A method and apparatus for obtaining the opening pressure of a battery thermal runaway valve

Abstract

This application provides a method and apparatus for obtaining the opening pressure of a battery thermal runaway valve, relating to the field of battery safety technology. The method includes acquiring the physical properties, ambient temperature, and ambient pressure of the battery under test; triggering thermal runaway using a thermal runaway testing device based on a set triggering method to obtain the battery temperature-time relationship and valve opening temperature during the thermal runaway process; calculating the internal pressure change of the battery based on the battery temperature-time relationship and valve opening temperature; and calculating the battery thermal runaway valve opening pressure based on the internal pressure change of the battery. This method calculates the battery thermal runaway valve opening pressure based on the physical properties of the battery under test, eliminating the need for pressure sensors on the battery, ensuring the airtightness of the battery before thermal runaway occurs. It solves the problems of existing methods requiring pressure sensors, leading to poor battery airtightness, and the risk of pressure sensor damage during thermal runaway, making pressure testing unsustainable and costly.

Description

Technical Field

[0001] This application relates to the field of battery safety technology, and more specifically, to a method and apparatus for obtaining the opening pressure of a battery thermal runaway valve. Background Technology

[0002] With the widespread application of lithium-ion batteries in new energy vehicles, their safety performance has attracted close attention from society. A key aspect of battery safety design is the assessment and protection against thermal runaway. Thermal runaway is accompanied by violent heat and gas generation reactions. Quantifying the pressure changes caused by heat and gas generation during thermal runaway and obtaining the corresponding valve opening pressure is of great significance for the safety design of lithium-ion batteries.

[0003] Existing technologies primarily employ pressure sensors to obtain the internal pressure of batteries. However, this method has several drawbacks. First, installing pressure sensors is destructive to the battery, requiring drilling holes in the battery surface to enable the sensors to detect internal pressure changes. This process is cumbersome, makes it difficult to ensure airtightness, and can damage the battery. Second, the pressure changes rapidly during thermal runaway, necessitating the use of high-precision pressure sensors to obtain accurate internal pressure data. High-precision pressure sensor equipment is expensive, and the high-temperature fumes generated during thermal runaway can render pressure testing equipment unusable, making pressure testing unsustainable and costly. Summary of the Invention

[0004] The purpose of this application is to provide a method and apparatus for obtaining the opening pressure of a battery thermal runaway valve. The method calculates the opening pressure of the battery thermal runaway valve based on the physical properties of the battery under test. It eliminates the need to place a pressure sensor on the battery, ensuring the airtightness of the battery before thermal runaway occurs. This solves the problems of existing methods that require the use of a pressure sensor, resulting in poor battery airtightness and the pressure sensor being easily damaged during the thermal runaway process, making pressure testing difficult to continue and costly.

[0005] This application provides a method for obtaining the opening pressure of a battery thermal runaway valve, the method comprising:

[0006] Obtain the physical properties, ambient temperature, and ambient pressure of the battery under test;

[0007] Based on the set triggering method and using a thermal runaway test device to trigger thermal runaway, the battery temperature-time relationship and valve opening temperature during the thermal runaway process are obtained.

[0008] The internal pressure change of the battery is calculated based on the battery temperature-time relationship and valve opening temperature.

[0009] The thermal runaway valve opening pressure is calculated based on the internal pressure changes of the battery.

[0010] In the above implementation process, the thermal runaway opening pressure of the battery is calculated based on the physical property parameters of the battery under test. There is no need to place pressure sensors on the battery, which reduces the difficulty of testing, ensures the airtightness of the battery before thermal runaway occurs, avoids the problem of high-temperature flue gas during thermal runaway causing sensor failure, and allows for continuous valve opening pressure testing of different batteries. This solves the problems of existing methods that require the use of pressure sensors, resulting in poor battery airtightness and the fact that pressure sensors are easily damaged during thermal runaway, making pressure testing unsustainable and costly.

