A lithium battery needle test test device

Abstract

The application discloses a lithium battery needle-puncture test device in the technical field of lithium battery needle-puncture test equipment, and aims to solve the problem that it is inconvenient to perform explosion test research on lithium batteries in a closed environment in the prior art. The device comprises a reaction box, a driving device and a control unit, a sealing shell is slidably arranged in the reaction box, the sealing shell is used for overcoming spring elastic force and pushing a measuring scale to move a corresponding distance when explosion occurs, a gas outlet for pressure relief is arranged on the reaction box, the gas outlet is used for maintaining a certain air pressure in the reaction cavity before explosion occurs, and a high-frequency dynamic pressure sensor for detecting air pressure is further arranged on the reaction box. The application is used for exploring explosion characteristics of lithium batteries when puncture explosion occurs, the device can conveniently calculate instantaneous data generated when explosion occurs, reaction can occur in a relatively closed environment without the support of a high-pressure container, waste gas generated by the device is convenient to timely treat, and the device has a good application prospect.

Description

Technical Field

[0001] This invention relates to a lithium battery needle penetration test apparatus, belonging to the technical field of lithium battery needle penetration test equipment. Background Technology

[0002] The lithium battery nail penetration test involves placing a fully charged battery on a flat surface and piercing it radially with a steel needle with a diameter of 3-8mm. The test results in the battery not catching fire or exploding. In practical applications, foreign objects can penetrate the battery pack, potentially causing a short circuit. The nail penetration test effectively reflects this short circuit scenario. When the steel needle penetrates, it provides a pathway for an internal short circuit, creating multiple short circuit paths within the battery. It effectively simulates both internal and external short circuits simultaneously. During this process, the battery's electrical energy is converted into heat and stored internally. The short circuit causes a concentrated burst and release of energy within a short period, potentially leading to smoke, leakage, or even fire and explosion. Therefore, the nail penetration test is more likely to result in fire and explosion compared to other types of safety tests. Conducting theoretical and experimental research on the combustion and explosion processes of lithium batteries is crucial for understanding the hazards posed by short circuits in lithium batteries.

[0003] In conventional studies of explosion characteristics, lithium batteries are typically tested in open environments. This method allows hazardous gases from the explosion to directly disperse into the surrounding environment, posing a significant risk. Furthermore, it makes it difficult to study and measure the relevant characteristics of the explosion within a confined space. To address this, publication number CN109813755A proposes a pressure vessel for measuring lithium battery explosion characteristic parameters. This vessel primarily utilizes temperature and pressure sensors to measure data before and after the explosion, enabling the investigation of data generated during the explosion. It provides a reliable enclosed space for measuring the explosion characteristics of lithium batteries. However, this device has three drawbacks:

[0004] Firstly, high-pressure storage tanks are expensive to use, complex to operate and inherently dangerous. Furthermore, if observation is conducted by placing a camera inside the tank instead of using a pressure-resistant transparent material, the camera is easily damaged, and the black smoke produced by combustion can easily obscure the camera's view. Therefore, if the above problems are to be solved, it is difficult to balance low cost and high safety.

[0005] Secondly, the device detonates the lithium battery by heating. Without a control group, it is difficult to distinguish the heat generated by the explosion and the short-circuit combustion. Furthermore, there may be a situation where the lithium battery leaks gas before the test. At this time, the pressure and temperature inside the storage tank will continue to rise during the test, making it difficult to effectively capture and distinguish the energy and characteristics generated at the moment of the explosion.

[0006] Third, the device conducts an explosion reaction test in a closed container. The high concentration of hazardous gases generated during the test will accumulate inside the high-pressure container. After the test, the high concentration of hazardous gases cannot be effectively eliminated, which is detrimental to the personal safety of the test personnel. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a lithium battery needle penetration test device for exploring the explosion characteristics of lithium batteries when puncture and explosion occur. The device can conveniently calculate the instantaneous data generated when the explosion occurs, and the reaction can occur in a relatively closed environment without the support of a high-pressure container. The waste gas generated by the device is easy to treat in a timely manner and has good application prospects.

