Battery pack thermal runaway testing device

Abstract

The utility model provides a battery pack thermal runaway testing device, which comprises a box body filled with immersion liquid; the battery module is located in the box body, and the battery module comprises at least one battery; the heating assembly comprises a heating film, a connecting wire harness and a plug connector, the heating film is arranged on at least one side of the battery in the first direction, the plug connector is fixed to the box body and extends out of the box body, and the two ends of the connecting wire harness are connected with the heating film and the plug connector respectively. The connecting wire harness is respectively connected with the heating film and the plug connector, so that the thermal runaway test can be carried out without opening the box body, the problem of liquid leakage does not exist, the plug connector is arranged on the box body, the influence of immersion liquid on the function of the heating assembly is avoided, and the immersed thermal runaway test is realized.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery pack thermal runaway testing device. Background Art

[0002] As an electrochemical energy storage technology, lithium-ion batteries have the characteristics of long cycle life, high charge and discharge efficiency, strong adaptability, fast response speed, short construction period, and flexible geographical space configuration. They have been widely used in the fields of power and energy storage. However, there is a risk of thermal runaway in batteries, so thermal runaway reliability testing of battery packs is particularly important. In related technologies, the box is usually opened directly to heat the battery cells, but in the immersion thermal runaway test, due to the immersion liquid in the box, opening the box to directly heat the battery cells will have the risk of leakage, and will also cause the heating device to short-circuit or fail to reach the thermal runaway temperature, which cannot meet the conditions of the immersion thermal runaway test. Utility Model Content

[0003] In view of this, the present application provides a battery pack thermal runaway test device, in which the two ends of the connecting harness of the heating component are respectively connected to the heating film and the connector, and the connector is arranged on the box body to reduce the possibility of leakage and the impact of the immersion liquid on the heating component, thereby meeting the conditions of the immersion thermal runaway test.

[0004] To solve the above problems, the technical solutions provided by this application are as follows:

[0005] In a first aspect, the present application provides a battery pack thermal runaway test device, comprising:

[0006] a box body filled with an immersion liquid;

[0007] A battery module is located in the box, and the battery module includes at least one battery; and

[0008] The heating assembly includes a heating film, a connecting harness and a connector. The heating film is arranged on at least one side of the battery along a first direction. The connector is fixed on a box body and extends from the box body. Two ends of the connecting harness are respectively connected to the heating film and the connector.

[0009] In an optional embodiment of the present application, the heat insulation component is arranged on a side of the heating film away from the battery along the first direction.

[0010] In an optional embodiment of the present application, there are two heating films, which are arranged on opposite sides of the battery along the first direction, and there are two thermal insulation components, which are respectively arranged on the side of the heating film away from the battery along the first direction.

[0011] In an optional embodiment of the present application, the heating film includes a positive electrode and a negative electrode;

[0012] The connector includes a first pin and a second pin, and there are two connecting harnesses. The first pin is connected to the positive poles of the two heating films through the connecting harnesses, and the second pin is connected to the negative poles of the two heating films through the connecting harnesses, wherein the two connecting harness parts are fixed as a whole.

[0013] In an optional embodiment of the present application, the heating film includes an intersecting long side and a short side, the length of the long side along the first direction is 330mm-340mm, and the length of the short side along the second direction is 190mm-195mm;

[0014] The heating film also includes: a wire outlet, which is arranged on the heating film and extends from the short side to the inner wall of the box body; there is an installation distance between the wire outlet and the long side of the heating film along the second direction, and the installation distance is 60mm-100mm.

[0015] In an optional embodiment of the present application, the connector further includes a plug-in shell, the plug-in shell is sealed and fixed on the box body, and the first pin and the second pin are detachably disposed in the plug-in shell.

[0016] In an optional embodiment of the present application, the thermal insulation component is aerogel, and the thermal conductivity of the aerogel is less than or equal to 0.023 W / (k·m).

[0017] In an optional embodiment of the present application, the battery module further includes:

[0018] The two end plates are arranged on opposite sides of the battery along a first direction, and the heating component and the heat insulation component are located between the end plates and the battery along the first direction.

