Thermal runaway multi-scene simulation and test device for energy storage battery and test method thereof

Abstract

The invention relates to the field of battery safety test, and discloses an energy storage battery thermal runaway multi-scene simulation and test device and a test method thereof, and the device comprises a main body test box, a thermal runaway trigger system, a gas management and analysis system, a safety protection system and a data acquisition and control system. Wherein the main body test box adopts an upper-layer, middle-layer and lower-layer functional partition structure, so that efficient isolation between a reaction region and a control region is realized; the thermal runaway triggering system integrates three triggering modes of heating, needling and over-charging and over-discharging, and can simulate various abuse scenes; and the gas management and analysis system is provided with an explosion venting device with an adjustable explosion pressure threshold value, so that the safety and the flexibility of the test are improved. Through integrated design, accurate reproduction of various thermal runaway scenes, safe and controllable process and quantitative evaluation of results are realized, and a comprehensive and objective evaluation basis is provided for the safety performance of the energy storage battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery safety testing, in particular to a multi-scenario simulation and testing device for thermal runaway of energy storage batteries and a testing method thereof. BACKGROUND

[0002] As the core unit of electrochemical energy storage systems, the safety performance of energy storage batteries is the key to determine whether the entire system can operate reliably. Under extreme abuse conditions, such as overheating, mechanical damage or electrical abuse, energy storage batteries may trigger thermal runaway. This process releases a large amount of heat and flammable gas, which can easily lead to serious safety accidents such as fire and explosion. Therefore, it is crucial to comprehensively test and evaluate the thermal runaway characteristics of batteries before their research and development, production and application.

[0003] Currently, the testing methods for battery thermal runaway mainly focus on thermal abuse, mechanical abuse and electrical abuse. However, in specific testing practices, existing technical solutions and equipment generally have some limitations. Usually, performing these different types of abuse tests requires relying on multiple independent experimental platforms, for example, thermal abuse tests are conducted in dedicated high-temperature test chambers, while mechanical abuse tests require additional needle-punching or extrusion equipment. This separate testing mode not only makes the operation process cumbersome and the testing efficiency low, but more importantly, due to differences in testing environment, fixation method and data acquisition system, it is difficult to ensure the uniformity of conditions between different testing scenarios, which further affects the horizontal comparability of test results.

[0004] In addition, existing testing devices also fail to fully meet the growing demand for refined testing in terms of safety protection and flexibility of scenario simulation. Many testing chambers are equipped with safety relief devices, and the burst pressure threshold is fixed. This design is not adaptable when facing different specifications, different energy densities, and different gas production characteristics of the batteries to be tested. Both too high or too low relief thresholds cannot balance the safety of the testing process and the integrity of the data.

[0005] In terms of data analysis and evaluation, the current evaluation of the severity of thermal runaway largely depends on the qualitative or semi-quantitative interpretation of multiple independent data curves such as temperature, voltage, and pressure. This approach lacks a unified, objective and comprehensive quantitative evaluation standard that reflects the severity of thermal runaway. Therefore, when directly comparing the intrinsic safety performance of batteries with different chemical systems, or evaluating the effectiveness of different thermal management schemes in suppressing thermal runaway, the existing analysis method cannot provide an intuitive and reliable basis for judgment, limiting the further development of battery safety technology. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a thermal runaway multi-scenario simulation and testing device for energy storage batteries and a testing method thereof, and the technical problems to be solved by the present application are that in the existing thermal runaway testing of energy storage batteries, the testing platform has dispersed functions, single simulation capability, insufficient safety adaptability, and the evaluation results are difficult to be uniformly quantified and compared.

[0007] To achieve the above object, the present application is implemented by the following technical solutions: a thermal runaway multi-scenario simulation and testing device for energy storage batteries and a testing method thereof, comprising:

[0008] The main test box, the thermal runaway triggering system, the gas management and analysis system, the safety protection system, and the data acquisition and control system. The thermal runaway triggering system is arranged in the main test box and is used for triggering thermal runaway of the battery to be tested. The gas management and analysis system is in communication with the main test box and is used for managing and analyzing the gas generated by thermal runaway. The safety protection system is used for ensuring the safety of the testing process. The data acquisition and control system is electrically connected with the above-mentioned systems to realize unified control of the testing process and synchronous acquisition of the testing data.

