Battery cell thermal runaway gas production detection device and detection method

Abstract

The invention discloses a battery cell thermal runaway gas production detection device and method, the device comprises an explosion-proof box, a trigger assembly, a first temperature sensor, a gas guide pipe and a gas flowmeter, the explosion-proof box is used for placing a to-be-detected battery cell, the trigger assembly is used for triggering thermal runaway of the to-be-detected battery cell, and the first temperature sensor is used for detecting thermal runaway of the to-be-detected battery cell. The first temperature sensor is arranged at the position of an exhaust port of an anti-explosion valve of the battery cell to be detected so as to detect the temperature of gas exhausted by the battery cell to be detected at the moment of thermal runaway, and an air inlet of the air guide pipe is formed in the anti-explosion box and used for being communicated with the exhaust port of the anti-explosion valve of the battery cell to be detected; a gas outlet of the gas guide pipe is arranged in the explosion-proof box, and the gas flow meter is used for detecting the gas discharge rate of the battery cell to be detected at the moment of thermal runaway. The cell thermal runaway gas production detection device disclosed by the invention can obtain the instantaneous gas production temperature and the instantaneous gas production rate when the cell thermal runaway occurs, and is used for accurately guiding the optimization design of an anti-explosion valve so as to improve the design reliability of the anti-explosion valve.

Description

Technical Field

[0001] The present invention relates to the technical field of battery cell testing devices, and in particular, to a device and method for detecting gas generated during thermal runaway of a battery cell. Background Art

[0002] The thermal runaway of the battery cells of power batteries is mainly caused by factors such as overcharging and discharging, internal short circuit, mechanical damage, high and low temperature environments, and manufacturing defects. During the thermal runaway process of the battery cells, not only a large amount of heat is generated instantaneously, but also flammable and toxic gases are produced.

[0003] In related technologies, in order to prevent the battery cells from exploding during thermal runaway, an explosion-proof valve is provided on the top cover of the battery cells to discharge the heat and gas generated by the battery cells during thermal runaway. Therefore, the gas generation temperature and gas generation rate at the moment of thermal runaway of the battery cells are the key calibration parameters of the explosion-proof valve. However, currently in the battery cell thermal runaway detection device, only the test of the gas generation amount during the thermal runaway of the battery cells is concentrated, and relatively few key calibration parameters are referred to in the design of the explosion-proof valve, resulting in poor design reliability of the explosion-proof valve. Summary of the Invention

[0004] The present disclosure aims to solve at least one of the technical problems in the related technologies to some extent. For this purpose, the present disclosure provides a device for detecting gas generated during thermal runaway of a battery cell, which can obtain the instantaneous gas generation temperature and instantaneous gas generation rate during thermal runaway of the battery cell, and is used to accurately guide the optimization design of the explosion-proof valve to improve the design reliability of the explosion-proof valve.

[0005] The device for detecting gas generated during thermal runaway of the battery cell according to the embodiments of the present disclosure includes an explosion-proof box, a triggering assembly, a first temperature sensor, a gas guide pipe, and a gas flow meter. The explosion-proof box is used to place the battery cell to be tested; the triggering assembly is arranged inside or outside the explosion-proof box and is used to trigger the thermal runaway of the battery cell to be tested; the first temperature sensor is arranged at the exhaust port position of the explosion-proof valve of the battery cell to be tested to detect the temperature of the gas discharged by the battery cell to be tested at the moment of thermal runaway; the intake port of the gas guide pipe is arranged inside the explosion-proof box and is used to communicate with the exhaust port of the explosion-proof valve of the battery cell to be tested, and the outlet of the gas guide pipe is arranged inside the explosion-proof box; the gas flow meter is arranged on the gas guide pipe and is used to detect the rate of the gas discharged by the battery cell to be tested at the moment of thermal runaway.

[0006] In some embodiments, the device for detecting gas generated during thermal runaway of the battery cell according to the embodiments of the present disclosure includes a pressure sensor and a second temperature sensor. The pressure sensor is arranged on the gas guide pipe and is used to detect the pressure value inside the gas guide pipe after the thermal runaway of the battery cell to be tested; the second temperature sensor is arranged inside the explosion-proof box and is used to detect the internal environment temperature of the explosion-proof box.