[0019] In an optional embodiment of the present application, the battery pack thermal runaway test device further includes:

[0020] The temperature-sensing and pressure-sensing test assembly comprises a temperature-sensing and pressure-sensing part and a temperature-sensing and pressure-sensing line. The temperature-sensing and pressure-sensing part is arranged on the box body. One end of the temperature-sensing and pressure-sensing line is connected to the temperature-sensing and pressure-sensing part, and the other end is connected to the battery module.

[0021] In an optional embodiment of the present application, the box body includes an upper cover and a lower cover, the upper cover and the lower cover are sealed to form a cavity, and the battery module, the heating film, the connecting harness and the heat insulation component are arranged in the cavity;

[0022] A support assembly is provided on one side of the lower cover facing the battery module, and is configured to support the battery module. The support assembly is provided with a harness groove along the second direction, and the harness groove is configured to place temperature and pressure sensitive wires.

[0023] The battery pack thermal runaway test device provided in the present application includes at least the following beneficial effects: the connecting wiring harness connects the heating film and the connector respectively, so that the thermal runaway test can be carried out without opening the box, and there is no leakage problem. The connector is arranged on the box to prevent the immersion liquid from affecting the function of the heating component, thereby meeting the conditions for the immersion thermal runaway test and realizing the immersion thermal runaway test. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A schematic diagram of an explosion of a battery pack thermal runaway test device provided in one embodiment of the present application.

[0026] Figure 2 An exploded schematic diagram of a battery module provided in one embodiment of the present application.

[0027] Figure 3 An exploded schematic diagram of a battery module provided in another embodiment of the present application.

[0028] Figure 4 A schematic diagram of the assembly of a battery module and a lower cover provided in one embodiment of the present application.

[0029] Figure 5 A schematic diagram of the structure of a heating component provided in one embodiment of the present application.

[0030] Figure 6 A schematic diagram of the structure of a heating component provided in another embodiment of the present application.

[0031] Fig. 7A and 7B A schematic structural diagram of a lower cover provided in another embodiment of the present application.

[0032] Reference numerals: 100-battery pack thermal runaway test device; 10-box; 101-upper cover; 102-lower cover; 103-support assembly; 104-sealing ring; 1031-wiring harness slot; 1032-first support member; 1033-second support member; 1034-connector; 20-battery module; 201-battery; 202-end plate; 203-output row; 204-plastic bracket; 205- Insulating block; 206-steel strip; 207-connecting row; 30-heating assembly; 301-heating film; 3011-wire outlet; 302-connecting harness; 303-connector; 3031-first pin; 3031-second pin; 3033-connector housing; 40-thermal insulation assembly; 50-temperature and pressure testing assembly; 501-temperature and pressure sensing component; 502-temperature and pressure sensing wire; A-long side; B-short side. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0034] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying 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 present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0035] The present application may repeat reference numerals and / or reference letters in different implementations. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various implementations and / or settings discussed.

[0036] The battery pack thermal runaway testing device provided in the present application will be described in detail below in conjunction with specific embodiments and drawings.

[0037] See also Figure 1-Figure 4The present application provides a battery pack thermal runaway test device 100, which includes: a box body 10, a battery module 20 and a heating component 30, the box body 10 is filled with an immersion liquid, and the battery module 20 and the heating component 30 are both located in the box body 10 and immersed in the immersion liquid.

[0038] Specifically, the battery module 20 includes at least one battery 201 , and the heating component 30 heats the battery 201 to perform a thermal runaway test.

[0039] Furthermore, the heating assembly 30 includes a heating film 301, a connecting harness 302 and a connector 303. The heating film 301 is arranged on at least one side of the battery 201 along the first direction X. The connector 303 is fixed on the box body 10 and extends from the box body 10. The two ends of the connecting harness 302 are respectively connected to the heating film 301 and the connector 303.

