An apparatus and method for verifying the effectiveness of a fire extinguishing medium for a battery module

Abstract

The present invention discloses a verification device and method for the effectiveness of a fire extinguishing medium for a battery module, relating to the technical field of detection equipment. It includes: an explosion-proof container for placing the battery cell group for the test; a heating module for heating the battery cell group for the test; a monitoring module for measuring and recording the temperature and voltage of the battery cell group during the test in real time; a fire fighting unit for simulating the fire fighting system when the battery cell group is in use and spraying the fire extinguishing medium onto the battery cell group; and an atmosphere adjustment module for adjusting the oxygen content inside the explosion-proof container. Through the verification device and method for the effectiveness of the fire extinguishing medium for the battery module, the present invention can help users verify the fire extinguishing effectiveness of various fire extinguishing media on the battery module to be used in the market. Furthermore, it can help users screen out the most suitable fire extinguishing medium for extinguishing the fire of this battery module.

Description

Technical Field

[0001] The present invention relates to the technical field of detection equipment, and specifically to a device and method for verifying the effectiveness of a fire extinguishing medium for a battery module. Background Art

[0002] The mainstream fire extinguishing media for battery modules on the market include perfluoropropane, heptafluoropropane, and aerosol. However, perfluoropropane is expensive by itself and difficult to store in large quantities for fire extinguishing when necessary. After the spraying of heptafluoropropane, there are residues in the surrounding environment, which have an impact on the environment for many years, and personnel cannot enter the spraying site for a short time. At the same time, it also has slight corrosiveness and can corrode the surrounding components. After the use of aerosol, it will adhere to the surface of the battery cells and is difficult to clean up subsequently.

[0003] Therefore, there is an urgent need to develop or select a fire extinguishing medium suitable for battery modules from the existing fire extinguishing media. When conducting research and development or selection, it is necessary to verify the effectiveness of the fire extinguishing medium for battery modules. Currently, there is no device or method for verifying the effectiveness of a fire extinguishing medium for battery modules on the market. Summary of the Invention

[0004] The purpose of the present invention is to provide a device and method for verifying the effectiveness of a fire extinguishing medium for a battery module to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A device for verifying the effectiveness of a fire extinguishing medium for a battery module, which includes: an explosion-proof container for placing a battery cell group for testing; a heating module for heating the battery cell group for testing; a monitoring module for measuring and recording the temperature and voltage of the battery cell group during the test in real time; a fire fighting unit for simulating the fire protection system when the battery cell group is in use and spraying a fire extinguishing medium onto the battery cell group; an atmosphere adjustment module for adjusting the oxygen content inside the explosion-proof container.

[0006] Preferably in this technical solution, it further includes: an ignition module for igniting the battery cell group during the test.

[0007] Preferably in this technical solution, the heating module includes: a power supply and a heating plate, the heating plate is electrically connected to the power supply, and the ignition module is an igniter.

[0008] Preferably, in this technical solution, the monitoring module is a multi-channel temperature and voltage monitoring device, and the multi-channel temperature and voltage monitoring device includes: multiple groups of voltage detection probes, multiple groups of temperature sensors, and a display device. The multiple groups of voltage detection probes are used to monitor the voltage of the battery cells, the multiple groups of temperature sensors are used to monitor the temperature of the battery cells, and the display device displays and records the data transmitted by the multiple groups of voltage detection probes and the multiple groups of temperature sensors.

[0009] Preferably, in this technical solution, the atmosphere adjustment module includes: a gas tank, a gas delivery pipe, a solenoid valve, and a gas detector. The gas detector is used to monitor the oxygen content around the battery cell group. The gas tank is connected to the explosion-proof container through the gas delivery pipe, and the solenoid valve is arranged on the gas delivery pipe.