[0007] In some embodiments, the cell thermal runaway gas production detection device of the present disclosure includes a gas collection device, the gas collection device is communicated with the explosion-proof box through a first pipeline, a first control valve and a filter are arranged on the first pipeline, the first control valve is used to control the on-off of the gas in the first pipeline, and the filter is used to filter the solid particles in the gas of the first pipeline.

[0008] In some embodiments, a heating device is arranged on the first pipeline, and the heating device is used to heat the gas in the first pipeline.

[0009] In some embodiments, the cell thermal runaway gas production detection device of the present disclosure further includes: a vacuum pump, the vacuum pump is communicated with the explosion-proof box through a second pipeline and is used to evacuate the explosion-proof box, and a second control valve for controlling the on-off of the gas in the second pipeline is arranged on the second pipeline; and / or

[0010] A gas storage tank, the gas storage tank is used to store protective gas, the gas storage tank is communicated with the explosion-proof box through a third pipeline, and a third control valve for controlling the on-off of the gas in the third pipeline is arranged on the third pipeline.

[0011] In some embodiments, the cell thermal runaway gas production detection device of the present disclosure further includes a fixing component, the fixing component is arranged in the explosion-proof box, the fixing component includes a support rod, a first clamping piece and a second clamping piece, the support rod is connected with the explosion-proof box, the first clamping piece and the second clamping piece are arranged on the support rod at intervals along the length direction of the support rod, at least one of the first clamping piece and the second clamping piece is adjustable in position along the length direction of the support rod, and the first clamping piece and the second clamping piece are used to clamp the large surface of the cell to be tested.

[0012] In some embodiments, a heat insulation piece is arranged between the first clamping piece and / or the second clamping piece and the cell to be tested.

[0013] In some embodiments, the triggering component is a charging power supply, the charging power supply is arranged outside the explosion-proof box and is electrically connected to the cell to be tested in the explosion-proof box through a charging wire, and the charging power supply is used to overcharge the cell to be tested so that the cell to be tested undergoes thermal runaway.

[0014] In some embodiments, the triggering component is a heating sheet, the heating sheet is arranged on the surface of the cell to be tested and is used to heat the cell to be tested so that the cell to be tested undergoes thermal runaway.

[0015] In some embodiments, the triggering component is a needle punching machine, the needle punching machine is arranged in the explosion-proof box, and the needle of the needle punching machine is used to penetrate the cell to be tested so that the cell to be tested undergoes thermal runaway.

[0016] The method for detecting gas generated during thermal runaway of an electric cell according to an embodiment of the present disclosure, which applies the device for detecting gas generated during thermal runaway of an electric cell described in any of the above embodiments, includes:

[0017] Place the electric cell to be tested inside the explosion-proof box;

[0018] Trigger thermal runaway of the electric cell to be tested through the triggering component;

[0019] Detect the temperature of the gas discharged by the electric cell to be tested at the moment of thermal runaway through the first temperature sensor;

[0020] Detect the rate of the gas discharged by the electric cell to be tested at the moment of thermal runaway through the gas flow meter.

[0021] During the test of the device for detecting gas generated during thermal runaway of the electric cell of the present disclosure, the triggering component is used to trigger thermal runaway of the electric cell to be tested. A large amount of heat and gas are generated by the electric cell to be tested at the moment of thermal runaway. The explosion-proof valve on the electric cell to be tested opens under the action of the internal gas pressure of the electric cell to be tested, and the high-temperature and high-pressure gas generated inside the electric cell to be tested is discharged through the exhaust port of the explosion-proof valve. The first temperature sensor arranged at the position of the exhaust port of the explosion-proof valve of the electric cell to be tested can timely detect the instantaneous gas generation temperature at the exhaust port of the explosion-proof valve of the electric cell to be tested. The gas discharged from the exhaust port of the explosion-proof valve of the electric cell to be tested enters the gas guide pipe, and the gas flow meter arranged on the gas guide pipe can timely detect the instantaneous gas generation rate of the electric cell to be tested. Thus, the device for detecting gas generated during thermal runaway of the electric cell of the present disclosure can obtain the instantaneous gas generation temperature and the instantaneous gas generation rate when the electric cell to be tested undergoes thermal runaway, which is used to accurately guide the optimization design of the explosion-proof valve, making the design of the explosion-proof valve highly reliable. Description of the Drawings

[0022] Figure 1 is a schematic structural diagram of the device for detecting gas generated during thermal runaway of an electric cell according to an embodiment of the present invention.