[0040] In conventional thermal runaway tests, the box is usually open and the heating film is heated directly. This structure is not suitable for immersion thermal runaway tests. If the box is open, the immersion liquid will leak, and the heating film cannot be heated directly. The heating assembly 30 in the embodiment of the present application is suitable for an immersion battery pack test device. The box 10 is sealed, and the connecting harness 302 is respectively connected to the connector 303 and the heating film 301.

[0041] Specifically, the box 10 is a sealed structure filled with immersion liquid for testing the safety performance of the battery module 20 in a high temperature environment. In one embodiment, the box 10 can be made of, for example, Al5083 material, but is not limited thereto. The thermal runaway test is performed directly in the box 10. The connector 303 is located on the box 10 and is connected to the heating film 301 through the connecting harness 302. The heating film 301 does not need to be opened to heat the heating film 301, thereby avoiding leakage of the box 10.

[0042] In one embodiment, the heating film 301 is, for example, square and is suitable for square batteries, such as lithium iron phosphate batteries, but not limited thereto. The shape of the heating film 301 can be changed according to the different adaptability of the battery, for example, if the battery is a cylindrical battery, the heating film 301 can be formed into a cylindrical shape, for example, depending on the actual application. In one embodiment, the power of the heating film 301 can be, for example, more than 2200W, which is suitable for thermal runaway heating tests of ultra-large batteries, meets the test requirements, and solves the problem of insufficient power of the heating film 301 for heating thermal runaway of large batteries in immersion battery packs.

[0043] In an optional embodiment of the present application, the battery pack thermal runaway testing device 100 further includes a heat insulation component 40 , and the heat insulation component 40 is arranged along the first direction X on a side of the heating component 30 away from the battery 201 .

[0044] Furthermore, the thermal insulation component 40 is arranged on the side of the heating film 301 away from the battery 201. The thermal insulation component 40 has a thermal insulation effect, thereby reducing the heat dissipation speed of the heating film 301 and preventing the heating film 301 from dissipating heat too quickly and failing to meet the temperature conditions of thermal runaway.

[0045] Specifically, the box body 10 is also provided with positive and negative pole sockets of the battery pack, and the heating component 30 also includes a thermocouple (not shown), and the thermocouple and the heating film 301 are integrally formed, but not limited to this.

[0046] See also Figure 3 In one embodiment, the battery module 20 includes a plurality of batteries 201 arranged along a first direction X, and the plurality of batteries 201 are connected by adhesive strips or foam. For example, a thermal runaway test may be performed on one or two of the batteries 201 , and a heating film 301 and a thermal insulation assembly 40 are disposed on one or two of the batteries 201 .

[0047] In another optional embodiment of the present application, there are two heating films 301, and the two heating films 301 are arranged on opposite sides of the battery 201 along the first direction X. There are two thermal insulation components 40, which are respectively arranged on the side of the heating film 301 away from the battery 201 along the first direction X, thereby improving the heating efficiency.

[0048] Specifically, the number of thermal insulation components 40 is adaptively changed according to the number of heating films 301, which is subject to actual application. The thermal insulation components 40 are used to reduce the heat dissipation speed of the heating film 301 to prevent the heating film 301 from dissipating heat too quickly and failing to meet the temperature conditions of thermal runaway.

[0049] See also Figure 5 and Figure 6 In an optional embodiment of the present application, the heating film 301 includes a positive electrode and a negative electrode; the connector 303 includes a first pin 3031 and a second pin 3032, and the number of connecting harnesses 302 is two. The first pin 3031 is connected to the positive electrodes of the two heating films 301 through a connecting harness 302, and the second pin 3032 is connected to the negative electrodes of the two heating films 301 through another connecting harness 302, wherein the two connecting harnesses 302 are partially fixed as a whole.

[0050] Specifically, when there are two heating films 301, for example, a 2-in-1 method is adopted, that is, one end of the connecting wire harness 302 extends from one side of the heating film 301 and extends toward the plug connector 303, and the end of the connecting wire harness 302 facing the plug connector 303 is merged into a wire harness, and the merged wire harness is respectively connected to the first pin 3031 and the second pin 3032. The cross-sectional area of ​​the connecting wire harness 302 is, for example, 2.5mm 2 -5mm 2The cross-sectional area of ​​the wire harness formed by merging the two connecting wire harnesses 302 is, for example, 4 mm 2 -8mm 2 , the specific details shall be subject to actual application.

