Battery and heat dissipation method when battery thermal runaway occurs

Abstract

The present disclosure relates to a battery and a heat dissipation method when the battery is in thermal runaway. The battery comprises: a plurality of battery cells arranged in multiple rows; each battery cell has an explosion-proof valve at the bottom; when the battery cell overheats, the explosion-proof valve opens, and the eruption material generated by the battery cell erupts from the bottom of the battery cell; a bottom shell; the bottom shell has a sealed exhaust passage; the bottom of the battery cell is embedded in the sealed exhaust passage, and the battery cell is sealed and connected with the sealed exhaust passage; an exhaust valve is located at the exhaust passage opening of the sealed exhaust passage. In this application, when the battery cell is in thermal runaway and the bottom erupts, the eruption material and hot gas can be erupted into the sealed exhaust passage through the cooperation of the battery cell and the sealed exhaust passage, so as to be discharged out of the battery pack through the sealed exhaust passage, thereby reducing the spread of high-temperature gas and conductive polymer to the entire battery pack after the battery cell is in thermal runaway, and further reducing the probability of fire and explosion of the battery pack.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of new energy vehicles, and particularly relates to a battery and a heat dissipation method when the battery is in thermal runaway. BACKGROUND

[0002] With the increasing popularity of new energy vehicles, battery safety becomes particularly important. In particular, the battery has a thermal runaway of the battery cell. After the thermal runaway of the battery cell, high-temperature gas and conductive polymer will spread to the entire battery pack, which is easy to cause arc drawing and trigger thermal runaway of other battery cells, thereby causing the battery pack to catch fire and explode. Therefore, an effective solution is needed for the thermal runaway of the battery cell. SUMMARY

[0003] Therefore, the embodiments of the present disclosure aim to provide a battery and a heat dissipation method when the battery is in thermal runaway.

[0004] The technical solution of the present disclosure is implemented as follows:

[0005] In a first aspect, the present disclosure provides a battery.

[0006] The battery provided by the embodiments of the present disclosure comprises:

[0007] a battery cell; wherein a plurality of battery cells are arranged in multiple rows; the bottom of the battery cell has an explosion-proof valve; wherein when the battery cell is overheated, the explosion-proof valve is opened, and the battery cell generates spewing substances from the bottom of the battery cell;

[0008] a bottom shell; the bottom shell has a sealed exhaust passage; the bottom of the battery cell is embedded in the sealed exhaust passage, and the battery cell is sealed and connected with the sealed exhaust passage;

[0009] an exhaust valve located at an exhaust passage opening of the sealed exhaust passage.

[0010] In some embodiments, the sealed exhaust passage has a stepped groove near the surface of the battery cell; the bottom of the battery cell is located in the stepped groove; wherein

[0011] the stepped groove has a first stepped hole and a second stepped hole; the diameter of the first stepped hole is greater than the diameter of the battery cell; the diameter of the second stepped hole is less than the diameter of the battery cell, and the diameter of the second stepped hole is greater than the diameter of the explosion-proof valve of the battery cell;

[0012] the stepped groove is in communication with the sealed exhaust passage through the first stepped hole and the second stepped hole.

[0013] In some embodiments, the bottom of the battery cell and the edge of the stepped groove of the sealed exhaust passage have a structural adhesive; the structural adhesive is used to seal and connect the battery cell and the sealed exhaust passage.

[0014] In some embodiments, the bottom shell comprises a bottom plate and a frame;

[0015] The sealed exhaust passage is located in the bottom plate, and the battery cells are distributed on the bottom plate;

[0016] The exhaust valve is located on the frame, and the bottom plate and the frame are sealingly connected.

[0017] In some embodiments, the sealing between the bottom plate and the frame comprises one of the following:

[0018] Welding, gluing, screw connection.

[0019] In some embodiments, the stepped grooves on the surface of the sealed exhaust passage are distributed in multiple rows; wherein one battery cell is located in one stepped groove.

[0020] In some embodiments, the first distance between the first stepped hole and the battery cell is smaller than the second distance between the second stepped hole and the battery cell.

[0021] The difference between the diameter of the first stepped hole and the diameter of the battery cell is a first difference, and the difference between the diameter of the second stepped hole and the diameter of the battery cell is a second difference; wherein the first difference ranges from 0.5mm to 1mm, and the second difference ranges from 1mm to 2mm.

[0022] In some embodiments, the exhaust valve comprises an explosion-proof exhaust valve.

[0023] In some embodiments, the battery cell is cylindrical.

