Method, system and device for testing thermal runaway of power battery

Abstract

The invention relates to the technical field of power battery testing, in particular to a power battery thermal runaway testing method, system and device. The device comprises a needling machine body integrated hydraulic system, a needling assembly is vertically arranged above the needling machine body integrated hydraulic system and is driven by the hydraulic system to feed in the Z direction, a steel needle with a built-in heating assembly is installed at the front end, and a plurality of temperature collecting points are arranged in the steel needle at different positions in the axial direction; the battery fixing assembly comprises a supporting platform fixed to the needling machine body and a replaceable fixing clamp and is located over the needling assembly. The voltage temperature monitoring assembly comprises a voltage sensor connected with the positive and negative electrodes of the battery and temperature sensors arranged at the positive and negative electrodes, the large surface, the side surface and steel needle temperature acquisition points of the battery; the control assembly is in signal connection with the hydraulic system, the heating assembly and the voltage and temperature monitoring assembly. According to the technical scheme, the problem that needling and internal heating cannot be integrally implemented or serially implemented in the prior art can be solved.

Description

Technical Field

[0001] This invention relates to the field of power battery testing technology, specifically to a method, system, and apparatus for testing thermal runaway of power batteries. Background Technology

[0002] In numerous fields such as new energy vehicles and energy storage systems, the safety and reliability of power batteries are crucial as core components. Battery thermal runaway is one of the key factors affecting the safety of power batteries. Once thermal runaway occurs, the battery rapidly releases a large amount of heat, triggering serious safety accidents such as combustion and explosion, causing not only huge economic losses but also potentially endangering human lives. Therefore, conducting thermal runaway tests on power batteries and comprehensively evaluating their thermal runaway performance under various operating conditions has become an important step in ensuring battery safety.

[0003] The needle penetration test, a commonly used method for triggering battery thermal runaway, is widely applied in battery safety testing. Its principle involves inserting a steel needle into the battery at a certain speed, damaging the internal structure, causing an internal short circuit, and thus triggering thermal runaway. This test method is relatively simple to operate and can, to some extent, simulate the situation where a battery is punctured by a sharp object during actual use, providing important evidence for assessing battery safety.

[0004] However, with the rapid development of battery technology, battery energy density is constantly increasing, and the internal structure and materials of batteries are becoming increasingly complex. Under these circumstances, simple nail penetration tests are no longer sufficient to effectively trigger battery thermal runaway. Many new batteries only show localized damage after nail penetration tests and do not trigger large-scale thermal runaway reactions, making it impossible to effectively simulate and evaluate the safety performance of batteries under actual abuse conditions.

[0005] To more effectively trigger battery thermal runaway, researchers have attempted to use external heating. External heating typically involves placing a heating device outside the battery, transferring heat to the battery's interior via thermal conduction, raising the battery temperature until thermal runaway is triggered. However, this method has several drawbacks. Firstly, external heating is time-consuming, requiring a considerable amount of time to reach the thermal runaway temperature conditions. This not only increases the testing cycle and reduces efficiency, but also causes the overall battery temperature to rise continuously during prolonged heating, negatively impacting the thermal runaway outcome and making it difficult to accurately reflect the true situation of thermal runaway under normal operating conditions. Secondly, external heating makes it difficult to precisely control the heating location and intensity, preventing targeted heating of critical internal battery components, thus affecting the accuracy and repeatability of thermal runaway triggering.

[0006] In contrast, internal battery heating can trigger battery thermal runaway more directly and effectively. By placing heating elements inside the battery and connecting positive and negative leads to an external heating power source, specific locations inside the battery can be precisely heated, rapidly increasing the local temperature and thus reliably triggering battery thermal runaway. This method has significant advantages such as high repeatability and high trigger rate, providing more accurate and reliable test data for battery thermal runaway research.