[0023] Figure 2 is a schematic diagram of the connection of a partial structure of the device for detecting gas generated during thermal runaway of an electric cell according to an embodiment of the present invention.

[0024] Figure 3 is a schematic structural diagram of the fixing component of the device for detecting gas generated during thermal runaway of an electric cell according to an embodiment of the present invention.

[0025] Reference Signs:

[0026] 100. Battery cell thermal runaway gas production detection device; 200. Battery cell to be tested; 1. Explosion-proof box; 101. Box cover; 102. Box body; 2. Explosion-proof valve; 3. Air duct; 4. Gas flow meter; 5. Pressure sensor; 6. Gas collection device; 7. First pipeline; 8. First control valve; 9. Filter; 10. Charging power supply; 11. Vacuum pump; 12. Second pipeline; 13. Second control valve; 14. Gas storage tank; 15. Third pipeline; 16. Third control valve; 17. Fixing component; 1701. Support rod; 1702. First clamping piece; 1703. Second clamping piece; 18. Heat insulation piece; 19. Data acquisition recorder. Detailed implementation manners

[0027] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0028] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings.

[0029] As Figures 1 to 3 shown, the battery cell thermal runaway gas production detection device 100 according to the embodiment of the present invention includes an explosion-proof box 1, a triggering component, a first temperature sensor, an air duct 3 and a gas flow meter 4. The explosion-proof box 1 includes a box cover 101 and a box body 102. The box cover 101 covers the box body 102. The explosion-proof box 1 is used to place the battery cell 200 to be tested. The triggering component is arranged inside or outside the explosion-proof box 1 and is used to trigger the thermal runaway of the battery cell 200 to be tested. The first temperature sensor is arranged at the exhaust port of the explosion-proof valve 2 of the battery cell to be tested to detect the temperature of the gas discharged by the battery cell to be tested at the moment of thermal runaway. The intake port of the air duct 3 is arranged inside the explosion-proof box 1 and is used to communicate with the exhaust port of the explosion-proof valve 2 of the battery cell to be tested. The outlet of the air duct 3 is arranged inside the explosion-proof box 1. The gas flow meter 4 is arranged on the air duct 3 and is used to detect the rate of the gas discharged by the battery cell to be tested at the moment of thermal runaway.

[0030] During the test of the battery cell thermal runaway gas production detection device 100 according to the embodiment of the present invention, first, open the box cover 101 of the explosion-proof box 1, place the battery cell 200 to be tested in the box body 102, then arrange the first temperature sensor at the exhaust port of the explosion-proof valve 2 of the battery cell 200 to be tested, then connect the intake port of the air duct 3 with the exhaust port of the explosion-proof valve 2 of the battery cell 200 to be tested, and make the outlet of the air duct 3 also located inside the box body 102. Finally, cover the box cover 101 on the box body 102 to form a sealed explosion-proof cavity.