[0024] In a second aspect, the present disclosure provides a heat dissipation method for a battery in thermal runaway, wherein the battery comprises battery cells; wherein a plurality of battery cells are distributed in multiple rows; the bottom of the battery cell has an explosion-proof valve; wherein when the battery cell overheats, the explosion-proof valve opens, and the battery cell generates eruption material from the bottom of the battery cell;

[0025] A bottom shell; the bottom shell has a sealed exhaust passage; the bottom of the battery cell is embedded in the sealed exhaust passage, and the battery cell is sealingly connected with the sealed exhaust passage;

[0026] An exhaust valve located at the exhaust passage opening of the sealed exhaust passage;

[0027] The method comprises:

[0028] Monitoring the presence state of the battery cells in the battery;

[0029] If the battery cells in the battery overheat and generate material eruption, the erupted material and hot gas are discharged from the exhaust passage opening through the sealed exhaust passage.

[0030] The battery according to the embodiment of the present disclosure comprises: battery cells; wherein the battery cells are arranged in multiple rows; the bottom of the battery cell is provided with an explosion-proof valve; when the battery cell overheats, the explosion-proof valve opens, and the eruption material generated by the battery cell erupts from the bottom of the battery cell; a bottom shell; the bottom shell is provided with a sealed exhaust passage; the bottom of the battery cell is embedded in the sealed exhaust passage, and the battery cell is in sealing connection with the sealed exhaust passage; and an exhaust valve is arranged at the exhaust passage opening of the sealed exhaust passage. In the present application, when the battery cell erupts from the bottom after thermal runaway, the eruption material and hot gas can be erupted into the sealed exhaust passage through the cooperation of the battery cell and the sealed exhaust passage, so as to be discharged out of the battery pack through the sealed exhaust passage, thereby reducing the spread of high-temperature gas and conductive polymer to the entire battery pack after thermal runaway of the battery cell, and further reducing the probability of fire and explosion of the battery pack.

[0031] Additional aspects and advantages of the present disclosure will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a schematic diagram of a battery structure according to an exemplary embodiment Figure 1 ;

[0033] Figure 2 is a schematic diagram of a battery structure according to an exemplary embodiment Figure 2 ;

[0034] Figure 3 is a schematic diagram of a battery structure according to an exemplary embodiment Figure 3 ;

[0035] Figure 4 is a flow chart of a heat dissipation method when the battery is in thermal runaway according to an exemplary embodiment. DETAILED DESCRIPTION

[0036] The embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present disclosure, and cannot be understood as a limitation of the present disclosure.

[0037] At present, with the increasing popularity of new energy vehicles, battery safety becomes particularly important. Especially, the battery has a battery cell thermal runaway. After the battery cell thermal runaway, high-temperature gas and conductive polymer will spread to the entire battery pack, which is easy to cause arc, trigger other battery cell thermal runaway, and thus cause the battery pack to catch fire and explode. Therefore, an effective solution is needed for the battery cell thermal runaway.

[0038] In view of the above, the present disclosure provides a battery. Figure 1 is a schematic diagram of a battery structure according to an exemplary embodiment Figure 1 As shown in Figure 1 , the battery comprises:

[0039] a plurality of battery cells 10; wherein the plurality of battery cells 10 are arranged in multiple rows; the bottom of each battery cell 10 is provided with an explosion-proof valve; when the battery cell 10 overheats, the explosion-proof valve opens, and the eruption material generated by the battery cell 10 erupts from the bottom of the battery cell 10;

[0040] a bottom shell 11; the bottom shell 11 is provided with a sealed exhaust passage 12; the bottom of the battery cell 10 is embedded in the sealed exhaust passage 12, and the battery cell 10 is sealingly connected to the sealed exhaust passage 12;

[0041] an exhaust valve 13 located at the exhaust passage opening of the sealed exhaust passage 12.

[0042] In an exemplary embodiment, the battery cell 10 can be a cylindrical battery cell 10, and a large number of battery cells 10 can be arranged in multiple rows in the battery pack. Each battery cell 10 is provided with an explosion-proof valve at the bottom. When the battery cell 10 overheats, the explosion-proof valve opens, and the eruption material generated by the battery cell 10 can erupt from the bottom of the battery cell 10.