[0007] However, internal battery heating also has significant drawbacks. Placing heating elements inside the battery requires additional processing steps during manufacturing, demanding extremely high precision. It's crucial to ensure a good fit between the heating element and the battery's internal structure, as well as maintain the sealing performance of the lead wires to prevent leakage and other safety issues during use. This poses a significant challenge to battery manufacturing processes and quality control, increasing production costs and complexity. Especially for finished batteries, which have already undergone sealing and welding processes, placing heating elements internally is virtually impossible, severely limiting the effectiveness of internal heating methods in thermal runaway testing of finished batteries. Summary of the Invention

[0008] The purpose of this invention is to provide a method, system, and device for testing thermal runaway of power batteries. This technical solution can solve the problem that needle penetration and internal heating cannot be implemented in an integrated or sequential manner in the prior art.

[0009] To achieve the above objectives, in a first aspect, the present invention provides a power battery thermal runaway testing device, comprising: The needle-punching machine body is used to form the main support and integrate the hydraulic system; The acupuncture assembly is vertically mounted above the acupuncture machine body, driven by the hydraulic system and feedable in the Z-axis. A steel needle is provided at the front end of the acupuncture assembly. A heating element is built inside the steel needle. The heating element is connected to an external heating power supply and has several temperature acquisition points at different positions along the internal axis of the steel needle. A battery fixing assembly, located directly above the acupuncture assembly, includes a support platform fixed to the acupuncture machine body and a replaceable fixing clamp. A voltage and temperature monitoring component includes a voltage sensor and a temperature sensor. The voltage sensor is connected to the positive and negative terminals of a battery, and the temperature sensor is arranged at the positive and negative terminals, the large surface, the side surface, and the temperature acquisition point of the battery. The control component is signal-connected to the hydraulic system, the heating component, and the voltage and temperature monitoring component.

[0010] The beneficial effects of the basic solution: The temperature monitoring component enables comprehensive capture of multi-dimensional battery parameters. It monitors the electrochemical state changes of the battery's positive and negative electrodes in real time through voltage sensors, and covers key external areas such as the positive and negative electrodes, the main surface, and the sides of the battery through temperature sensors. Furthermore, it captures the internal temperature at the puncture site using temperature acquisition points along the axis of the steel needle. Compared to traditional methods that rely solely on visual phenomena such as smoke and fire to determine thermal runaway, this data-driven approach is more accurate and avoids the delays and errors inherent in human observation.

[0011] The control components can quickly make decisions about the test process based on real-time data. If abnormal parameters are detected, indicating that thermal runaway is about to occur, protective measures can be taken in advance. If thermal runaway has been triggered and reaches the preset danger threshold, the test can also be terminated in time to prevent the accident from escalating, greatly improving the safety and controllability of the testing process. For example, in the testing of new energy vehicle batteries, it can avoid equipment damage or personal injury caused by sudden thermal runaway.

[0012] By controlling the working modes of the puncture and heating components, the system can simulate various thermal runaway triggering scenarios. For example, when working simultaneously, it can simulate extreme conditions where the battery suffers puncture damage while being in a high-temperature environment, such as the situation where the battery is punctured by heat after a collision with a new energy vehicle. During operation, it can test the battery response under two different failure sequences: puncture first and then heating, and heating first and then puncture, covering complex scenarios combining mechanical abuse and thermal abuse.

[0013] Traditional testing devices often suffer from inconsistent triggering conditions, leading to significant variations in test results. This new device, however, utilizes a hydraulic system to drive the needle-piercing assembly for stable Z-axis feeding, while a heating assembly provides controllable heat output. The coordinated operation of these two components is precisely controlled by a control unit, reducing human and environmental interference during testing and ensuring repeatable results under identical conditions. This is crucial for batch battery testing, safety comparisons between different batches, and industry standard testing, providing comparable and objective data for battery safety evaluation.

[0014] This device overcomes the limitations of traditional testing methods that focus on a single dimension of temperature acquisition. The heating element inside the steel needle, combined with temperature acquisition points, can obtain the core internal temperature of the battery puncture site, while temperature sensors positioned outside the battery capture the overall external temperature distribution, achieving simultaneous acquisition of internal and external temperatures. This comprehensive temperature data clearly presents the entire process of thermal runaway from internal triggering to outward diffusion, such as the rate of internal temperature rise and the speed of heat transfer to the battery's surface and sides.