[0010] Based on the above verification device, the present invention also proposes a method for verifying the effectiveness of the fire extinguishing medium for a battery module, including a method for verifying the thermal runaway of the battery module. The specific verification method is as follows:

[0011] S1: First, connect at least 3 fully charged battery cells in series, and bundle multiple battery cells together in the manner of large surfaces being in contact with each other to obtain a battery cell group. The first 3 battery cells in the battery cell group are sequentially named: the first battery cell, the second battery cell, and the third battery cell, and make the first large surface of the first battery cell face outward. Then, install a heating plate on the first large surface of the first battery cell, and then arrange voltage detection probes and temperature sensors in the battery cell group;

[0012] S2: Place the battery cell group and the fire fighting unit into the explosion-proof container, and electrically connect the heating plate to the power supply. Electrically connect the display device to the voltage detection probes and the temperature sensors respectively;

[0013] S3: Turn on the heating plate and the power supply to make the heating plate heat the first battery cell until the first battery cell has a thermal runaway, then stop heating, and spray the fire extinguishing medium on the battery cell group through the fire fighting unit until the explosion-proof container is filled with the fire extinguishing medium, then stop the fire fighting unit. After the test starts and before the explosion-proof container is filled with the fire extinguishing medium, keep the oxygen content in the explosion-proof container consistent with that of the air through the atmosphere adjustment module;

[0014] S4: Monitor and record the monitoring data of the voltage detection probes and the temperature sensors within 2 hours from the start of heating of the heating plate to the stop of spraying by the fire fighting unit.

[0015] Preferably, in this technical solution, the method for arranging the voltage detection probe and the temperature sensor in step S1 is as follows: When bundling the battery cells, connect the three groups of voltage detection probes to the positive and negative electrode posts of the first battery cell, the second battery cell, and the third battery cell respectively. At the same time, set the first temperature sensor, the second temperature sensor, the third temperature sensor, the fourth temperature sensor, the fifth temperature sensor, and the sixth temperature sensor on the first side surface and the second large surface of the first battery cell, the first large surface and the second large surface of the second battery cell, and the first large surface and the second large surface of the third battery cell respectively. Set the eighth temperature sensor and the ninth temperature sensor between the positive and negative electrodes on the top surface of the first battery cell and on the negative electrode respectively.

[0016] Preferably, in this technical solution, the thermal runaway determination condition of the first battery cell in step S3 is:

[0017] a. The first battery cell generates a voltage drop, and the drop value exceeds 25% of the initial voltage;

[0018] b. The temperature at any monitoring point reaches the maximum operating temperature specified by the manufacturer;

[0019] c. The temperature rise rate at any monitoring point ≥ 1 °C / s and lasts for more than 3 s;

[0020] When a and c occur simultaneously or b and c occur simultaneously, it is determined that the first battery cell has a thermal runaway.

[0021] Preferably, this technical solution further includes a method for verifying the ignition of the battery module, and the specific verification method is as follows:

[0022] N1: Name a fully charged battery cell as the fourth battery cell, install a heating plate on the first large surface of the fourth battery cell, and then arrange a voltage detection probe and a temperature sensor on the fourth battery cell;

[0023] N2: Place the fourth battery cell and the fire fighting unit into an explosion-proof container, electrically connect the heating plate to the power supply, and electrically connect the display device to the voltage detection probe and the temperature sensor respectively;

[0024] N3: Turn on the heating plate and the power supply to make the heating plate heat the fourth battery cell until the fourth battery cell has a thermal runaway and emits combustible gas and smoke from the spray valve. After continuously spraying for 5 seconds, use an igniter to ignite the combustible gas and smoke. And when combustion occurs inside the explosion-proof container and lasts for 60 seconds, use the fire fighting unit to spray a fire extinguishing medium onto the fourth battery cell until the explosion-proof container is filled with the fire extinguishing medium, then stop the fire fighting unit. After the start of the test and before the explosion-proof container is filled with the fire extinguishing medium, keep the oxygen content in the explosion-proof container consistent with that of the air through the atmosphere adjustment module;

[0025] N4: Monitor and record the monitoring data of the voltage detection probe and the temperature sensor within 2 hours after the heating plate starts heating until the fire fighting unit stops spraying.

