A monitoring device for battery thermal runaway

Abstract

This invention belongs to the field of battery testing technology and provides a monitoring device for battery thermal runaway, including a sealed reaction vessel, a data logger, an exhaust tester, and a clamp. The clamp is used to hold the battery under test and is placed inside the sealed reaction vessel. The data logger is located outside the sealed reaction vessel and is connected to the battery under test via a circuit to record the temperature and internal pressure of the battery. The exhaust tester is located outside the sealed reaction vessel and is connected to the sealed reaction vessel via a pipeline to exhaust the gas inside the sealed reaction vessel and detect the internal pressure of the sealed reaction vessel. This invention allows for comprehensive monitoring of lithium batteries in a sealed environment. It can not only monitor the temperature and pressure of the battery under test and obtain the relationship curve of internal pressure change over time during battery thermal runaway, as well as the curve of pressure change over time inside the sealed reaction vessel after the safety valve is opened, but also monitor the temperature curves of different locations of the lithium battery in real time.

Description

Technical Field

[0001] This utility model belongs to the field of battery testing technology, and specifically relates to a monitoring device for battery thermal runaway. Background Technology

[0002] Thermal runaway in lithium batteries is an extremely complex and dangerous process that can be triggered by a variety of factors, such as overcharging, over-discharging, short circuits, and high temperatures. During thermal runaway, a series of violent chemical reactions occur inside the battery, causing a rapid rise in temperature and the generation of large amounts of gas. If these gases are not dissipated in a timely and effective manner, the internal pressure of the battery will increase dramatically, potentially leading to serious safety accidents such as battery explosions and fires.

[0003] As a crucial component for lithium battery safety, the design of the safety valve's structural parameters is paramount to ensuring battery safety. The primary function of the safety valve is to rapidly open when the internal pressure exceeds a certain threshold, releasing the pressure and preventing further damage and dangerous situations. However, if the opening pressure of the safety valve is set too high, it may fail to open when a large amount of gas has already accumulated inside the battery and the pressure has reached a dangerous level, thus increasing the risk of battery explosion. Conversely, if the opening pressure is set too low, the safety valve may accidentally open under normal operating conditions, leading to decreased battery performance and shortened lifespan. Secondly, the opening area of ​​the safety valve is also a critical parameter. If the opening area is too small, even if the safety valve opens promptly, it cannot quickly release the large amount of gas generated, resulting in insufficient pressure reduction. Conversely, if the opening area is too large, it may affect the overall structural strength of the battery, impacting its performance and safety. Utility Model Content

[0004] To address the problems in the background art, this utility model proposes a monitoring device for battery thermal runaway.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A monitoring device for battery thermal runaway includes a sealed reaction vessel, a data logger, an exhaust tester, and a clamp;

[0007] The clamp is used to hold the battery to be tested;

[0008] The clamp is placed inside the sealed reaction vessel;

[0009] The data logger is located outside the sealed reaction vessel and is connected to the battery under test via a line to record the temperature and internal pressure of the battery under test.

[0010] The exhaust tester is located outside the sealed reaction vessel and is connected to the sealed reaction vessel through a pipeline. It is used to detect the internal pressure of the sealed reaction vessel and thus obtain the gas production and exhaust rates of the battery under test.

[0011] Preferably, an experimental platform is installed at the bottom of the inner cavity of the sealed reaction vessel, and the experimental platform is used to prevent the clamps holding the battery under test.

[0012] Preferably, a support base is installed at the bottom of the sealed reaction vessel;

[0013] An observation window is provided on the surface of the sealed reaction vessel.

[0014] Preferably, the data logger is connected to a temperature sensing wire and an internal pressure test wire. The temperature sensing wire is connected to the battery under test inside the sealed reaction vessel for real-time detection of the temperature of the battery under test.

[0015] The internal pressure test lead is connected to the battery under test and is used to detect the internal pressure of the battery under test in real time.

[0016] Preferably, the exhaust gas tester is connected to a static pressure test tube and a dynamic pressure test tube;

[0017] Both the static pressure test tube and the dynamic pressure test tube are connected to the end of the sealed reaction vessel.

[0018] Preferably, the clamp includes a fixing plate, a heating plate, insulation cotton, and fixing bolts;

[0019] One of the heating plates is attached to one side of the battery under test;

[0020] Two insulating cotton materials are provided, one attached to the surface of the heating plate and the other attached to the other side of the battery under test.