[0008] To achieve the above objectives, the present invention employs the following technical solution:

[0009] The present invention provides a lithium battery needle penetration test device, including a reaction chamber, a driving device and a control unit. The reaction chamber is divided into a reaction cavity and a sliding cavity. A positioning device for fixing the lithium battery is installed in the reaction cavity. A sealing shell that is tightly fitted to the inner wall of the sliding cavity is slidably disposed in the sliding cavity.

[0010] The interior of the reaction chamber is provided with a mounting plate for mounting the probe, and the driving device is used to drive the mounting plate to drive the probe to perform a puncture action on the lithium battery.

[0011] A positioning plate is provided at the end of the sliding cavity away from the reaction cavity. Several sliding rods are installed on the sealing shell, which slide through the positioning plate. Each sliding rod is fitted with a spring at both ends that abut against the positioning plate and the sealing shell respectively. A measuring scale is also tightly slidably fitted on the positioning plate, with one end of the measuring scale abutting against the sealing shell.

[0012] The reaction chamber has an air outlet on the wall of the chamber where the sliding cavity is located. A tail gas treatment pipe is connected to the air outlet and a flow limiting valve is installed on the tail gas treatment pipe. A fitting plate that can fit tightly against the inner wall of the sliding cavity is installed on the side of the sealing shell facing the reaction cavity. The fitting plate has mating holes that correspond to the air outlet.

[0013] The walls used to form the reaction cavity form a heat-insulating and pressure-maintaining structural layer. A high-frequency dynamic pressure sensor connected to the reaction cavity is installed on the reaction chamber, and the high-frequency dynamic pressure sensor is electrically connected to the control unit.

[0014] Specifically, one end of the measuring scale is equipped with a connecting plate for abutting against the sealing shell, and a guide rod that slides through the positioning plate is installed on the connecting plate.

[0015] Specifically, it also includes a sealed water tank and a stove. The exhaust end of the exhaust gas treatment pipe is connected to the bottom of the sealed water tank, and an exhaust pipe is connected to the top of the sealed water tank. An ignition device is installed on the stove, and the exhaust end of the exhaust pipe is connected to a nozzle pointing to the ignition device.

[0016] Specifically, it also includes a gas cylinder, and the fuel for the ignition device is the gas supplied from the gas cylinder to the ignition device.

[0017] Specifically, a pressure relief valve and a pressure gauge are installed on the exhaust pipe, and both the pressure relief valve and the pressure gauge are electrically connected to the control unit.

[0018] Specifically, the positioning plate is equipped with a friction pad for contacting the measuring scale.

[0019] Specifically, the reaction chamber includes a main body and an extension arm spliced ​​onto the main body, the extension arm being used to extend the length of the sliding cavity.

[0020] Specifically, the driving device is located on the outside of the reaction chamber, and the driving rod of the driving device passes through the reaction chamber and connects to the mounting plate. A piston wall is installed inside the reaction cavity of the reaction chamber, and the piston wall is used to cooperate with the inner wall of the reaction cavity of the reaction chamber to achieve a tight fit with the wall surface of the mounting plate.

[0021] Specifically, the reaction chamber of the reaction box has an operation port, and there are sliding grooves on both sides of the operation port. A sealing plate for sealing the operation port is slidably disposed between the two sliding grooves.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0023] 1. This invention sets up a reaction cavity and a movable cavity inside the reaction chamber, and uses the elastic effect of the sealing shell to seal the vent, so that the gas pressure in the reaction cavity can be maintained at a constant value before the explosion. At this time, the pressure difference between the explosion and the explosion can be easily measured using a high-frequency dynamic pressure sensor. When the explosion occurs, the flow rate increases instantaneously, and the flow limiting valve can automatically close. At this time, the impact is concentrated on the sealing shell, and the impact energy is converted into work to overcome the spring. The maximum value of the spring displacement can be easily measured by a measuring ruler to estimate the energy generated by the impact. This provides a better and broader basis for the study of the explosion characteristics of lithium battery nail penetration test.

