Battery thermal runaway multi-dimensional simulation method and system and battery thermal runaway thermal baffle design method

Abstract

The invention provides a battery thermal runaway multi-dimensional simulation method and system and a battery thermal runaway thermal baffle design method. Performing thermal runaway test on the to-be-tested battery to obtain battery thermal runaway data; and optimizing the initial battery thermal runaway model through the battery thermal runaway data to obtain a battery thermal runaway model so as to determine the relationship between each chemical reaction rate and the battery simulation temperature in the battery thermal runaway process, and constructing a three-dimensional battery thermal spreading model according to the chemical reaction rate in the battery thermal runaway model. Therefore, the heat production power of the to-be-simulated battery is simulated. The battery thermal runaway multi-dimensional simulation method provided by the invention is suitable for thermal runaway simulation of various batteries, an initial battery thermal runaway model is optimized through data of a thermal runaway experiment, the research expenditure and time cost of thermal runaway are reduced, a three-dimensional data model is constructed through each chemical reaction rate in one-dimensional battery thermal runaway, and the simulation process is simplified.

Description

Technical Field

[0001] The present invention relates to the field of battery thermal runaway simulation, and in particular to a battery thermal runaway multi-dimensional simulation method and system, and a battery thermal runaway insulation board design method. Background Art

[0002] With the widespread use of batteries in electric vehicles, the problem of fires caused by battery thermal runaway has become increasingly prominent. Therefore, in-depth analysis of the principles of thermal runaway and the establishment of relevant models that can accurately predict the temperature and voltage changes during battery thermal runaway are crucial for thermal runaway warning and efficient thermal insulation design of battery systems.

[0003] The heat generated by battery thermal runaway mainly includes the decomposition of SEI film (Solid Electrolyte Interphase), the reaction between the negative electrode and the electrolyte, the reaction between the positive electrode and the negative electrode, and the decomposition reaction of the electrolyte. Usually, the heat generation model of battery thermal runaway is calculated using the Arrhenius formula, which involves multiple chemical reaction kinetic parameters, such as: pre-frequency factor A, activation energy E, and unit enthalpy value H. In order to obtain accurate kinetic parameters, it is often necessary to conduct DSC (Differential Scanning Calorimetry) experiments, that is, it is necessary to disassemble the battery in an inert glove box and prepare proportional samples. When processing experimental data, it is necessary to combine multiple calculation principles, which is often time-consuming and laborious. In addition, the kinetic parameters found often cannot establish a corresponding thermal runaway model for a specific battery due to different battery capacities and sizes, so effective thermal insulation design cannot be performed.

[0004] Therefore, how to provide a battery thermal runaway simulation method with high efficiency, high accuracy and high applicability is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a battery thermal runaway multi-dimensional simulation method and system and a battery thermal runaway insulation board design method to solve at least one of the above-mentioned technical problems.

[0006] In order to achieve the above-mentioned purpose and other related purposes, the technical solution provided by this application is as follows.

[0007] According to a first aspect of an embodiment of the present application, a multi-dimensional simulation method for battery thermal runaway is provided, comprising:

[0008] Perform a thermal runaway test on the battery to be tested to obtain the battery thermal runaway data;

[0009] Optimizing an initial battery thermal runaway model based on the battery thermal runaway data to obtain a battery thermal runaway model, wherein the battery thermal runaway model is used to characterize the relationship between each chemical reaction rate of the battery to be simulated and the battery simulation temperature;

[0010] A three-dimensional battery heat propagation model is constructed based on each of the chemical reaction rates to achieve heat generation power simulation of the battery to be simulated, wherein the three-dimensional battery heat propagation model is used to characterize the relationship between each of the chemical reaction rates and the three-dimensional heat power of the battery to be simulated.

[0011] In one embodiment of the present invention, the method also includes: dividing the battery thermal runaway data into a gentle stage and a sudden drop stage based on the voltage change characteristics in the battery thermal runaway data; establishing a temperature-voltage mapping relationship for the gentle stage and the sudden drop stage respectively; inputting the temperature-voltage mapping relationship into the battery thermal runaway model for voltage prediction to obtain a battery simulation voltage.

[0012] In one embodiment of the present invention, the initial battery thermal runaway model construction step includes: obtaining geometric parameters of the battery to be simulated, the geometric parameters including thermal runaway influencing factors and battery data; determining each of the chemical reaction rates based on a preset chemical reaction relationship and the thermal runaway influencing factors; calculating the total thermal power of the battery to be simulated according to each of the chemical reaction rates, and determining the battery simulation temperature according to the total thermal power, the battery data and the operating time of the battery to be simulated, to obtain the initial battery thermal runaway model.

[0013] In one embodiment of the present invention, an initial battery thermal runaway model is optimized based on the battery thermal runaway data to obtain a battery thermal runaway model, including: adjusting each thermal runaway influencing factor in the initial battery thermal runaway model and determining its weight, and locking the key influencing factor according to the weight of each thermal runaway influencing factor; obtaining the battery simulation temperature based on the initial battery thermal runaway model, and establishing a temperature loss relationship based on the battery simulation temperature and the actual temperature in the battery thermal runaway data, and determining a temperature root mean square error threshold according to the temperature loss relationship; inputting the initial key influencing factor into the initial battery thermal runaway model for temperature simulation to obtain an initial battery simulation temperature; judging whether the initial battery simulation temperature meets the temperature root mean square error threshold, if not, adjusting the value of the corresponding key influencing factor according to a preset adjustment threshold until the adjusted battery simulation temperature meets the temperature root mean square error threshold to obtain the battery thermal runaway model.

[0014] In one embodiment of the present invention, each thermal runaway influencing factor in the initial battery thermal runaway model is adjusted and its weight is determined, and the key influencing factor is locked according to the weight of each thermal runaway influencing factor, including: setting each thermal runaway influencing factor to a related preset thermal runaway influencing threshold and obtaining the corresponding battery simulation temperature, and adjusting the value of each thermal runaway influencing factor respectively, and obtaining the corresponding battery simulation temperature according to the adjusted thermal runaway influencing factor; determining the weight of each thermal runaway influencing factor according to the change of each thermal runaway influencing factor and the corresponding change of the battery simulation temperature; comparing the weights of each thermal runaway influencing factor, and locking the key influencing factor according to the comparison result.