[0021] Two fixing plates are respectively set on the outside of the corresponding insulation cotton and connected by several fixing bolts, so that the clamp forms a structure that tightly clamps the battery to be tested.

[0022] Preferably, the fixing plate is a steel plate.

[0023] Preferably, four fixing bolts are provided.

[0024] Preferably, the battery under test includes a battery body, a top cover, a steel pipe, a two-way valve, and a safety valve;

[0025] The upper cover plate is installed on one surface of the battery body;

[0026] The steel pipe is installed on the upper cover plate and is in contact with the battery body;

[0027] The two-way valve is installed at the end of the steel pipe away from the upper cover plate, and the two-way valve is connected to the internal pressure test line;

[0028] The safety valve passes through the upper cover and is connected to the battery body.

[0029] Preferably, the temperature sensing wire is connected to the surface of the battery body.

[0030] The beneficial effects of this utility model are:

[0031] 1. The device of this utility model can perform comprehensive monitoring of lithium batteries in a sealed environment. It can not only monitor the temperature and pressure of the battery under test, obtain the relationship curve of internal pressure change over time during thermal runaway, and the curve of pressure change over time inside the sealed reaction vessel after the safety valve is opened, but also monitor the temperature curves at different locations of the lithium battery in real time. Furthermore, by measuring the gas generation and exhaust rates inside the battery under test, the device provides data support for the design of the safety valve opening area, ensuring that the lithium battery has sufficient exhaust space and effectively enhancing its safety performance.

[0032] 2. This utility model enables flexible connection between the battery under test and the monitoring device. This flexibility not only improves testing efficiency but also adapts to the testing needs of lithium batteries of different specifications and types, greatly expanding the application scope. At the same time, flexible connection reduces errors caused by equipment incompatibility, further improving testing accuracy. In addition, the device and method of this utility model have advantages in cost control. They can meet the requirements of high-precision testing while effectively reducing equipment investment and maintenance costs, making them extremely cost-effective and practical.

[0033] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention can be realized and obtained through the structures pointed out in the description and the accompanying drawings. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A schematic diagram of the structure of the monitoring device for battery thermal runaway according to this utility model is shown;

[0036] Figure 2 A schematic diagram of the internal structure of the sealed reaction vessel of this utility model is shown;

[0037] Figure 3 A schematic diagram of the clamp of this utility model holding the battery to be tested is shown;

[0038] Figure 4 A schematic diagram of the structure of the battery under test according to this utility model is shown;

[0039] Figure 5 A schematic diagram of the glove box of this utility model is shown;

[0040] Figure 6 The curves showing the changes in temperature and internal pressure of the battery under test during the testing of this utility model are illustrated.

[0041] Figure 7 The curve showing the change of internal pressure of the sealed reaction vessel of this invention over time is shown.

[0042] In the diagram: 1. Sealed reaction vessel; 101. Observation window; 102. Support base; 103. Experimental platform; 104. Heating rod adapter; 2. Data logger; 201. Temperature sensing wire; 202. Internal pressure test wire; 3. Exhaust tester; 301. Static pressure test tube; 302. Dynamic pressure test tube; 4. Battery under test; 401. Battery body; 402. Top cover plate; 403. Steel pipe; 404. Two-way valve; 405. Safety valve; 5. Clamp; 501. Fixing plate; 502. Heating plate; 503. Insulation cotton; 504. Fixing bolt; 6. Glove box; 601. Glove hole. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0044] like Figure 1The diagram shows a monitoring device for battery thermal runaway. The device includes a sealed reaction vessel 1, a data logger 2, and an exhaust tester 3. The interior of the sealed reaction vessel 1 is a closed environment, allowing the object to be tested to be placed within this closed environment to avoid interference from external factors. The data logger 2 is located outside the sealed reaction vessel 1 and is connected to a temperature sensing wire 201 and an internal pressure testing wire 202. The temperature sensing wire 201 can be connected to the object to be tested to measure temperature changes, and similarly, the internal pressure testing wire 202 is connected to the object to measure internal pressure changes. The exhaust tester 3 is located outside the sealed reaction vessel 1 and is connected to it via a pipeline. It is used to exhaust gas from the sealed reaction vessel 1 and to detect the internal pressure of the sealed reaction vessel 1.

[0045] It should be noted that the temperature data and internal pressure data of the test object obtained can be recorded by the data logger 2. By studying these data, the temperature and internal pressure change curves of the test object before and after thermal runaway can be obtained, and the cause of thermal runaway can be obtained, providing a reference for subsequent design and improvement.

