A safety performance experimental protection device for lithium batteries

Abstract

The present invention relates to the technical field of battery inspection and detection, and specifically to a lithium battery safety performance experiment protection device, which includes a test bench, a first protective cover is arranged outside the test bench, the first protective cover surrounds the test bench, a second protective cover is arranged outside the first protective cover, the second protective cover surrounds the first protective cover, the first protective cover is fixedly connected with a first air inlet pipe and an air outlet pipe, the first air inlet pipe and the air outlet pipe are both connected to the inside of the first protective cover, the air outlet pipe is fixedly connected with an exhaust pump, the second protective cover is fixedly connected with a second air inlet pipe, the air outlet pipe is fixedly connected to the second protective cover, the second air inlet pipe is connected to the inside and outside of the second protective cover, the air outlet pipe is connected to the outside of the second protective cover, the other end of the first air inlet pipe is connected to the outside of the second protective cover, and the other end of the second air inlet pipe is connected to a gas generating device capable of conveying inert gas. The present application has the effect of being able to protect test personnel, reduce the harm of test personnel to battery experiments, and reduce environmental pollution.

Description

Technical Field

[0001] The present invention relates to the technical field of battery inspection and testing, and particularly relates to a protection device for lithium battery safety performance experiments. Background Art

[0002] Batteries are widely used in electric vehicles, energy storage devices, mobile phones, electrical appliances, industry, and consumer goods fields. In recent years, with the large-scale use of electric vehicles in society, some problems have also been encountered. For example, a small number of electric vehicles have caught fire due to various reasons, resulting in the combustion of the entire vehicle, or the rupture of lithium batteries has caused toxic electrolyte leakage into the air. The risks of energy storage equipment catching fire, burning, and exploding, and the risks of lithium-ion power batteries catching fire and burning come from the instantaneous release of the chemical energy of the battery at high temperatures (high-voltage electric shock is not within the scope of discussion in this article), manifested as: thermal runaway and thermal diffusion of the battery causing the combustion or explosion of the entire vehicle, or the leakage of toxic gases from the electrolyte. The thermal runaway of in-vehicle power lithium batteries is the main cause of fire and explosion accidents in new energy vehicles and lithium battery energy storage devices. Lithium battery fires have the characteristics of high combustion intensity, high combustion temperature, the generation of a large amount of toxic and harmful gases, and difficult fire fighting, and there is also a risk of explosion. There are also risks such as explosion and combustion during the detection process of lithium batteries, which need to be controlled.

[0003] There is a prior invention patent with an application publication number of CN113835398A, which protects a safety system for a power battery laboratory, including: a central processing unit, a test process unit, a high-pressure fine water mist unit, a storage room monitoring unit, an accident fan unit, and a building fire protection unit; wherein, the test process unit is configured to be able to control the test process of at least one tested power battery, and includes the following components: an operating console, an environmental chamber, a temperature control component for controlling the temperature of the environmental chamber; and a power supply component for the test process unit; the high-pressure fine water mist unit is configured to be able to spray a cooling and flame-retardant medium into the environmental chamber in the form of high-pressure fine water mist; wherein, the central processing unit is signal-connected to a beacon, and the central processing unit further includes a buzzer. This application also provides a method for a power battery laboratory, as well as a device, a computer program product, and a computer storage medium for implementing the method.

[0004] In the above technical solution, when the battery is being inspected and tested, since the battery may catch fire or explode during the inspection and testing process, and at the same time, it will generate toxic and harmful gases, which will harm the physical health of the test personnel and also cause environmental pollution. Summary of the Invention

[0005] To solve the problem that existing battery experiments are prone to harm the physical health of test personnel and the environment, the present invention provides a protection device for lithium battery safety performance experiments.

[0006] The technical solution of the present invention is as follows:

[0007] The present invention provides a protection device for lithium battery safety performance experiments, including a test bench. A first protective cover is arranged outside the test bench, and the first protective cover surrounds the test bench. A second protective cover is arranged outside the first protective cover, and the second protective cover surrounds the first protective cover. The first protective cover is fixedly connected with a first air inlet pipe and an air outlet pipe. Both the first air inlet pipe and the air outlet pipe communicate with the inside of the first protective cover. The air outlet pipe is fixedly connected with an air extraction pump. The second protective cover is fixedly connected with a second air inlet pipe. The air outlet pipe is fixedly connected to the second protective cover. The second air inlet pipe communicates the inside and outside of the second protective cover. The air outlet pipe communicates with the outside of the second protective cover. The other end of the first air inlet pipe communicates with the outside of the second protective cover. The other end of the second air inlet pipe communicates with a gas generating device capable of transporting inert gas.