[0009] In a specific embodiment, the main test box adopts a functional partition and isolation design and comprises a lower box, a middle box, and an upper box. The middle box serves as a core test area and is used for placing the battery to be tested. The lower box and the middle box and the upper box and the middle box are both arranged in isolation. This structure realizes physical isolation of the functional modules: part of the key control components of the data acquisition and control system are arranged in the lower box to avoid the influence of high temperature generated by the test on the stability thereof; part of the components of the gas management and analysis system, such as the explosion relief device and the gas sampling interface, are arranged in the upper box to facilitate the diversion, collection, and safe relief of the gas. The three-layer box structure forms a multiple safety barrier to effectively block the diffusion of heat and pressure to the outside.

[0010] In order to comprehensively simulate various misuse scenarios, the thermal runaway triggering system integrates multiple triggering modes. Specifically, it can include at least one of a heating component, a needle piercing mechanism, and an overcharge and overdischarge circuit, so as to flexibly realize heating triggering, needle piercing triggering, or overcharge and overdischarge triggering, and reproduce various real scenarios such as thermal misuse, mechanical misuse, and electrical misuse.

[0011] In order to improve the safety and flexibility of the test, the gas management and analysis system comprises an explosion relief device with an adjustable explosion pressure threshold. The test personnel can set a safe explosion pressure threshold in advance according to the specifications of the battery to be tested or the expected reaction intensity . The threshold can be set through an adjusting mechanism, and the setting parameters of the adjusting mechanism and satisfy a specific functional relationship, which can be expressed as:

[0012] ;

[0013] When the pressure in the main test box exceeds a set threshold , the explosion relief device will be activated instantaneously to achieve safe release of pressure, thereby protecting equipment and personnel safety and adapting to different testing needs.

[0014] To further enhance the safety protection capability, the safety protection system can include a protection mechanism and / or an immersion liquid system arranged in the main test box. The protection mechanism can effectively shield the key ports (such as sensor interfaces) on the inner wall of the main test box to reduce the direct impact and pollution of high-speed eruption materials generated in the instant of thermal runaway. The immersion liquid system is used to contain immersion liquid, which not only can realize immersion thermal runaway test, but also can absorb reaction heat and extinguish open flames to a certain extent.

[0015] The second aspect of the present application provides a method for simulating and testing thermal runaway of energy storage batteries in multiple scenarios, which uses any of the aforementioned devices.

[0016] The method includes the following steps: first (S1), placing the battery to be tested in the main test box of the device; then (S2), according to the testing purpose, selecting a triggering mode of the thermal runaway triggering system and setting the corresponding test parameters. For example, when heating triggering is selected, the target heating temperature and / or the heating rate can be set; when needle triggering is selected, the penetration speed and / or the needle diameter of the needle can be set; and when overcharge triggering is selected, the charging current and / or the cutoff voltage can be set. Next (S3), starting the test, triggering the battery to be tested by the thermal runaway triggering system according to the set parameters until thermal runaway occurs. During the entire test process (S4), the data acquisition and control system collects and records multi-dimensional data such as temperature, pressure, and gas composition in real time. To accurately capture the transient characteristics of thermal runaway, the sampling rate of data acquisition can be set to no less than 10 kHz. After the test is completed (S5), based on the complete test data collected, the thermal runaway characteristics of the battery to be tested are analyzed and evaluated in depth.

[0017] In one specific embodiment, after step S3, the method can further include collecting the gas generated during the thermal runaway process by the gas management and analysis system online or offline, and analyzing the specific gas composition and concentration.

[0018] In another specific embodiment, the analysis and evaluation process in step S5 can include quantitative evaluation of the thermal runaway risk of the battery. For example, based on the real-time collected temperature data and pressure data , a comprehensive thermal runaway risk evaluation index The calculation formula can be defined as:

[0019] ;

[0020] wherein, represents the maximum temperature rise rate during the test process, represents the maximum pressure rise rate, and and are weight coefficients preset according to experience or standards. The index provides an intuitive quantitative basis for evaluating the severity of thermal runaway of different batteries or under different working conditions.