[0046] like Figure 2 As shown, a support base 102 is welded to the bottom of the sealed reaction vessel 1. At least two support bases 102 are provided, distributed along the length of the sealed reaction vessel 1. Additionally, a support platform 103 is installed at the bottom of the inner cavity of the sealed reaction vessel 1. This support platform 103 can hold a clamp 5. The clamp 5 can hold the object to be tested, such as the battery 4 to be tested. Furthermore, an observation window 101 can be opened on the surface of the sealed reaction vessel 1, through which the battery 4 to be tested can be observed.

[0047] In addition, combined Figure 1 It is known that the sealed reaction vessel 1 has flange interfaces at the top and ends, and the temperature sensing wire 201 can enter the interior of the sealed reaction vessel 1 through the flange interface at the top. At the same time, an installation channel is also reserved on the sealed reaction vessel 1, which can be used to seal and install the internal pressure test wire 202.

[0048] Furthermore, the exhaust tester 3 can be connected to the flange interface at the end via a pipeline, thereby achieving communication with the interior of the sealed reaction vessel 1. Specifically, the exhaust tester 3 is connected to a static pressure test tube 301 and a dynamic pressure test tube 302. The static pressure test tube 301 can be sealed and connected through a reserved channel at the end of the sealed reaction vessel 1, and the dynamic pressure test tube 302 can be connected to the flange interface at the end of the sealed reaction vessel 1. The exhaust tester 3 can both exhaust the gas inside the sealed reaction vessel 1 and monitor the internal pressure (static and dynamic pressure) of the sealed reaction vessel 1 in real time, keeping it at the target state and providing a stable environment for the testing of the battery 4 under test.

[0049] likeFigure 3 As shown, the clamp 5 includes a fixing plate 501, a heating plate 502, insulation cotton 503, and fixing bolts 504. One heating plate 502 is attached to one side of the battery 4 to be tested; two insulation cotton 503s are provided, one attached to the surface of the heating plate 502 and the other attached to the other side of the battery 4 to be tested, which is opposite to the heating plate 502; two fixing plates 501 (preferably steel plates) are respectively provided on the outside of the corresponding insulation cotton 503 and are connected by four fixing bolts 504, so that the clamp 5 forms a structure that tightly clamps the battery 4 to be tested.

[0050] Optionally, the heating plate 502 can be connected to the heating rod adapter 104 via wires. The heating rod adapter 104 is located inside the sealed reaction vessel 1 and can be connected to a high-power heating device to meet the temperature requirements of the battery 4 under test.

[0051] It should be noted that the insulation cotton 503, with a size equal to that of the large surface area of ​​the battery cell, is installed on both sides of the battery under test 4. This effectively maintains the uniformity and stability of the battery temperature, reducing the impact of temperature fluctuations on the test results. Furthermore, the heating plate can control the temperature environment of the battery under test 4 to meet the needs of different testing scenarios. Finally, the clamps 5 bolts ensure reliable fixation, simulating real-world lithium battery usage scenarios.

[0052] like Figure 4 As shown, the battery under test 4 includes a battery body 401, a top cover 402, a steel pipe 403, a two-way valve 404, and a safety valve 405. The top cover 402 is mounted on one surface of the battery body 401, and the steel pipe 403 is mounted on the top cover 402 and in contact with the battery body 401. The two-way valve 404 is mounted on the end of the steel pipe 403 furthest from the top cover 402; the two-way valve 404 is also connected to an internal pressure test line 202 for real-time monitoring of the internal pressure of the battery under test 4; the temperature sensing line 201 is connected to either the battery body 401 or the top cover 402 for real-time monitoring of the temperature of the battery under test 4. The safety valve 405 passes through the top cover 402 and is connected to the battery body 401. When the gas generated by the cells inside the battery body 401 reaches a certain pressure, the safety valve 405 will open.

[0053] It should be noted that the top cover plate 402 adopts an integrally formed boss structure with internally machined threaded holes adapted to the imperial standard. Through a G1 / 8 external thread to 1 / 8 ferrule adapter, the cover plate is sealed to the steel pipe 403 with an outer diameter of 1 / 8 inch. One end of the adapter is screwed into the inner hole of the boss, and the other end is clamped to the outer wall of the steel pipe 403 through the ferrule structure, thereby creating a gas transmission channel between the inside of the lithium battery and the external equipment.