[0026] Preferably, in this technical solution, the layout method of the temperature sensor in step N1 is as follows: a first temperature sensor is respectively arranged on the first major surface of the fourth battery cell, a seventh temperature sensor is arranged on the second side surface of the fourth battery cell, and an eighth temperature sensor and a ninth temperature sensor are respectively arranged on the top surface of the fourth battery cell between the positive and negative electrode posts and on the negative electrode post.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] Through the battery module fire extinguishing medium effectiveness verification device and method, it can help users verify the fire extinguishing effectiveness of various fire extinguishing media on the battery modules they want to use in the market. Furthermore, it can help users screen out the most suitable fire extinguishing medium for extinguishing the fire of this battery module. At the same time, for users who develop fire extinguishing media for battery modules, they can also verify the effectiveness of the developed fire extinguishing media through this verification device and verification method. Thus, it helps them determine the use effect and R & D direction of the fire extinguishing medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of the device of the present invention;

[0030] Figure 2 is a schematic diagram of the temperature sensor setting of the battery module thermal runaway test proposed by the present invention;

[0031] Figure 3 is a schematic diagram of the temperature sensor setting of the battery module fire test proposed by the present invention;

[0032] Figure 4 is an isometric view of the battery cell proposed by the present invention;

[0033] Figure 5 is a temperature result diagram of the thermal runaway verification method using perfluoromethylcyclohexane as the fire extinguishing medium;

[0034] Figure 6 is a temperature result diagram of the fire verification method using perfluoromethylcyclohexane as the fire extinguishing medium;

[0035] Figure 7 is a temperature result diagram of the thermal runaway verification method using water as the fire extinguishing medium;

[0036] Figure 8 is a temperature result diagram of the fire verification method using water as the fire extinguishing medium;

[0037] Figure 9Temperature result graph of the thermal runaway verification method using silicone oil as a fire extinguishing medium;

[0038] Figure 10 Temperature result graph of the ignition verification method using silicone oil as a fire extinguishing medium.

[0039] In the figure: 1. Explosion-proof container; 2. Heating module; 21. Heating plate; 3. Monitoring module; 31. First temperature sensor; 32. Second temperature sensor; 33. Third temperature sensor; 34. Fourth temperature sensor; 35. Fifth temperature sensor; 36. Sixth temperature sensor; 37. Seventh temperature sensor; 38. Eighth temperature sensor; 39. Ninth temperature sensor; 4. Fire fighting unit; 5. Ignition module; 6. Battery cell group; 61. First battery cell; 62. Second battery cell; 63. Third battery cell; 64. Fourth battery cell; 611. First major surface; 612. Second major surface; 613. First side surface; 614. Second side surface; 615. Top surface; 616. Bottom surface; 7. Atmosphere adjustment module. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0041] It should be noted that in the description of the present invention, the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are 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 should not be construed as a limitation of the present invention.

[0042] In addition, it should be understood that, for the convenience of description, the sizes of the various components shown in the accompanying drawings are not drawn in actual proportional relationships. For example, the thickness or width of some layers may be exaggerated relative to other layers.

[0043] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined or described in one drawing, it will not be necessary to further discuss and describe it specifically in the description of the subsequent drawings.

[0044] Before understanding the present invention, it should be clear that in order to make the measurement results of the present invention accurate and make the heat transfer uniform among different battery cells. The battery cells used in the present invention are as follows Figure 4 shown, which is an isometric view of the battery cell used in the test of the present invention. The battery cell is a cuboid structure and has six planes on its exterior. Among them, the two planes parallel to its length direction and width direction are the first large surface 611 and the second large surface 612 respectively; the two planes parallel to its length direction and thickness direction are the first side surface 613 and the second side surface 614 respectively; the two planes parallel to its width direction and thickness direction are the top surface 615 and the bottom surface 616 respectively. And the positive and negative electrode posts of the battery cell are respectively arranged on the top surface 615.