[0021] The present application provides a multi-scene simulation and testing device for thermal runaway of energy storage batteries and a testing method thereof. The device has the following beneficial effects:

[0022] 1. The system integrates the simulation functions of multiple abuse scenes such as heating, needle piercing, and overcharging and overdischarging on a single platform. Compared with the traditional method of using multiple independent devices for dispersed testing, the present application can perform abuse testing of the same batch of batteries in different dimensions under the same hardware reference and environmental conditions, fundamentally eliminating the system error caused by differences in equipment and environment, and ensuring high horizontal comparability between the test results.

[0023] 2. The reaction zone in the middle where severe thermal runaway may occur is completely separated from the lower precise control and power supply unit through solid physical isolation. This design not only acts as a firewall to effectively prevent damage to the core control components caused by high-temperature, high-pressure gas and electrolyte leakage, but also shields strong electromagnetic interference, ensuring the stability and measurement accuracy of the data acquisition system during high-transient changes.

[0024] 3. By introducing a burst pressure threshold adjustable explosion relief device, the test personnel can customize the safety threshold according to the energy density, size specification, and expected gas production of the battery to be tested. Whether it is a small gas production consumer battery or a severe reaction large-capacity power battery, the test box can be kept closed to the maximum extent to obtain more complete pressure change data while ensuring the safety of personnel and equipment.

[0025] 4. The present application can accurately capture the steep increase moment of temperature, pressure, and other key parameters and the peak value of their change rate at a much higher sampling rate than traditional devices. This not only obtains simple result data, but also provides high-resolution time slices for in-depth understanding of the internal mechanism of thermal runaway of different battery systems and identification of early warning features.

[0026] 5. By constructing and introducing a thermal runaway risk assessment index The two most core dynamic indicators in the thermal runaway process, the maximum temperature rise rate and the maximum pressure rise rate, are weighted and fused. This makes the severity of thermal runaway under different batteries and different trigger conditions can be represented by a direct value, providing direct, reliable and easy-to-compare data support for battery selection, safety design and optimization of thermal management strategy. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The overall structure block diagram of the energy storage battery thermal runaway multi-scenario simulation and testing device of the present application is shown in the figure.

[0028] Figure 2 The structure sectional view of the main test box of the present application is shown in the figure.

[0029] Figure 3 The structure schematic diagram of the adjustable explosion relief device of the present application is shown in the figure.

[0030] Figure 4 The working principle block diagram of the data acquisition and control system of the present application is shown in the figure.

[0031] Figure 5 The flow chart of the energy storage battery thermal runaway multi-scenario simulation and testing method of the present application is shown in the figure. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the specification of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0033] Please refer to the drawings attached Figures 1 to 5 The energy storage battery thermal runaway multi-scenario simulation and testing device and its testing method provided by the embodiments of the present application include a main test box, and a thermal runaway trigger system, a gas management and analysis system, a safety protection system and a data acquisition and control system arranged in or connected with the main test box. The five systems are functionally related to each other and precisely coordinated in time sequence, and together constitute a complete testing and analysis platform.

[0034] The thermal runaway trigger system is arranged in the interior of the main test box and directly acts on the battery to be tested. The gas management and analysis system is connected with the upper space of the main test box through a pipeline to effectively collect and process the gas generated in the thermal runaway process. The components of the safety protection system are distributed inside and outside the main test box to form a three-dimensional safety barrier. The data acquisition and control system as the control center of the device is electrically connected with the sensors and actuators distributed in each system through signal cables to form a closed-loop measurement and control network.

[0035] The overall workflow of the device embodies the precise coordination between systems. A typical test procedure can include the following steps:

[0036] First, the test personnel set the trigger mode, key parameters, and safety threshold according to the test requirements through the human-computer interaction interface of the data acquisition and control system.

[0037] Subsequently, the battery to be tested is securely placed in the designated position inside the main test box.

[0038] After the test starts, the data acquisition and control system issues instructions to drive the thermal runaway trigger system to accurately apply the preset abuse conditions to the battery to be tested, in order to induce thermal runaway.