[0043] In an exemplary embodiment, the battery cells 10 are arranged in multiple rows on the bottom shell 11 of the battery pack, the bottom shell 11 is provided with a sealed exhaust passage 12, the bottom of the battery cell 10 is embedded in the sealed exhaust passage 12, and the battery cell 10 is sealingly connected to the sealed exhaust passage 12, so that the battery cell 10 cooperates with the sealed exhaust passage 12. When the battery cell 10 erupts at the bottom after thermal runaway, the eruption material and hot gas can be erupted into the sealed exhaust passage 12, and then discharged out of the battery pack through the sealed exhaust passage 12, thereby reducing the spread of high-temperature gas and conductive polymer to the entire battery pack after the battery cell 10 thermal runaway, and further reducing the probability of fire and explosion of the battery pack.

[0044] In some embodiments, the sealed exhaust passage 12 is provided with a stepped groove near the surface of the battery cell 10; the bottom of the battery cell 10 is located in the stepped groove; wherein,

[0045] the stepped groove is provided with a first stepped hole and a second stepped hole; the diameter of the first stepped hole is greater than the diameter of the battery cell 10; the diameter of the second stepped hole is smaller than the diameter of the battery cell 10, and the diameter of the second stepped hole is greater than the diameter of the explosion-proof valve of the battery cell 10;

[0046] the stepped groove is in communication with the sealed exhaust passage 12 through the first stepped hole and the second stepped hole.

[0047] In an exemplary embodiment, the first stepped hole is closer to the battery cell 10 than the second stepped hole. The battery cell 10 is inserted into the first stepped hole. In this way, the material and hot gas ejected by the battery cell 10 can be ejected into the sealed exhaust passage 12 through the second stepped hole.

[0048] In some embodiments, the bottom of the battery cell 10 and the edge of the stepped groove of the sealed exhaust passage 12 have a structural adhesive 24; the structural adhesive 24 is used to seal the battery cell 10 and the sealed exhaust passage 12.

[0049] In an exemplary embodiment, as shown in the figure, the battery cell 10 and the edge of the stepped groove can be sealed by the structural adhesive 24, so that the battery cell 10 and the sealed exhaust passage 12 are sealed.

[0050] In some embodiments, the bottom shell 11 includes a bottom plate and a frame;

[0051] The sealed exhaust passage 12 is located in the bottom plate, and the battery cells 10 are distributed on the bottom plate;

[0052] The exhaust valve 13 is located on the frame, and the bottom plate and the frame are sealed.

[0053] In an exemplary embodiment, Figure 2 is a schematic diagram of a battery structure according to an exemplary embodiment Figure 2 As Figure 4 shown, the battery structure is divided into battery cells 10, battery box frame beams 21, and integrated bottom plates 22 from top to bottom. The integrated bottom plate 22 contains a sealed exhaust passage, an exhaust valve 13, and a structural adhesive 24. The battery cell 10 is sealed above the sealed exhaust passage by the structural adhesive 24. The bottom of the battery cell is placed in the sealed exhaust passage.

[0054] The exhaust valve 13 is located at the passage opening of the sealed exhaust passage 12 and is embedded in the sealed exhaust passage 12. When the battery cell 10 triggers thermal runaway, the bottom explosion-proof valve of the battery cell 10 opens, and the high-temperature gas and the ejected material are ejected into the sealed exhaust passage 12. The ejected material is evenly distributed inside the cavity of the sealed exhaust passage 12. The high-temperature gas follows the cavity path of the sealed exhaust passage 12 and is discharged outside the battery pack through the explosion-proof valve on the battery box frame beam 21.

[0055] In some embodiments, the sealing method between the bottom plate and the frame includes one of the following:

[0056] welding, gluing, screw connection.

[0057] In the example embodiment, the bottom plate and the frame are connected by welding, gluing or screws to seal the bottom plate and the frame, so that when the battery is in thermal runaway, high-temperature gas will not escape to the area where the battery cell 10 is arranged.

[0058] In some embodiments, the stepped groove on the surface of the sealed exhaust passage 12 is distributed in multiple rows; wherein one battery cell 10 is located in one stepped groove.

[0059] In the example embodiment, the stepped groove on the surface of the sealed exhaust passage 12 is multiple. The battery cell 10 is arranged in correspondence with the stepped groove, so that one battery cell 10 is located in one stepped groove. When the battery cell 10 triggers thermal runaway, the explosion-proof valve at the bottom of each battery cell 10 can be opened, and the high-temperature gas and the spewing material are spewed into the sealed exhaust passage 12. The spewing material is uniformly distributed inside the cavity of the sealed exhaust passage 12. The high-temperature gas follows the path of the cavity of the sealed exhaust passage 12, passes through the explosion-proof valve on the battery box frame beam 21, and discharges the high-temperature gas outside the battery pack.

