Battery thermal runaway test system

Abstract

The utility model relates to the technical field of batteries, in particular to a battery thermal runaway testing system which comprises a shell, a thermal runaway triggering mechanism and a pressure measuring mechanism, the shell is provided with a containing cavity, and the containing cavity is used for containing a to-be-tested battery; the thermal runaway triggering mechanism is arranged in the accommodating cavity and is used for enabling the to-be-tested battery to generate thermal runaway; the pressure measuring mechanism is arranged in the accommodating cavity and is in contact with at least one side of the battery to be measured, the pressure measuring mechanism is provided with a plurality of pressure measuring point positions, and each pressure measuring point position is in contact with the corresponding part of the battery to be measured so as to measure the pressure borne by different parts in the thermal runaway process of the battery to be measured. According to the invention, the pressure borne by different parts of the to-be-measured battery in the thermal runaway process can be measured, and the distribution characteristics of the air pressure in the shell in the thermal runaway process of the battery can be reflected more truly and accurately.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery thermal runaway testing system. Background Technology

[0002] During thermal runaway, lithium-ion batteries continuously release heat and generate a large amount of gas, causing an increase in internal temperature and pressure. This can ultimately lead to the opening of the explosion-proof valve or even a fire and explosion. Measuring the gas production rate and type during thermal runaway corresponds to changes in temperature and gas production, ultimately affecting the battery's internal pressure and thus the opening of the explosion-proof valve. Measuring internal pressure is crucial for studying the reaction mechanism of thermal runaway and the safety performance of lithium batteries.

[0003] Current research categorizes the measurement of internal pressure changes in lithium-ion batteries caused by gas production into two main types: destructive and non-destructive measurements. Destructive measurements typically involve drilling holes in the cover plate to reach the pressure sensor, thus measuring pressure changes in a localized area of ​​the cover plate. This method not only affects the original battery structure but also only measures pressure changes in a specific area of ​​the cover plate. Non-destructive measurements utilize the deformable nature of the aluminum casing under pressure to indirectly measure internal pressure. However, current technologies employ large-area, overall measurement methods that not only introduce the influence of electrode pressure but also fail to accurately reflect the true internal pressure distribution of the battery. Utility Model Content

[0004] This application provides a battery thermal runaway testing system to solve the problem in the prior art that the measurement of internal pressure during battery thermal runaway cannot truly reflect the internal gas pressure distribution of the battery.

[0005] This application provides a battery thermal runaway testing system, including:

[0006] The housing has a receiving cavity for placing the battery under test.

[0007] A thermal runaway triggering mechanism, located within the containment cavity, is used to induce thermal runaway in the battery under test.

[0008] The pressure measuring mechanism is disposed in the receiving cavity and is in contact with at least one side of the battery under test. The pressure measuring mechanism has multiple pressure measuring points, each of which is in contact with a corresponding part of the battery under test to measure the pressure borne by different parts of the battery under test during thermal runaway.

[0009] In one possible design, the pressure measuring mechanism includes:

[0010] The first pressure plate is located inside the housing and can be close to or far from the battery under test;

[0011] There are multiple pressure sensors, which are spaced apart and arranged on the side of the first pressure plate near the battery under test.

[0012] In one possible design, a soft layer is provided on the side of the first pressure plate closest to the battery under test, and a limiting hole is formed on the soft layer, in which the pressure sensor is fitted.

[0013] In one possible design, the thermal runaway trigger mechanism includes:

[0014] A heating plate is placed inside the receiving cavity and is in contact with the surface of the battery to be tested;

[0015] The second pressure plate is located inside the receiving cavity. The second pressure plate brings the heating plate into contact with the surface of the battery under test by being close to the heating plate.

[0016] In one possible design, the housing has an air inlet and an air outlet, which are respectively connected to the receiving cavity. The air inlet is used to introduce inert gas into the receiving cavity, and the air outlet is used to discharge the gas in the receiving cavity to the outside of the receiving cavity.