[0008] The beneficial effects achieved by the present invention are as follows: When the battery is being experimented on the test bench, the air extraction pump extracts a part of the air inside the first protective cover, making the environment in a low-oxygen environment and reducing the possibility of battery combustion. The first protective cover and the second protective cover will block the toxic gases, high temperature or impact generated by the battery combustion or explosion. Inert gas is also input between the second protective cover and the first protective cover to further reduce the risk of combustion, and at the same time, increasing the air pressure will reduce the impact generated by the explosion.

[0009] Furthermore, the first air inlet pipe is fixedly connected with a first regulating valve, and one end of the second air inlet pipe extending out of the second protective cover is fixedly connected with a second regulating valve.

[0010] Through the above scheme, the first regulating valve can control the gas flow rate of the first air inlet pipe, and the second regulating valve can control the gas flow rate of the second air inlet pipe, facilitating the user to control the gas composition and air pressure inside the first protective cover and the second protective cover.

[0011] Furthermore, it also includes a control system: The control system includes a pressure detection module, a flow calculation module, and a flow control module;

[0012] The pressure detection module includes a first pressure sensor arranged inside the first protective cover and a second pressure sensor arranged inside the second protective cover. The first pressure sensor detects the first air pressure value inside the first protective cover and outputs it. The second pressure sensor detects the second air pressure value inside the second protective cover and outputs it;

[0013] The flow calculation module receives the input target air pressure value, compares the first air pressure value with the target air pressure value, outputs a deflation signal when the air pressure value is greater than the target air pressure value, and outputs a gas supplement signal when the air pressure value is less than the target air pressure value. The flow calculation module compares the second air pressure value with the first air pressure value, and when the first air pressure value is greater than the second air pressure value, it outputs a pressurization signal;

[0014] When the flow control module receives the air release signal, it increases the power of the air extraction pump and controls the first regulating valve to close. When the flow control module receives the air supply signal, it shuts down the air extraction pump and controls the first regulating valve to increase the flow rate. When the flow control module receives the pressurization signal, it controls the second regulating valve to increase the flow rate.

[0015] Through the above solution, the control system automatically obtains the first air pressure value and the second air pressure value and controls the air extraction pump, the first regulating valve, and the second regulating valve according to the obtained data to automatically adjust the air pressure and gas components in the first protective cover and the second protective cover.

[0016] Further, the flow control module includes a first flow sensor disposed in the first air inlet pipe and a second flow sensor disposed in the air outlet pipe. The first flow sensor detects the gas flow rate in the first air inlet pipe to obtain the first flow rate information, and the second flow sensor detects the gas flow rate in the air outlet pipe to obtain the second flow rate information.

[0017] Through the above solution, the flow control module can obtain the flow rate of the first air inlet pipe and the second air inlet pipe to achieve more precise control and facilitate the user to monitor the conditions of the first air inlet pipe and the second air inlet pipe.

[0018] Further, the air outlet pipe is fixedly connected with a first filter layer and a second filter layer. The first filter layer and the second filter layer both cover the longitudinal section of the air outlet pipe. The first filter layer is composed of activated carbon, and the second filter layer is composed of a breathable material with sodium hydroxide.

[0019] Through the above solution, the activated carbon can adsorb organic pollutant impurities, and the sodium hydroxide can filter acidic gases generated in the battery experiment, such as HF, etc.

[0020] Further, the air outlet pipe is fixedly connected with a spraying device. The control system further includes a smoke detection module and a fire extinguishing processing module;

[0021] The smoke detection module includes a smoke sensor disposed in the first protective cover. The smoke sensor detects the smoke concentration in the first protective cover and outputs a fire extinguishing signal when the detected smoke concentration exceeds a preset value;

[0022] The fire extinguishing processing module controls the spraying device to start after receiving the fire extinguishing signal.

