer 8 further includes a second portion 803 covering the surface of the box body 5 facing the pressure relief mechanism, and the first portion 802 and the second portion 803 are connected and formed integrally.

[0127] The first portion 802 covers the wall of the pressure relief hole 501, ensuring electrical insulation in the pressure relief channel area. The second portion 803 covers the surface of the housing 5 facing the pressure relief mechanism, extending the protection range of the insulation layer 8. The first portion 802 and the second portion 803 are seamlessly connected, eliminating the splicing gaps that may exist in traditional split insulation layers 8, preventing conductive materials (such as electrolyte and metal particles) from passing through the gaps and causing short circuits or leakage. The insulation layer 8 continuously covers the wall of the pressure relief hole 501 and the surface of the housing 5, ensuring the integrity of the electrical insulation and improving the safety of the battery pack.

[0128] The first portion 802 of the insulating layer 8 covers the hole wall while retaining a drain hole 801 in the center to ensure a smooth pressure relief channel. The drain hole 801 has the same diameter as the pressure relief hole 501 of the protective layer 7 to avoid obstruction of gas flow.

[0129] For example, the first part 802 and the second part 803 of the insulating layer 8 are formed at one time through processes such as die-cutting, injection molding, and spraying, thereby reducing processing steps and manual intervention and improving production efficiency. One-piece molding avoids the problem of difficult alignment of the split insulating layer 8, ensuring that the pressure relief hole 501 discharge hole 801 is aligned with the pressure relief hole 501 of the protective layer 7. In the event of thermal runaway of the battery, the one-piece insulating layer 8 can not only prevent the conductive material from causing a short circuit, but also ensure that the pressure relief channel is unobstructed, reducing the risk of explosion or fire. Through the coordinated design of local insulation and overall protection, the impact of the failure of a single battery cell 6 on other batteries is reduced, protecting the safety of the entire battery module.

[0130] In the above structure, by providing the insulating layer 8, the risk of short circuit between some fragments of the pressure relief mechanism and the box body 5 caused by the conduction of high-temperature and high-pressure materials after the pressure relief mechanism is opened is reduced.

[0131] In some optional embodiments, the battery device 2 includes a battery cell assembly, a housing 5, and a protective layer 7. The battery cell assembly includes a plurality of battery cells 6, and the battery cells 6 are provided with a pressure relief mechanism. The housing 5 has a storage space 5c, and the battery cell assembly is arranged in the storage space 5c. The housing 5 is provided with a pressure relief hole 501 connected to the storage space 5c, and at least a portion of the pressure relief hole 501 is arranged corresponding to the pressure relief mechanism to release the substance released by the battery cell 6 through the pressure relief mechanism. The protective layer 7 is connected to the housing 5 and covers the pressure relief hole 501. The protective layer 7 is located outside the storage space 5c. A weak area 701 is provided on the protective layer 7, and at least a portion of the weak area 701 is arranged corresponding 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 to form a channel on the protective layer 7 that is connected to the pressure relief hole 501. The orthographic projection of the pressure relief hole 501 on the protective layer 7 falls within the weak zone 701, and the area of ​​the weak zone 701 is larger than the orthographic projection of the pressure relief hole 501 on the protective layer 7. The weak zone 701 is formed by a plurality of spaced through holes arranged along a circular path. The protective layer 7 is provided on the side of the housing 5 facing away from the storage space 5c. The side of the housing 5 facing the storage space 5c is also provided with an insulating layer 8, which is used to insulate the battery cells 6 from the housing 5. The insulating layer 8 has drainage holes 801 at the position corresponding to the pressure relief hole 501.

[0132] An embodiment of the present application also provides an electrical device comprising the battery device 2 described in the above embodiment, which is configured to provide electrical energy. The electrical device comprises the battery device 2 described above, which includes multiple battery cells 6. A pressure relief mechanism provided within each battery cell 6 activates when the pressure or temperature within the battery cell 6 reaches a threshold, releasing the high-temperature, high-pressure substances within. This reduces the risk of explosion or combustion of the battery cell 6, improves the safety of the battery cell 6 during operation, and minimizes 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 substances released from the pressure relief mechanism, thereby minimizing damage to the surrounding battery cells 6. For example, the high-temperature, high-pressure substances can melt the insulating layer 8 on the surface of the battery cell 6, causing the battery cell 6 to experience electrical leakage, short circuit, and other faults. The provision of the pressure relief hole 501 can mitigate the occurrence of these faults. Furthermore, in order to improve the sealing performance at 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 interior of the box body 5 through the pressure relief hole 501. In addition, a weak area 701 is provided on the protective layer 7 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, thereby smoothly releasing the material from the pressure relief hole 501. The orthographic projection of the pressure relief hole 501 on the protective layer 7 falls within the range 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 on the protective layer 7. The weak area 701 can completely cover the pressure relief hole 501 and be sealed with the box body 5, thereby reducing the risk of external moisture or impurities entering the interior of the box body 5 through the pressure relief hole. In addition, 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 materials on the non-weak areas of the protective layer 7, improves the connection stability between the protective layer 7 and the box body 5 in the non-weak areas, reduces the risk of the protective layer 7 being peeled off from the box body 5 when the pressure relief mechanism is opened, and improves the sealing performance of the protective layer 7.