[0031] After the test cell 200 is installed in the explosion-proof box 1, the test cell 200 is triggered by a triggering component to cause thermal runaway. A large amount of heat and gas are generated by the test cell 200 at the moment of thermal runaway (millisecond level). The explosion-proof valve 2 on the test cell 200 opens under the action of the internal gas pressure of the test cell 20. The high-temperature and high-pressure gas generated inside the test cell 200 is discharged through the exhaust port of the explosion-proof valve 2. The first temperature sensor provided at the exhaust port position of the explosion-proof valve 2 of the test cell 200 can timely detect the instantaneous gas production temperature at the exhaust port of the explosion-proof valve 2 of the test cell 200. The gas discharged from the exhaust port of the explosion-proof valve 2 of the test cell 200 enters the gas guide pipe 3. The gas flow meter 4 provided on the gas guide pipe 3 can timely detect the instantaneous gas production rate of the test cell 200. Thus, the test cell thermal runaway gas production detection device 100 according to the embodiment of the present invention can obtain the instantaneous gas production temperature and the instantaneous gas production rate when the test cell 200 undergoes thermal runaway, which is used to accurately guide the optimized design of the explosion-proof valve 2, so that the design reliability of the explosion-proof valve 2 is relatively high.

[0032] In some embodiments, the test cell thermal runaway gas production detection device 100 according to the embodiment of the present invention includes a pressure sensor 5 and a second temperature sensor. The pressure sensor 5 is provided on the gas guide pipe 3 and is used to detect the pressure value in the gas guide pipe 3 after the test cell 200 undergoes thermal runaway. The second temperature sensor is provided in the explosion-proof box 1 and is used to detect the internal environmental temperature of the explosion-proof box 1.

[0033] It should be noted that the gas generated by the test cell 200 during thermal runaway is mainly caused by the decomposition of the electrolyte at high temperature. This gas may cause a fire or even an explosion when mixed with air under appropriate conditions, resulting in losses to personnel and equipment. To reduce the unnecessary damage caused by the thermal runaway gas, it is necessary to analyze and study the physical parameters such as the temperature, gas production volume, composition, and proportion of the gas during the thermal runaway process.

[0034] The test and calculation of the gas production volume of the test cell 200 during thermal runaway are carried out based on the ideal gas state equation. This method has a simple principle, convenient calculation, and high accuracy, and is also a widely used method for calculating the gas production volume during thermal runaway. During the test process, the gas production volume can be calculated by the following formula:

[0035] Pt*(V0 - Vcell) = nt*R*Tt;

[0036] Vgas = (nt – n0)*Vm

[0037] Where:

[0038] V0: The internal volume of the explosion-proof box 1;

[0039] Vcell: The volume of the test cell 200 to be tested and its test fixture;

[0040] Pt: The reading of the pressure sensor 5 at time t when the thermal runaway of the battery cell 200 to be measured progresses;

[0041] n0 and nt: The amount of substance of the gas inside the explosion-proof box 1 at the starting moment of the thermal runaway and at time t when the thermal runaway of the battery cell 200 to be measured progresses, respectively;

[0042] Vm: The molar volume concentration of an ideal gas at 273.15 K and 101.325 kPa; Vm = 22.4 L / mol;

[0043] Vgas: The total gas production amount of the battery cell 200 to be measured at time t when the thermal runaway test of the battery cell 200 to be measured progresses;

[0044] Tt: The internal gas temperature of the explosion-proof box 1 at time t when the thermal runaway test of the battery cell 200 to be measured progresses;

[0045] R: The gas constant; R = 8.314 J / (mol*K);

[0046] The parameter Pt can be measured by the pressure sensor 5, the parameter Tt can be measured by the second temperature sensor, and the remaining parameters can be measured by existing technologies or are common knowledge. Therefore, the battery cell thermal runaway gas production detection device 100 of the embodiment of the present invention can measure the total gas production amount during the thermal runaway of the battery cell 200 to be measured, which is used to accurately guide the treatment of the gas generated after the thermal runaway of the battery cell 200 to be measured and reduce unnecessary damage caused by the thermal runaway gas.

[0047] Optionally, the temperatures detected by the first temperature sensor and the second temperature sensor can be recorded by the data acquisition recorder 19.

[0048] In some embodiments, the battery cell thermal runaway gas production detection device 100 of the embodiment of the present invention includes a gas collection device 6. The gas collection device 6 is communicated with the explosion-proof box 1 through a first pipeline 7. A first control valve 8 and a filter 9 are provided on the first pipeline 7. The first control valve 8 is used to control the on-off of the gas in the first pipeline 7, and the filter 9 is used to filter solid particles in the gas in the first pipeline 7.