[0011] Furthermore, obtaining the physical property parameters of the battery under test includes:

[0012] Obtain the internal and external dimensions of the battery under test, and calculate the total volume V and the internal solid volume V0. S And volume utilization rate, which is expressed as:

[0013] Obtain the mass m of the battery under test and calculate its bulk density:

[0014] Obtain the capacity C and plateau voltage U of the battery under test, and calculate the energy density:

[0015] Obtain the total gas production m of the same type of battery ge and gas molar mass M ∞ And calculate the gas production rate:

[0016] Obtain the specific heat capacity c of the same type of battery S 1. Heat generation start temperature T1, heat generation maximum temperature T3, and calculate the proportion of heat generation from internal short circuits:

[0017] In the above implementation process, the basic physical properties of the battery under test are obtained, including size parameters, mass parameters, capacity energy parameters, gas generation parameters, heat generation parameters, etc., so as to calculate the thermal runaway valve opening pressure and avoid the use of pressure sensors.

[0018] Furthermore, the calculation of the internal pressure change of the battery based on the battery temperature-time relationship and the valve opening temperature includes:

[0019] Based on the battery temperature-time relationship and the valve opening temperature, the temperature conversion rate and valve opening temperature conversion rate during the thermal runaway process are calculated. The temperature conversion rate is expressed as follows:

[0020]

[0021] Where T(t) represents the relationship between battery temperature and time;

[0022] The valve opening temperature conversion rate is expressed as:

[0023]

[0024] Among them, T V Indicates the valve opening temperature;

[0025] The gas production conversion rate is calculated based on the valve opening temperature conversion rate, and the gas production conversion rate is expressed as follows:

[0026] α g (t)=K g α T (t);

[0027] Among them, K g Indicates a factor based on the triggering method;

[0028] Calculate the internal pressure changes of the battery during thermal runaway:

[0029]

[0030] Where R0 represents the universal gas coefficient, T a P represents ambient temperature. a This indicates environmental pressure.

[0031] In the above implementation process, the internal pressure change of the battery is calculated based on the relationship between battery temperature and time and the valve opening temperature, so as to calculate the opening pressure of the battery thermal runaway valve based on the internal pressure change of the battery.

[0032] Furthermore, the calculation of the battery thermal runaway opening valve pressure based on the internal pressure change of the battery includes:

[0033] make The battery thermal runaway valve opening pressure is expressed as:

[0034]

[0035] In the above implementation process, a specific method for calculating the opening pressure of the battery thermal runaway valve based on the internal pressure change of the battery is given, which avoids many problems such as poor battery airtightness and easy damage to the pressure sensor caused by using a pressure sensor to obtain the internal pressure change of the battery to calculate the opening pressure of the battery thermal runaway valve.

[0036] Furthermore, prior to the step of triggering thermal runaway based on a set triggering method and using a thermal runaway testing device, the method further includes:

[0037] After placing the battery under test in the test fixture, it is placed in the thermal runaway test device.

[0038] In the above implementation process, the test fixture is used to ensure that the change in the total volume of the battery under test during thermal runaway is negligible, thereby enhancing the accuracy of the calculation results.

[0039] This application embodiment also provides a battery thermal runaway valve opening pressure acquisition device, the device comprising:

[0040] The parameter acquisition module is used to acquire the physical properties, ambient temperature, and ambient pressure of the battery under test.

[0041] The thermal runaway parameter acquisition module is used to trigger thermal runaway based on a set triggering method and using a thermal runaway test device to obtain the battery temperature-time relationship and valve opening temperature during the thermal runaway process.

[0042] The pressure change calculation module is used to calculate the internal pressure change of the battery based on the battery temperature-time relationship and the valve opening temperature.

[0043] The valve opening pressure calculation module is used to calculate the battery thermal runaway valve opening pressure based on the internal pressure changes of the battery.

[0044] In the above implementation process, the thermal runaway opening pressure of the battery is calculated based on the physical property parameters of the battery under test. There is no need to place pressure sensors on the battery, which reduces the difficulty of testing, ensures the airtightness of the battery before thermal runaway occurs, avoids the problem of high-temperature flue gas during thermal runaway causing sensor failure, and allows for continuous valve opening pressure testing of different batteries. This solves the problems of existing methods that require the use of pressure sensors, resulting in poor battery airtightness and the fact that pressure sensors are easily damaged during thermal runaway, making pressure testing unsustainable and costly.

[0045] Furthermore, the parameter acquisition module includes:

[0046] The size parameter calculation module is used to obtain the internal and external dimensions of the battery under test, and to calculate the total volume V and the internal solid volume V0. S And volume utilization rate, which is expressed as:

[0047] The mass parameter calculation module is used to obtain the mass m of the battery under test and calculate its bulk density.