[0017] One possible design also includes:

[0018] An inert gas generator, used to produce inert gas;

[0019] A gas composition detection device used to detect the composition of gases;

[0020] The first valve has a first end, a second end, and a third end. The first end is connected to the output end of the inert gas generator, the second end is connected to the inlet, and the third end and the outlet are respectively connected to the input end of the gas composition detection device.

[0021] One possible design also includes:

[0022] Hazardous gas treatment device, used to absorb harmful gases;

[0023] The second valve has a fourth end, a fifth end, and a sixth end. The fourth end is connected to the gas outlet, the fifth end is connected to the input end of the gas composition detection device, and the sixth end and the output end of the gas composition detection device are respectively connected to the input end of the harmful gas treatment device.

[0024] In one possible design, the hazardous gas treatment device includes:

[0025] The water tank has an inlet and an outlet;

[0026] Absorbent solution, filling the water tank;

[0027] The activated carbon layer is located near the top inside the water tank.

[0028] In one possible design, the housing has an explosion-proof door; and / or, the housing has an observation window.

[0029] In one possible design, a limiting groove is provided on the inner bottom wall of the housing, which is used to place the battery to be tested, and the pressure measuring mechanism is located in the limiting groove.

[0030] The beneficial effects of this application are as follows:

[0031] The battery thermal runaway testing system of this application includes a casing, a thermal runaway triggering mechanism, and a pressure measuring mechanism. The pressure measuring mechanism has multiple pressure measuring points. By making each pressure measuring point contact the corresponding part of the battery under test, the pressure borne by different parts of the battery under test during thermal runaway can be measured, which is beneficial to more realistically and accurately reflect the distribution characteristics of gas pressure inside the casing during thermal runaway. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 Schematic diagram of the battery thermal runaway testing system provided in the embodiments of this application Figure 1 ;

[0034] Figure 2 Schematic diagram of the battery thermal runaway testing system provided in the embodiments of this application Figure 2 ;

[0035] Figure 3 Schematic diagram of the battery thermal runaway testing system provided in the embodiments of this application Figure 3 ;

[0036] Figure 4 This is a schematic diagram of the pressure measuring mechanism of the battery thermal runaway testing system provided in the embodiments of this application;

[0037] Figure 5 A schematic diagram of the harmful gas treatment device of the battery thermal runaway test system provided in this application embodiment.

[0038] Figure label:

[0039] 100. Shell; 110. Receiving cavity; 120. Air inlet; 130. Air outlet; 140. Limiting groove; 150. Explosion-proof door; 160. Observation window; 200. Thermal runaway triggering mechanism; 210. Heating plate; 220. Second pressure plate; 300. Pressure measuring mechanism; 310. First pressure plate; 320. Pressure sensor; 330. Soft layer; 400. Battery under test; 500. Inert gas generator; 600. Gas composition detection device; 700. Harmful gas treatment device; 710. Water tank; 720. Absorbent liquid; 730. Activated carbon layer; 810. First valve; 811. First end; 812. Second end; 813. Third end; 820. Second valve; 821. Fourth end; 822. Fifth end; 823. Sixth end; 830. Third valve. Detailed Implementation

[0040] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] The following is combined with Figures 1-5 This describes the battery thermal runaway test system provided in the embodiments of this application.