[0015] In one embodiment of the present invention, a temperature loss relationship is established based on the battery simulation temperature and the actual temperature in the battery thermal runaway data, including: performing characteristic analysis on the change of the actual temperature to obtain temperature characteristics; determining a temperature error weight based on the temperature characteristics, and establishing the temperature loss relationship based on the temperature error weight, the battery simulation temperature and the actual temperature.

[0016] In one embodiment of the present invention, a three-dimensional battery heat propagation model is constructed based on each of the chemical reaction rates, including: obtaining the volume average temperature of the battery to be simulated; performing network division on the battery to be simulated to obtain a plurality of preset battery grids; inputting each of the chemical reaction rates into a preset transport standard equation to construct a scalar relationship for each of the chemical reactions, wherein the scalar relationship is used to characterize the chemical reaction process of battery thermal runaway; importing the volume average temperature and each of the scalar relationships into the preset chemical reaction relationship to establish a chemical reaction rate-thermal power mapping relationship of a preset battery grid; and constructing a three-dimensional battery heat propagation model for the battery to be simulated according to the chemical reaction rate-thermal power mapping relationship.

[0017] In one embodiment of the present invention, after constructing the three-dimensional battery heat propagation model, the method further includes: configuring the three-dimensional battery heat propagation model according to preset configuration conditions to obtain an initial three-dimensional battery heat propagation model; starting the initial three-dimensional battery heat propagation model, and obtaining battery heat propagation data output by the three-dimensional battery heat propagation model according to a preset time threshold; comparing the battery heat propagation data with the battery thermal runaway data, and verifying the three-dimensional battery heat propagation model based on the comparison result.

[0018] In one embodiment of the present invention, before performing a thermal runaway test on a battery to be tested, the method further includes: performing multiple charge and discharge processes on the battery to be tested according to a preset current threshold to form a protective layer on the negative electrode of the battery to be tested; and setting the charge state of the battery to be tested to a preset charge threshold.

[0019] According to the second aspect of an embodiment of the present application, a battery thermal runaway insulation board design method is also provided. The method can be applied to the battery thermal runaway multi-dimensional simulation method as described above, including: establishing a battery pack geometric model based on the three-dimensional battery heat propagation model; inserting an insulation board into the battery pack geometric model, acquiring and analyzing the battery simulation data of the insulation board to determine the target insulation board.

[0020] In one embodiment of the present invention, a heat insulation board is inserted into the geometric model of the battery pack, and battery heat spread data of the heat insulation board is obtained and analyzed to determine a target heat insulation board, including: inserting heat insulation boards with different physical parameters, different thicknesses and different areas into the geometric model of the battery pack; determining the physical parameters, thickness and area of ​​the heat insulation board according to the battery heat spread data to obtain the target heat insulation board.

[0021] According to the third aspect of the embodiment of the present application, a battery thermal runaway multi-dimensional simulation system is also provided, the system comprising: a thermal runaway test module, used to perform a thermal runaway test on a battery to be tested to obtain battery thermal runaway data; an optimization module, used to optimize an initial battery thermal runaway model based on the battery thermal runaway data to obtain a battery thermal runaway model, wherein the battery thermal runaway model is used to characterize the relationship between each chemical reaction rate of the battery to be simulated and the battery simulation temperature; a thermal runaway simulation module, used to construct a three-dimensional battery thermal propagation model based on each of the chemical reaction rates to achieve heat generation power simulation of the battery to be simulated, wherein the three-dimensional battery thermal propagation model is used to characterize the relationship between each of the chemical reaction rates and the three-dimensional thermal power of the battery to be simulated.

[0022] The present application provides a battery thermal runaway multi-dimensional simulation method, system and battery thermal runaway insulation board design method, the method comprising: conducting a thermal runaway test on a battery to be tested to obtain battery thermal runaway data; optimizing an initial battery thermal runaway model through the battery thermal runaway data to obtain a battery thermal runaway model to determine the relationship between each chemical reaction rate and the battery simulation temperature during the battery thermal runaway process, and constructing a three-dimensional battery thermal propagation model according to the chemical reaction rates in the battery thermal runaway model, thereby realizing the heat generation power simulation of the battery to be simulated. The battery thermal runaway multi-dimensional simulation method provided in the present application is applicable to a variety of batteries, and is not limited to the thermal runaway simulation of a specific battery of a certain battery. The initial battery thermal runaway model is optimized through the data of the thermal runaway experiment, reducing the research funds and time costs of thermal runaway, and a three-dimensional data model is constructed through the chemical reaction rates in the one-dimensional battery thermal runaway to simplify the simulation process.

[0023] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present invention, and together with the specification, are used to explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0025] Figure 1 is a flow chart of a multi-dimensional simulation method for battery thermal runaway shown in an exemplary embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of an optimized initial battery thermal runaway model shown in an exemplary embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of battery simulation data and experimental data shown in an exemplary embodiment of the present invention;

[0028] Figure 4 is a comparison diagram of simulation temperature and experimental temperature shown in an exemplary embodiment of the present invention;

[0029] Figure 5 is a schematic diagram of a geometric model of a battery cell and a battery pack according to an exemplary embodiment of the present invention;

[0030] Figure 6 is a schematic diagram showing the temperature of the side of a battery cell in a battery pack geometric model, the temperature at the same position of a heat shield and the corresponding experimental temperature according to an exemplary embodiment of the present invention;

[0031] Figure 7 is a schematic diagram showing the voltage on the side of a battery cell in a battery pack geometric model, the voltage at the same position of a heat shield, and the corresponding experimental voltage according to an exemplary embodiment of the present invention;

[0032] Figure 8 It is a block diagram of a battery thermal runaway multi-dimensional simulation system shown in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0033] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0034] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0035] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0036] The ARC test is an experimental method used to measure the heat release characteristics of a substance under adiabatic conditions. The ARC test, full name Adiabatic Accelerating Calorimeter, is mainly used to evaluate the exothermic reaction of chemical substances under extreme conditions. Through the ARC test, the relationship between the self-heat release rate and temperature of a substance can be obtained, thereby analyzing its thermal safety.