[0024] 2. When the reaction occurs inside this device, the rapidly increasing pressure is converted into a change in the volume of the reaction cavity. Therefore, there is no need for a special high-pressure vessel to meet the test requirements, which can effectively improve the safety of the test and reduce the cost of using the device.

[0025] 3. This device, by utilizing a sealed water tank and an ignition device, can treat gases such as CH4, CO, C2H4, H2S, HF, HCl, SO2, and HCN generated during the experiment, which can effectively reduce pollution generated during the experiment and help ensure the personal safety of surrounding experimental personnel. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of an experimental device provided in an embodiment of the present invention;

[0027] Figure 2 This is a side view of a testing apparatus provided in an embodiment of the present invention;

[0028] Figure 3 This is the present invention. Figure 2 An AA-direction sectional view of a test apparatus provided in the embodiment;

[0029] Reference numerals: 1. Reaction chamber; 101. Main chamber; 102. Extension arm; 2. Mounting plate; 3. Drive device; 4. Positioning device; 5. Probe; 6. Gas outlet; 7. Sealing shell; 8. Fitting plate; 9. Mating hole; 10. Flow limiting valve; 11. Positioning plate; 12. Slide rod; 13. Spring; 14. Connecting plate; 15. Measuring scale; 16. Guide rod; 18. Friction plate; 19. Piston wall; 20. High-frequency dynamic pressure sensor; 21. Exhaust gas treatment pipe; 22. Sealed water tank; 23. Stove; 24. Ignition device; 25. Gas cylinder; 26. Water pipe; 27. Exhaust valve; 28. Exhaust pipe; 29. ​​Gas nozzle; 30. Slide groove; 31. Sealing plate; 32. Control unit; 33. Pressure relief valve; 34. Pressure gauge. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0031] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] Example:

[0034] This invention provides a lithium battery needle penetration test apparatus for investigating the explosion characteristics of lithium batteries during puncture and explosion. The apparatus can conveniently calculate instantaneous data generated during the explosion, and the reaction can occur in a relatively closed environment without the need for a high-pressure container. The waste gas generated by the apparatus is easy to treat in a timely manner, showing good application prospects. To realize the structural functions of the apparatus, it is configured to include a reaction chamber 1, a drive device 3, and a control unit 32. Specifically, the interior of the reaction chamber 1 is divided into a reaction cavity and a sliding cavity, as shown in the reference... Figure 3 As shown, the left side of the reaction chamber 1 is a sliding cavity, and the right side is a reaction cavity for needle puncture testing. To ensure normal testing function within the reaction cavity, a positioning device 4 for fixing the lithium battery needs to be installed inside the reaction cavity, and a mounting plate 2 for mounting the probe 5 is installed inside the reaction chamber 1. The driving device 3 is used to drive the mounting plate 2 to move the probe 5 to perform the puncture action on the lithium battery.