[0045] As Figure 1 shown, the present invention provides a technical solution: a verification device for the effectiveness of a fire extinguishing medium for a battery module includes: an explosion-proof container 1, a heating module 2, a monitoring module 3, a fire fighting unit 4, and an atmosphere adjustment module 7. The explosion-proof container 1 is used to place the battery cell group 6 or the battery cells for the test, and the main purpose of the explosion-proof container 1 is to prevent the battery cell group 6 or the battery cells from exploding and burning during the test and hurting people. Therefore, the explosion-proof container 1 needs to have a certain protection ability. The heating module 2 is used to heat the battery cells in the battery cell group 6. In the present invention, the heating module 2 can be various. For example, electric heating, microwave heating, or direct heating using a flame spraying device can be adopted. In a specific embodiment of the present invention, the heating module 2 includes: a power supply and a heating plate 21, and the heating plate 21 is electrically connected to the power supply. And the heating plate 21 can be closely attached to the first large surface 611 of the battery cell. The monitoring module 3 is used to measure and record the temperature and voltage of the battery cell group 6 in real time during the test. The monitoring module 3 can adopt any device on the market that can be used for temperature and voltage monitoring at the same time. It can also separately adopt a voltage monitoring device and a temperature monitoring device to monitor the temperature and voltage of the battery cell group 6. In a specific embodiment of the present invention, the monitoring module 3 is a multi-channel temperature and voltage monitoring device. The multi-channel temperature and voltage monitoring device includes: multiple groups of voltage detection probes, multiple groups of temperature sensors, and a display device. The multiple groups of voltage detection probes are used to monitor the voltage of the battery cell, the multiple groups of temperature sensors are used to monitor the temperature of the battery cell, and the display device displays and records the data transmitted by the multiple groups of voltage detection probes and the multiple groups of temperature sensors. And the fire fighting unit 4 is used to simulate the fire fighting system when the battery cell group 6 is in use and spray the fire extinguishing medium onto the battery cell group 6. Therefore, in the present invention, no restrictions are imposed on the fire fighting unit 4. During the test, it is preferably the fire fighting system actually used for the battery cell group 6 as the fire fighting unit 4 of the present invention. For example, the patent number is: CN105576305A, and the name is: Battery pack safety management system, which discloses a specific fire fighting device for spraying a fire extinguishing medium to extinguish the fire of the battery pack. When it is necessary to verify the effectiveness of the fire extinguishing medium for such a battery module, this fire fighting device can be selected.

[0046] It should be clear that the atmosphere adjustment module 7 is used to adjust the oxygen content inside the explosion-proof container 1. Since the verification device and verification method are used to verify the effectiveness of the fire extinguishing medium. And the traditional explosion-proof container 1 has the same actual use environment as the battery, which is a closed device. After the battery catches fire or explodes in a closed device, the burning battery will automatically go out due to lack of oxygen inside. Therefore, by adjusting the atmosphere state of the explosion-proof container 1 through the atmosphere adjustment module 7, the oxygen inside it is made consistent with the atmosphere, thereby improving the accuracy of verification. Therefore, it should be clear that the atmosphere adjustment module 7 can be of various types. In the present invention, the atmosphere adjustment module 7 includes: a gas tank, a gas delivery pipe, a solenoid valve, and a gas detector. The gas detector is used to monitor the oxygen content around the battery cell group 6. The gas tank is connected to the explosion-proof container 1 through the gas delivery pipe, and the solenoid valve is arranged on the gas delivery pipe. During verification, when the gas detector detects that the oxygen content inside the explosion-proof container 1 is lower than that of the air. The solenoid valve automatically opens, and at this time, the gas tank can deliver the gas inside it to the explosion-proof container 1 to adjust the oxygen content inside the explosion-proof container 1. When the oxygen content inside the explosion-proof container 1 reaches the air content, the solenoid valve automatically closes. Of course, in other embodiments, in order to stabilize the oxygen content inside the explosion-proof container 1, the opening and closing size of the solenoid valve can be used to stably adjust the oxygen content inside the explosion-proof container 1 in real time. The linkage between the gas detector and the solenoid valve is a very mature existing technology, so it will not be elaborated here.

[0047] It should be clear that since other combustible gases and smoke will be generated in the explosion-proof container 1 during verification, the gas pressure inside the gas tank needs to be greater than the gas pressure inside the explosion-proof container 1 to produce a positive input. It has been found through multiple practices that it is more appropriate to control the gas pressure inside the gas tank to 3 atmospheres. At the same time, the gas inside the gas tank is mainly a mixture of nitrogen and oxygen, and the volume ratio of oxygen to nitrogen is 23:77 to 30:70.

[0048] Furthermore, in order to more clearly verify the effectiveness of the fire extinguishing medium. The device of the present invention further includes an ignition module 5, and the ignition module 5 is used to ignite the battery cell group 6 during the test. Thereby verifying the fire extinguishing effectiveness of the fire extinguishing medium. In the present invention, the ignition module 5 can be any device as long as it can ignite the combustible gases and smoke generated after the battery cell group 6 gets thermally out of control. Specifically, in this embodiment, the ignition module 5 is an igniter.