[0023] Through the above solution, the spraying device can perform spraying treatment on the passing gas to further absorb the smoke and purify the discharged gas.

[0024] Further, the first air inlet pipe is internally connected to the second protective cover. One end of the first air inlet pipe extending into the second protective cover is fixedly connected with an electromagnetic valve. The control system further includes a temperature detection module and a risk control module;

[0025] The temperature detection module includes a first temperature sensor disposed within a first protective cover. The first temperature sensor detects the temperature value within the first protective cover and outputs it.

[0026] The risk control module presets a risk temperature value. The risk control module compares the temperature value with the risk temperature value. When the temperature value is higher than the risk temperature value, the risk control module opens the solenoid valve and controls the second regulating valve to increase the flow rate.

[0027] Through the above solution, when a fire may occur during the battery experiment, the temperature rises. At this time, the control system increases the input amount of inert gas, further reducing the oxygen content in the air and reducing the possibility of combustion.

[0028] Furthermore, a fire extinguishing device is fixedly connected to the position of the first protective cover corresponding to above the test bench. The fire extinguishing device is fixedly connected to a storage tank storing heptafluorobutane or carbon dioxide. The control system further includes a danger judgment module and a fire extinguishing control module.

[0029] The temperature detection module further includes a second temperature sensor disposed on the test bench. The second temperature sensor detects the temperature value of the battery and outputs it.

[0030] The danger judgment module presets a fire judgment table. The fire judgment table includes the temperature value within the first protective cover, the temperature value of the battery, and the numerical range of the smoke concentration during battery ignition. When any one of the temperature value within the first protective cover, the temperature value of the battery, and the smoke concentration is within the fire judgment table, an alarm signal is output.

[0031] After receiving the alarm signal, the fire extinguishing control module controls the fire extinguishing device to start.

[0032] Through the above solution, the fire extinguishing device can release heptafluorobutane or carbon dioxide and can quickly extinguish the fire. When the control system detects a fire, it can automatically extinguish the fire.

[0033] Furthermore, a first pressure relief pipeline is fixedly connected to the first protective cover. The first pressure relief pipeline communicates the interior of the first protective cover and the exterior of the second protective cover.

[0034] Through the above solution, the first pressure relief pipeline can play a role in balancing the air pressure within the first protective cover and avoid excessive air pressure within the first protective cover.

[0035] Furthermore, an explosion-proof lamp is fixedly connected within the first protective cover, and multiple cameras are fixedly connected within the first protective cover. The cameras are arranged around the test bench.

[0036] Through the above solution, the explosion-proof lamp reduces the possibility of being damaged by battery explosion while providing illumination. Multiple cameras capture the test images from multiple angles, helping the user conduct the experiment, collect experimental data, and monitor the experimental process.

[0037] A lithium battery safety performance experimental protection device of the present invention has the following advantages:

[0038] 1. When the battery is being experimented on the test bench, the air pump pumps out a part of the air in the first protective cover, making the environment in a low-oxygen environment and reducing the possibility of the battery burning. The first protective cover and the second protective cover will block the toxic gases, high temperature or impact generated by the battery burning or exploding. Inert gas is also input between the second protective cover and the first protective cover to further reduce the risk of combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0040] Figure 2 is a cross-sectional view of the test bench, the first protective cover and the second protective cover of the present invention;

[0041] Figure 3 is a cross-sectional view of the air outlet pipe, the first air inlet pipe and the second air inlet pipe of the present invention;

[0042] Figure 4 is a system block diagram of the control system of the present invention.

[0043] In the figure, 1, test bench; 2, first protective cover; 21, first air inlet pipe; 211, first regulating valve; 212, solenoid valve; 22, air outlet pipe; 221, air pump; 222, first filter layer; 223, second filter layer; 224, spraying device; 23, first pressure relief pipe; 24, fire extinguishing device; 241, storage tank; 25, explosion-proof lamp; 26, camera; 27, entrance and exit; 271, access door; 28, second pressure relief pipe; 3, second protective cover; 31, second air inlet pipe; 311, gas generating equipment; 312, second regulating valve; 4, control system; 41, pressure detection module; 411, first pressure sensor; 412, second pressure sensor; 42, flow calculation module; 43, flow control module; 431, first flow sensor; 432, second flow sensor; 44, smoke detection module; 441, smoke sensor; 45, fire extinguishing processing module; 46, temperature detection module; 461, first temperature sensor; 462, second temperature sensor; 47, risk control module; 48, danger judgment module; 49, fire extinguishing control module. DETAILED DESCRIPTION OF THE INVENTION

[0044] For the convenience of those skilled in the art to understand the present invention, the following describes the specific embodiments of the present invention with reference to the drawings.