[0051] In one embodiment, the number of the heating film 301 is one, the first pin 3031 is connected to the positive electrode of the heating film 301 through the connecting harness 302, the second pin 3032 is connected to the negative electrode of the heating film 301 through the connecting harness 302, the number of the connecting harness 302 is also two, the function of the connecting harness 302 is to electrically connect the first pin 3031 and the second pin 3032 to the heating film 301, and the cross-sectional area of ​​the connecting harness 302 can be, for example, 2.5mm 2 .

[0052] In an optional embodiment of the present application, the heating film 301 includes intersecting long sides A and short sides B, the length of the long side A along the first direction X is 330 mm-340 mm, and the length of the short side B along the second direction Y is 190 mm-195 mm, but is not limited thereto. Exemplarily, the heating film 301 includes two opposite long sides A and two opposite short sides B, wherein the long side A and the short side B may be vertically connected.

[0053] Furthermore, the heating film 301 also includes: a wire outlet 3011, which is arranged on the heating film 301 and extends from the short side B to the inner wall of the box body 10; the wire outlet 3011 has an installation distance along the second direction Y and the long side A of the heating film 301, and the installation distance is 60mm-100mm.

[0054] It can be understood that the wire outlet 3011 is located at the short side B of the heating film 301 and extends from the short side B to the inner wall of the box 10, that is, it is located on the outside of the heating film 301. The wire outlet 3011 is configured to constrain the connecting harness 302. One end of the connecting harness 302 passes through the wire outlet 3011 and is connected to the positive and negative poles of the heating film 301, and the other end is connected to the first pin 3031 and the second pin 3032.

[0055] Furthermore, the outlet 3011 has an installation distance from the long side A of the heating film 301 along the second direction Y. In one embodiment, the outlet 3011 is 82.5 mm away from the long side, ensuring that the connection harness 302 is located in the middle of the edge of the heating film 301, avoiding affecting the outlet of the connection harness 302 when the battery module 20 is subsequently fixed. In one embodiment, the battery module 20 further includes a plurality of steel strips 206 for fixing the plurality of batteries 201 as a whole, wherein the fixing positions of the plurality of steel strips 206 avoid the position of the outlet 3011 of the heating film 301.

[0056] In an optional embodiment of the present application, the connector 303 also includes a plug shell 3033, which is sealed and fixed on the box body 10 to reduce the risk of insufficient sealing. The first pin 3031 and the second pin 3032 are detachably arranged in the plug shell 3033.

[0057] Specifically, to facilitate assembly, the plug-in shell 3033 can be fixed to the box body 10 by, for example, sealant, and the first pin 3031 and the second pin 3032 move with the connecting harness 302. The first pin 3031 and the second pin 3032 can be provided with, for example, a protective cover to prevent the first pin 3031 and the second pin 3032 from being damaged. When a thermal runaway test is required, the first pin 3031 and the second pin 3032 are inserted into the plug-in shell 3033, thereby simplifying the assembly process and the testing process.

[0058] Furthermore, the protection level of the connector 303 reaches IP67, meeting the test conditions for thermal runaway of an immersed battery pack.

[0059] In an optional embodiment of the present application, the number of batteries 201 is two, the two batteries 201 are arranged along the first direction X, and heating films 301 are provided on opposite sides of the two batteries 201 close to the inner wall of the box body 10 .

[0060] Specifically, when it is necessary to perform a thermal runaway test on two batteries 201, the two batteries 201 are connected by, for example, foam or adhesive tape, and two heating films 301 are arranged on the side of the two batteries 201 away from the foam or adhesive tape to heat the batteries 201. In addition, a thermal insulation component 40 is arranged on the side of the two heating films 301 away from the batteries 201 to implement a thermal runaway test of an immersed battery pack.