[0049] Based on the above-mentioned device for verifying the effectiveness of the fire extinguishing medium for battery modules, the present invention proposes a method for verifying the effectiveness of the fire extinguishing medium for battery modules. It includes a method for verifying the thermal runaway of the battery module, and the specific verification method is as follows:

[0050] S1: First, connect at least three fully charged battery cells in series, and then bundle multiple battery cells together in the way that their large faces are in contact with each other to obtain a battery cell group 6. The first three battery cells in the battery cell group 6 are named as the first battery cell 61, the second battery cell 62, and the third battery cell 63 in sequence, and make the first large face 611 of the first battery cell 61 face outward. Then, install a heating plate 21 on the first large face 611 of the first battery cell 61, and then arrange voltage detection probes and temperature sensors in the battery cell group 6.

[0051] As Figure 2 shown, in this method, the arrangement method of the voltage detection probes and temperature sensors is as follows: when bundling the battery cells, connect three groups of voltage detection probes to the positive and negative electrode posts of the first battery cell 61, the second battery cell 62, and the third battery cell 63 respectively. At the same time, set the first temperature sensor 31, the second temperature sensor 32, the third temperature sensor 33, the fourth temperature sensor 34, the fifth temperature sensor 35, and the sixth temperature sensor 36 on the first side face 613 and the second large face 612 of the first battery cell 61, the first large face 611 and the second large face 612 of the second battery cell 62, and the first large face 611 and the second large face 612 of the third battery cell 63 respectively. Set the eighth temperature sensor 38 and the ninth temperature sensor 39 between the positive and negative electrodes on the top face 615 of the first battery cell 61 and on the negative electrode respectively.

[0052] S2: Place the battery cell group 6 and the fire fighting unit 4 into the explosion-proof container 1, and electrically connect the heating plate 21 to the power supply. Electrically connect the display device to the voltage detection probes and temperature sensors respectively.

[0053] S3: Turn on the heating plate 21 and the power supply, so that the heating plate 21 heats the first battery cell 61 until the first battery cell 61 has a thermal runaway, then stop heating, and spray a fire extinguishing medium onto the battery cell group 6 through the fire fighting unit 4 until the explosion-proof container 1 is filled with the fire extinguishing medium, then stop the fire fighting unit 4. After the test starts and before the explosion-proof container 1 is filled with the fire extinguishing medium, keep the oxygen content in the explosion-proof container 1 the same as that in the air through the atmosphere adjustment module 7.

[0054] Among them: The thermal runaway determination conditions of the first battery cell 61 are:

[0055] a The first battery cell 61 generates a voltage drop, and the drop value exceeds 25% of the initial voltage;

[0056] b The temperature at any monitoring point reaches the maximum working temperature specified by the manufacturer;

[0057] c The temperature rise rate at any monitoring point ≥ 1 °C / s and lasts for more than 3 s;

[0058] When a and c occur simultaneously or b and c occur simultaneously, it is determined that the first battery cell 61 has a thermal runaway.

[0059] S4: Monitor and record the monitoring data of the voltage detection probe and the temperature sensor within 2 hours after the heating plate 21 starts heating until the fire fighting unit 4 stops spraying.

[0060] Meanwhile, in order to further verify the effectiveness of the fire extinguishing medium for extinguishing fires in the battery module. The method for verifying the effectiveness of the fire extinguishing medium for the battery module further includes a method for verifying the ignition of the battery module, and the specific verification method is as follows:

[0061] N1: Name a fully charged battery cell as the fourth battery cell 64, install the heating plate 21 on the first major surface 611 of the fourth battery cell 64, and then arrange a voltage detection probe and a temperature sensor on the fourth battery cell 64.

[0062] As Figure 3 shown, the arrangement method of the temperature sensor is: respectively set the first temperature sensor 31 on the first major surface 611 of the fourth battery cell 64, set the seventh temperature sensor 37 on the second side surface 614 of the fourth battery cell 64, and set the eighth temperature sensor 38 and the ninth temperature sensor 39 on the top surface 615 of the fourth battery cell 64 between the positive and negative electrode posts and on the negative electrode post respectively.

[0063] N2: Place the fourth battery cell 64 and the fire fighting unit 4 into the explosion-proof container 1, electrically connect the heating plate 21 to the power supply, and electrically connect the display device to the voltage detection probe and the temperature sensor respectively.