[0048] The capacity and energy parameter calculation module is used to obtain the capacity C and plateau voltage U of the battery under test, and to calculate the energy density.

[0049] The gas production parameter calculation module is used to obtain the total gas production m of batteries of the same model. ge and gas molar mass M ∞ And calculate the gas production rate:

[0050] The heat generation parameter calculation module is used to obtain the specific heat capacity c of the same type of battery. S 1. Heat generation start temperature T1, heat generation maximum temperature T3, and calculate the proportion of heat generation from internal short circuits:

[0051] In the above implementation process, the basic physical properties of the battery under test are obtained, including size parameters, mass parameters, capacity energy parameters, gas generation parameters, heat generation parameters, etc., so as to calculate the thermal runaway valve opening pressure and avoid the use of pressure sensors.

[0052] Furthermore, the pressure change calculation module includes:

[0053] The temperature conversion rate calculation module is used to calculate the temperature conversion rate and valve opening temperature conversion rate during thermal runaway based on the battery temperature-time relationship and the valve opening temperature. The temperature conversion rate is expressed as:

[0054]

[0055] Where T(t) represents the relationship between battery temperature and time;

[0056] The valve opening temperature conversion rate is expressed as:

[0057]

[0058] Among them, T V Indicates the valve opening temperature;

[0059] The gas production conversion rate calculation module is used to calculate the gas production conversion rate based on the valve opening temperature conversion rate, wherein the gas production conversion rate is expressed as:

[0060] α g (t)=K g α T (t);

[0061] Among them, K g Indicates a factor based on the triggering method;

[0062] The battery internal pressure change calculation module is used to calculate the internal pressure changes of the battery during thermal runaway.

[0063]

[0064] Where R0 represents the universal gas coefficient, T a P represents ambient temperature. a This indicates environmental pressure.

[0065] In the above implementation process, the internal pressure change of the battery is calculated based on the relationship between battery temperature and time and the valve opening temperature, so as to calculate the opening pressure of the battery thermal runaway valve based on the internal pressure change of the battery.

[0066] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor runs the computer program to enable the electronic device to perform the battery thermal runaway valve opening pressure acquisition method described in any of the above-described embodiments.

[0067] This application also provides a readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, the battery thermal runaway valve opening pressure acquisition method described in any of the above-described embodiments is performed. Attached Figure Description

[0068] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0069] Figure 1 A flowchart illustrating a method for obtaining the opening pressure of a battery thermal runaway valve, as provided in this application embodiment;

[0070] Figure 2 A flowchart illustrating the specific implementation of the battery thermal runaway valve opening pressure acquisition method provided in this application embodiment;

[0071] Figure 3 A flowchart for obtaining physical property parameters provided in the embodiments of this application;

[0072] Figure 4 A flowchart for calculating the internal pressure change of a battery provided in an embodiment of this application;

[0073] Figure 5 The battery temperature and temperature change rate curves over time are provided in the embodiments of this application;

[0074] Figure 6 The battery internal pressure variation curve over time is provided in the embodiments of this application;

[0075] Figure 7 A structural block diagram of a battery thermal runaway valve opening pressure acquisition device provided in this application embodiment;

[0076] Figure 8 A structural block diagram of another battery thermal runaway valve opening pressure acquisition device provided in this application embodiment;

[0077] Figure 9 This is a structural block diagram of an embodiment of the present application that includes an auxiliary measuring device.

[0078] icon:

[0079] 100 - Parameter Acquisition Module; 101 - Size Parameter Calculation Module; 102 - Mass Parameter Calculation Module; 103 - Capacity Energy Parameter Calculation Module; 104 - Gas Generation Parameter Calculation Module; 105 - Heat Generation Parameter Calculation Module; 200 - Thermal Runaway Parameter Acquisition Module; 300 - Pressure Change Calculation Module; 301 - Temperature Conversion Rate Calculation Module; 302 - Gas Generation Conversion Rate Calculation Module; 303 - Battery Internal Pressure Change Calculation Module; 400 - Valve Opening Pressure Calculation Module. Detailed Implementation

[0080] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0081] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0082] Example 1

[0083] Please refer to Figure 1 , Figure 1 A flowchart illustrating a method for obtaining the opening pressure of a battery thermal runaway valve, provided in an embodiment of this application. The method specifically includes the following steps:

[0084] Step S100: Obtain the physical properties, ambient temperature, and ambient pressure of the battery under test;

[0085] like Figure 2 The diagram shown is a flowchart illustrating the specific implementation of the method for obtaining the opening pressure of the battery thermal runaway valve. Among other things, as... Figure 3 The diagram shows the flowchart for obtaining physical property parameters. Step S100 specifically includes the following steps:

[0086] Step S101: Obtain the internal and external dimensions of the battery under test, and calculate the total volume V and the internal solid volume V0. S And volume utilization rate, which is expressed as:

[0087] Step S102: Obtain the mass m of the battery under test and calculate its bulk density.