[0045] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It 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. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0046] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0047] The present invention provides a protection device for lithium battery safety performance experiments, as Figure 1 and Figure 2 shown, which includes a test bench 1. A first protective cover 2 is arranged outside the test bench 1, and the first protective cover 2 surrounds the test bench 1. A second protective cover 3 is arranged outside the first protective cover 2, and the second protective cover 3 surrounds the first protective cover 2. Both the first protective cover 2 and the second protective cover 3 are made of explosion-proof materials such as stainless steel. Entrance and exit openings 27 for people to enter and exit are provided on both the first protective cover 2 and the second protective cover 3, and access doors 271 capable of covering the corresponding entrance and exit openings 27 are arranged at the positions corresponding to the entrance and exit openings 27 on both the first protective cover 2 and the second protective cover 3.

[0048] As Figure 2 and Figure 3As shown, the first protective cover 2 is fixedly connected with a first air inlet pipe 21 and an air outlet pipe 22. Both the first air inlet pipe 21 and the air outlet pipe 22 communicate with the inside of the first protective cover 2. The air outlet pipe 22 is fixedly connected to the second protective cover 3, and the air outlet pipe 22 communicates with the outside of the second protective cover 3. The other end of the first air inlet pipe 21 communicates with the outside of the second protective cover 3 and the outside of the first protective cover 2. The air outlet pipe 22 is fixedly connected with an air extraction pump 221. The second protective cover 3 is fixedly connected with a second air inlet pipe 31. The second air inlet pipe 31 communicates with the inside and outside of the second protective cover 3, and the other end of the second air inlet pipe 31 communicates with a gas generating device 311 capable of transporting inert gas. The inert gas can be nitrogen, and the gas generating device 311 can be a nitrogen storage tank or a nitrogen generator. When the battery is being experimented on the test bench 1, the air extraction pump 221 extracts a part of the air inside the first protective cover 2, making the environment in a low-oxygen environment and reducing the possibility of the battery catching fire. Inert gas is also input between the second protective cover 3 and the first protective cover 2 to further reduce the risk of combustion.

[0049] As Figure 2 and Figure 3 shown, the air outlet pipe 22 is fixedly connected with a first filter layer 222 and a second filter layer 223. Both the first filter layer 222 and the second filter layer 223 cover the longitudinal section of the air outlet pipe 22. The first filter layer 222 is composed of activated carbon, and the second filter layer 223 is composed of a breathable material with sodium hydroxide. The activated carbon can adsorb organic pollutant impurities, and sodium hydroxide can filter acidic gases generated in the battery experiment, such as HF. The air outlet pipe 22 is fixedly connected with a spraying device 224. The spraying device 224 is used to spray liquid into the air outlet pipe 22 to further absorb the smoke and purify the discharged gas.

[0050] As Figure 2 and Figure 3 shown, one end of the first air inlet pipe 21 extending out of the second protective cover 3 is fixedly connected with a first regulating valve 211, and one end of the first air inlet pipe 21 extending into the second protective cover 3 is fixedly connected with an electromagnetic valve 212. The second air inlet pipe 31 is fixedly connected with a second regulating valve 312. The first regulating valve 211 can control the gas flow rate of the air in the first air inlet pipe 21, and the first regulating valve 211 can control the gas flow rate of the air in the first air inlet pipe 21. The second regulating valve 312 can control the gas flow rate of the second air inlet pipe 31, facilitating the user to control the gas composition and air pressure inside the first protective cover 2 and the second protective cover 3. The first air inlet pipe 21 communicates with the inside of the second protective cover 3, and one end of the first air inlet pipe 21 extending into the second protective cover 3 is fixedly connected with an electromagnetic valve 212. The first air inlet pipe 21 can receive the inert gas inside the second protective cover 3 and let the inert gas enter the first protective cover 2 to further reduce the oxygen content in the air and reduce the possibility of combustion occurring.