[0049] For example, as Figure 1As shown, the gas collection device 6 can be a gas collection bag. After the test cell 200 undergoes thermal runaway, the first control valve 8 is opened, and the gas in the explosion-proof box 1 enters the first pipeline 7. After the gas in the first pipeline 7 passes through the filter 9 to filter out solid suspended particles, clean gas is obtained and enters the gas collection device 6. The clean gas in the gas collection device 6 is sent to the laboratory for analysis of the composition and proportion of the gas by equipment such as a gas chromatograph, a mass spectrometer, or an infrared spectrometer. By filtering out the solid suspended particles in the gas through the filter 9, it is possible to avoid the solid suspended particles in the gas from causing wear, interference, or blockage to precision detection instruments, which is beneficial to improving the reliability and lifespan of the detection instruments.

[0050] Optionally, a heating device is provided on the first pipeline 7, and the heating device is used to heat the gas in the first pipeline 7. It can be understood that some gases with relatively low condensation points in the gas generated when the test cell 200 undergoes thermal runaway are likely to liquefy on the first pipeline 7 when cooled, resulting in the inability to accurately collect all the gas components of the test cell 200 during thermal runaway in the gas collection device 6. By providing a heating device on the first pipeline 7 to heat the gas flowing through the first pipeline 7, it is possible to avoid the condensation of some gases with relatively low condensation points on the inner wall of the first pipeline 7, so that the gas in the gas collection device 6 is all the gas components generated by the test cell 200 during thermal runaway, which is beneficial to improving the test reliability of the test cell thermal runaway gas production detection device 100 according to the embodiments of the present invention.

[0051] In some embodiments, as Figure 1 shown, the test cell thermal runaway gas production detection device 100 according to the embodiments of the present invention includes a vacuum pump 11. The vacuum pump 11 is connected to the explosion-proof box 1 through a second pipeline 12 and is used to evacuate the explosion-proof box 1. A second control valve 13 for controlling the on / off of the gas in the second pipeline 12 is provided on the second pipeline 12.

[0052] It can be understood that the gas generated by the thermal runaway of the test cell 200 is mainly caused by the decomposition of the electrolyte at high temperatures. This gas may cause a fire or even an explosion when mixed with air under appropriate conditions. Before conducting the test on the gas production during the thermal runaway of the test cell 200, it is necessary to check the airtightness of the entire detection device. Specifically, the second control valve 13 is opened and the third control valve 16 is closed. The explosion-proof box 1 is evacuated by the vacuum pump 11 until it reaches -98 kPa and is maintained in this state for 10 minutes. If the pressure change in the explosion-proof box 1 is less than 1 kPa, it is considered that the explosion-proof box 1 used in this test has qualified airtightness and subsequent tests can be carried out.

[0053] In some embodiments, as Figure 1As shown in the figure, the cell thermal runaway gas generation detection device 100 according to the embodiment of the present invention includes a gas storage tank 14 for storing a protective gas. The gas storage tank 14 is connected to the explosion-proof box 1 through a third pipeline 15, and a third control valve 16 for controlling the on-off of the gas in the third pipeline 15 is provided on the third pipeline 15.

[0054] After the explosion-proof box 1 passes the sealing test, the second control valve 13 is closed and the third control valve 16 is opened to replace the air in the explosion-proof box 1 with the protective gas (such as inert gas) in the gas storage tank 14, so as to avoid the explosion caused by the mixture of the gas generated by the thermal runaway of the cell under test 200 and the air in the explosion-proof box 1, thereby improving the test safety. Specifically, when evacuating the explosion-proof box 1 and filling it with the protective gas, it is repeated three times or more.

[0055] In some embodiments, the cell thermal runaway gas generation detection device 100 according to the embodiment of the present invention further includes a fixing component 17 provided in the explosion-proof box 1. The fixing component 17 includes a support rod 1701, a first clamping member 1702, and a second clamping member 1703. The support rod 1701 is connected to the box body 102. The first clamping member 1702 and the second clamping member 1703 are arranged on the support rod 1701 at intervals along the length direction of the support rod 1701, and at least one of the first clamping member 1702 and the second clamping member 1703 is adjustable in position along the length direction of the support rod 1701. The first clamping member 1702 and the second clamping member 1703 are used to clamp the large surface of the cell under test 200.