[0039] During the intense reaction of thermal runaway, the safety protection system is automatically activated or activated according to the preset logic to ensure the safety of the equipment and the environment; at the same time, the gas management and analysis system performs pressure relief, collection, and composition analysis on the high-temperature and high-pressure gas generated instantaneously.

[0040] During the entire test, the data acquisition and control system records real-time, synchronized multi-dimensional data streams such as temperature, pressure, and gas concentration through high-speed sensors, and processes the data after the test to generate a detailed analysis report. Through this series of steps, the device can safely and efficiently complete the whole-chain test work from triggering, process monitoring, safety management to data analysis on an integrated platform.

[0041] The figure is a structural cross-sectional view of the main test box in the embodiment of the present application. The main test box adopts special functional zoning and multi-layer protection design in structure. The box body can be composed of high-temperature and corrosion-resistant materials, such as 316L stainless steel, and a high-temperature corrosion-resistant coating is applied to the inner wall to resist the erosion of high temperature and corrosive substances generated during the thermal runaway process.

[0042] The main test box is separated into lower, middle, and upper boxes in the vertical direction. The middle box is the core reaction area that contains and conducts battery testing, and its structure is specially strengthened to withstand the instantaneous high-pressure impact that may be caused by thermal runaway. The opening such as the box door adopts a double-sealed structure resistant to high temperature to ensure the air tightness during the test. Inside the middle box, an adjustable battery fixing device is provided, which can accommodate batteries to be tested of different sizes and specifications and securely position them in the center of the test area.

[0043] The lower box is located at the bottom of the whole device, and is physically isolated from the middle box by a layer of high-efficiency thermal insulation material. This space is used to house some of the precise electronic components of the data acquisition and control system, such as the controller, data acquisition card, and power module. This isolated design takes advantage of the natural convection principle of hot air rising, supplemented by physical isolation, effectively avoiding the adverse effects of the high temperature generated by the middle box during testing on the performance stability of the electronic components in the lower box.

[0044] The upper box is located at the top of the device and is also isolated from the middle box. Its main function is to serve as a buffer area for gas management and explosion relief. Some key components of the gas management and analysis system, such as the explosion relief device and gas sampling interface, are integrated here. Such a layout is conducive to the upward flow of high-temperature gas generated by thermal runaway, and orderly pressure release and sampling analysis.

[0045] The thermal runaway triggering system has all its execution components integrated inside the middle box, which can accurately induce thermal runaway in the battery in multiple preset ways. When simulating thermal abuse scenarios, the heating components in the system, such as ceramic heating plates or flexible polyimide heating films attached to the surface of the battery, will heat the battery to a specific temperature at a set heating rate under the regulation of a control algorithm (such as PID control).

[0046] When simulating mechanical abuse scenarios, the needle puncture mechanism in the system will be activated. This mechanism consists of a servo motor driving a ball screw, which can control a needle made of high-hardness materials such as tungsten steel to pierce the specified location of the battery body at a precisely controllable speed (e.g. 1-100 mm / s) and displacement. The diameter of the needle can also be replaced according to the test standards.

[0047] When simulating electrical abuse scenarios, a programmable overcharge and overdischarge circuit will be connected to the battery under test. This circuit, as a high-precision DC power supply and load, can apply a charging current far exceeding the design specifications of the battery or charge it to an extremely high cutoff voltage, thereby triggering internal short circuits and thermal runaway.

[0048] One of the core components of the gas management and analysis system is the explosion relief device installed in the upper box. This device includes a mechanical structure composed of a scale adjustment mechanism, a compression flange, and a rupture disc. Its innovation lies in the fact that the burst pressure threshold is adjustable. By rotating the adjustment mechanism, the pre-tightening force on the rupture disc can be changed, thereby setting different burst pressures. There is a pre-calibrated functional relationship between the threshold and the set parameters of the adjustment mechanism :

[0049]

[0050] where, represents the burst pressure threshold, in Pascals (Pa); represents a quantitative setting value of the adjustment mechanism, such as the number of rotations or the reading on a dial. In a specific linear model, this relationship can be simplified as , where is the calibration coefficient, is the base pressure corresponding to the initial pre-tightening force. When the pressure in the box exceeds the set , the rupture disc will instantaneously rupture, safely guiding the overpressure gas to the external treatment system. In addition, the upper box is also provided with a gas sampling interface for leading the gas generated by thermal runaway to the external mass spectrometer or Fourier transform infrared spectrometer for online component analysis.