[0051] As Figure 2 and Figure 3As shown, a first pressure relief pipeline 23 is fixedly connected to the first protective cover 2. The first pressure relief pipeline 23 communicates the inside of the first protective cover 2 and the outside of the second protective cover 3. A second pressure relief pipeline 28 is fixedly connected to the first protective cover 2. The second pressure relief pipeline 28 communicates the inside and outside of the first protective cover 2. The first pressure relief pipeline 23 and the second pressure relief pipeline 28 can balance the air pressure inside the first protective cover 2 and prevent the air pressure inside the first protective cover 2 from being too high.

[0052] As Figure 2 and Figure 3 shown, an explosion-proof lamp 25 is fixedly connected inside the first protective cover 2, and a plurality of cameras 26 are fixedly connected inside the first protective cover 2. The cameras 26 are arranged around the test bench 1. The explosion-proof lamp 25 provides illumination while reducing the possibility of being damaged by battery explosion. The plurality of cameras 26 monitor the test images from multiple angles to help the user conduct the test and collect experimental data. A fire extinguishing device 24 is fixedly connected to the position of the first protective cover 2 corresponding to the upper part of the test bench 1. The fire extinguishing device 24 is fixedly connected to a storage tank 241 storing heptafluorobutane or carbon dioxide. The fire extinguishing device 24 can release heptafluorobutane or carbon dioxide and can quickly extinguish the fire.

[0053] As Figure 4 shown, the test bench 1 is connected to a control system 4. The control system 4 includes a pressure detection module 41, a flow calculation module 42, a flow control module 43, a smoke detection module 44, a fire extinguishing processing module 45, a temperature detection module 46, a risk control module 47, a danger judgment module 48, and a fire extinguishing control module 49.

[0054] As Figure 3 and Figure 4 shown, the pressure detection module 41 includes a first pressure sensor 411 arranged inside the first protective cover 2 and a second pressure sensor 412 arranged inside the second protective cover 3. The first pressure sensor 411 detects the first air pressure value inside the first protective cover 2 and outputs it. The second pressure sensor 412 detects the second air pressure value inside the second protective cover 3 and outputs it.

[0055] As Figure 4 shown, the flow calculation module 42 receives the input target air pressure value, compares the first air pressure value with the target air pressure value, outputs a deflation signal when the air pressure value is greater than the target air pressure value, outputs an air supply signal when the air pressure value is less than the target air pressure value, and the flow calculation module 42 compares the second air pressure value with the first air pressure value. When the first air pressure value is greater than the second air pressure value, it outputs a pressurization signal.

[0056] As Figure 3 and Figure 4As shown in the figure, the flow control module 43 includes a first flow sensor 431 disposed in the first air inlet pipe 21 and a second flow sensor 432 disposed in the air outlet pipe 22. The first flow sensor 431 detects the gas flow velocity in the first air inlet pipe 21 to obtain the first flow velocity information, and the second flow sensor 432 detects the gas flow velocity in the air outlet pipe 22 to obtain the second flow velocity information. When the flow control module 43 receives the air release signal, it increases the power of the air extraction pump 221 and controls the first regulating valve 211 to close. When the flow control module 43 receives the air supply signal, it reduces the power of the air extraction pump 221 and controls the first regulating valve 211 to increase the flow rate. When the flow control module 43 receives the pressurization signal, it controls the second regulating valve 312 to increase the flow rate. The control system 4 can control the air pressure and gas flow at various locations within the protection device, making it difficult for the battery to catch fire or explode.

[0057] As Figure 3 and Figure 4 shown in the figure, the smoke detection module 44 includes a smoke sensor 441 disposed in the first protective cover 2. The smoke sensor 441 detects the smoke concentration within the first protective cover 2 and outputs a fire extinguishing signal when the detected smoke concentration exceeds a preset value. After receiving the fire extinguishing signal, the fire extinguishing processing module 45 controls the spray device 224 and the fire extinguishing device 24 to start. When there is a large amount of smoke within the protection device, the control system 4 will turn on the spray device 224 and the fire extinguishing device 24 to reduce the amount of smoke spreading outside the device.