[0061] In an optional embodiment of the present application, the thermal insulation component 40 is aerogel, which is a ceramic fiber material. The thermal conductivity of the aerogel is, for example, less than or equal to 0.023 W / (k·m).

[0062] In an optional embodiment of the present application, the battery module 20 further includes:

[0063] The two end plates 202 are arranged on opposite sides of the battery 201 along the first direction X. The heating assembly 30 and the insulation assembly 40 are located between the end plates 202 and the battery 201 along the first direction X. The end plates 202 are used to fix multiple batteries, the heating film 301 and the insulation assembly 40.

[0064] Furthermore, the battery module 20 also includes a positive and negative output row 203, a connecting row 207, a plastic bracket 204 and an insulating block 205. The plastic bracket 204 is arranged on the side of the battery 201 away from the lower cover 102, and is used to position the poles of the battery 201 and support the positive and negative output rows 203. The positive and negative output rows 203 are located on the plastic bracket 204 and connect the positive and negative poles of the battery 201. The connecting row 207 connects the positive and negative poles of two adjacent batteries 201. The insulating block 205 is arranged on the end plate 202, and is used to isolate the end plate 202 from the positive and negative output rows and the connecting row 207 from electrical connection.

[0065] See also Figure 3 and Figure 4 In an optional embodiment of the present application, the battery pack thermal runaway test device 100 further includes:

[0066] The temperature and pressure sensing test assembly 50 includes a temperature and pressure sensing component 501 and a temperature and pressure sensing line 502 . The temperature and pressure sensing component 501 is disposed on the box 10 . One end of the temperature and pressure sensing line 502 is connected to the temperature and pressure sensing component 501 , and the other end is connected to the battery module 20 .

[0067] Specifically, the temperature and pressure sensing test assembly 50 is used to sense the temperature and voltage of the battery module 20 .

[0068] See also Figure 1 In an optional embodiment of the present application, the box body 10 includes an upper cover 101 and a lower cover 102, and the upper cover 101 and the lower cover 102 are sealed to form a cavity, and the battery module 20, the heating film 301, the connecting harness 302 and the insulation component 40 are arranged in the cavity.

[0069] Specifically, a sealing ring 104 is provided between the upper cover 101 and the lower cover 102 for sealing the box body 10 to ensure that the immersion liquid is filled without leakage.

[0070] See also Fig. 7A and Figure 7B A support assembly 103 is provided on one side of the lower cover 102 facing the battery module 20 and is configured to support the battery module 20 . The support assembly 103 is provided with a harness groove 1031 along the second direction Y, and the harness groove 1031 is configured to place the temperature and pressure sensing wires 502 .

[0071] Specifically, the support assembly 103 includes a relatively parallel first support member 1032 and a second support member 1033. The first support member 1032 and the second support member 1033 protrude toward a side close to the battery module 20 and are configured to support the end plate 202 of the battery module 20. A plurality of connectors 1034 are further provided between the first support member 1032 and the second support member 1033 to improve the strength of the support assembly 103. The height of the plurality of connectors 1034 along the second direction Y is less than the height of the first support member 1032 and the second support member 1033 along the second direction Y. The height difference is used for the immersion liquid to immerse the bottom of the battery module 20, thereby ensuring that the battery 201 can fully contact the immersion liquid and ensure the accuracy of the thermal runaway result. The first direction X and the second direction Y are perpendicular to each other.

[0072] Furthermore, in order to reduce the complexity of battery pack assembly and protect the temperature-sensing and pressure-sensing wires 502 to a certain extent, a harness groove 1031 is provided on the support assembly 103 to place the temperature-sensing and pressure-sensing wires 502 , and the harness groove 1031 does not penetrate the lower cover 102 .

[0073] In an optional embodiment of the present application, a side of the heating film 301 close to the battery 201 has adhesive, so that the heating film 301 is attached to the battery 201 .