[0060] In some embodiments, the first distance between the first stepped hole and the battery cell 10 is less than the second distance between the second stepped hole and the battery cell 10.

[0061] The difference between the diameter of the first stepped hole and the diameter of the battery cell 10 is a first difference, and the difference between the diameter of the second stepped hole and the diameter of the battery cell 10 is a second difference; wherein the first difference is in the range of 0.5mm-1mm; and the second difference is in the range of 1mm-2mm.

[0062] In the example embodiment, the sealed exhaust integrated bottom plate 22 is precisely controlled by the stepped hole size to realize the functions of support, exhaust and flow guide. The diameter of the first stepped hole is greater than the outer diameter of the cylindrical battery cell 10 by 0.5-1mm to ensure that the battery cell 10 is embedded; the diameter of the second stepped hole is greater than the diameter of the explosion-proof valve of the battery cell 10 by 1-2mm to ensure that the explosion-proof valve opens smoothly when the battery cell 10 is in thermal runaway; and the difference between the diameters of the first stepped hole and the second stepped hole is used for supporting the battery cell 10 and sealing the battery cell 10.

[0063] In the example embodiment, the exhaust valve 13 includes an explosion-proof exhaust valve 13.

[0064] The present disclosure provides a heat dissipation method for a battery in thermal runaway, wherein the battery includes battery cells 10; wherein a plurality of battery cells 10 are arranged in multiple rows; the bottom of the battery cell 10 has an explosion-proof valve; wherein when the battery cell 10 is overheated, the explosion-proof valve opens, and the spewing material generated by the battery cell 10 is spewed from the bottom of the battery cell 10;

[0065] A bottom shell 11 is provided, and the bottom shell 11 has a sealed exhaust passage 12; the bottom of the battery cell 10 is embedded in the sealed exhaust passage 12, and the battery cell 10 is sealingly connected with the sealed exhaust passage 12.

[0066] An exhaust valve 13 is arranged at an exhaust passage opening of the sealed exhaust passage 12.

[0067] Figure 4 A flow chart of a heat dissipation method for a battery in thermal runaway is shown according to an exemplary embodiment. As shown in the flow chart, the method comprises: ​

[0068] Step 40: monitoring the present state of the battery cell;

[0069] Step 41: if the battery cell is overheated and generates a substance eruption, the erupted substance and hot gas are discharged from the exhaust passage opening through the sealed exhaust passage.

[0070] In the exemplary embodiment, the battery cells are arranged in multiple rows and parallel to each other on the bottom shell of the battery pack, the bottom shell has a sealed exhaust passage, the bottom of the battery cell is embedded in the sealed exhaust passage, and the battery cell is sealingly connected with the sealed exhaust passage, so that the battery cell cooperates with the sealed exhaust passage. When the battery cell is in thermal runaway and the bottom erupts, the erupted substance and hot gas can be erupted into the sealed exhaust passage, so as to be discharged out of the battery pack through the sealed exhaust passage, thereby reducing the spread of high-temperature gas and conductive polymer to the entire battery pack after the battery cell is in thermal runaway, and further reducing the probability of fire and explosion of the battery pack.

[0071] ​It should be noted that the logical and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor- containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or a combination of the above. For the purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be a product of the manufacturing and / or processing, and / or an article of manufacture. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electronic connection having one or more wires (electronic devices), a portable computer diskette (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber (optical devices), and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example via optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and stored in a computer memory.

[0072] It should be understood that portions of the present disclosure can be implemented in hardware, software, firmware, or combinations thereof. In the above embodiments, a number of steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or a combination thereof, can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0073] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the present specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0074] In the description of the present disclosure, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0075] In addition, the terms "first", "second", and the like used in the embodiments of the present disclosure are only for descriptive purposes, and cannot be understood as indicating or implying relative importance, or implicitly indicating the number of technical features referred to in the embodiments. Therefore, the features defined with the terms "first", "second" and the like in the embodiments of the present disclosure can explicitly or implicitly indicate that at least one such feature is included in the embodiments. In the description of the present disclosure, the meaning of the word "multiple" is at least two or two or more, such as two, three, four, etc., unless otherwise specifically limited in the embodiments.

[0076] In the present disclosure, unless otherwise specifically defined or limited in the embodiments, the terms "mounting", "connecting", "connecting" and "fixing" and the like appearing in the embodiments should be understood broadly, for example, the connection can be a fixed connection, or a detachable connection, or integrated, which can be understood, or can be a mechanical connection, an electrical connection, etc. Of course, it can also be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements, or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific implementation situation.