[0051] The safety protection system provides multiple safeguards. Inside the main test box, a remotely controllable protection mechanism is provided, such as a metal baffle that can be flipped. Before thermal runaway occurs, the baffle can shield the observation window or fragile sensor port on the box body, preventing it from being directly impacted by the ejecta and high-temperature gas flow. The device also integrates a set of immersion liquid system, which can inject dielectrically good and high flash point insulating coolant (such as fluorinated liquid) into the middle box for immersion testing. This liquid not only effectively absorbs heat, but also to some extent inhibits the generation of flames. The outside or interlayer of the box body also integrates a cooling system, such as a forced air cooling or water cooling channel, for quickly reducing the temperature of the box body after the test is completed.

[0052] The data acquisition and control system is the nerve center of the entire device. The system is equipped with a variety of high-precision sensors, such as armored K-type thermocouples (range 0-1300℃, accuracy ±1℃) for measuring battery and environmental temperature, and piezoresistive pressure sensors (range 0-2MPa, accuracy ±0.5%FS) for monitoring the pressure in the box. The signals of all sensors are connected to a high-speed data acquisition card, which has a maximum synchronous sampling rate of 100kHz, ensuring that any rapid changes occurring at the moment of thermal runaway can be accurately captured. The operation of the entire system is controlled by a software platform on the host computer, which provides a graphical user interface for programming the test process, setting parameters, displaying real-time data curves, and automatically generating test reports

[0053] The present application also provides a method for simulating and testing thermal runaway of energy storage batteries in multiple scenarios. The method is implemented by the device described above. The core of the method is to provide a standardized and repeatable process to comprehensively evaluate the thermal runaway characteristics of the battery.

[0054] In one specific embodiment, the test method comprises the following core steps: first (S1), the energy storage battery cell to be tested is placed and fixed on the fixing device in the main test box, and the corresponding temperature, voltage, etc. sensors are connected. Then (S2), on the software interface of the data acquisition and control system, a thermal runaway triggering mode is selected, and specific test parameters are set. Next (S3), the test program is started, and the thermal runaway triggering system starts to apply abuse conditions to the battery to be tested according to the preset parameters. During the whole process (S4), the data acquisition and control system records the key data in real time at a high frequency. Finally (S5), after the test is completed, the system automatically saves all the data for in-depth analysis and evaluation.

[0055] In this embodiment, the test is carried out by using the heating triggering mode. In step S2, the test personnel select the heating triggering mode and set the specific test parameters, for example, set the temperature rising rate to 5℃ / min and the target temperature of thermal runaway triggering to 280℃. After the test is started, the heating assembly starts to heat the battery to be tested, and the data acquisition system starts to record the key data such as the surface temperature of the battery, the environmental temperature in the box, and the pressure in the box in real time at a sampling rate of not less than 10kHz. When the battery occurs thermal runaway, the gas management and analysis system can be started synchronously to introduce the generated gas into the external analysis instrument for composition and concentration analysis.

[0056] In another embodiment, the test can be carried out by using the needle piercing triggering mode. The preparation steps are similar to the foregoing embodiment. In the parameter setting step S2, the test personnel select the needle piercing triggering mode and set the operating parameters of the needle piercing mechanism, for example, set the piercing speed of the needle to 80mm / s and select the needle with a diameter of 3mm. After the program is started, the needle piercing mechanism drives the needle to pierce into the battery accurately, and the instantaneous changes of voltage, temperature and pressure caused by internal short circuit are recorded synchronously.

[0057] The analysis and evaluation process of the test data in step S5 of the method of the present application includes the quantitative evaluation of the thermal runaway risk. The evaluation is based on the temperature data and pressure data collected in step S4. First, the original data is processed, for example, by difference calculation, to obtain the temperature change rate curve and the pressure change rate curve , and the maximum temperature rising rate and the maximum pressure rising rate in the whole process are extracted therefrom.