[0088] Step S103: Obtain the capacity C and plateau voltage U of the battery under test, and calculate the energy density:

[0089] Step S104: Obtain the total gas production m of the same type of battery ge and gas molar mass M ∞ And calculate the gas production rate:

[0090] It should be noted that the total gas production m is obtained through the gas production testing device. ge and gas molar mass M ∞ Since this was a destructive experiment, the above parameters were obtained using batteries of the same model.

[0091] Step S105: Obtain the specific heat capacity c of the same type of battery. S 1. Heat generation start temperature T1, heat generation maximum temperature T3, and calculate the proportion of heat generation from internal short circuits:

[0092] Similarly, this step is a destructive experiment, and the parameters are obtained using the same type of battery.

[0093] Step S200: Based on the set triggering method, thermal runaway is triggered using a thermal runaway test device to obtain the battery temperature-time relationship and valve opening temperature during the thermal runaway process;

[0094] Prior to the step of triggering thermal runaway based on a set triggering method and using a thermal runaway testing device, the method further includes:

[0095] After placing the battery under test in the test fixture, it is placed in the thermal runaway test device.

[0096] Specifically, the battery under test is placed in the test fixture to ensure that the change in its total volume during thermal runaway is negligible. In addition, the triggering method (such as adiabatic self-heating triggering, heating plate triggering, needle penetration triggering, etc.) needs to be determined according to actual needs, and the battery under test is placed in the corresponding thermal runaway test device.

[0097] Several temperature data acquisition devices are arranged on the surface of the battery under test. Thermal runaway is triggered by a thermal runaway test device. The raw data is processed by a data processing and analysis device to obtain the relationship between battery temperature and time (T = T(t) during the thermal runaway process (T1≤T≤T3), and the valve opening temperature T is also obtained. V .

[0098] Step S300: Calculate the internal pressure change of the battery based on the battery temperature-time relationship and valve opening temperature;

[0099] Specifically, such as Figure 4The diagram shown is a flowchart for calculating the internal pressure change of the battery. Step S300 includes the following steps:

[0100] Step S301: Calculate the temperature conversion rate and valve opening temperature conversion rate during thermal runaway based on the battery temperature-time relationship and the valve opening temperature. The temperature conversion rate is expressed as:

[0101]

[0102] Where T(t) represents the relationship between battery temperature and time;

[0103] The valve opening temperature conversion rate is expressed as:

[0104]

[0105] Among them, T V Indicates the valve opening temperature;

[0106] Step S302: Calculate the gas production conversion rate based on the valve opening temperature conversion rate, wherein the gas production conversion rate is expressed as:

[0107] α g (t)=K g α T (t);

[0108] Among them, K g This represents a triggering method-based factor used to characterize the co-occurrence of gas production and heat production. It takes a value of 1 when triggered by adiabatic autogenous heat, and can be calibrated through pre-experiments under other triggering methods.

[0109] Step S303: Calculate the internal pressure changes of the battery during thermal runaway:

[0110]

[0111] Where R0 represents the universal gas coefficient, T a P represents ambient temperature. a This indicates environmental pressure.

[0112] Based on the ideal gas law, by quantifying the pressure changes caused by heat and gas generation during the thermal runaway process, the formula for the internal pressure change of the battery during the thermal runaway process can be obtained.

[0113] Step S400: Calculate the battery thermal runaway opening valve pressure based on the internal pressure change of the battery, specifically:

[0114] make The battery thermal runaway valve opening pressure is expressed as:

[0115]

[0116] The above calculation results can be stored and displayed on a data visualization device such as a monitor, or exported to other devices via a data export device.

[0117] For example, for an NCM ternary battery with a capacity of 100Ah and an energy density of 200Wh / kg, the valve opening pressure was obtained using the above method. The specific steps and data recording are as follows:

[0118] Step S11: Obtain the basic physical properties of the battery to be tested, including size parameters, mass parameters, capacity and energy parameters, gas generation parameters, heat generation parameters, etc.