[0077] In the present disclosure, unless otherwise specifically defined or limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0078] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above-described embodiments are exemplary, and it is not construed that the present disclosure is limited to the above-described embodiments, and a person of ordinary skill in the art can make changes, modifications, replacements, and variations to the above-described embodiments within the scope of the present disclosure.

Claims

1. A battery, characterized in that, include: A battery cell; wherein multiple battery cells are arranged in multiple rows side by side; the bottom of each battery cell has an explosion-proof valve; wherein, when the battery cell overheats, the explosion-proof valve opens, and the ejected material generated by the battery cell is ejected from the bottom of the battery cell; the battery cell is cylindrical. A bottom shell; the bottom shell has a sealed venting channel; the bottom of the battery cell is embedded in the sealed venting channel, and the battery cell is sealed to the sealed venting channel; the surface of the sealed venting channel near the battery cell has a stepped groove; the bottom of the battery cell is located in the stepped groove; wherein, the stepped groove has a first stepped hole and a second stepped hole; the diameter of the first stepped hole is larger than the diameter of the battery cell; the diameter of the second stepped hole is smaller than the diameter of the battery cell, and the diameter of the second stepped hole is larger than the diameter of the explosion-proof valve of the battery cell. The stepped groove communicates with the sealed exhaust channel through the first stepped hole and the second stepped hole, and the stepped grooves on the surface of the sealed exhaust channel are arranged in multiple rows in parallel; wherein, one battery cell is located in one stepped groove; the first distance between the first stepped hole and the battery cell is less than the second distance between the second stepped hole and the battery cell; the difference between the diameter of the first stepped hole and the diameter of the battery cell is a first difference value, and the difference between the diameter of the second stepped hole and the diameter of the battery cell is a second difference value; wherein, the difference value of the first difference value ranges from 0.5mm to 1mm; and the difference value of the second difference value ranges from 1mm to 2mm. An exhaust valve is located at the exhaust port of the sealed exhaust channel.

2. The battery according to claim 1, characterized in that, The bottom of the battery cell and the edge of the stepped groove of the sealed venting channel have structural adhesive; the structural adhesive is used to seal the battery cell and the sealed venting channel together.

3. The battery according to claim 1, characterized in that, The bottom shell includes a bottom plate and a frame; The sealed exhaust channel is located inside the base plate, and the battery cells are distributed on the base plate; The exhaust valve is located on the frame, and the base plate and the frame are sealed together.

4. The battery according to claim 3, characterized in that, The sealing method between the base plate and the frame includes one of the following: Welding, gluing, and screw connections.

5. The battery according to claim 1, characterized in that, The exhaust valve includes an explosion-proof exhaust valve.

6. A method for heat dissipation during battery thermal runaway, characterized in that, The battery includes battery cells; wherein multiple battery cells are arranged in multiple rows side by side; each battery cell has an explosion-proof valve at its bottom; wherein, when the battery cell overheats, the explosion-proof valve opens, and the ejected material generated by the battery cell is ejected from the bottom of the battery cell; the battery cell is cylindrical. A bottom shell; the bottom shell has a sealed venting channel; the bottom of the battery cell is embedded in the sealed venting channel, and the battery cell is sealed to the sealed venting channel; the surface of the sealed venting channel near the battery cell has a stepped groove; the bottom of the battery cell is located in the stepped groove; wherein, the stepped groove has a first stepped hole and a second stepped hole; the diameter of the first stepped hole is larger than the diameter of the battery cell; the diameter of the second stepped hole is smaller than the diameter of the battery cell, and the diameter of the second stepped hole is larger than the diameter of the explosion-proof valve of the battery cell. The stepped groove communicates with the sealed exhaust channel through the first stepped hole and the second stepped hole, and the stepped grooves on the surface of the sealed exhaust channel are arranged in multiple rows in parallel; wherein, one battery cell is located in one stepped groove; the first distance between the first stepped hole and the battery cell is less than the second distance between the second stepped hole and the battery cell; the difference between the diameter of the first stepped hole and the diameter of the battery cell is a first difference value, and the difference between the diameter of the second stepped hole and the diameter of the battery cell is a second difference value; wherein, the difference value of the first difference value ranges from 0.5mm to 1mm; and the difference value of the second difference value ranges from 1mm to 2mm. An exhaust valve is located at the exhaust port of the sealed exhaust channel; The method includes: Monitor the state of the cells in the battery; If the battery cell overheats and produces a material ejection, the ejected material and hot gas are discharged from the exhaust channel through the sealed exhaust channel.

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