[0037] SEI film (Solid Electrolyte Interphase) is a passivation layer formed on the surface of electrode material when the electrode material and electrolyte react at the solid-liquid interface during the first charge and discharge process of liquid lithium-ion batteries. This passivation layer has the characteristics of solid electrolytes, is an electronic insulator, and is also an excellent conductor of Li+, allowing lithium ions to pass freely, so it is called "solid electrolyte interface film".

[0038] Arrhenius equation is an important equation that describes the relationship between chemical reaction rate and temperature.

[0039] The Kissinger equation is a method for estimating the kinetic parameters of thermal decomposition, especially the activation energy of thermal decomposition reactions.

[0040] Electrochemical P2D model refers to the parameters in the mathematical model used to describe the performance of electrochemical devices such as batteries or capacitors in the field of electrochemistry.

[0041] Thermal runaway heat coupling refers to the phenomenon that when a battery experiences thermal runaway, the explosion-proof valve of the battery cell is separated from the battery cell pole, causing thermal energy and electrical energy to affect each other.

[0042] With the widespread use of batteries in electric vehicles, the problem of fires caused by battery thermal runaway has become increasingly prominent. Therefore, in-depth analysis of the principles of thermal runaway and the establishment of relevant models that can accurately predict the temperature and voltage changes during battery thermal runaway are crucial for thermal runaway warning and efficient thermal insulation design of battery systems.

[0043] The heat generation of battery thermal runaway mainly includes the decomposition of SEI film, the reaction between the negative electrode and the electrolyte, the reaction between the positive electrode and the negative electrode, and the decomposition reaction of the electrolyte. Usually, the battery thermal runaway heat generation model is calculated using the Arrhenius formula, which involves multiple chemical reaction kinetic parameters, such as: pre-frequency factor A, activation energy E, and unit enthalpy value H. In order to obtain accurate kinetic parameters, DSC experiments are often required, that is, the battery needs to be disassembled in an inert glove box, and proportional samples need to be prepared. The processing of experimental data requires the use of Kissinger for linear fitting and other steps, which increases the cost. In addition, the kinetic parameters found are often different due to the capacity and size of the battery, which makes it impossible to establish a corresponding thermal runaway related model for a specific battery, and it is impossible to set up an effective thermal insulation design in a targeted manner. In addition, when the battery undergoes a thermal runaway self-heating reaction, it is also very important to establish an efficient way to obtain the corresponding relationship between temperature and voltage in the battery. The commonly used methods currently include RC equivalent circuit, electrochemical P2D model, and thermal runaway heat generation coupling, but the above methods require the measurement of many parameters, and the parameter adjustment process is also relatively time-consuming. Therefore, it is crucial to quickly establish the relationship between temperature and voltage when the battery undergoes thermal runaway in order to predict the battery output voltage.

[0044] See also Figure 1 , Figure 1 It is a flow chart of a multi-dimensional simulation method for battery thermal runaway shown in an exemplary embodiment of the present invention.

[0045] like Figure 1 As shown, in an exemplary embodiment, a multi-dimensional simulation method for battery thermal runaway includes at least steps S110 to S130, which are described in detail as follows:

[0046] In step S110, a thermal runaway test is performed on the battery to be tested to obtain battery thermal runaway data.

[0047] Specifically, the battery to be tested is placed in a device with adjustable temperature, and an ARC experiment is performed on the battery to be tested. The initial temperature of the ARC experiment can be set to 40°C, the temperature rise gradient is set to 5°C, each heating time is set to 30-60 minutes, and the battery thermal runaway data acquisition time of the battery to be tested is set to 15 minutes. First, the battery to be tested is placed in an initial experimental temperature of 40°C, maintained for 30-60 minutes, and the battery thermal runaway data of the battery to be tested at the initial experimental temperature is collected. The experimental temperature is adjusted to 45°C and maintained for 30-60 minutes, and the battery thermal runaway data corresponding to the adjusted experimental temperature is collected. By analogy, after adjusting the experimental temperature for multiple times, the battery thermal runaway data of the battery to be tested is obtained. Among them, the experimental temperature can be adjusted according to the time situation, and the temperature is not limited here.

[0048] In detail, before the thermal runaway test of the battery to be tested is carried out, it also includes: performing multiple charge and discharge treatments on the battery to be tested according to a preset current threshold to form a protective layer between the electrode material and the electrolyte of the battery to be tested; setting the charge state of the battery to be tested to the preset charge threshold. Specifically, before the ARC experiment, the battery to be tested is subjected to three or more standard charge and discharge cycle tests based on a current threshold of 1 / 3C rate to form a stable SEI film between the negative electrode of the battery to be tested and the electrolyte, and a stable SEI film between the positive electrode of the battery to be tested and the electrolyte, and then the battery state of the battery to be tested is set to 1, that is, the charge in the battery to be tested is in a full state, so that the battery to be tested releases the most heat when the thermal runaway experiment is carried out.

[0049] In step S120, the initial battery thermal runaway model is optimized based on the battery thermal runaway data to obtain a battery thermal runaway model, wherein the battery thermal runaway model is used to characterize the relationship between each chemical reaction rate of the battery to be simulated and the battery simulation temperature.

[0050] In detail, the steps of constructing the initial battery thermal runaway model include: obtaining the geometric parameters of the battery to be simulated, the geometric parameters including the thermal runaway influencing factor and the battery data; determining the rates of each chemical reaction based on the preset chemical reaction equation and the thermal runaway influencing factor; calculating the total thermal power of the battery to be simulated according to each of the chemical reaction rates, and determining the battery simulation temperature according to the total thermal power, the battery data and the operating time of the battery to be simulated, to obtain the initial battery thermal runaway model.

[0051] Specifically, the geometric parameters related to the battery are obtained, including the size parameters of the battery, the thermal parameters of the battery and the chemical reaction kinetic parameters of the battery. The size parameters of the battery include the length, width, height of the battery and the length, width and thickness of the positive and negative electrodes of the battery; the thermal parameters of the battery include the density, specific heat capacity, anisotropic thermal conductivity and the convection heat transfer coefficient of the experimental environment; the chemical reaction kinetic parameters of the battery include: the equivalent density of each reactant, the reaction activation energy, the unit reaction enthalpy value, the pre-frequency factor, and the dimensionless reaction concentration.