[0015] By combining synchronously monitored voltage data, researchers can conduct in-depth analysis of the correlation between battery electrochemical performance and temperature changes during thermal runaway, accurately determining the severity of thermal runaway. This includes factors such as the time difference between a sudden voltage drop and a rapid temperature rise, and the impact of temperature differences in different locations on the degree of battery failure. This data provides crucial information for optimizing battery thermal management systems, improving battery casing and internal separator materials, and refining battery pack structural design, thereby driving the development of inherently safer power batteries.

[0016] The battery mounting fixtures are replaceable, allowing for compatibility with individual cells or battery pack systems of different sizes and models. This eliminates the need for custom-designed testing equipment for different battery specifications, broadening the applicability of the device. The modular design not only reduces the purchase cost of testing equipment but also improves its utilization rate. It is particularly suitable for battery R&D companies and third-party testing organizations, addressing diverse testing needs and enhancing the overall efficiency of testing work.

[0017] As a feasible preferred embodiment, the steel needle is made of metal, ceramic, or a combination of metal and ceramic, and the feeding speed is in the range of 0.1 mm / s to 10 mm / s; the needle penetration stroke of the steel needle is not less than 1 / 3 of the thickness of the battery being tested in the penetration direction.

[0018] As a preferred feasible option, the heating component is in close contact with the inner wall of the steel needle.

[0019] As a feasible preferred solution, the steel needle is a detachable structure that can be pulled out and reset after the test, and the steel needle can be reused.

[0020] As a feasible preferred option, the temperature acquisition points are distributed along the axial direction of the steel needle.

[0021] As a feasible preferred solution, the control component can perform two test modes: needle puncture followed by heating or preheating followed by needle puncture and heating, and automatically end the test after thermal runaway is triggered or after a preset heating time is reached.

[0022] Secondly, the present invention also proposes a method for testing the thermal runaway of a power battery, which utilizes the aforementioned thermal runaway testing device for a power battery, characterized in that it includes: A battery fixing assembly is used to fix individual cells or battery pack systems onto a support platform. The individual cells have voltage sensing lines arranged at the positive and negative terminals, and temperature sensing lines arranged at the positive and negative terminals, the large surface, and the side. In addition to the triggered cells, the battery pack system also has temperature sensing lines arranged around the cells. Turn on the power to the device, adjust the steel needle to the position to be punctured by adjusting the components, use the control system to confirm whether the temperature and voltage data are normal, and set the puncture parameters and heating parameters. Acupuncture and heating were performed. After the test, the controller of the operating equipment was used to remove the needle-piercing components and reset each component to its initial state. The voltage and temperature during the test were recorded and analyzed to evaluate the thermal runaway characteristics and extent of the battery.

[0023] As a feasible and preferred solution, acupuncture and heating are implemented in the following two ways: First, needle puncture, then heat: A hydraulic press drives the needle puncture assembly to puncture a single cell or battery pack system at a set speed, reaching the set puncture stroke. The battery voltage, external temperature, and internal temperature are monitored in real time. If no thermal runaway occurs, the heating assembly is activated to heat the inserted steel needle, continuously heating the battery's interior. The battery voltage, external temperature, and internal temperature are monitored in real time until thermal runaway is triggered or the preset heating time is reached. Or... Preheating followed by needle puncture heating: First, the steel needle is preheated to the set temperature by the heating component. Then, the needle puncture component is pushed by the hydraulic press to puncture the single cell or battery pack system at the set needle puncture speed to reach the set needle puncture stroke. At the same time as puncture, the heating component is activated to rapidly heat the inside of the battery by the steel needle. The battery voltage, external temperature and internal temperature are monitored in real time until thermal runaway is triggered or the preset heating time is reached.

[0024] As a feasible preferred solution, the needle-punching parameters include needle-punching speed and needle-punching formation. The needle-punching speed is adjustable in the range of 0.1 mm / s to 10 mm / s, and the needle-punching stroke is not less than 1 / 3 of the thickness of the battery being tested in the punching direction. The heating parameters include heating power and preheating temperature. The heating power can be adjusted in the range of 50 W to 2000 W, and the preheating temperature can be adjusted in the range of 50℃ to 200℃.