[0042] Reference Figure 1As shown, the battery thermal runaway testing system provided in this application embodiment includes a housing 100, a thermal runaway triggering mechanism 200, and a pressure measuring mechanism 300. The housing 100 has a receiving cavity 110 for placing a battery 400 under test. The thermal runaway triggering mechanism 200 is disposed in the receiving cavity 110 and is used to cause the battery 400 under test to undergo thermal runaway. For example, the thermal runaway triggering mechanism 200 triggers the battery to undergo thermal runaway by transferring heat to the battery. The pressure measuring mechanism 300 is disposed in the receiving cavity 110 and is in contact with at least one side of the battery 400 under test. The pressure measuring mechanism 300 has multiple pressure measuring points, each of which is in contact with a corresponding part of the battery 400 under test to measure the pressure borne by different parts of the battery 400 under test during the thermal runaway process. In some specific embodiments, the pressure measuring mechanism 300 includes two symmetrically arranged pressure measuring mechanisms 300, which are symmetrically arranged on opposite sides of the battery under test 400. Each pressure measuring mechanism 300 measures the pressure borne by an outer side wall of the battery under test 400 by contacting that side wall. In other embodiments, the pressure measuring mechanism 300 may be one or three, etc., and each pressure measuring mechanism 300 is provided with multiple pressure measuring points at intervals. Each pressure measuring point measures the pressure borne by the battery at that location by contacting a portion of the outer side wall of the battery under test 400. In some specific embodiments, the inner bottom wall of the housing 100 is provided with a limiting groove 140 for placing the battery under test 400, and the pressure measuring mechanism 300 is disposed within the limiting groove 140. Specifically, the rear sidewall of the limiting groove 140 contacts the rear outer sidewall of the battery under test 400, thus limiting the battery under test 400. A certain gap exists between the front sidewall of the limiting groove 140 and the front outer sidewall of the battery under test 400, allowing gas to easily flow out through this gap if the explosion-proof valve breaks during pressure testing. Two pressure measuring mechanisms 300 are symmetrically distributed on the left and right inner sidewalls of the limiting groove 140, respectively, and abut against the left and right outer sidewalls of the battery under test 400. Due to the balanced internal and external forces on the battery, the two pressure measuring mechanisms 300 can measure the pressure at different locations on the battery.

[0043] Using the technical solution in the above embodiments, since the pressure measuring mechanism 300 has multiple pressure measuring points, by making each pressure measuring point contact the corresponding part of the battery under test 400, it is possible to measure the pressure borne by different parts of the battery under test 400 during thermal runaway, which is beneficial to more realistically and accurately reflect the distribution characteristics of the air pressure inside the casing 100 during the thermal runaway of the battery.

[0044] Reference Figure 1As shown in some embodiments provided in this application, the pressure measuring mechanism 300 includes a first pressure plate 310 and a pressure sensor 320. The first pressure plate 310 is disposed within the housing 100 and can be close to or away from the battery 400 under test. Multiple pressure sensors 320 are provided, spaced apart on the side of the first pressure plate 310 closest to the battery 400 under test. Specifically, the first pressure plate 310 is parallel to the outer surface of the battery 400 under test, and the pressure sensor 320 is a button pressure sensor 320, with its outer surface flush with the outer surface of the first pressure plate 310. Before testing, the position of the first pressure plate 310 is adjusted so that the pressure sensor 320 is in contact with the outer surface of the battery under test 400 but not pressing against it, i.e., the pressure value of the pressure sensor 320 is zero, simulating the force state of the battery when thermal runaway has not occurred. During the test, by acquiring the pressure value of the pressure sensor 320 in real time, the pressure borne by various parts of the battery during thermal runaway can be obtained, thus obtaining a more realistic force distribution law of the battery during thermal runaway. In some specific embodiments, the pressure measuring mechanism 300 also includes a driver, such as a linear slide, a cylinder, a hydraulic cylinder, or a linear motor. The side of the first pressure plate 310 facing away from the battery under test 400 is connected to the driver. Driven by the driver, it can move closer to or further away from the battery under test 400. By adjusting the moving distance of the driver, the pressure sensor 320 and the outer surface of the battery under test 400 can be adjusted to be in contact but not pressing against each other, so as to simulate the force state of the battery when thermal runaway has not occurred. In other embodiments, the movement of the first pressure plate 310 can also be adjusted manually, for example, the first pressure plate 310 is connected to a threaded rod, and the position of the first pressure plate 310 can be adjusted by rotating the threaded rod.