[0052] The preset chemical reaction relationship is the Arrhenius formula. The rates of each chemical reaction when thermal runaway of the battery occurs are determined based on the Arrhenius formula and the thermal runaway influencing factor, and the corresponding thermal power is calculated based on each chemical reaction rate, equivalent density and preset volume.

[0053] The factors affecting thermal runaway include: pre-frequency factor A, unit reaction enthalpy H, equivalent density W, activation energy E, ideal gas constant R, and normalized concentration C of chemical reaction.

[0054] The heat-generating chemical reactions that cause thermal runaway of the battery include SEI film decomposition, decomposition reaction of the negative electrode and the electrolyte, decomposition reaction of the positive electrode and decomposition reaction of the electrolyte.

[0055] It can be seen that the chemical reaction rate generated by the decomposition reaction of the SEI film is as shown in expression (1), and the heat power generated in the preset volume by the decomposition reaction of the SEI film is as shown in expression (2):

[0056]

[0057] In expressions (1)-(2), is the chemical reaction rate generated by the decomposition reaction of the SEI film, Q sei (T,c sei ) is the heat power generated in the preset volume by the decomposition reaction of the SEI film, H sei is the unit reaction enthalpy, A sei is the pre-frequency factor of the SEI film, W sei is the equivalent density of SEI film, E sei is the activation energy of the SEI film, R is the ideal gas constant, c sei is the normalized concentration of SEI film decomposition reaction, and T is the temperature.

[0058] The chemical reaction rate generated by the decomposition reaction between the negative electrode and the electrolyte is shown in expression (3), and the heat power generated within the preset volume by the decomposition reaction between the negative electrode and the electrolyte is shown in expression (4).

[0059]

[0060] In expressions (3)-(4), is the chemical reaction rate generated by the decomposition reaction between the negative electrode and the electrolyte, Q ne (T,c ne , z) is the heat power generated in the preset volume by the decomposition reaction of the negative electrode and the electrolyte, H ne is the unit reaction enthalpy, W ne is the equivalent density of the negative electrode material, A ne is the pre-frequency factor of the reaction between the negative electrode and the electrolyte, E ne is the activation energy of the reaction between the negative electrode and the electrolyte, R is the ideal gas constant, c ne is the normalized concentration of the negative electrode reaction, z sei is the normalized concentration of the metastable SEI film generated during the reaction between the negative electrode and the electrolyte, and T is the temperature.

[0061] The chemical reaction rate generated by the decomposition reaction of the positive electrode is shown in expression (5), and the heat power generated in the preset volume of the decomposition reaction of the positive electrode is shown in expression (6),

[0062]

[0063] In expressions (5)-(6), is the chemical reaction rate generated by the decomposition reaction of the positive electrode, Q pe (T,c pe ) is the heat power generated in the preset volume of the decomposition reaction of the positive electrode, H pe is the unit reaction enthalpy, W pe is the equivalent density of the positive electrode material, A pe is the pre-frequency factor of the positive electrode material, E pe is the activation energy of the positive electrode material, R is the ideal gas constant, α is the normalized concentration of the decomposition reaction of the positive electrode material, and T is the temperature.

[0064] The chemical reaction rate generated by the decomposition reaction of the electrolyte is shown in expression (7), and the heat power generated in the preset volume by the decomposition reaction of the electrolyte is shown in expression (8),

[0065]

[0066] In expressions (7)-(8), is the chemical reaction rate generated by the decomposition reaction of the electrolyte, Q e (T,c e ) is the heat power generated in the preset volume by the decomposition reaction of the electrolyte, H e is the unit reaction enthalpy, W e is the equivalent density of the electrolyte, A e is the pre-frequency factor of the electrolyte, E eis the activation energy of the electrolyte, R is the ideal gas constant, c e is the normalized concentration of the electrolyte decomposition reaction, and T is the temperature.

[0067] It can be seen from the above expression that the thermal power generated by the corresponding preset volume can be calculated according to the rate of each chemical reaction and the unit reaction enthalpy value. After determining the thermal power generated by the preset volume, the thermal power generated by each chemical reaction of the entire battery to be simulated can be determined according to the thermal power generated by the preset volume, and the thermal power generated by each chemical reaction is added to obtain the total thermal power of the battery to be simulated. The total thermal power of the battery to be simulated is shown in expression (9).

[0068] Q abuse =Q sei +Q ne +Q pe +Q e (9)

[0069] In expression (9), Q abuse is the total thermal power of the battery to be simulated, Q sei is the heat generation power of SEI film decomposition reaction, Q ne is the heat generated by the reaction between the negative electrode and the electrolyte, Q pe is the heat generation power of the decomposition reaction of the positive electrode material, Q e It is the heat generation power of the electrolyte decomposition reaction.

[0070] The temperature change rate of the battery is determined according to the total thermal power and the mass, specific heat capacity and volume of the battery. The temperature change rate of the battery is shown in expression (10):

[0071]

[0072] In expression (10), is the temperature change rate of the battery, Q abuse Indicates the total thermal power, M b is the mass of the battery (1.77 kg in this embodiment), C p is the specific heat capacity of the battery (in this embodiment, it is 1100 J / (kg·K), V is the volume of the battery (in this embodiment, it is 7.92688×10 -4 m 3 ).

[0073] The battery simulation temperature is calculated according to the battery temperature change rate, battery operation time, and initial temperature to obtain the initial battery thermal runaway model. The expression of the initial battery thermal runaway model is shown in (11):

[0074]

[0075] In expression (11), T(t) represents the temperature at which the battery undergoes thermal runaway, T(0) is the initial temperature, and t is the battery operating time. is the rate of change of battery temperature.

[0076] In detail, the initial battery thermal runaway model is optimized based on the battery thermal runaway data to obtain the battery thermal runaway model, including: adjusting each thermal runaway influencing factor in the initial battery thermal runaway model and determining its weight, and locking the key influencing factor according to the weight of each thermal runaway influencing factor; obtaining the battery simulation temperature based on the initial battery thermal runaway model, and establishing a temperature loss relationship based on the battery simulation temperature and the actual temperature in the battery thermal runaway data, and determining the temperature root mean square error threshold according to the temperature loss relationship; inputting the initial key influencing factor into the initial battery thermal runaway model for temperature simulation to obtain the initial battery simulation temperature; judging whether the initial battery simulation temperature meets the temperature root mean square error threshold, if not, adjusting the value of the corresponding key influencing factor according to the preset adjustment threshold until the adjusted battery simulation temperature meets the temperature root mean square error threshold to obtain the battery thermal runaway model.