[0035] This device measures impact energy by configuring a sliding cavity. Its specific structure is as follows: A sealing shell 7, tightly fitted to the inner wall of the sliding cavity, is slidably disposed within the cavity. A positioning plate 11 is positioned at the end of the sliding cavity furthest from the reaction cavity. Several sliding rods 12, penetrating the positioning plate 11, are mounted on the sealing shell 7. Each sliding rod 12 is fitted with a spring 13, with its two ends respectively contacting the positioning plate 11 and the sealing shell 7. A measuring scale 15 is also tightly fitted to the positioning plate 11, with one end of the measuring scale 15 contacting the sealing shell 7. Through this structural configuration, when an explosion occurs, the impact energy is concentrated on the sealing shell 7. At this time, the sealing shell 7 as a whole overcomes the spring force 13 and the frictional force with the inner wall of the reaction chamber 1, doing work. The measuring scale 15 is then pushed out through the sealing shell 7. The maximum value of the pushed-out distance is the work done by the impact energy overcoming the spring force 13. It should be noted that the measuring scale 15 should maintain optimal friction during setup to prevent it from flying too far due to inertia. The impact energy can be calculated by measuring the spring 13 and the related frictional work. Temperature changes before and after the reaction can be measured by a temperature sensor. To avoid a continuous increase in pressure within the container during the reaction, requiring a high-pressure container, an outlet 6 is provided on the wall of the reaction chamber 1 where the sliding cavity is located. A tail gas treatment pipe 21 is connected to the outlet 6 to treat the tail gas generated by the explosion or combustion. To prevent the impact energy from leaking out through the outlet 6 during an explosion, a flow-limiting valve 10 is installed on the tail gas treatment pipe 21. In this state, during an explosion, the high-speed airflow can automatically close the flow-limiting valve 10, ensuring that the impact effect is mainly manifested in the displacement change of the sealing shell 7. To ensure a constant gas pressure within the reaction cavity before the explosion, a fitting plate 8 is installed on the side of the sealing shell 7 facing the reaction cavity. This plate 8 fits tightly against the inner wall of the sliding cavity, and a mating hole 9 corresponding to the vent 6 is provided on the fitting plate 8. In this state, a certain pressure within the reaction cavity can be preset. When the gas pressure is slightly higher, the mating hole 9 and the vent 6 can leak. When the gas pressure returns to its original state, the plate 8 can automatically close under the force of the spring 13, thus ensuring that the gas pressure within the reaction cavity does not change significantly before the explosion. After the explosion, the fitting plate 8 can preferably be removed entirely from the vent 6, allowing the generated gas to flow out through the exhaust gas treatment pipe 21. The spring 13 will automatically reset after the gas pressure recovers.To ensure the validity of the experiment, the walls forming the reaction cavity need to be designed to form a thermal insulation and pressure-maintaining structure layer. Thermal insulation is used to prevent heat loss from affecting the accuracy of experimental data, while pressure maintenance is used to prevent gas leakage from affecting the acquisition of the final experimental results. To further investigate the impact force and gas pressure generated at the moment of explosion, a high-frequency dynamic pressure sensor 20 connected to the reaction cavity can be installed on the reaction chamber 1. The high-frequency dynamic pressure sensor 20 is electrically connected to the control unit 32 for acquiring and analyzing relevant data after the experiment.

[0036] When using the above-mentioned device, there is no need to prepare a high-pressure container. The operation is simple and the cost is low. In addition to the explosion characteristic research function provided by the existing device, it can also realize the calculation of the explosion impact force and impact energy. It has important reference significance for the study of the hazard of the explosion characteristics of lithium battery needle penetration test. In addition, the gas generated by the chemical reaction can be treated by the relevant exhaust gas device, resulting in low pollution and high test safety.

[0037] This invention considers that if the measuring scale 15 has a slight tilt angle during operation, the resistance it experiences will increase sharply. To ensure a stable sliding direction for the measuring scale 15, a connecting plate 14 is installed at one end of the measuring scale 15 to abut against the sealing shell 7. A guide rod 16 that slides through the positioning plate 11 is installed on the connecting plate 14. By using the guide rod 16 for guidance, it can be ensured that the measuring scale 15 does not deviate during movement, thereby facilitating the accurate calculation of experimental data. In the lithium battery needle penetration test apparatus provided by this embodiment, to reduce the amount of movement of the measuring scale 15 roller core, a friction plate 18 for contacting the measuring scale 15 can be installed on the positioning plate 11.