[0045] Reference Figure 4 As shown, in some embodiments provided in this application, a soft layer 330 is provided on the side of the first pressure plate 310 near the battery 400 under test. A limiting hole is formed on the soft layer 330, and the pressure sensor 320 is fitted into the limiting hole. Specifically, the thickness of the soft layer 330 is equal to the thickness of the pressure sensor 320 to ensure that the outer surface of the pressure sensor 320 is flush with the outer surface of the soft layer 330. In some specific embodiments, the soft layer 330 is made of aerogel material. Aerogel has a low elastic modulus and is more prone to deformation. When the battery experiences thermal runaway, the aerogel has a smaller impact on the deformation of the battery casing. By providing a soft layer 330 on the first pressure plate 310 and fixing the pressure sensor 320 on the soft layer 330, it can be ensured that when the battery 400 under test experiences thermal runaway, the deformation of other locations besides the contact point between the battery 400 and the pressure sensor 320 is not affected, thereby facilitating more realistic testing results.

[0046] Reference Figure 1As shown, in some embodiments provided in this application, the thermal runaway triggering mechanism 200 includes a heating plate 210 and a second pressure plate 220. The heating plate 210 is disposed within the receiving cavity 110 and contacts the surface of the battery under test 400. The second pressure plate 220 is disposed within the receiving cavity 110, and the second pressure plate 220 abuts against the surface of the battery under test 400 by being close to the heating plate 210. Specifically, the second pressure plate 220 is disposed above the battery under test 400, and the heating plate 210 is disposed between the battery under test 400 and the second pressure plate 220. The heating plate 210 is an electric heating plate. By energizing the heating plate 210, the battery under test 400 can be externally heated, thereby triggering thermal runaway of the battery under test 400. By setting the second pressure plate 220, the heating plate 210 can effectively contact the battery under test 400, which is beneficial to improving the efficiency of heat transfer. In some specific embodiments, the thermal runaway triggering mechanism 200 further includes a driver, such as a linear slide, cylinder, hydraulic cylinder, or linear motor. The side of the second pressure plate 220 facing away from the battery under test 400 is connected to the driver. Driven by the driver, it can move closer to or further away from the battery under test 400. By adjusting the movement distance of the driver, the distance between the second pressure plate 220 and the battery under test 400 can be adjusted so that the heating plate 210 between the second pressure plate 220 and the battery under test 400 can effectively contact the battery under test 400, thereby improving the efficiency of heat transfer and shortening the test time. In other embodiments, the movement of the second pressure plate 220 can also be manually adjusted, for example, the second pressure plate 220 is connected to a threaded rod, and the position of the second pressure plate 220 can be adjusted by rotating the threaded rod.

[0047] Reference Figure 2 As shown, in some embodiments of this application, the housing 100 has an explosion-proof door 150 through which the battery under test 400 is inserted or removed. An observation window 160 is provided on the explosion-proof door 150, which is made of transparent tempered glass to facilitate observation of the entire process of heating triggering thermal runaway of the battery.

[0048] Reference Figure 2 As shown, in some embodiments of this application, the housing 100 has an air inlet 120 and an air outlet 130, which are respectively connected to the receiving cavity 110. The air inlet 120 is used to introduce inert gas into the receiving cavity 110, and the air outlet 130 is used to exhaust the gas in the receiving cavity 110 to the outside of the receiving cavity 110. In this way, the inert gas introduced into the receiving cavity 110 through the air inlet 120 can purge the original air in the receiving cavity 110 and provide safe and pollution-free inert gas again. On the one hand, this can improve the safety of the experiment, and on the other hand, it can provide a basis for the component detection of the gas generated by thermal runaway.