[0064] N3: Turn on the heating plate 21 and the power supply, so that the heating plate 21 heats the fourth battery cell 64 until the fourth battery cell 64 undergoes thermal runaway and emits combustible gas and smoke from the spray valve. After continuously spraying for 5 seconds, use an igniter to ignite the combustible gas and smoke. And when combustion occurs inside the explosion-proof container 1 and lasts for 60 seconds, spray the fire extinguishing medium onto the fourth battery cell 64 through the fire fighting unit 4 until the explosion-proof container 1 is filled with the fire extinguishing medium, then stop the fire fighting unit 4. After the start of the test and before the explosion-proof container 1 is filled with the fire extinguishing medium, keep the oxygen content in the explosion-proof container 1 consistent with that of the air through the atmosphere adjustment module 7.

[0065] N4: Monitor and record the monitoring data of the voltage detection probe and the temperature sensor within 2 hours after the heating plate 21 starts heating until the fire fighting unit 4 stops spraying.

[0066] Specifically, the inventor verified the fire extinguishing effectiveness of perfluoromethylcyclohexane, water, and silicone oil for the battery module through the device and method for verifying the effectiveness of the fire extinguishing medium for the battery module of the present invention respectively.

[0067] Among them: In step S1, the battery cell group 6 consists of 9 battery cells, and the remaining steps and parameters are the same as described above. When recording the test results, the test data of the first temperature sensor 31, the second temperature sensor 32, the third temperature sensor 33, the fourth temperature sensor 34, the fifth temperature sensor 35, the sixth temperature sensor 36, the seventh temperature sensor 37, the eighth temperature sensor 38, and the ninth temperature sensor 39 are named 1#, 2#, 3#, 4#, 5#, 6#, 7#, 8#, and 9# respectively. Specifically, the obtained test results are as Figures 5 to 10 shown. Figure 5 It is a temperature result graph of the thermal runaway verification method using perfluoromethylcyclohexanone as the fire extinguishing medium; Figure 6 It is a temperature result graph of the ignition verification method using perfluoromethylcyclohexanone as the fire extinguishing medium; Figure 7 It is a temperature result graph of the thermal runaway verification method using water as the fire extinguishing medium; Figure 8 It is a temperature result graph of the ignition verification method using water as the fire extinguishing medium; Figure 9 It is a temperature result graph of the thermal runaway verification method using silicone oil as the fire extinguishing medium; Figure 10 It is a temperature result graph of the ignition verification method using silicone oil as the fire extinguishing medium.

[0068] Specifically, in the three groups of tests of battery module thermal runaway, no deflagration occurred when perfluoromethylcyclohexanone, water, and silicone oil were sprayed respectively in the case of battery module thermal runaway. During the 2 hours when the entire battery module was soaked in the fire extinguishing medium, no explosion occurred, and except for the first heated battery cell 61 having thermal runaway, no other battery cells had thermal runaway. Among them, when using perfluoromethylcyclohexanone for the test, the voltage of the first battery cell 61 dropped to zero from 3.33V from 3094 seconds to 3194 seconds; when using water for the test, the voltage of the first battery cell 61 dropped to zero from 3.33V from 3094 seconds to 3199 seconds; when using silicone oil for the test, the voltage of the first battery cell 61 dropped to zero from 3.33V from 3096 seconds to 3198 seconds. From Figure 5 , Figure 7 and Figure 9 For the battery module thermal runaway test results, it can be seen that perfluoromethylcyclohexanone has the most obvious temperature control effect, the fastest temperature drop rate, and can well control the re - warming of the battery cells; water has a good temperature reduction and control effect, can effectively reduce the surface temperature of the battery cells, but the effect is average; the effect of silicone oil is the least obvious. After spraying silicone oil, it can be seen that the temperature does not drop within a period of time, the temperature tends to be in an equilibrium state, and there is no temperature drop performance in a short time, and the effect is the worst. Therefore, in the battery module thermal runaway test, the temperature reduction effects of perfluoromethylcyclohexanone, water, and silicone oil decrease in turn.