[0077] Specifically, in an exemplary embodiment, the activation energy E, the pre-frequency factor A, and the unit reaction enthalpy H in the initial battery thermal runaway model are all set to the relevant preset thermal runaway impact thresholds, which may be the initial value or a specified value, to obtain the first battery simulation temperature output by the initial battery thermal runaway model, and gradually adjust the value of the activation energy E to obtain the second battery simulation temperature output by the initial thermal runaway model after the activation energy E is adjusted. Similarly, the pre-frequency factor A and the unit reaction enthalpy H are adjusted respectively to obtain the second battery simulation temperature output by the initial thermal runaway model after each thermal runaway impact factor is adjusted, and the second battery simulation temperature output by the initial thermal runaway model after each thermal runaway impact factor is adjusted is obtained. The thermal runaway influence factors related to the thermal runaway influence factor and the preset thermal runaway influence threshold are used to determine the change of each thermal runaway influence factor, the change of each thermal runaway influence factor corresponding to the battery simulation temperature is determined according to the first battery simulation temperature and the second battery simulation temperature, and a mapping relationship between the change of each thermal runaway influence factor and the change of the battery simulation temperature is constructed to determine the influence weight of each thermal runaway influence factor on the initial battery thermal runaway module, and the weight of the activation energy E, the weight of the pre-frequency factor A and the weight of the unit reaction enthalpy H are compared with each other, and the one with the largest weight in the comparison result is taken as the key influencing factor of the battery thermal runaway, and the key influencing factor is the unit reaction enthalpy H.

[0078] The battery simulation temperature is obtained based on the initial thermal runaway model, and the temperature loss relationship is established according to the battery simulation temperature and the actual temperature measured by the ARC experiment. The temperature loss relationship is shown in expression (12):

[0079]

[0080] In expression (12), RMSE is the root mean square error of temperature, N is the total number of battery simulation temperatures, and T sim (i) is the battery simulation temperature, T exe (i) is the actual temperature, i is a positive integer.

[0081] According to the temperature loss relationship, the temperature RMS error with the smallest value is set as the temperature RMS error threshold.

[0082] like Figure 2 As shown, in an exemplary embodiment, the H sei , the reaction between the negative electrode and the electrolyte H ne , the decomposition reaction of the positive electrode H pe And the decomposition reaction of the electrolyte H e The initial values ​​of 5 , 1.714×10 6 , 3.14×10 5 , 1.55×10 5 , set the upper and lower limits of all unit reaction enthalpy to (1×10 5 -1×10 7 ), input the initial unit reaction enthalpy into the initial battery thermal runaway model for temperature simulation, and use the least squares optimization algorithm to determine whether the battery simulation temperature meets the temperature root mean square error threshold. If it does, the corresponding unit reaction enthalpy is determined. If it does not meet the temperature root mean square error threshold, the preset adjustment threshold (1×10 -15 ) adjust the value of each unit reaction enthalpy until the adjusted battery simulation temperature meets the temperature root mean square error threshold, that is, obtain the four unit reaction enthalpy values ​​with the smallest average relative error, and obtain the battery thermal runaway simulation model.

[0083] In more detail, a temperature loss relationship is established based on the battery simulation temperature and the actual temperature in the battery thermal runaway data, including: performing a characteristic analysis on the change of the actual temperature to obtain a temperature characteristic; determining a temperature error weight based on the temperature characteristic, and establishing a temperature loss relationship based on the temperature error weight, the battery simulation temperature and the actual temperature. Specifically, thermal runaway of a battery occurs mainly because the chemical reaction inside the battery gets out of control, causing the battery to release a large amount of heat to the outside, causing the battery to heat up and have adverse effects on the battery itself or other devices. Therefore, when establishing a temperature loss relationship, it is necessary to analyze the actual temperature changes in the battery thermal runaway data. The actual temperature changes of the battery include the self-heating stage before the battery diaphragm completely collapses and the rapid heating stage after the isolation membrane collapses. According to the characteristics of the temperature change, the temperature error weight in the self-heating stage is set to the first preset temperature error weight, which can be 0.4, and the temperature error weight in the rapid heating stage is set to the second preset temperature error weight, which is 0.6. Thus, a temperature loss relationship is established based on the temperature error weight, the battery simulation temperature and the actual temperature, wherein the temperature error weight can be adjusted according to the actual situation and is not limited here.

[0084] In detail, the multi-dimensional simulation method for battery thermal runaway also includes: dividing the battery thermal runaway data into a gentle stage and a sudden drop stage based on the voltage change characteristics in the battery thermal runaway data; establishing the temperature-voltage mapping relationship in the gentle stage and the sudden drop stage respectively; inputting the temperature-voltage mapping relationship into the battery thermal runaway model for voltage prediction to obtain the battery simulation voltage. Specifically, the battery thermal runaway data of the battery to be tested for ARC experiment is analyzed, and the battery thermal runaway data is divided into a gentle stage and a sudden drop stage according to the change characteristics of the battery voltage. The temperature is used as the independent variable and the voltage is used as the dependent variable. The mapping relationship between temperature and voltage is established using polynomial linear fitting. The mapping relationship between temperature and voltage is shown in expressions (13)-(15):

[0085]

[0086] In expressions (13)-(15), Voltage(T) is the voltage and T(t) is the battery simulation temperature.

[0087] The temperature-voltage mapping relationship is input into the battery thermal runaway model, the thermocouple and model in the thermal runaway process are established, the battery simulation voltage is obtained, and the voltage in the thermal runaway stage is accurately predicted, such as Figure 3 As shown in Figure 2, the simulation of the temperature and voltage of the single battery is as follows: Figure 3 shown.

[0088] In step S130, a three-dimensional battery heat propagation model is constructed based on each chemical reaction rate to achieve heat generation power simulation of the battery to be simulated. The three-dimensional battery heat propagation model is used to characterize the relationship between each chemical reaction rate and the three-dimensional heat power of the battery to be simulated.