[0049] Reference Figure 3As shown, in some embodiments of this application, the battery thermal runaway test system further includes an inert gas generator 500, a gas composition detection device 600, and a first valve 810. The inert gas generator 500 is used to generate inert gas, for example, the inert gas generator 500 is a nitrogen generator; the gas composition detection device 600 is used to detect gas composition, for example, the gas composition detection device 600 is a gas chromatograph; the first valve 810 is a three-way valve, having a first end 811, a second end 812, and a third end 813. The first end 811 is connected to the output end of the inert gas generator 500, the second end 812 is connected to the inlet 120, and the third end 813 and the outlet 130 are respectively connected to the input end of the gas composition detection device 600. Before the test, the first end 811, the second end 812, and the third end 813 of the first valve 810 are opened, so that the inert gas generated in the inert gas generator 500 enters the receiving cavity 110 and the gas composition detection device 600 through the first valve 810, respectively, thereby clearing the air in the receiving cavity 110, the gas composition detection device 600, and the pipeline, ensuring that the gas in the receiving cavity 110, the gas composition detection device 600, and the pipeline is a safe and unpolluted inert gas. When the gas composition detection device 600 detects that the composition of inert gas (e.g., nitrogen) in the gas is 100%, the first end 811, the second end 812, and the third end 813 of the first valve 810 are closed, and the thermal runaway test can then be carried out.

[0050] Reference Figure 3As shown, in some embodiments of this application, the battery thermal runaway test system further includes a harmful gas treatment device 700 and a second valve 820. The harmful gas treatment device 700 is used to absorb harmful gases. The second valve 820 has a fourth end 821, a fifth end 822 and a sixth end 823. The fourth end 821 is connected to the gas outlet 130, the fifth end 822 is connected to the input end of the gas composition detection device 600, and the sixth end 823 and the output end of the gas composition detection device 600 are respectively connected to the input end of the harmful gas treatment device 700. Specifically, a third valve 830 is provided between the output end of the gas composition detection device 600 and the input end of the hazardous gas treatment device 700. During the test, the sixth end 823 of the second valve 820 is normally closed. By intermittently opening the fourth end 821 and the sixth end 823 of the second valve 820 and intermittently closing the third valve 830, the thermal runaway gas in the containment cavity 110 can enter the gas composition detection device 600 in stages for composition detection, thereby realizing the measurement of the gas composition generated at different stages of thermal runaway. After the test, the fourth end 821 and the sixth end 823 of the second valve 820 are opened, and the fifth end 822 of the second valve 820 is closed, allowing the thermal runaway gas in the containment cavity 110 to enter the hazardous gas treatment device 700 for exhaust gas treatment; and the third end 813 of the first valve 810 is opened to use inert gas to remove the thermal runaway gas in the gas composition detection device 600, allowing the thermal runaway gas to enter the hazardous gas treatment device 700 for exhaust gas treatment.

[0051] Reference Figure 5 As shown in some embodiments of this application, the hazardous gas treatment device 700 includes a water tank 710, an absorbent liquid 720, and an activated carbon layer 730. The water tank 710 has an inlet and an outlet. The absorbent liquid 720 is filled inside the water tank 710. The activated carbon layer 730 is disposed inside the water tank 710 near the top. Thermal runaway gas enters the absorbent liquid 720 in the water tank 710 through the inlet. Specifically, the absorbent liquid 720 is water. The absorbent liquid 720 can remove vapor and particulate matter flowing out with the gas. The thermal runaway gas escaping from above the absorbent liquid 720 continues to rise through the activated carbon layer 730, thereby removing hazardous gases such as carbon monoxide and fluorides from the thermal runaway gas. Finally, the unpolluted gas is discharged through the outlet.

[0052] The workflow of the battery thermal runaway testing system in this application is as follows:

[0053] Place the battery 400 to be tested into the receiving cavity 110, adjust the second pressure plate 220 to make the heating plate 210 effectively contact the battery 400 to be tested; adjust the first pressure plate 310 to make the readings of all pressure sensors 320 zero, and close the explosion-proof door 150.

[0054] Before the test, open the first end 811, the second end 812 and the third end 813 of the first valve 810 so that the inert gas generated in the inert gas generator 500 enters the receiving chamber 110 and the gas composition detection device 600 through the first valve 810 respectively. When the gas composition detection device 600 detects that the composition of inert gas in the gas is 100%, close the first end 811, the second end 812 and the third end 813 of the first valve 810, and close the fourth end 821, the fifth end 822 and the sixth end 823 of the second valve 820 to prepare for the test.