[0038] This invention specifically provides a tail gas treatment device to ensure experimental safety. Since the exhaust gas produced by lithium battery combustion mainly contains CH4, CO, C2H4, H2S, HF, HCl, SO2, and HCN, and these types of gases indicate that those insoluble in water are flammable, the tail gas treatment device includes a sealed water tank 22 and a stove 23. The outlet of the tail gas treatment pipe 21 is connected to the bottom of the sealed water tank 22, and an exhaust pipe 28 is connected above the sealed water tank 22. An ignition device 24 is installed on the stove 23, and a nozzle 29 pointing towards the ignition device 24 is connected to the outlet of the exhaust pipe 28. After the above gases are filtered by the sealed water tank 22, the remaining CH4, CO, and C2H4 gases leak out from the exhaust pipe 28. These are then ignited by the ignition device 24, and the final products are released as carbon dioxide and water, giving the device good safety emission capabilities. The structure of the sealed water tank 22 can be referred to... Figure 1As shown, in order to achieve liquid inlet and outlet, a water pipe 26 can be connected to the bottom of the sealed water tank 22. In order to ensure that water is injected into the sealed water tank 22, an air vent valve 27 can be installed above the sealed water tank 22 to release air pressure.

[0039] In order to ensure that the exhaust gas can continue to burn, the device also includes a gas cylinder 25. At this time, the fuel for the ignition device 24 is the gas supplied from the gas cylinder 25 to the ignition device 24, so that the gas can continue to burn at the position of the ignition device 24.

[0040] Since the air layer at the top of the sealed water tank 22 has a similar air pressure to that inside the reaction cavity, further control of the air pressure in the sealed water tank 22 is required if the air pressure in the reaction cavity needs to be controlled. For this purpose, a pressure relief valve 33 and a pressure gauge 34 can be installed on the exhaust pipe 28. Both the pressure relief valve 33 and the pressure gauge 34 are electrically connected to the control unit 32. When the pressure measured by the pressure gauge 34 exceeds the rated value, the pressure relief valve 33 opens to release potentially high-pressure flammable gas until the pressure drops to the set range and then closes.

[0041] To facilitate sealing of the sealing shell 7, a sealing strip needs to be installed along the movement stroke of the sealing shell 7. At this time, the sealing strip should be installed inside the sliding cavity. If the reaction chamber 1 is an integral structure, the assembly of its sealing strip and sealing shell 7 will be difficult and further testing and debugging will be difficult. Therefore, the reaction chamber 1 is set to include a main body 101 and an extension arm 102 spliced ​​on the main body 101. The extension arm 102 is used to lengthen the length of the sliding cavity. When it is necessary to adjust the assembly, the extension arm 102 can be removed directly.

[0042] Considering the stroke of the drive device 3, if the drive device 3 is placed inside the reaction chamber 1, the distance the brake probe 5 moves will be very short. Therefore, the drive device 3 can be placed outside the reaction chamber 1. In this case, the drive rod of the drive device 3 will pass through the reaction chamber 1 and connect to the mounting plate 2. At this time, it is difficult to achieve a good sealing effect at the point where the drive rod passes through. The device installs a piston wall 19 inside the reaction cavity of the reaction chamber 1. By using the piston wall 19 to cooperate with the inner wall of the reaction cavity of the reaction chamber 1 to achieve a tight fit with the wall of the mounting plate 2, even if the top of the reaction chamber 1 is not sealed, the tight contact between the mounting plate 2 and the piston wall 19 can achieve good airtightness inside the reaction cavity.

[0043] To facilitate operations inside the device, an operating port is provided at the location of the reaction cavity in the reaction chamber 1. To achieve a seal for the operating port, grooves 30 are provided on both sides of the operating port, and a sealing plate 31 for sealing the operating port is slidably disposed between the two grooves 30. The specific structural shape can be referred to Figure 1 Configure as shown.