[0056] Specifically, as Figure 2 and Figure 3 shown, the support rod 1701 extends in the vertical direction, the bottom end of the support rod 1701 is connected to the box body 102, both the first clamping member 1702 and the second clamping member 1703 are plate bodies, the first clamping member is located at the top of the support rod 1701, and the second clamping member 1703 is located below the first clamping member 1702.

[0057] When installing the battery cell 200 to be tested, first adjust the position of at least one of the first clamping member 1702 and the second clamping member 1703 along the length direction of the support rod 1701, so that there is enough accommodation space between the first clamping member 1702 and the second clamping member 1703 to place the battery cell 200 to be tested. Then, face the large surfaces on both sides of the battery cell 200 to be tested towards the first clamping member 1702 and the second clamping member 1703 respectively. After that, adjust the position of at least one of the first clamping member 1702 and the second clamping member 1703 along the length direction of the support rod 1701, so that the first clamping member 1702 and the second clamping member 1703 clamp the battery cell 200 to be tested. Since the large surfaces of the battery cell 200 to be tested are clamped by the first clamping member 1702 and the second clamping member 1703, when the battery cell 200 to be tested undergoes thermal runaway, it is possible to avoid the expansion of the large surfaces of the battery cell 200 during the initial gas generation stage, which may cause temperature measurement deviation during the thermal runaway process. Thus, it can reduce or even avoid the measurement deviation of the first temperature sensor on the explosion-proof valve 2 or other temperature sensors on the battery cell 200 to be tested, which is further conducive to improving the reliability of the test results.

[0058] In addition, by adjusting the positions of the first clamping member 1702 and the second clamping member 1703 on the support rod 1701, the battery cell 200 to be tested can be positioned at the middle position of the cavity of the explosion-proof box 1, so that the temperature in the cavity of the explosion-proof box 1 is more uniform and local overheating of the explosion-proof box 1 can be avoided.

[0059] Optionally, the number of the support rods 1701 is multiple, and the outer circumferential surface of the support rod has an external thread. An adjusting nut is provided on each support rod 1701. By screwing the adjusting nut to adjust the positions of the first clamping member 1702 and the second clamping member 1703, the fixing assembly 17 has a simple structure and is convenient to adjust.

[0060] In some embodiments, a heat insulation member 18 is provided between the first clamping member 1702 and the battery cell 200 to be tested. For example, the heat insulation member 18 is a high-temperature resistant heat insulation cotton. By providing the heat insulation member 18 between the first clamping member 1702 and the battery cell 200 to be tested, it is possible to avoid the heat for the self-heating of the battery cell 200 to be tested from being conducted to the first clamping member 1702, resulting in an incomplete thermal runaway reaction.

[0061] In some embodiments, a heat insulation member 18 is provided between the second clamping member 1703 and the battery cell 200 to be tested. For example, the heat insulation member 18 is a high-temperature resistant heat insulation cotton. By providing the heat insulation member 18 between the second clamping member 1703 and the battery cell 200 to be tested, it is possible to avoid the heat for the self-heating of the battery cell 200 to be tested from being conducted to the second clamping member 1703, resulting in an incomplete thermal runaway reaction.

[0062] In some embodiments, such as Figure 1As shown, the triggering component is the charging power supply 10, such as a constant voltage and constant current power supply. The charging power supply 10 is arranged outside the explosion-proof box 1 and is electrically connected to the battery cell 200 to be tested inside the explosion-proof box 1 through a charging wire. The charging power supply 10 is used to overcharge the battery cell 200 to be tested, so that the battery cell 200 to be tested undergoes thermal runaway.

[0063] In some embodiments, the triggering component is a heating sheet. The heating sheet is arranged on the surface of the battery cell 200 to be tested for heating the battery cell 200 to be tested, so that the battery cell 200 to be tested undergoes thermal runaway.