[0055] Powering the heating plate 210 triggers thermal runaway of the battery under test 400.

[0056] During the thermal runaway test, the fourth end 821 and the sixth end 823 of the second valve 820 are intermittently opened, and the third valve 830 is intermittently closed, so that the thermal runaway gas in the containment cavity 110 enters the gas composition detection device 600 in stages for composition detection; after each detection is completed, the third valve 830 is opened, so that the gas in the gas composition detection device 600 enters the harmful gas treatment device 700 for exhaust gas treatment;

[0057] After the test, open the fourth end 821 and the sixth end 823 of the second valve 820, close the fifth end 822 of the second valve 820, and open the third end 813 of the first valve 810. Use inert gas to remove the thermal runaway gas in the gas composition detection device 600, so that all the thermal runaway gas enters the harmful gas treatment device 700 for exhaust gas treatment.

[0058] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0060] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0061] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0062] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A battery thermal runaway testing system, characterized in that, include: The housing has a receiving cavity for holding the battery to be tested; A thermal runaway triggering mechanism is disposed within the receiving cavity and is used to cause the battery under test to undergo thermal runaway. A pressure measuring mechanism is disposed within the receiving cavity and is in contact with at least one side of the battery under test. The pressure measuring mechanism has multiple pressure measuring points, each of which is in contact with a corresponding part of the battery under test to measure the pressure borne by different parts of the battery under test during thermal runaway.

2. The battery thermal runaway testing system according to claim 1, characterized in that, The pressure measuring mechanism includes: The first pressure plate is disposed inside the housing and can be close to or far away from the battery under test; There are multiple pressure sensors, which are respectively arranged at intervals on the side of the first pressure plate near the battery under test.

3. The battery thermal runaway testing system according to claim 2, characterized in that: The first pressure plate has a soft layer on the side near the battery under test, and a limiting hole is formed on the soft layer, in which the pressure sensor is fitted.

4. The battery thermal runaway testing system according to claim 1, characterized in that, The thermal runaway triggering mechanism includes: A heating plate is disposed within the receiving cavity and is in contact with the surface of the battery to be tested; A second pressure plate is disposed within the receiving cavity, and the second pressure plate brings the heating plate into contact with the surface of the battery under test by being close to the heating plate.

5. The battery thermal runaway testing system according to any one of claims 1-4, characterized in that, The housing has an air inlet and an air outlet, which are respectively connected to the receiving cavity. The air inlet is used to introduce inert gas into the receiving cavity, and the air outlet is used to discharge the gas in the receiving cavity to the outside of the receiving cavity.

6. The battery thermal runaway testing system according to claim 5, characterized in that, Also includes: An inert gas generator, used to produce inert gas; A gas composition detection device used to detect the composition of gases; A first valve has a first end, a second end, and a third end. The first end is connected to the output end of the inert gas generator, the second end is connected to the air inlet, and the third end and the air outlet are respectively connected to the input end of the gas composition detection device.

7. The battery thermal runaway testing system according to claim 6, characterized in that, Also includes: Hazardous gas treatment device, used to absorb harmful gases; The second valve has a fourth end, a fifth end, and a sixth end. The fourth end is connected to the gas outlet, the fifth end is connected to the input end of the gas composition detection device, and the sixth end and the output end of the gas composition detection device are respectively connected to the input end of the harmful gas treatment device.

8. The battery thermal runaway testing system according to claim 7, characterized in that, The hazardous gas treatment device includes: A water tank having an inlet and an outlet; Absorbent liquid is used to fill the water tank; An activated carbon layer is placed inside the water tank near the top.

9. The battery thermal runaway testing system according to any one of claims 1-4, characterized in that: The housing has an explosion-proof door; and / or, the housing has an observation window.

10. The battery thermal runaway testing system according to any one of claims 1-4, characterized in that: The inner bottom wall of the housing is provided with a limiting groove, which is used to place the battery to be tested, and the pressure measuring mechanism is disposed in the limiting groove.

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