[0025] Thirdly, the present invention also provides a power battery thermal runaway test system, which utilizes the aforementioned power battery thermal runaway test method. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0027] Figure 2 This is a schematic diagram of the internal structure of the machine.

[0028] Figure 3 This is a schematic diagram of the integrated acupuncture heating component.

[0029] Reference numerals: 1. Steel needle; 2. Support platform; 3. Hydraulic system; 4. Heating component. Detailed Implementation

[0030] To make the technical solution and advantages of this application clearer, the technical solution of the present invention will be further described in detail below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only some embodiments of the present invention, and are only used to explain this application, not to limit it. It should be noted that the technical features or combinations of technical features described in the following embodiments should not be considered isolated; they can be combined with each other to achieve better technical effects. The same reference numerals appearing in the accompanying drawings of the following embodiments represent the same features or components, and can be applied to different embodiments.

[0031] Furthermore, unless otherwise defined, the technical or scientific terms used in the description of this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0032] The present invention will now be described in further detail with reference to the accompanying drawings.

[0033] Example 1 Reference Figure 1 and Figure 2 This disclosure provides a power battery thermal runaway testing device, including a needle penetration body, a needle penetration assembly, a heating assembly 4, a battery fixing assembly, a voltage and temperature monitoring assembly, and a control assembly.

[0034] The acupuncture machine body is located at the bottom of the device, serving as the main support structure for the entire device. The acupuncture machine body integrates a hydraulic system 3, which drives the acupuncture components to perform acupuncture operations and provides electrical power to the heating components 4.

[0035] The needle assembly is propelled by a hydraulic system 3 and includes a replaceable steel needle 1. The steel needle 1 can be made of metal or non-metal (such as ceramic) or a combination of both to suit different testing needs.

[0036] The steel needle 1 is installed at the front end of the needle-piercing assembly, and its advancing speed and penetration depth are controlled by the hydraulic system 3. The needle-piercing speed can be adjusted arbitrarily within the range of 0.1 mm / s to 10 mm / s to meet the requirements of different testing conditions.

[0037] In one embodiment, the surface of the steel needle 1 is provided with a non-stick coating to prevent battery material residue.

[0038] The needle assembly is vertically mounted above the needle machine body to ensure that the steel needle 1 can accurately penetrate the battery cell or battery pack system fixed on the battery fixing assembly.

[0039] Reference Figure 3 The heating component 4 is rod-shaped and built into the steel needle 1 of the acupuncture component. In this embodiment, the heating power can be adjusted from 50W to 2000W to meet different heating requirements.

[0040] The heating component 4 is connected to an external heating power source via wires. Temperature acquisition points are arranged at different positions inside the steel needle 1. These acquisition points are connected to a monitoring device via signal lines to achieve real-time monitoring of the heating temperature.

[0041] The heating component 4 is tightly fitted inside the steel needle 1 to ensure that the heating energy can be efficiently transferred to the battery.

[0042] The battery securing assembly includes a support platform 2 and a securing clamp for securely securing individual batteries or battery pack systems to the device.

[0043] The support platform 2 is connected to the needle-punching machine body by bolts or other fixing methods to ensure stability during the test. The fixing fixture is customized according to the shape and size of the battery to ensure that the battery does not shift during the test.

[0044] The battery fixing component is located directly above the needle piercing component, which facilitates the accurate insertion of the steel needle 1 into the battery.

[0045] The voltage and temperature monitoring component includes a voltage sensor and a temperature sensor, which are used to monitor the voltage changes and internal and external temperature changes of the battery during the testing process, respectively.

[0046] The voltage sensor is connected to the positive and negative terminals of the battery, while the temperature sensor is arranged as needed at the positive and negative terminals, the main surface, the side, and the temperature acquisition point inside the steel needle 1.

[0047] All sensors are connected to the monitoring device via signal lines to enable real-time data acquisition and transmission.

[0048] Sensors are placed at key locations on the battery and steel needle 1 to ensure accurate reflection of changes in the battery's state during testing.