[0089] In detail, the volume average temperature of the battery to be simulated is obtained; the battery to be simulated is divided into a network to obtain multiple preset battery grids; each chemical reaction rate is input into a preset transport standard equation to construct a scalar relationship for each chemical reaction, wherein the scalar relationship is used to characterize the chemical reaction process of battery thermal runaway; the volume average temperature and each scalar relationship are imported into the preset chemical reaction relationship to establish a chemical reaction rate-thermal power mapping relationship of the preset battery grid; and a three-dimensional battery heat propagation model of the battery to be simulated is constructed according to the chemical reaction rate-thermal power mapping relationship.

[0090] Specifically, the volume average temperature of the battery to be simulated is obtained, and the battery to be simulated is divided into multiple grids to obtain multiple preset battery grids; when establishing a three-dimensional model of the battery, the data of each grid is first obtained to simplify the data processing process, so that the three-dimensional model of the battery can be established more accurately.

[0091] The preset transport standard equation is an equation that describes the change of a scalar in space with time and spatial position. It is suitable for solving the diffusion of concentration and temperature. The expression of the preset transport standard equation is shown in (16):

[0092]

[0093] In expression (16), represents the transient term, represents the convection term, represents the diffusion term, represents the source term, φ k represents the variable to be solved, (k=1,…,N) indicates whether the dimension is one, two or three dimensions.

[0094] The chemical reaction rates in the battery thermal runaway model are taken as Source term, transient term The density ρ in is set to 1, the convection term is not considered, the diffusion coefficient is set to 1e-15, and the dimensionless parameters of each chemical reaction are used as the variables to be solved. k , and the dimensionless parameter C of the SEI film decomposition reaction is obtained sei , dimensionless parameter C of the reaction between the negative electrode and the electrolyte ne , decomposition reaction of the positive electrode C pe and the dimensionless parameter C of the electrolyte decomposition reaction e, and establish four corresponding scalar relationships of chemical reactions according to each dimensionless parameter, import the volume average temperature and each scalar relationship into the Arrhenius formula to obtain the chemical reaction rate-thermal power mapping relationship of a single preset battery grid; merge the chemical reaction rate-thermal power mapping relationships of multiple single preset battery grids to obtain a three-dimensional battery heat propagation model of the battery to be simulated.

[0095] In an exemplary embodiment of the present application, after constructing the three-dimensional battery heat propagation model, it also includes: configuring the three-dimensional battery heat propagation model according to preset configuration conditions to obtain an initial three-dimensional battery heat propagation model; starting the initial three-dimensional battery heat propagation model, and obtaining the battery heat propagation data output by the three-dimensional battery heat propagation model according to a preset time threshold; comparing the battery heat propagation data with the battery thermal runaway data, and verifying the three-dimensional battery heat propagation model based on the comparison result. Specifically, the physical property parameters of the material of the battery to be simulated are set, the wall condition of the simulated battery is set to adiabatic, and the scalar data of each chemical reaction is set, C sei , C ne , C pe , C e The values ​​are set to 0.15, 1, 0.04, and 1 respectively to obtain the scalar relationship of each chemical reaction. The initial three-dimensional battery heat propagation model is started. The battery heat propagation data output by the initial three-dimensional battery heat propagation model is obtained at regular intervals. The battery simulation temperature in the battery heat propagation data is compared with the actual temperature measured by the ARC experiment to verify the accuracy of the three-dimensional battery heat propagation model. The three-dimensional model simulation and experimental temperature results are shown in Figure 2. Figure 4 shown.

[0096] In a second aspect, the present application also provides a method for designing a battery thermal runaway insulation board, which is applied to the multi-dimensional simulation method for battery thermal runaway as described above, including:

[0097] Establish a battery pack geometry model based on a three-dimensional battery heat spread model;

[0098] Insert a heat shield into the battery pack geometry model and acquire and analyze battery simulation data of the heat shield to determine the target heat shield.

[0099] In detail, Figure 5As shown, a battery pack geometric model is established based on a three-dimensional battery heat spread model, including: forming a battery pack through multiple single cells (i.e., a three-dimensional battery heat spread model), inserting a heat insulation layer between two adjacent batteries, placing a heating plate at the positive electrode of the battery pack, and setting a mica plate at both ends of the battery pack. A battery pack geometric model with a thickness of 2 mm and an area consistent with the contact surface of two adjacent electrodes and a heat insulation layer is established. After meshing the battery pack geometric model, it is imported into the three-dimensional model loader, and a mapping relationship between chemical reaction rate and thermal power is established in the corresponding area. The physical property parameters of each part are set and the corresponding battery heat spread data is solved. It should be noted that this calculation needs to consider convection heat transfer and thermal radiation, and the volume heat generation power of the heating plate must be input. The convection heat transfer coefficient is set to 40W / (m 2 K), the emissivity ε is set to 0.4, and the volume heat generation power of the heating plate is set to 14765639.77 W / m 3 .

[0100] Insert a heat insulation board into the battery pack geometric model, obtain and analyze the battery simulation data of the heat insulation board to determine the target heat insulation board, including: inserting heat insulation boards with different physical parameters, different thicknesses and different areas into the battery pack geometric model; determine the physical parameters, thickness and area of ​​the heat insulation board according to the battery heat spread data to obtain the target heat insulation board.

[0101] Specifically, glass fiber, asbestos or ceramic fiber materials are inserted into the geometric model of the battery pack, and the first preset temperature threshold T1 and the first heat propagation time interval Δt1 of the center of the contact surface of the single cell in the simulation process of the three-dimensional battery heat propagation model with the insulation layer are recorded, and the surface temperature change rate of the single cell is determined according to the first preset temperature threshold T1 and the first heat propagation time interval Δt1; the second preset temperature threshold T2 and the second heat propagation time interval Δt2 of the center of the contact surface of the single cell at the same position outside the insulation layer are obtained, and the surface temperature change rate outside the insulation layer is determined according to the second preset temperature threshold T2 and the second heat propagation time interval Δt2, and the insulation effect of each insulation material is determined according to the surface temperature change rate of the single cell, the surface temperature change rate outside the insulation layer and the insulation material, and the physical properties of the insulation board are determined according to the insulation effect. After determining the physical parameters of the thermal insulation board, the geometric models of the battery pack with thermal insulation boards of different thicknesses such as 2mm, 3mm, 4mm, and 5mm are established respectively, and the target thickness of the thermal insulation board is obtained according to the determination principle of the physical parameters of the thermal insulation board; after determining the physical parameters and thickness of the thermal insulation board, thermal insulation boards with different coverage areas are set, and the corresponding geometric model of the battery pack is established. It should be noted that the coverage area must take into account the reserved space actually arranged in the battery system. According to the determination principle of the physical parameters of the thermal insulation board, the target area of ​​the thermal insulation board is obtained, and the target thermal insulation board is obtained.