[0064] In some embodiments, the triggering component is a needle punching machine. The needle punching machine is arranged inside the explosion-proof box 1, and the needles of the needle punching machine are used to penetrate the battery cell 200 to be tested, so that the battery cell 200 to be tested undergoes thermal runaway.

[0065] The stop conditions for triggering thermal runaway in the above several methods are the same. When testing the voltage change of the battery cell 200 to be tested until the temperature, gas production rate or pressure inside the explosion-proof box 1 suddenly changes, the triggering component is stopped from triggering the thermal runaway of the battery cell 200 to be tested. Thus, the battery cell thermal runaway gas production detection device 100 according to the embodiments of the present invention can perform thermal runaway tests on the battery cell 200 to be tested under different triggering conditions, analyze the gas production differences of different battery cells 200 to be tested through the test data obtained under different thermal runaway triggering conditions, and design and optimize battery cell components such as the explosion-proof valve 2 according to the maximum temperature, maximum gas production rate and gas production amount during thermal runaway, which is further beneficial to improving the design reliability of battery cell components such as the explosion-proof valve 2.

[0066] The battery cell thermal runaway gas production detection device 100 according to the embodiments of the present invention has the advantages of simple structure, low preparation cost, high safety factor and rich test items. Through the gas flowmeter 4 and the pressure sensor 5, the steam temperature, gas production rate at the moment of thermal runaway of the battery cell 200 to be tested and the gas production amount during the entire thermal runaway process can be accurately obtained. At the same time, in order to accurately obtain the thermal runaway gas components, the gas can be kept at a constant temperature when transported to the gas collection device 6, avoiding the condensation of some gases with lower condensation points due to cooling and resulting in the inability to accurately collect the thermal runaway gas components. And the invention is equipped with multiple ways to trigger the thermal runaway of the battery cell 200 to be tested, can complete thermal runaway gas production test experiments under different triggering conditions, and analyze the gas production differences of different battery cells 200 to be tested for the experimental data, and design and optimize battery cell components such as the explosion-proof valve 2 according to the maximum temperature, maximum gas production rate and gas production amount during thermal runaway, and can be used to study the gas production differences of the battery cell 200 to be tested under different thermal runaway triggering conditions.

[0067] The battery cell thermal runaway gas production detection method according to the embodiments of the present invention is applied to the battery cell thermal runaway gas production detection device 100 described in any of the above embodiments, and includes:

[0068] Place the battery cell 200 to be tested inside the explosion-proof box 1;

[0069] Trigger the thermal runaway of the cell under test through the trigger component;

[0070] Detect the temperature of the gas discharged by the cell under test at the moment of thermal runaway through the first temperature sensor;

[0071] Detect the rate of the gas discharged by the cell under test at the moment of thermal runaway through the gas flowmeter 4.

[0072] The method for detecting gas production during thermal runaway of the cell in the embodiment of the present invention can obtain the instantaneous gas production temperature and the instantaneous gas production rate when the cell 200 under test undergoes thermal runaway, which is used to accurately guide the optimization design of the explosion-proof valve 2, making the design of the explosion-proof valve 2 highly reliable.

[0073] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention 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 thus cannot be construed as a limitation of the present invention.

[0074] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0075] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may mean 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 being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is less than that of the second feature.

[0077] In the present invention, the terms "one embodiment", "some embodiments", "exemplification", "specific exemplification", or "some exemplifications", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or exemplification are included in at least one embodiment or exemplification of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or exemplification. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or exemplifications in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or exemplifications described in this specification and the features of different embodiments or exemplifications.

[0078] Although the above embodiments have been shown and described, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions, and variations made by those of ordinary skill in the art to the above embodiments are within the protection scope of the present invention.