[0049] The control components use a microprocessor or PLC (Programmable Logic Controller) as the core, and integrate an operating interface and necessary control software.

[0050] The control component is connected to the hydraulic system 3 of the needle-punching component, the heating power supply of the heating component 4, and the monitoring device of the voltage and temperature monitoring component via electrical signal lines, so as to realize centralized control and data acquisition of the entire testing process.

[0051] Example 2 This disclosure also provides a method for testing thermal runaway of a power battery, including the following steps.

[0052] Step S100: Battery fixing and sensor wire arrangement Use battery securing components to secure individual batteries or battery pack systems to support platform 2.

[0053] For a single battery cell, voltage sensing lines are placed at the positive and negative terminals to monitor changes in battery voltage. Temperature sensing lines are placed at the positive and negative terminals, the main surface, and the sides to monitor the temperature of various parts of the battery.

[0054] For battery pack systems, in addition to the triggered cells, temperature sensing lines should also be placed around the surrounding cells to comprehensively monitor temperature changes.

[0055] Step S200, Equipment preparation and parameter setting, includes: Turn on the device power and adjust the steel needle 1 to the position to be pierced by adjusting the components.

[0056] Use the control system to confirm that data such as temperature and voltage are normal, and ensure that the equipment is in standby mode.

[0057] Set acupuncture parameters: Needle puncture speed: Adjustable within the range of 0.1mm / s to 10mm / s according to actual needs; Needle penetration stroke: not less than 1 / 3 of the thickness of the battery being tested in the penetration direction.

[0058] Set heating parameters: Heating power: Adjustable within the range of 50W to 2000W according to actual needs; Preheating temperature (if using preheating method): 50-200℃ adjustable.

[0059] Step 3: Perform acupuncture and heating, including: In one embodiment, acupuncture is performed first, followed by heating: The operating equipment controller uses a hydraulic press to push the needle-piercing assembly to pierce individual cells or battery pack systems at a set needle-piercing speed, achieving the set needle-piercing stroke.

[0060] Real-time monitoring of battery voltage, external temperature, and internal temperature.

[0061] If no thermal runaway occurs, the heating component 4 is activated to heat the inserted steel needle 1, thereby continuously heating the inside of the battery through the steel needle 1.

[0062] Continue to monitor the battery voltage, external temperature, and internal temperature in real time until thermal runaway is triggered or the preset heating time is reached.

[0063] In another embodiment, preheating followed by needle-prick heating is employed: First, the steel needle 1 is preheated to the set temperature (50-200℃) by the heating component 4.

[0064] The operating equipment controller uses a hydraulic press to push the needle-piercing assembly to pierce individual cells or battery pack systems at a set needle-piercing speed, achieving the set needle-piercing stroke.

[0065] The heating component 4 is activated simultaneously with the insertion, and the steel needle 1 rapidly heats the inside of the battery.

[0066] The battery voltage, external temperature, and internal temperature are monitored in real time until thermal runaway is triggered or the preset heating time is reached.

[0067] Step 4: End of Experiment and Data Recording, including: After the test, the operator pulls out the needle assembly from the control unit and resets each component to its initial state for the next test. The steel needle 1 can be reused.

[0068] Record and analyze data such as voltage and temperature during the test to assess the thermal runaway characteristics and extent of the battery.

[0069] This disclosure also provides a power battery thermal runaway test system, which utilizes the aforementioned power battery thermal runaway test method.

[0070] The above content is merely an embodiment of the present invention. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all prior art in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can improve and implement this solution based on the guidance provided in this application and their own capabilities. Some typical well-known structures or systems should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A power battery thermal runaway testing device, characterized in that, include: The needle-punching machine body is used to form the main support and integrate the hydraulic system; The acupuncture assembly is vertically mounted above the acupuncture machine body, driven by the hydraulic system and feedable in the Z-axis. A steel needle is provided at the front end of the acupuncture assembly. A heating element is built inside the steel needle. The heating element is connected to an external heating power supply and has several temperature acquisition points at different positions along the internal axis of the steel needle. A battery fixing assembly, located directly above the acupuncture assembly, includes a support platform fixed to the acupuncture machine body and a replaceable fixing clamp. A voltage and temperature monitoring component includes a voltage sensor and a temperature sensor. The voltage sensor is connected to the positive and negative terminals of the battery, and the temperature sensor is arranged at the positive and negative terminals, the large surface, the side surface, and the temperature acquisition point of the battery. as well as The control component is signal-connected to the hydraulic system, the heating component, and the voltage and temperature monitoring component.