[0102] like Figure 6As shown in Figure 2, the simulation temperature in the battery pack geometry model is compared with the experimental temperature. The data output by the battery pack geometry model coincides with the experimental data. Figure 7 As shown in the figure, the simulated voltage in the battery pack geometric model is compared with the experimental voltage. The simulated voltage and the experimental voltage have the same output trend, which verifies the effectiveness and accuracy of the thermal insulation board in the battery pack geometric model.

[0103] According to simulation experiments, it was found that a certain ceramic fiber material has the best comprehensive thermal insulation performance. Its thickness was finally determined to be 4mm, and its coverage area is 140mm*100mm. The area of ​​a single side of the battery is 148mm*104mm, and the coverage area is about 90.96%. When a single battery has thermal runaway, this material can suppress the spread of heat and prevent the occurrence of heat spread.

[0104] In a third aspect, the present application also provides a battery thermal runaway multi-dimensional simulation system, such as Figure 8 As shown, in an exemplary embodiment, the battery thermal runaway multi-dimensional simulation system includes at least a thermal runaway test module 810, an optimization module 820 and a thermal runaway simulation module 830, which are described in detail as follows:

[0105] A thermal runaway test module 810 is used to perform a thermal runaway test on the battery to be tested and obtain battery thermal runaway data;

[0106] An optimization module 820 is used to optimize the initial battery thermal runaway model based on the battery thermal runaway data to obtain a battery thermal runaway model, wherein the battery thermal runaway model is used to characterize the relationship between the chemical reaction rates of the battery to be simulated and the battery simulation temperature;

[0107] The thermal runaway simulation module 830 is used to construct a three-dimensional battery heat propagation model based on each chemical reaction rate to achieve heat generation power simulation of the battery to be simulated, wherein the three-dimensional battery heat propagation model is used to characterize the relationship between each chemical reaction rate and the three-dimensional thermal power of the battery to be simulated.

[0108] It should be noted that the battery thermal runaway multi-dimensional simulation system provided in the above embodiment and the battery thermal runaway multi-dimensional simulation method provided in the above embodiment belong to the same concept, wherein the contents of the operations performed by each module have been described in detail in the embodiment of the battery thermal runaway multi-dimensional simulation method, and will not be repeated here.

[0109] The present application provides a multi-dimensional simulation method and system for battery thermal runaway and a design method for a battery thermal runaway insulation board. The simulation method comprises: performing a thermal runaway test on a battery to be tested to obtain battery thermal runaway data; constructing an initial battery thermal runaway model based on the Arrhenius formula and related parameters, optimizing key influencing factors in the initial battery thermal runaway model through the battery thermal runaway data, and obtaining a battery thermal runaway model to determine the relationship between each chemical reaction rate and the battery simulation temperature during the battery thermal runaway process, thereby eliminating the need for tedious DSC experiments and saving research funds and time costs; establishing a temperature-voltage mapping relationship for the temperature change characteristics in the battery thermal runaway data, and then simulating the simulated voltage of the battery to be simulated in combination with the battery thermal runaway model to achieve a simulated prediction of the voltage; constructing a three-dimensional battery heat propagation model according to the chemical reaction rate in the battery thermal runaway model, thereby achieving a heat generation power simulation of the battery to be simulated and simplifying the battery simulation process. The multi-dimensional simulation method for battery thermal runaway provided in this application can completely solve the problem that the parameters in the literature cannot be applied in the design directly according to the initial thermal runaway reaction parameters after the battery capacity, size, and material system change. The multi-dimensional battery thermal runaway simulation model established after parameter optimization, and the average relative error between the battery simulation data and the temperature measured by the ARC experiment can be controlled within 2%, with high accuracy; on the basis of the battery thermal runaway model, the relationship between the chemical reaction rate and the thermal power is written based on the Arrhenius formula, and a three-dimensional battery thermal propagation model is established. In the three-dimensional simulation of the battery, only the thermal power data of multiple preset grids need to be calculated, and the volumetric heat generation power of the battery is added to simplify the simulation process. The corresponding heat insulation board can also be designed according to the three-dimensional battery thermal propagation model, saving the time for designing the material type, thickness and coverage area of ​​the heat insulation board, and the number of experiments for testing the thermal insulation performance of the battery module thermal runaway experiment can be reduced through simulation, saving the development cost in the thermal insulation design.

[0110] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A multi-dimensional simulation method for battery thermal runaway, characterized in that: include: Perform a thermal runaway test on the battery to be tested to obtain the battery thermal runaway data; Optimizing an initial battery thermal runaway model based on the battery thermal runaway data to obtain a battery thermal runaway model, wherein the battery thermal runaway model is used to characterize the relationship between each chemical reaction rate of the battery to be simulated and the battery simulation temperature; A three-dimensional battery heat propagation model is constructed based on each of the chemical reaction rates to achieve heat generation power simulation of the battery to be simulated, wherein the three-dimensional battery heat propagation model is used to characterize the relationship between each of the chemical reaction rates and the three-dimensional heat power of the battery to be simulated.

2. The multi-dimensional simulation method for battery thermal runaway according to claim 1, characterized in that: The method further comprises: Dividing the battery thermal runaway data into a gentle phase and a sudden drop phase based on voltage variation characteristics in the battery thermal runaway data; Establishing mapping relationships between temperature and voltage in the gentle phase and the sudden drop phase respectively; The temperature-voltage mapping relationship is input into the battery thermal runaway model to perform voltage prediction to obtain a battery simulation voltage.