[0069] Specifically, in the three groups of tests on the battery module catching fire, when perfluoromethylcyclohexanone, water, and silicone oil were sprayed respectively while the module cells were in thermal runaway and burning, no deflagration occurred. During the spraying of perfluoromethylcyclohexanone, water, and silicone oil respectively, the flames ignited by the battery module could be extinguished, the temperature of the battery module could drop, and there was no re - warming or re - ignition phenomenon, indicating that when the cells caught fire, spraying perfluoromethylcyclohexanone, water, or silicone oil could control the spread of the fire. However, from Figure 6 , Figure 8 and Figure 10 in the battery module fire - starting test results, when using perfluoromethylcyclohexanone as the fire - extinguishing medium, the battery module has the fastest temperature - decreasing speed and the most obvious temperature - decreasing effect; when using water as the fire - extinguishing medium, the temperature - decreasing effect of the battery module is average; while when using silicone oil as the fire - extinguishing medium, the temperature - decreasing effect of the battery module is the least obvious. When silicone oil is injected, the temperature still has an upward trend and the temperature drops slowly, and silicone oil cannot quickly reduce the surface temperature of the battery module. Therefore, in the battery module fire - starting test, the usage effects of perfluoromethylcyclohexanone, water, and silicone oil decrease in turn.

[0070] In summary, through this verification device and verification method, comprehensive consideration can be carried out. The fire - extinguishing media suitable for battery modules in various different application scenarios can be screened out. Also, this verification device and verification method can be used for the effect evaluation during the research and development of fire - extinguishing media for battery modules.

[0071] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An apparatus for verifying the effectiveness of a fire extinguishing medium for a battery module, characterized in that, Comprising: An explosion-proof container (1) for placing a battery cell group (6) for testing; the battery cell group (6) includes at least three fully charged battery cells; the battery cells are connected in series and bundled together in a manner that the large faces are in contact; the first three battery cells are a first battery cell (61), a second battery cell (62), and a third battery cell (63) in sequence, and the first large face (611) of the first battery cell (61) faces outward. A heating module (2), including a power supply and a heating plate (21), the heating plate (21) being electrically connected to the power supply; the heating module (2) is used to heat the battery cell group (6) for testing; the heating plate (21) is disposed on the large face of the first battery cell (61). A monitoring module (3) for measuring and recording in real time the temperature and voltage of the battery cell group (6) during the test; the monitoring module (3) includes three groups of voltage detection probes and first to ninth temperature sensors (31 - 39). The three groups of voltage detection probes are respectively connected to the positive and negative electrode posts of the first battery cell (61), the second battery cell (62), and the third battery cell (63). The first temperature sensor (31), the second temperature sensor (32), the third temperature sensor (33), the fourth temperature sensor (34), the fifth temperature sensor (35), and the sixth temperature sensor (36) are respectively disposed on the first side face (613) and the second large face (612) of the first battery cell (61), the first large face (611) and the second large face (612) of the second battery cell (62), and the first large face (611) and the second large face (612) of the third battery cell (63); the eighth temperature sensor (38) and the ninth temperature sensor (39) are respectively disposed between the positive and negative electrodes on the top face (615) of the first battery cell (61) and on the negative electrode. A fire fighting unit (4) for simulating a fire fighting system during the use of the battery cell group (6) and spraying a fire extinguishing medium onto the battery cell group (6). An atmosphere regulating module (7) for regulating the oxygen content inside the explosion-proof container (1). A gas tank, a gas delivery pipe, a solenoid valve, and a gas detector, the gas detector being used to monitor the oxygen content around the battery cell group (6), the gas tank being connected to the explosion-proof container (1) through the gas delivery pipe, and the solenoid valve being disposed on the gas delivery pipe. The gas pressure inside the gas tank is 3 atmospheres.

2. The validity verification device for the fire extinguishing medium used in the battery module according to claim 1, characterized in that, It further includes: an ignition module (5) for igniting the battery cell group (6) during the test.

3. The validity verification device for the fire extinguishing medium of a battery module according to claim 2, characterized in that, The ignition module (5) is an igniter.