[0074] The battery pack thermal runaway test device provided in the present application includes at least the following working process or principle: the battery pack thermal runaway test device 100 includes: a box 10, a battery module 20, a heating component 30 and a heat insulation component 40, the heating component 30 includes a heating film 301, a connecting harness 302 and a plug-in 303, the plug-in 303 is located on the box 10, and is connected to the heating film 301 through the connecting harness 302, and the heating film 301 does not need to be opened to heat the box 10, thereby avoiding leakage of the box 10; the heat insulation component 40 is arranged on the side of the heating film 301 away from the battery 201, reducing the heat dissipation speed of the heating film 301, avoiding the heating film 301 from dissipating heat too quickly and failing to meet the temperature conditions of thermal runaway, meeting the immersion thermal runaway test conditions, and completing the thermal runaway test. In addition, in order to facilitate movement and assembly, the first pin 3031 and the second pin 3032 are detachably arranged in the plug-in housing 3033.

[0075] In summary, although the present application has been disclosed as above with preferred embodiments, the above preferred embodiments are not intended to limit the present application. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined in the claims.

Claims

1. A battery pack thermal runaway test device, characterized in that: include: a box body filled with an immersion liquid; A battery module is located in the box, and the battery module includes at least one battery; and The heating assembly includes a heating film, a connecting harness and a connector, wherein the heating film is arranged on at least one side of the battery along a first direction, the connector is fixed on the box body and extends from the box body, and the two ends of the connecting harness are respectively connected to the heating film and the connector.

2. The battery pack thermal runaway test device according to claim 1, characterized in that: Also includes: A heat insulation component is arranged along the first direction on a side of the heating film away from the battery.

3. The battery pack thermal runaway test device according to claim 2, characterized in that: There are two heating films, which are arranged on opposite sides of the battery along the first direction. There are two thermal insulation components, which are respectively arranged on one side of the heating film away from the battery along the first direction.

4. The battery pack thermal runaway test device according to claim 3, characterized in that: The heating film comprises a positive electrode and a negative electrode; The connector includes a first pin and a second pin, and the number of the connecting harnesses is two. The first pin is connected to the positive poles of the two heating films respectively through one connecting harness, and the second pin is connected to the negative poles of the two heating films respectively through another connecting harness, wherein the two connecting harness parts are fixed as a whole.

5. The battery pack thermal runaway test device according to claim 4, characterized in that: The heating film comprises an intersecting long side and a short side, the length of the long side along the first direction is 330 mm-340 mm, and the length of the short side along the second direction is 190 mm-195 mm; The heating film further includes: a wire outlet, which is arranged on the heating film and extends from the short side to the inner wall of the box body; there is an installation distance between the wire outlet and the long side of the heating film along the second direction, and the installation distance is 60mm-100mm.

6. The battery pack thermal runaway test device according to claim 4, characterized in that: The plug connector also includes a plug shell, which is sealed and fixed on the box body, and the first pin and the second pin are detachably arranged in the plug shell.

7. The battery pack thermal runaway test device according to claim 2, characterized in that: The thermal insulation component is aerogel, and the thermal conductivity of the aerogel is less than or equal to 0.023 W / (k·m).

8. The battery pack thermal runaway test device according to claim 2, characterized in that: The battery module also includes: Two end plates are arranged on opposite sides of the battery along the first direction, and the heating component and the heat insulation component are located between the end plates and the battery along the first direction.

9. The battery pack thermal runaway test device according to any one of claims 2 to 3, characterized in that: Also includes: The temperature-sensing and pressure-sensing test assembly comprises a temperature-sensing and pressure-sensing component and a temperature-sensing and pressure-sensing line. The temperature-sensing and pressure-sensing component is arranged on the box body. One end of the temperature-sensing and pressure-sensing line is connected to the temperature-sensing and pressure-sensing component, and the other end is connected to the battery module.

10. The battery pack thermal runaway test device according to claim 9, characterized in that: The box body comprises an upper cover and a lower cover, wherein the upper cover and the lower cover are sealed to form a cavity, and the battery module, the heating film, the connecting harness and the heat insulation assembly are arranged in the cavity; A support assembly is provided on a side of the lower cover facing the battery module, and is configured to support the battery module. The support assembly is provided with a harness groove along the second direction, and the harness groove is configured to place the temperature and pressure sensitive wires.

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