3. The multi-dimensional simulation method for battery thermal runaway according to claim 1, characterized in that: The initial battery thermal runaway model construction steps include: Acquiring geometric parameters of the battery to be simulated, wherein the geometric parameters include thermal runaway influencing factors and battery data; Determining the chemical reaction rate based on a preset chemical reaction relationship and the thermal runaway influencing factor; The total thermal power of the battery to be simulated is calculated according to each of the chemical reaction rates, and the battery simulation temperature is determined according to the total thermal power, the battery data and the operating time of the battery to be simulated, so as to obtain the initial battery thermal runaway model.

4. The multi-dimensional simulation method for battery thermal runaway according to claim 3, characterized in that: The initial battery thermal runaway model is optimized based on the battery thermal runaway data to obtain a battery thermal runaway model, including: Adjusting each thermal runaway influencing factor in the initial battery thermal runaway model and determining its weight, and locking the key influencing factor according to the weight of each thermal runaway influencing factor; Acquiring the battery simulation temperature based on the initial battery thermal runaway model, establishing a temperature loss relationship according to the battery simulation temperature and the actual temperature in the battery thermal runaway data, and determining a temperature root mean square error threshold according to the temperature loss relationship; Inputting the initial key influencing factors into the initial battery thermal runaway model to perform temperature simulation to obtain an initial battery simulation temperature; Determine whether the initial battery simulation temperature meets the temperature root mean square error threshold. If not, adjust the value of the corresponding key influencing factor according to the preset adjustment threshold until the adjusted battery simulation temperature meets the temperature root mean square error threshold, thereby obtaining the battery thermal runaway model.

5. The multi-dimensional simulation method for battery thermal runaway according to claim 4, characterized in that: Adjusting each thermal runaway influencing factor in the initial battery thermal runaway model and determining its weight, and locking the key influencing factor according to the weight of each thermal runaway influencing factor, including: Setting each thermal runaway influence factor to a related preset thermal runaway influence threshold and obtaining a corresponding battery simulation temperature, and adjusting the value of each thermal runaway influence factor respectively, and obtaining a corresponding battery simulation temperature according to the adjusted thermal runaway influence factor; Determining the weight of each thermal runaway influencing factor according to the change amount of each thermal runaway influencing factor and the change amount of the corresponding battery simulation temperature; The weights of the thermal runaway influencing factors are compared, and the key influencing factors are locked according to the comparison results.

6. The multi-dimensional simulation method for battery thermal runaway according to claim 4, characterized in that: A temperature loss relationship is established according to the battery simulation temperature and the actual temperature in the battery thermal runaway data, including: Performing characteristic analysis on the change of the actual temperature to obtain temperature characteristics; A temperature error weight is determined according to the temperature feature, and the temperature loss relationship is established according to the temperature error weight, the battery simulation temperature and the actual temperature.

7. The multi-dimensional simulation method for battery thermal runaway according to claim 3, characterized in that: A three-dimensional battery heat propagation model is constructed based on the chemical reaction rates, including: Obtaining the volume average temperature of the battery to be simulated; Performing network division on the battery to be simulated to obtain a plurality of preset battery grids; Inputting the chemical reaction rates into a preset transport standard equation to construct a scalar relationship for each chemical reaction, wherein the scalar relationship is used to characterize the chemical reaction process of battery thermal runaway; Importing the volume average temperature and each of the scalar relationships into the preset chemical reaction relationship to establish a chemical reaction rate-thermal power mapping relationship of a preset battery grid; A three-dimensional battery heat propagation model of the battery to be simulated is constructed according to the chemical reaction rate-thermal power mapping relationship.

8. The multi-dimensional simulation method for battery thermal runaway according to claim 7, characterized in that: After constructing the three-dimensional battery heat propagation model, the method further includes: The three-dimensional battery heat propagation model is configured according to preset configuration conditions to obtain an initial three-dimensional battery heat propagation model; Starting the initial three-dimensional battery heat propagation model, and acquiring battery heat propagation data output by the three-dimensional battery heat propagation model according to a preset time threshold; The battery heat propagation data is compared with the battery thermal runaway data, and the three-dimensional battery heat propagation model is verified based on the comparison result.

9. The multi-dimensional simulation method for battery thermal runaway according to claim 1, characterized in that: Before the thermal runaway test of the battery under test, it also includes: Performing multiple charge and discharge processes on the battery to be tested according to a preset current threshold value to form a protective layer between the electrode material and the electrolyte of the battery to be tested; The charge state of the battery to be tested is set to a preset charge threshold.

10. A method for designing a battery thermal runaway insulation board, characterized in that: The method is implemented by using the multi-dimensional simulation method for battery thermal runaway according to any one of claims 1 to 9, comprising: Establishing a battery pack geometry model based on a three-dimensional battery heat propagation model, wherein the battery pack geometry model is used to characterize a mapping relationship between a chemical reaction rate and a thermal power among a plurality of batteries; A heat shield is inserted into the battery pack geometric model, and battery heat propagation data of the heat shield is acquired and analyzed to determine a target heat shield.

11. The battery thermal runaway insulation board design method according to claim 10, characterized in that: Inserting a heat shield into the battery pack geometric model, acquiring and analyzing battery heat propagation data of the heat shield to determine a target heat shield, including: Inserting heat insulation boards with different physical parameters, different thicknesses and different areas into the battery pack geometric model; The physical parameters, thickness and area of ​​the heat insulation board are determined according to the battery heat spread data to obtain a target heat insulation board.

12. A multi-dimensional simulation system for battery thermal runaway, characterized in that: The system comprises: Thermal runaway test module, used to perform thermal runaway test on the battery to be tested and obtain battery thermal runaway data; An optimization module, used for optimizing an initial battery thermal runaway model based on the battery thermal runaway data to obtain a battery thermal runaway model, wherein the battery thermal runaway model is used to characterize the relationship between each chemical reaction rate of the battery to be simulated and the battery simulation temperature; The thermal runaway simulation module is used to construct a three-dimensional battery heat propagation model based on each of the chemical reaction rates to achieve heat generation power simulation of the battery to be simulated, wherein the three-dimensional battery heat propagation model is used to characterize the relationship between each of the chemical reaction rates and the three-dimensional thermal power of the battery to be simulated.

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