4. A method for verifying the effectiveness of a fire extinguishing medium for a battery module, characterized in that, Including a method for verifying thermal runaway of a battery module, and the specific verification method is as follows: S1: First, connect at least three fully charged battery cells in series, and bundle multiple battery cells together in the way that their large faces are in contact with each other to obtain a battery cell group (6). The first three battery cells in the battery cell group (6) are named as the first battery cell (61), the second battery cell (62), and the third battery cell (63) in sequence, and make the first large face (611) of the first battery cell (61) face outwards. Then, install a heating plate (21) on the first large face (611) of the first battery cell (61), and then arrange voltage detection probes and temperature sensors in the battery cell group (6). The arrangement method of the voltage detection probes and temperature sensors in step S1 is: when bundling the battery cells, connect three groups of voltage detection probes to the positive and negative electrode posts of the first battery cell (61), the second battery cell (62), and the third battery cell (63) respectively. At the same time, set the first temperature sensor (31), the second temperature sensor (32), the third temperature sensor (33), the fourth temperature sensor (34), the fifth temperature sensor (35), and the sixth temperature sensor (36) on the first side face (613) and the second large face (612) of the first battery cell (61), the first large face (611) and the second large face (612) of the second battery cell (62), and the first large face (611) and the second large face (612) of the third battery cell (63) respectively. Set the eighth temperature sensor (38) and the ninth temperature sensor (39) between the positive and negative electrodes on the top face (615) of the first battery cell (61) and on the negative electrode. S2: Place the battery cell group (6) and the fire fighting unit group (4) into the explosion-proof container (1), and electrically connect the heating plate (21) to the power supply. Electrically connect the display device to the voltage detection probes and temperature sensors respectively. S3: Turn on the heating plate (21) and the power supply, so that the heating plate (21) heats the first battery cell (61) until the first battery cell (61) has a thermal runaway, then stop heating. And spray a fire extinguishing medium from the fire fighting unit group (4) to the battery cell group (6) until the explosion-proof container (1) is filled with the fire extinguishing medium, then stop the fire fighting unit group (4). After the test starts and before the explosion-proof container (1) is filled with the fire extinguishing medium, keep the oxygen content in the explosion-proof container (1) the same as that in the air through the atmosphere adjustment module (7). S4: Monitor and record the monitoring data of the voltage detection probes and temperature sensors within 2 hours from the start of heating of the heating plate (21) to the stop of spraying by the fire fighting unit group (4). It also includes a verification method for the ignition of the battery module, and the specific verification method is as follows: N1: Name a fully charged battery cell as the fourth battery cell (64), install a heating plate (21) on the first large face (611) of the fourth battery cell (64), and then arrange voltage detection probes and temperature sensors on the fourth battery cell (64). N2: Place the fourth battery cell (64) and the fire fighting unit group (4) into the explosion-proof container (1), and electrically connect the heating plate (21) to the power supply. Electrically connect the display device to the voltage detection probes and temperature sensors respectively. N3: Connect the heating plate (21) to the power supply so that the heating plate (21) heats the fourth battery cell (64) until the fourth battery cell (64) experiences thermal runaway and combustible gas and smoke are ejected from the spray valve. After continuously ejecting for 5 seconds, use an igniter to ignite the combustible gas and smoke. And when combustion occurs inside the explosion-proof container (1) and continues for 60 seconds, spray a fire extinguishing medium towards the fourth battery cell (64) through the fire protection unit (4) until the explosion-proof container (1) is filled with the fire extinguishing medium, then stop the fire protection unit (4). After the start of the test and before the explosion-proof container (1) is filled with the fire extinguishing medium, keep the oxygen content in the explosion-proof container (1) consistent with that of the air through the atmosphere adjustment module (7); N4: Monitor and record the monitoring data of the voltage detection probe and the temperature sensor within 2 hours after the heating plate (21) starts heating until the fire protection unit (4) stops spraying; The layout method of the temperature sensor in step N1 is as follows: respectively set the first temperature sensor (31) on the first major surface (611) of the fourth battery cell (64), set the seventh temperature sensor (37) on the second side surface (614) of the fourth battery cell (64), and set the eighth temperature sensor (38) and the ninth temperature sensor (39) on the top surface (615) of the fourth battery cell (64) between the positive and negative terminal posts and on the negative terminal post respectively.

5. A method for verifying the effectiveness of a fire extinguishing medium for a battery module according to claim 4, characterized in that, The thermal runaway determination conditions of the first battery cell (61) in step S3 are: a) The first battery cell (61) generates a voltage drop, and the drop value exceeds 25% of the initial voltage; b) The temperature at any monitoring point reaches the maximum operating temperature specified by the manufacturer; c) The temperature rise rate at any monitoring point ≥ 1 °C / s and lasts for more than 3 s; When a) and c) occur simultaneously or b) and c) occur simultaneously, it is determined that the first battery cell (61) has experienced thermal runaway.

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