[0119]

[0120]

[0121] Table 1 Basic physical properties of the battery

[0122] Step S12: Perform adiabatic self-heating triggering in the adiabatic calorimeter. Place the battery to be tested in the test fixture and put it into the adiabatic calorimeter.

[0123] Step S13: Set up the appropriate test environment and obtain the ambient temperature T through an environmental parameter measuring device. a and environmental pressure P a The specific environmental parameters are shown in the table below;

[0124]

[0125] Table 2 Environmental Parameters

[0126] Step S14: Arrange temperature sensing wires on the large surface, top surface, and bottom surface of the battery under test. Trigger adiabatic self-heating using an adiabatic calorimeter. Process the temperature sensing wire data using a computer, and obtain the battery temperature change over time, T = T(t), by averaging the values ​​at each measuring point. Figure 5 The figure shows the curves of battery temperature and temperature change rate over time. The valve opening temperature T is obtained through instruments. V =109℃;

[0127] Step S15: Calculate the temperature conversion rate of the thermal runaway process (T1≤T≤T3). And obtain the valve opening temperature conversion rate corresponding to the valve opening temperature.

[0128] Step S16: Perform adiabatic self-generating heat triggering, at which point K g =1, the gas conversion rate α is calculated by computer. g (t)=K g α T (t)=α T(t);

[0129] Step S17: Calculate the internal pressure change of the battery during the thermal runaway process (T1≤T≤T3) using a computer. By substituting the specific values ​​of the parameters into Tables 1 and 2, the internal pressure change of the battery can be obtained, such as... Figure 6 The figure shows the curve of the battery's internal pressure changing over time.

[0130] Step S18: Let The opening pressure of the battery thermal runaway valve is calculated by computer.

[0131] Step S19: Store the above calculation results on the hard drive, display the above calculation results on the monitor, and export the above results to the USB flash drive via the USB interface.

[0132] This method eliminates the need for pressure sensors on the battery, reducing the difficulty of testing, ensuring the airtightness of the battery before thermal runaway occurs, and avoiding the problem of high-temperature flue gas causing the pressure testing equipment to fail during thermal runaway. The testing device can continuously conduct valve opening pressure tests on different batteries.

[0133] This method can be applied to energy storage devices with safety valves / explosion-proof valves and whose outer shell shape is not easily changed, such as hard-shell lithium-ion batteries, but the application scenarios are not limited to lithium-ion batteries, and no limitations are made here.

[0134] Example 2

[0135] This application provides a battery thermal runaway valve opening pressure acquisition device, which can be applied to the data processing and analysis device described in Embodiment 1, and can be implemented using a computer, such as... Figure 7 The diagram shown is a structural block diagram of a battery thermal runaway valve opening pressure acquisition device, which specifically includes:

[0136] The parameter acquisition module 100 is used to acquire the physical properties, ambient temperature, and ambient pressure of the battery under test.

[0137] For ambient temperature and pressure, environmental parameter measuring devices such as thermometers and pressure gauges can be used.

[0138] Temperature data acquisition devices, such as thermocouples, can be used to measure temperature changes during thermal runaway.

[0139] The thermal runaway parameter acquisition module 200 is used to trigger thermal runaway based on a set triggering method and using a thermal runaway test device to obtain the battery temperature-time relationship and valve opening temperature during the thermal runaway process.

[0140] Thermal runaway testing devices need to meet the requirement of being able to be triggered according to actual needs (such as adiabatic self-heating triggering, heating plate triggering, needle penetration triggering, etc.). The device includes test fixtures to ensure that the change in the total volume V of the battery during thermal runaway is negligible. An example of such a device is an adiabatic calorimeter that includes test fixtures.

[0141] The pressure change calculation module 300 is used to calculate the internal pressure change of the battery based on the battery temperature-time relationship and the valve opening temperature.

[0142] The valve opening pressure calculation module 400 is used to calculate the battery thermal runaway valve opening pressure based on the internal pressure change of the battery.