[0058] Subsequently, the thermal runaway risk evaluation index is calculated by the following formula :

[0059]

[0060] wherein:

[0061] is the thermal runaway risk assessment index, which is a comprehensive index for quantifying the severity of thermal runaway;

[0062] is the maximum temperature rise rate monitored during the test, with the unit of °C / s;

[0063] is the maximum pressure rise rate monitored during the test, with the unit of kPa / s;

[0064] and is a preset weight coefficient, the value of which is set according to different battery chemistries, safety standards or evaluation focuses, and usually satisfies .

[0065] For example, in a test, if the measured maximum temperature rise rate is 120 °C / s, the maximum pressure rise rate is 600 kPa / s, and the weight coefficient is set to , then the thermal runaway risk assessment index of the battery is calculated as . This index provides an intuitive and objective basis for comparing the severity of thermal runaway under different battery or different abuse conditions.

[0066] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit it, and other modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art should be covered within the scope of protection of the claims of the present application, as long as they do not deviate from the spirit and scope of the technical solutions of the present application.

[0067] Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A thermal runaway multi-scenario simulation and testing device for energy storage batteries, characterized in that, The device comprises: a main test box; a thermal runaway triggering system arranged in the main test box for triggering thermal runaway of a battery to be tested; a gas management and analysis system in communication with the main test box for managing and analyzing gases generated in thermal runaway; a safety protection system for ensuring safety of the test process; a data acquisition and control system electrically connected with the thermal runaway triggering system, the gas management and analysis system and the safety protection system for controlling the test process and acquiring test data.

2. The apparatus of claim 1, wherein, The main test box comprises a lower box, a middle box and an upper box, the middle box is used for placing the battery to be tested, the lower box is arranged in isolation from the middle box, and the upper box is arranged in isolation from the middle box; part of components of the data acquisition and control system are arranged in the lower box, and part of components of the gas management and analysis system are arranged in the upper box.

3. The apparatus of claim 1, wherein, The thermal runaway triggering system comprises at least one of a heating assembly, a needle puncture mechanism and an overcharge and overdischarge circuit to realize heating triggering, needle puncture triggering or overcharge and overdischarge triggering.

4. The apparatus of claim 1, wherein, The gas management and analysis system comprises a venting device, the burst pressure threshold of the venting device is adjustable; wherein the burst pressure threshold by adjusting the set parameter of the adjusting mechanism is controlled to satisfy the relationship: ； wherein, is a predetermined function relationship.

5. The apparatus of claim 1, wherein, The safety protection system comprises a protection mechanism and / or an immersion liquid system arranged in the main test box; the protection mechanism is used for shielding a port of the main test box to reduce contact of thermal runaway eruption materials with the port; and the immersion liquid system is used for containing immersion liquid to realize immersion testing.

6. A multi-scenario simulation and testing method for thermal runaway of energy storage batteries, characterized in that, The method comprises the following steps: S1: placing a battery to be tested in the main test box; S2: selecting a triggering mode of the thermal runaway triggering system and setting test parameters; S3: starting the test, triggering the battery to be tested to generate thermal runaway by the thermal runaway triggering system; S4: acquiring temperature, pressure and gas composition data in the test process in real time by the data acquisition and control system; S5: analyzing and evaluating thermal runaway characteristics of the battery to be tested based on the acquired test data.

7. The method of claim 6, wherein, In the S2, when heating triggering is selected, a heating temperature and / or a heating rate are set; when needle puncture triggering is selected, a puncture speed and / or a needle diameter are set; when overcharge triggering is selected, a charging current and / or a cutoff voltage are set.

8. The method of claim 6, wherein, After the S3, the method further comprises the step of collecting gases generated in thermal runaway by the gas management and analysis system and analyzing gas composition and concentration of the gases.

9. The method of claim 6, wherein, In the S4, the data acquisition and control system acquires data at a sampling rate of no less than 10 kHz.

10. The method of claim 6, wherein, In S5, the analysis and evaluation of the thermal runaway characteristics of the battery to be tested comprises: based on the collected temperature data and pressure data , calculating a thermal runaway risk assessment index , and the calculation formula is: ； wherein, is the maximum temperature rise rate, is the maximum pressure rise rate, and is a preset weight coefficient.

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