[0054] It should be further noted that the two-way valve 404 needs to be closed when it is not connected to the internal pressure test line 202, so as to prevent external air from entering the battery body 401.

[0055] like Figure 5 As shown, the battery 4 to be tested generally needs to be processed in a glove box 6. The glove box 6 is provided with a glove hole 601, and a vacuum pump is also provided next to the glove box 6. The vacuum pump is connected to the glove box 6 through a pipe to remove the air inside the glove box 6.

[0056] It should be noted that during the processing of the battery 4 to be tested: First, the glove box 6 is evacuated to remove any impurities, gases, and moisture that may be present inside. After reaching a vacuum, protective gas is introduced into the glove box 6 to create a stable operating environment. This initial step is extremely important, as it effectively avoids interference from impurities and moisture in subsequent tests, ensuring the accuracy and reliability of the test results.

[0057] Next, the critical operation is performed inside glove box 6.

[0058] Using a ceramic needle, puncture the safety valve 405 on the second explosion-proof device at the protrusion of the upper cover plate 402, and carefully peel off the valve plate of the safety valve 405. Then, using a G1 / 8 external thread to 1 / 8 ferrule, tightly connect the protrusion of the upper cover plate 402 to the steel pipe 403 to ensure that no gas leakage occurs during subsequent testing.

[0059] Next, connect the end of steel pipe 403 to the two-way valve 404 (typically made of 316L stainless steel). It is important to note that this two-way valve 404 should be closed before connecting to the internal pressure test line 202. This design aims to maintain the independence and stability of the entire system before connection, preventing external factors from interfering with the test results. These steps provide an accurate and reliable data foundation for subsequent internal pressure testing, strongly supporting the performance evaluation and safety assurance of lithium batteries.

[0060] The following is about Figures 1-4 The device described herein explains its operation process:

[0061] S1: Clamp the battery 4 to be tested using the clamp 5, and then place it into the sealed reaction vessel 1. Next, bring the temperature sensing wire 201 into contact with the surface of the battery body 401 (including the positive electrode, negative electrode and other surfaces) until the required temperature data can be monitored. At the same time, connect the internal pressure test wire to the two-way valve 404, and then the two-way valve 404 can be opened.

[0062] S2: The battery under test 4 is heated by the heating plate 502. If the internal pressure of the battery under test 4 reaches a certain value during the heating process, the safety valve 405 will open. Throughout the process, the data logger 2 and the exhaust tester 3 will monitor and record the data of the battery under test 4. The data logger 2 records the temperature change data and the internal pressure change data of the battery under test 4 over time, while the exhaust tester 3 records the pressure change data inside the sealed reaction vessel 1 (external pressure of the battery under test 4) over time. The gas production and exhaust rates of the battery under test 4 can also be obtained from this data.

[0063] S3: Analyze the data in S2 to optimize and improve the structure, size, and position of safety valve 405.

[0064] The aforementioned process is characterized by high precision, high reliability, and real-time performance, enabling a comprehensive and in-depth understanding of the pressure and temperature changes of the experimental device under various conditions. This provides further theoretical guidance and analysis for the design parameters of safety valve 405. It holds significant practical value and has broad application prospects in lithium battery research and development, quality control during production, and application research in the new energy field. Precise measurement and analysis of pressure and temperature can optimize product design, improve safety and performance, and drive the continuous development and progress of related technologies.

[0065] It should be noted that, in addition to high precision, the above structure also enables flexible connection between the battery under test 4 and the monitoring device. This flexibility not only improves testing efficiency but also adapts to the testing needs of lithium batteries of different specifications and types, greatly expanding the application scope. At the same time, flexible connection reduces errors caused by equipment incompatibility, further improving testing accuracy. In addition, the device and method of this utility model have advantages in cost control, meeting the requirements of high-precision testing while effectively reducing equipment investment and maintenance costs, resulting in extremely high cost-effectiveness and practical value.

[0066] like Figure 6 As shown, this is the temperature-pressure curve over time during lithium battery testing. The horizontal axis represents time (T / s, seconds), the left vertical axis represents temperature (T / ℃), and the right vertical axis represents pressure (P / MPa). Different curves represent different parameters.

[0067] The black dotted line represents the temperature change of heating plate 502. The initial rapid temperature increase (from room temperature to 500℃+ in a short time) simulates the thermal triggering conditions of the tested battery 4; the temperature is then gradually reduced as the test concludes.