[0058] As Figure 3 and Figure 4 shown in the figure, the temperature detection module 46 includes a first temperature sensor 461 disposed in the first protective cover 2 and a second temperature sensor 462 disposed on the test bench 1. The second temperature sensor 462 detects and outputs the temperature value of the battery, and the first temperature sensor 461 detects and outputs the temperature value within the first protective cover 2. The risk control module 47 has a preset risk temperature value. The risk control module 47 compares the temperature value with the risk temperature value. When the temperature value is higher than the risk temperature value, the risk control module 47 opens the solenoid valve 212 and controls the second regulating valve 312 to increase the flow rate. When a fire may occur during the battery experiment, the temperature rises. At this time, the control system 4 increases the amount of inert gas introduced, further reducing the oxygen content in the air and reducing the possibility of combustion.

[0059] As Figure 3 and Figure 4As shown, the danger judgment module 48 pre-stores a fire judgment table, which includes the temperature value inside the first protective cover 2, the temperature value of the battery, and the numerical range of the smoke concentration when the battery catches fire. When any one of the temperature value inside the first protective cover 2, the temperature value of the battery, and the smoke concentration is within the fire judgment table, an alarm signal is output. After receiving the alarm signal, the fire extinguishing control module 49 controls the fire extinguishing device 24 to start. The control system 4 can automatically extinguish the fire when a fire is detected.

[0060] The implementation principle of the lithium battery safety performance experiment protection device provided by the present invention is as follows: When the battery is experimented on the test bench 1, first, the first protective cover 2 and the second protective cover 3 are buckled on the test bench 1, and then the target air pressure value is set. The air pump 221 pumps away part of the air inside the first protective cover 2, making the environment in a low-oxygen environment and reducing the possibility of battery combustion. The first protective cover 2 and the second protective cover 3 will block the toxic gases, high temperature or impact generated by the battery combustion or explosion. Inert gas is also input between the second protective cover 3 and the first protective cover 2 to further reduce the combustion risk.

[0061] The above-described embodiments of the present invention do not constitute a limitation on the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A safety performance experimental protection device for a lithium battery, comprising a test bench (1), characterized in that: A first protective cover (2) is arranged outside the test bench (1), the first protective cover (2) surrounds the test bench (1), an explosion-proof lamp (25) is fixedly connected inside the first protective cover (2), a plurality of cameras (26) are fixedly connected inside the first protective cover (2), the cameras (26) are arranged around the test bench (1), a second protective cover (3) is arranged outside the first protective cover (2), the second protective cover (3) surrounds the first protective cover (2), the first protective cover (2) is fixedly connected with a first air inlet pipe (21) and an air outlet pipe (22), the first air inlet pipe (21) and the air outlet pipe (22) are both connected to the inside of the first protective cover (2), and the air outlet pipe (22) is fixedly connected with An air pump (221) is provided, the second protective cover (3) is fixedly connected to a second air inlet pipe (31), the air outlet pipe (22) is fixedly connected to the second protective cover (3), the second air inlet pipe (31) is connected to the inside and outside of the second protective cover (3), the air outlet pipe (22) is connected to the outside of the second protective cover (3), the other end of the first air inlet pipe (21) is connected to the outside of the second protective cover (3), and the other end of the second air inlet pipe (31) is connected to a gas generating device (311) capable of conveying inert gas; one end of the first air inlet pipe (21) extending out of the second protective cover (3) is fixedly connected to a first regulating valve (211), and the second air inlet pipe (31) is fixedly connected to a second regulating valve (312).