[0044] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A lithium battery needle penetration test apparatus, characterized in that, The system includes a reaction chamber (1), a drive device (3), a control unit (32), a sealed water tank (22), and a stove (23). The reaction chamber (1) is divided into a reaction cavity and a sliding cavity. A positioning device (4) for fixing the lithium battery is installed in the reaction cavity. A sealing shell (7) that fits tightly against the inner wall of the sliding cavity is slidably installed in the sliding cavity. The interior of the reaction chamber (1) is provided with a mounting plate (2) for mounting the probe (5), and the driving device (3) is used to drive the mounting plate (2) to drive the probe (5) to perform a puncture action on the lithium battery. A positioning plate (11) is provided at the end of the sliding cavity away from the reaction cavity. Several sliding rods (12) are installed on the sealing shell (7) and slide through the positioning plate (11). Each sliding rod (12) is fitted with a spring (13) with its two ends respectively abutting between the positioning plate (11) and the sealing shell (7). A measuring scale (15) is also tightly slidably fitted on the positioning plate (11). One end of the measuring scale (15) is used to abut against the sealing shell (7). The reaction chamber (1) has an air outlet (6) on the wall of the chamber where the sliding cavity is located. A tail gas treatment pipe (21) is connected to the air outlet (6). A flow limiting valve (10) is installed on the tail gas treatment pipe (21). A fitting plate (8) that can fit tightly against the inner wall of the sliding cavity is installed on the side of the sealing shell (7) facing the reaction cavity. A mating hole (9) that corresponds to the air outlet (6) is opened on the fitting plate (8). The walls used to form the reaction cavity form a heat-insulating and pressure-insulating structural layer between each other. A high-frequency dynamic pressure sensor (20) connected to the reaction cavity is installed on the reaction chamber (1). The high-frequency dynamic pressure sensor (20) is electrically connected to the control unit (32). The exhaust end of the exhaust pipe (21) is connected to the bottom of the sealed water tank (22). An exhaust pipe (28) is connected above the sealed water tank (22). An ignition device (24) is installed on the stove (23). An air nozzle (29) pointing to the ignition device (24) is connected to the exhaust end of the exhaust pipe (28).

2. The lithium battery needle penetration test apparatus according to claim 1, characterized in that, One end of the measuring scale (15) is fitted with a connecting plate (14) for abutting against the sealing shell (7), and a guide rod (16) for sliding through the positioning plate (11) is fitted on the connecting plate (14).

3. The lithium battery needle penetration test apparatus according to claim 1, characterized in that, It also includes a gas cylinder (25), and the fuel for the ignition device (24) is the gas supplied from the gas cylinder (25) to the ignition device (24).

4. The lithium battery needle penetration test apparatus according to claim 1, characterized in that, The exhaust pipe (28) is equipped with a pressure relief valve (33) and a pressure gauge (34), both of which are electrically connected to the control unit (32).

5. The lithium battery needle penetration test apparatus according to claim 1, characterized in that, The positioning plate (11) is equipped with a friction plate (18) for contacting the measuring scale (15).

6. The lithium battery needle penetration test apparatus according to claim 1, characterized in that, The reaction chamber (1) includes a main chamber (101) and an extension arm (102) spliced ​​on the main chamber (101). The extension arm (102) is used to extend the length of the sliding cavity.

7. The lithium battery needle penetration test apparatus according to claim 1, characterized in that, The driving device (3) is located on the outside of the reaction chamber (1). The driving rod of the driving device (3) passes through the reaction chamber (1) and connects to the mounting plate (2). A piston wall (19) is installed inside the reaction cavity of the reaction chamber (1). The piston wall (19) is used to cooperate with the inner wall of the reaction cavity of the reaction chamber (1) to achieve a tight fit with the wall of the mounting plate (2).

8. The lithium battery needle penetration test apparatus according to claim 1, characterized in that, The reaction chamber (1) has an operation port on its reaction cavity. Both sides of the operation port are provided with sliding grooves (30), and a sealing plate (31) for sealing the operation port is slidably arranged between the two sliding grooves (30).

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