[0068] The white square indicates the temperature of the test environment (the temperature inside the sealed reaction vessel 1).

[0069] The black triangle represents the temperature change curve of the battery under test 4, specifically the temperature change curve at the center of the surface of the battery under test 4 opposite to the heating plate 502. This curve lags behind the heating plate 502's temperature rise curve (heat conduction takes time). Its temperature initially remains stable, reaches its peak, and then gradually decreases under the action of the safety valve 405.

[0070] The solid black line P represents the pressure change of the battery under test, 4. Initially, the pressure is extremely low (close to 0). After heating is triggered, the pressure rises sharply, reaching the opening pressure of safety valve 405. Once safety valve 405 opens, the pressure quickly drops and stabilizes, corresponding to the process of gas generation and pressure release inside the battery.

[0071] like Figure 7 As shown, it is a curve of the sealed reaction vessel 1 changing over time. The pressure inside the vessel rises rapidly in the initial stage and reaches a peak, then slowly decreases and remains in a stable state.

[0072] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A monitoring device for battery thermal runaway, characterized in that, Includes a sealed reaction vessel (1), a data logger (2), an exhaust tester (3), and a fixture (5); The clamp (5) is placed inside the sealed reaction vessel (1) and is used to clamp the battery to be tested (4). The data logger (2) is located outside the sealed reaction vessel (1) and is connected to the battery under test (4) via a line to record the temperature and internal pressure of the battery under test (4); The exhaust tester (3) is located outside the sealed reaction vessel (1) and is connected to the sealed reaction vessel (1) through a pipeline. It is used to detect the internal pressure of the sealed reaction vessel (1) and thus obtain the gas production and exhaust rate of the battery (4) under test.

2. The monitoring device for battery thermal runaway according to claim 1, characterized in that, An experimental platform (103) is installed at the bottom of the inner cavity of the sealed reaction vessel (1). The experimental platform (103) is used to place a clamp (5) holding the battery (4) to be tested.

3. The monitoring device for battery thermal runaway according to claim 1, characterized in that, The bottom of the sealed reaction vessel (1) is equipped with a support base (102). An observation window (101) is provided on the surface of the sealed reaction vessel (1).

4. The monitoring device for battery thermal runaway according to claim 1, characterized in that, The data logger (2) is connected to a temperature sensing line (201) and an internal pressure test line (202). The temperature sensing line (201) is connected to the battery under test (4) inside the sealed reaction vessel (1) and is used to detect the temperature of the battery under test (4) in real time. The internal pressure test line (202) is connected to the battery under test (4) and is used to detect the internal pressure of the battery under test (4) in real time.

5. The monitoring device for battery thermal runaway according to claim 1, characterized in that, The exhaust tester (3) is connected to a static pressure test tube (301) and a dynamic pressure test tube (302). Both the static pressure test tube (301) and the dynamic pressure test tube (302) are connected to the end of the sealed reaction vessel (1).

6. The monitoring device for battery thermal runaway according to claim 1, characterized in that, The clamp (5) includes a fixing plate (501), a heating plate (502), insulation cotton (503), and fixing bolts (504); One of the heating plates (502) is attached to one side of the battery (4) under test; Two insulation cotton (503) are provided, one attached to the surface of the heating plate (502) and the other attached to the other side of the battery (4) to be tested; Two fixing plates (501) are respectively set on the outside of the corresponding insulation cotton (503) and connected by several fixing bolts (504) so ​​that the clamp (5) forms a structure to clamp the battery (4) to be tested.

7. A monitoring device for battery thermal runaway according to claim 6, characterized in that, The fixing plate (501) is a steel plate.

8. A monitoring device for battery thermal runaway according to claim 6, characterized in that, Four fixing bolts (504) are provided.

9. A monitoring device for battery thermal runaway according to claim 4, characterized in that, The battery under test (4) includes a battery body (401), a top cover plate (402), a steel pipe (403), a two-way valve (404), and a safety valve (405). The upper cover plate (402) is mounted on one surface of the battery body (401); The steel pipe (403) is installed on the upper cover plate (402) and contacts the battery body (401); The two-way valve (404) is installed at the end of the steel pipe (403) away from the upper cover plate (402), and the two-way valve (404) is connected to the internal pressure test line (202); The safety valve (405) passes through the upper cover plate (402) and is connected to the battery body (401).

10. A monitoring device for battery thermal runaway according to claim 9, characterized in that, The temperature sensing wire (201) is connected to the surface of the battery body (401).

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