[0133] In some embodiments of the present application, the protective layer 7 of the battery device 2 is arranged toward the outside of the electrical equipment.

[0134] Exemplarily, the electrical equipment is a vehicle, and the battery device 2 is arranged at the bottom of the vehicle body. The box body 5 includes a top wall and a bottom wall arranged opposite to each other, and the pressure relief hole 501 is arranged on the bottom wall. The top wall is connected to the bottom of the vehicle body, the bottom wall is arranged on the side of the top wall away from the vehicle body, and the protective layer 7 is arranged on the outside of the bottom of the vehicle body. When the pressure relief mechanism of the battery cell 6 is activated, the high-temperature and high-pressure substance passes through the pressure relief hole and breaks through the weak area 701 of the protective layer 7, causing it to partially or completely detach to form a pressure relief through hole. The high-temperature and high-pressure substance is discharged directly to the ground through the pressure relief channel to reduce harm to the occupants inside the vehicle and damage to the equipment inside the vehicle. Setting the protective layer 7 toward the outside can facilitate the discharge of substances released in the battery cell 6 to the outside, reducing the damage of high-temperature and high-pressure substances to electrical equipment. Furthermore, in order to improve the sealing performance at the pressure relief hole 501 and improve the stability of the battery cell 6 during normal operation, a protective layer 7 is set. The orthographic projection of the pressure relief hole 501 on the protective layer 7 falls within the range 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 on the protective layer 7, so that the edge of the weak area 701 and the pressure relief hole 501 are staggered in the thickness direction of the protective layer 7. In other words, there is a certain distance between the edge of the weak area 701 of the protective layer 7 and the edge of the pressure relief hole 501. Therefore, the weak area 701 can completely cover the pressure relief hole 501 and be sealed with the box body 5, thereby reducing the risk of external moisture or impurities entering the interior of the box body 5 through the pressure relief hole. In addition, after the pressure relief mechanism is activated, the high-temperature and high-pressure material can exert a certain impact force on the weak area 701 on the protective layer 7, causing the weak area 701 to partially or completely detach, forming a channel connected to the pressure relief hole on the protective layer 7, thereby smoothly releasing from the pressure relief hole. In addition, 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 materials on the non-weak areas of the protective layer 7, improves the connection stability between the protective layer 7 and the box body 5 in the non-weak areas, reduces the risk of the protective layer 7 being peeled off from the box body 5 when the pressure relief mechanism is opened, and improves the sealing performance of the protective layer 7.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present 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. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery device, characterized in that: include: A battery cell assembly, comprising a plurality of battery cells, wherein the battery cells are provided with a pressure relief mechanism; a box body having a storage space, wherein the battery cell assembly is disposed in the storage space, and a pressure relief hole communicating with the storage space is provided on the box body, wherein at least a portion of the pressure relief hole is disposed correspondingly to the pressure relief mechanism to release substances released by the battery cell via the pressure relief mechanism; A protective layer is connected to the box body and covers the pressure relief hole. The protective layer is located outside the accommodating space. A weak area is provided on the protective layer. At least a portion of the weak area is arranged corresponding 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 connected to 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.

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

3. The battery device according to claim 1, wherein: The weak area is formed by a local reduction in thickness of the protective layer.

4. The battery device according to claim 1, wherein: The weak area is formed by a plurality of through holes arranged at intervals and enclosed along an annular path.

5. The battery device according to claim 2, wherein: The battery cell assembly includes a plurality of battery cells arranged sequentially along a first direction, A plurality of the weak areas are arranged at intervals on the protective layer along the first direction and are provided in one-to-one correspondence with the pressure relief mechanism of each of the battery cells.

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

7. The battery device according to any one of claims 1 to 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 the following: 20 mm ≤ A ≤ 50 mm.

8. The battery device according to any one of claims 1 to 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 the following: 1mm≤B≤10mm.

9. The battery device according to any one of claims 1 to 5, characterized in that: The breakaway pressure threshold of the weak zone is lower than the opening pressure threshold of the pressure relief mechanism.

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

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

12. The battery device according to claim 11, wherein: The insulating layer at least includes a first portion covering the hole wall of the pressure relief hole; the insulating layer also includes a second portion covering the surface of the box body facing the pressure relief mechanism, and the first portion and the second portion are connected and formed integrally.

13. An electrical device, characterized in that: The electrical device comprises the battery device according to any one of claims 1 to 12, and the battery device is used to provide electrical energy.

14. The electrical equipment according to claim 13, characterized in that: The protective layer of the battery device is arranged toward the outside of the electrical equipment.

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