2. The safety performance experimental protection device for a lithium battery according to claim 1, wherein , further comprising a control system (4): the control system (4) comprises a pressure detection module (41), a flow calculation module (42) and a flow control module (43); The pressure detection module (41) comprises a first pressure sensor (411) arranged in the first protective cover (2) and a second pressure sensor (412) arranged in the second protective cover (3), the first pressure sensor (411) detecting a first air pressure value in the first protective cover (2) and outputting it, and the second pressure sensor (412) detecting a second air pressure value in the second protective cover (3) and outputting it; The flow calculation module (42) receives an input target air pressure value, compares the first air pressure value with the target air pressure value, outputs a deflation signal when the air pressure value is greater than the target air pressure value, and outputs a gas replenishment signal when the air pressure value is less than the target air pressure value; the flow calculation module (42) compares the second air pressure value with the first air pressure value, and outputs a pressurization signal when the first air pressure value is greater than the second air pressure value; When the flow control module (43) receives a deflation signal, the power of the air pump (221) is increased, and the first regulating valve (211) is controlled to be closed. When the flow control module (43) receives a gas replenishment signal, the air pump (221) is closed, and the first regulating valve (211) is controlled to increase the flow. When the flow control module (43) receives a pressurization signal, the second regulating valve (312) is controlled to increase the flow.

3. The safety performance experimental protection device for a lithium battery according to claim 2, wherein: The flow control module (43) includes a first flow sensor (431) disposed in the first air inlet pipe (21) and a second flow sensor (432) disposed in the air outlet pipe (22). The first flow sensor (431) detects the gas flow velocity in the first air inlet pipe (21) to obtain the first flow velocity information, and the second flow sensor (432) detects the gas flow velocity in the air outlet pipe (22) to obtain the second flow velocity information.

4. The safety performance experimental protection device for a lithium battery according to claim 2, wherein: The air outlet pipe (22) is fixedly connected with a first filter layer (222) and a second filter layer (223). Both the first filter layer (222) and the second filter layer (223) cover the longitudinal section of the air outlet pipe (22). The first filter layer (222) is composed of activated carbon, and the second filter layer (223) is composed of a breathable material with sodium hydroxide.

5. The safety performance experiment protection device for a lithium battery according to claim 4, wherein: The air outlet pipe (22) is fixedly connected with a spraying device (224). The control system (4) further includes a smoke detection module (44) and a fire extinguishing processing module (45); The smoke detection module (44) includes a smoke sensor (441) disposed in the first protective cover (2). The smoke sensor (441) detects the smoke concentration in the first protective cover (2), and outputs a fire extinguishing signal when the smoke sensor (441) detects that the smoke concentration exceeds a preset value; After receiving the fire extinguishing signal, the fire extinguishing processing module (45) controls the spraying device (224) to start.

6. The safety performance experimental protection device for a lithium battery according to claim 5, characterized in that: The first air inlet pipe (21) is internally communicated with the second protective cover (3). One end of the first air inlet pipe (21) extending into the second protective cover (3) is fixedly connected with an electromagnetic valve (212). The control system (4) further includes a temperature detection module (46) and a risk control module (47); The temperature detection module (46) includes a first temperature sensor (461) disposed in the first protective cover (2). The first temperature sensor (461) detects the temperature value in the first protective cover (2) and outputs it; The risk control module (47) presets a risk temperature value. The risk control module (47) compares the temperature value with the risk temperature value. When the temperature value is higher than the risk temperature value, the risk control module (47) opens the electromagnetic valve (212) and controls the second regulating valve (312) to increase the flow rate.

7. An experimental protection device for the safety performance of a lithium battery according to claim 6, characterized in that: A fire extinguishing device (24) is fixedly connected to the position of the first protective cover (2) corresponding to the upper part of the test bench (1). The fire extinguishing device (24) is fixedly connected with a storage tank (241) storing heptafluorobutane or carbon dioxide. The control system (4) further includes a danger judgment module (48) and a fire extinguishing control module (49); The temperature detection module (46) further includes a second temperature sensor (462) disposed on the test bench (1). The second temperature sensor (462) detects the temperature value of the battery and outputs it; The danger judgment module (48) pre-stores a fire judgment table. The fire judgment table includes the temperature value in the first protective cover (2), the temperature value of the battery, and the numerical range of the smoke concentration when the battery catches fire. When any one of the temperature value in the first protective cover (2), the temperature value of the battery, and the smoke concentration is within the fire judgment table, an alarm signal is output; After receiving the alarm signal, the fire extinguishing control module (49) controls the activation of the fire extinguishing device (24).

8. An experimental protection device for the safety performance of a lithium battery according to claim 7, characterized in that: A first pressure relief pipe (23) is fixedly connected to the first protective cover (2), and the first pressure relief pipe (23) communicates the inside of the first protective cover (2) with the outside of the second protective cover (3).

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