2. The power battery thermal runaway testing system according to claim 1, characterized in that, The steel needle is made of metal, ceramic, or a combination of metal and ceramic, and the feeding speed is in the range of 0.1 mm / s to 10 mm / s; the needle penetration stroke of the steel needle is not less than 1 / 3 of the thickness of the battery being tested in the penetration direction.

3. The power battery thermal runaway testing system according to claim 1, characterized in that, The heating component is in close contact with the inner wall of the steel needle.

4. The power battery thermal runaway testing system according to claim 1, characterized in that, The steel needle is a detachable structure, which can be pulled out and reset after the test, and the steel needle can be reused.

5. The power battery thermal runaway testing system according to claim 1, characterized in that, The temperature acquisition points are distributed along the axial direction of the steel needle.

6. The power battery thermal runaway testing system according to claim 1, characterized in that, The control component can perform two test modes: needle puncture followed by heating or preheating followed by needle puncture and heating, and automatically end the test after thermal runaway is triggered or the preset heating time is reached.

7. A method for testing the thermal runaway of a power battery, employing the power battery thermal runaway testing device as described in any one of claims 1-6, characterized in that, include: A battery fixing assembly is used to fix individual cells or battery pack systems onto a support platform. The individual cells have voltage sensing lines arranged at the positive and negative terminals, and temperature sensing lines arranged at the positive and negative terminals, the large surface, and the side. In addition to the triggered cells, the battery pack system also has temperature sensing lines arranged around the cells. Turn on the power to the device, adjust the steel needle to the position to be punctured by adjusting the components, use the control system to confirm whether the temperature and voltage data are normal, and set the puncture parameters and heating parameters. Acupuncture and heating were performed. After the test, the controller of the operating equipment was used to remove the needle-piercing components and reset each component to its initial state. The voltage and temperature during the test were recorded and analyzed to evaluate the thermal runaway characteristics and extent of the battery.

8. A method for testing thermal runaway of a power battery according to claim 1, characterized in that, Acupuncture and heating can be performed in the following two ways: First, needle puncture, then heat: A hydraulic press drives the needle puncture assembly to puncture a single cell or battery pack system at a set speed, reaching the set puncture stroke. The battery voltage, external temperature, and internal temperature are monitored in real time. If no thermal runaway occurs, the heating assembly is activated to heat the inserted steel needle, continuously heating the battery's interior. The battery voltage, external temperature, and internal temperature are monitored in real time until thermal runaway is triggered or the preset heating time is reached. Or... Preheating followed by needle puncture heating: First, the steel needle is preheated to the set temperature by the heating component. Then, the needle puncture component is pushed by the hydraulic press to puncture the single cell or battery pack system at the set needle puncture speed to reach the set needle puncture stroke. At the same time as puncture, the heating component is activated to rapidly heat the inside of the battery by the steel needle. The battery voltage, external temperature and internal temperature are monitored in real time until thermal runaway is triggered or the preset heating time is reached.

9. A method for testing thermal runaway of a power battery according to claim 1, characterized in that, The needle-piercing parameters include the needle-piercing speed and the needle-piercing formation. The needle-piercing speed is adjustable in the range of 0.1 mm / s to 10 mm / s, and the needle-piercing stroke is not less than 1 / 3 of the thickness of the battery in the piercing direction. The heating parameters include heating power and preheating temperature. The heating power can be adjusted in the range of 50 W to 2000 W, and the preheating temperature can be adjusted in the range of 50℃ to 200℃.

10. A power battery thermal runaway testing system, characterized in that, The method for testing thermal runaway of a power battery as described in any one of claims 7-9 was used.

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