[0143] Among them, such as Figure 8 The diagram shown is a structural block diagram of another battery thermal runaway valve opening pressure acquisition device. Figure 7 Based on this, the parameter acquisition module 100 includes:

[0144] The size parameter calculation module 101 is used to obtain the internal and external dimensions of the battery under test, and to calculate the total volume V and the internal solid volume V01. S And volume utilization rate, which is expressed as:

[0145] like Figure 9 The diagram shown is a structural block diagram including auxiliary measuring devices, where dimensional parameters can be obtained using dimensional measuring devices such as tape measures and X-ray detectors.

[0146] The mass parameter calculation module 102 is used to obtain the mass m of the battery under test and calculate its bulk density.

[0147] For quality parameters, a quality measuring device, such as a balance or other weight measuring instrument, can be used.

[0148] The capacity-energy parameter calculation module 103 is used to obtain the capacity C and plateau voltage U of the battery under test, and to calculate the energy density.

[0149] For capacity energy parameters, they can still be obtained using charge-discharge testing equipment, such as a charge-discharge testing cabinet.

[0150] Gas production parameter calculation module 104 is used to obtain the total gas production m of the same type of battery. ge and gas molar mass M ∞ And calculate the gas production rate:

[0151] Gas production parameters can be tested using a gas production testing device, such as a reaction vessel.

[0152] The heat generation parameter calculation module 105 is used to obtain the specific heat capacity c of the same type of battery. S 1. Heat generation start temperature T1, heat generation maximum temperature T3, and calculate the proportion of heat generation from internal short circuits:

[0153] For heat generation parameters, heat generation testing devices, such as adiabatic calorimeters, can be used.

[0154] The pressure change calculation module 300 includes:

[0155] Temperature conversion rate calculation module 301 is used to calculate the temperature conversion rate and valve opening temperature conversion rate during thermal runaway based on the battery temperature-time relationship and the valve opening temperature. The temperature conversion rate is expressed as:

[0156]

[0157] Where T(t) represents the relationship between battery temperature and time;

[0158] The valve opening temperature conversion rate is expressed as:

[0159]

[0160] Among them, T V Indicates the valve opening temperature;

[0161] Gas production conversion rate calculation module 302 is used to calculate the gas production conversion rate based on the valve opening temperature conversion rate, wherein the gas production conversion rate is expressed as:

[0162] α g (t)=K g α T (t);

[0163] Among them, K g Indicates a factor based on the triggering method;

[0164] Battery internal pressure change calculation module 303 is used to calculate the internal pressure change of the battery during thermal runaway:

[0165]

[0166] Where R0 represents the universal gas coefficient, T a P represents ambient temperature. a This indicates environmental pressure.

[0167] The data processing and analysis device is used to process, analyze (the specific implementation process corresponds to the method described in Embodiment 1), store, display, and export data. The data processing and analysis device may be implemented using a computer; the data storage device may be a hard disk; the data visualization device may be a display; and the data export device may be a USB interface.

[0168] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor runs the computer program to enable the electronic device to perform the battery thermal runaway valve opening pressure acquisition method described in Embodiment 1.

[0169] This application also provides a readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, the battery thermal runaway valve opening pressure acquisition method described in Embodiment 1 is performed.

[0170] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0171] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0172] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0173] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0174] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0175] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for obtaining the opening pressure of a battery thermal runaway valve, characterized in that, The method includes: Obtain the physical properties, ambient temperature, and ambient pressure of the battery under test; Based on the set triggering method and using a thermal runaway test device to trigger thermal runaway, the battery temperature-time relationship and valve opening temperature during the thermal runaway process are obtained. Calculating the internal pressure change of the battery based on the battery temperature-time relationship and valve opening temperature includes: calculating the temperature conversion rate and valve opening temperature conversion rate during thermal runaway based on the battery temperature-time relationship and valve opening temperature, wherein the temperature conversion rate is expressed as: ;in, This indicates the relationship between battery temperature and time. Indicates the initial temperature of heat generation. This indicates the highest heat generation temperature; the valve opening temperature conversion rate is expressed as: ;in, The valve opening temperature is indicated; the gas production conversion rate is calculated based on the temperature conversion rate, and the gas production conversion rate is expressed as: ;in, Indicates the factor based on the triggering method; calculates the internal pressure change of the battery during thermal runaway: ;in, Represents the universal gas coefficient. Indicates ambient temperature. Indicating environmental pressure, This indicates the specific heat capacity of batteries of the same model. Indicates the gas production rate. Indicates volume utilization rate. Represents the density of the substance. Indicates energy density, This indicates the proportion of heat generated by internal short circuits. Indicates the molar mass of the gas; The thermal runaway valve opening pressure is calculated based on the internal pressure changes of the battery.