Claims

1. A device for detecting gas generated by thermal runaway of an electric cell, characterized in that, Comprising: An explosion-proof box for placing the battery cell to be tested; A triggering component, which is arranged inside or outside the explosion-proof box and is used to trigger thermal runaway of the battery cell to be tested; A first temperature sensor, which is arranged at the exhaust port of the explosion-proof valve of the battery cell to be tested to detect the temperature of the gas discharged by the battery cell to be tested at the moment of thermal runaway; An air duct, the inlet of which is arranged inside the explosion-proof box and is used to communicate with the exhaust port of the explosion-proof valve of the battery cell to be tested, and the outlet of the air duct is arranged inside the explosion-proof box; A gas flow meter, which is arranged on the air duct and is used to detect the rate of the gas discharged by the battery cell to be tested at the moment of thermal runaway.

2. The cell thermal runaway gas generation detection device according to claim 1, wherein Comprising: A pressure sensor, which is arranged on the air duct and is used to detect the pressure value inside the air duct after thermal runaway of the battery cell to be tested; And A second temperature sensor, which is arranged inside the explosion-proof box and is used to detect the internal environment temperature of the explosion-proof box.

3. The cell thermal runaway gas generation detection device according to claim 2, characterized in that Comprising a gas collection device, the gas collection device is communicated with the explosion-proof box through a first pipeline, a first control valve and a filter are arranged on the first pipeline, the first control valve is used to control the on-off of the gas in the first pipeline, and the filter is used to filter solid particles in the gas in the first pipeline.

4. The cell thermal runaway gas generation detection device according to claim 3, wherein A heating device is arranged on the first pipeline, and the heating device is used to heat the gas in the first pipeline.

5. The gas generation detection device for thermal runaway of the battery cell according to claim 1, wherein, Further comprising: A vacuum pump, which is communicated with the explosion-proof box through a second pipeline and is used to evacuate the explosion-proof box, and a second control valve for controlling the on-off of the gas in the second pipeline is arranged on the second pipeline; and / or A gas storage tank, which is used to store protective gas, the gas storage tank is communicated with the explosion-proof box through a third pipeline, and a third control valve for controlling the on-off of the gas in the third pipeline is arranged on the third pipeline.

6. The cell thermal runaway gas generation detection device according to claim 1, wherein Further comprising a fixing component, the fixing component is arranged inside the explosion-proof box, the fixing component includes a support rod, a first clamping piece and a second clamping piece, the support rod is connected with the explosion-proof box, the first clamping piece and the second clamping piece are arranged on the support rod at intervals along the length direction of the support rod, at least one of the first clamping piece and the second clamping piece is adjustable in position along the length direction of the support rod, and the first clamping piece and the second clamping piece are used to clamp the large surface of the battery cell to be tested.

7. The cell thermal runaway gas generation detection device according to claim 6, wherein An adiabatic piece is arranged between the first clamping piece and / or the second clamping piece and the battery cell to be tested.

8. The battery cell thermal runaway gas generation detection device according to any one of claims 1-7, characterized in that, The triggering component is a charging power supply, the charging power supply is arranged outside the explosion-proof box and is electrically connected with the battery cell to be tested inside the explosion-proof box through a charging wire, and the charging power supply is used to overcharge the battery cell to be tested so that the battery cell to be tested undergoes thermal runaway.

9. The battery cell thermal runaway gas generation detection device according to any one of claims 1-7, characterized in that, The triggering component is a heating sheet, the heating sheet is arranged on the surface of the battery cell to be tested and is used to heat the battery cell to be tested so that the battery cell to be tested undergoes thermal runaway.

10. The battery cell thermal runaway gas generation detection device according to any one of claims 1-7, characterized in that, The triggering component is a pin machine, the pin machine is arranged inside the explosion-proof box, and the pins of the pin machine are used to penetrate the battery cell to be tested so that the battery cell to be tested undergoes thermal runaway.

11. A method for detecting gas generation during thermal runaway of an electric cell, which is applied to the device for detecting gas generation during thermal runaway of an electric cell according to any one of claims 1-10, characterized in that, Comprising: Placing the battery cell to be tested inside the explosion-proof box; Trigger the thermal runaway of the cell under test through the trigger component; Detect the temperature of the gas discharged by the cell under test at the moment of thermal runaway through the first temperature sensor; Detect the rate of the gas discharged by the cell under test at the moment of thermal runaway through the gas flow meter.

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