2. The method for obtaining the opening pressure of the battery thermal runaway valve according to claim 1, characterized in that, The acquisition of the physical property parameters of the battery under test includes: Obtain the internal and external dimensions of the battery under test, and calculate the total volume. V Internal solid volume And volume utilization rate, which is expressed as: ; Obtain the mass of the battery under test m And calculate the entity density: ; Obtain the capacity of the battery under test. C Platform voltage U And calculate the energy density: ; Obtain the total gas production of batteries of the same model and gas molar mass And calculate the gas production rate: ; Obtain the specific heat capacity of the same type of battery Heat generation starting temperature Maximum heat production temperature And calculate the proportion of heat generated by internal short circuits: .

3. The method for obtaining the opening pressure of the battery thermal runaway valve according to claim 1, characterized in that, The calculation of the battery thermal runaway valve opening pressure based on the internal pressure change of the battery includes: make The opening pressure for battery thermal runaway is expressed as: 。 4. The method for obtaining the opening pressure of the battery thermal runaway valve according to claim 1, characterized in that, Prior to the step of triggering thermal runaway based on a set triggering method and using a thermal runaway testing device, the method further includes: After placing the battery under test in the test fixture, it is placed in the thermal runaway test device.

5. A device for obtaining the opening pressure of a battery thermal runaway valve, characterized in that, The device includes: The parameter acquisition module is used to acquire the physical properties, ambient temperature, and ambient pressure of the battery under test. The thermal runaway parameter acquisition module is used to trigger thermal runaway based on a set triggering method and using a thermal runaway test device to obtain the battery temperature-time relationship and valve opening temperature during the thermal runaway process. A pressure change calculation module, used to calculate the internal pressure change of the battery based on the battery temperature-time relationship and the valve opening temperature, includes: a temperature conversion rate calculation module, used to calculate the temperature conversion rate and valve opening temperature conversion rate during thermal runaway based on the battery temperature-time relationship and the valve opening temperature, wherein the temperature conversion rate is expressed as: ;in, This indicates the relationship between battery temperature and time. Indicates the initial temperature of heat generation. This indicates the highest heat generation temperature; the valve opening temperature conversion rate is expressed as: ;in, The valve opening temperature is indicated; the gas production conversion rate calculation module is used to calculate the gas production conversion rate based on the temperature conversion rate, wherein the gas production conversion rate is expressed as: ;in, The factor represents the triggering method; the battery internal pressure change calculation module is used to calculate the battery internal pressure change during thermal runaway. ;in, Represents the universal gas coefficient. Indicates ambient temperature. Indicating environmental pressure, This indicates the specific heat capacity of batteries of the same model. Indicates the gas production rate. Indicates volume utilization rate. Represents the density of the substance. Indicates energy density, This indicates the proportion of heat generated by internal short circuits. Indicates the molar mass of the gas; The valve opening pressure calculation module is used to calculate the battery thermal runaway valve opening pressure based on the internal pressure changes of the battery.

6. The battery thermal runaway valve opening pressure acquisition device according to claim 5, characterized in that, The parameter acquisition module includes: The size parameter calculation module is used to obtain the internal and external dimensions of the battery under test and calculate the total volume. V Internal solid volume And volume utilization rate, which is expressed as: ; The mass parameter calculation module is used to obtain the mass of the battery under test. m And calculate the entity density: ; The capacity and energy parameter calculation module is used to obtain the capacity of the battery under test. C Platform voltage U And calculate the energy density: ; The gas production parameter calculation module is used to obtain the total gas production of batteries of the same model. and gas molar mass And calculate the gas production rate: ; The heat generation parameter calculation module is used to obtain the specific heat capacity of batteries of the same model. Heat generation starting temperature Maximum heat production temperature And calculate the proportion of heat generated by internal short circuits: .

7. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory being used to store a computer program, and the processor running the computer program to cause the electronic device to perform the battery thermal runaway valve opening pressure acquisition method according to any one of claims 1 to 4.

8. A readable storage medium, characterized in that, The readable storage medium stores computer program instructions, which, when read and executed by a processor, perform the battery thermal runaway valve opening pressure acquisition method according to any one of claims 1 to 4.

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