Battery pole group temperature simulation method and device

Abstract

The invention discloses a battery pole group temperature simulation method and device, and belongs to the technical field of batteries, and the battery pole group temperature simulation method comprises the steps: building a monopole piece geometric model, and carrying out the partitioning of the monopole piece geometric model, so as to form a plurality of monopole piece units; and modeling the monopole piece unit to obtain an electrochemical model. A single pole piece is divided into a plurality of single pole piece units, heat production information of the corresponding single pole piece units can be obtained through an established electrochemical model, then a pole group is divided into a plurality of pole group units corresponding to the single pole piece units, a heat transfer model is established for the pole group units, and the heat production information is input into the heat transfer model. The temperature information of the pole group unit can be obtained; through the method, heat production and temperature changes corresponding to different positions of the battery pole group can be simulated more accurately, the temperature distribution rule of the battery pole group can be described more accurately, and the error with the actual temperature is reduced.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a method and device for simulating battery pole group temperature. Background Art

[0002] Compared with traditional batteries, blade batteries have obvious changes in length scale. The increase in the length of blade batteries has a significant impact on the temperature distribution on the battery pole group. The traditional battery pole group heat generation simulation method cannot accurately simulate the temperature distribution on the battery pole group, the error is large, and it is not accurate enough. Summary of the invention

[0003] Purpose of the invention: The embodiments of the present application provide a method and device for simulating the temperature of a battery pole group, aiming to overcome the technical problem of being unable to accurately simulate the temperature distribution on the battery pole group.

[0004] Technical solution: A battery electrode group temperature simulation method according to an embodiment of the present application includes:

[0005] Establishing a monopole sheet geometric model, and partitioning the monopole sheet geometric model to form a plurality of monopole sheet units;

[0006] Modeling the monopole unit to obtain an electrochemical model;

[0007] Based on the electrochemical model and the measured constant rate charge and discharge data information of the battery, obtaining the heat generation information of the monopole unit;

[0008] Establishing a geometric model of the pole group, partitioning the geometric model of the pole group to form a plurality of pole group units, each of which corresponds to a single pole piece unit, and modeling the pole group units to obtain a heat transfer model;

[0009] Based on the coupling of the heat transfer model and the electrochemical model, and the heat generation information of the single pole piece unit, the temperature information corresponding to the pole group unit is obtained.

[0010] In some embodiments, the establishing of the monopole sheet geometric model and partitioning the monopole sheet geometric model to form a plurality of monopole sheet units includes:

[0011] Along the length direction X of the monopole sheet geometric model, the monopole sheet geometric model is divided into a plurality of regions based on the current density of the monopole sheet, and each region of the monopole sheet is determined as a monopole sheet unit.

[0012] In some embodiments, the step of establishing a geometric model of a pole group and partitioning the geometric model of the pole group to form a plurality of the pole group units includes:

[0013] The pole group includes a plurality of monopole sheets. Along the length direction X of the monopole sheet geometric model, the pole group geometric model is divided into a plurality of regions based on the regions of the monopole sheet geometric model. Each region of the pole group is determined as a pole group unit.

[0014] In some embodiments, modeling the monopolar unit to obtain an electrochemical model includes:

[0015] Defining material basis parameters of a material domain of the electrochemical model, wherein the material domain includes a negative current collector, a negative electrode, a separator, a positive electrode, and a positive current collector;

[0016] Defining variables in the electrochemical model, wherein the variables in the electrochemical model at least include battery voltage, positive electrode material charge state, negative electrode material charge state and battery initial temperature;

[0017] A variable probe in the electrochemical model is defined, where the variable probe is used to monitor the battery voltage and the battery temperature.

[0018] In some embodiments, the modeling of the monopolar unit to obtain an electrochemical model further includes:

[0019] The electrical grounding position is set to the surface where the end of the negative electrode tab is located, and the electrode current density acquisition position is set to the surface where the end of the positive electrode current collector is located.

[0020] In some embodiments, the electrochemical model is characterized by a governing equation, which includes solid-phase Ohm's law, liquid-phase Ohm's law, solid-phase ion diffusion, liquid-phase ion diffusion, and an electrochemical reaction equation.

[0021] In some embodiments, the step of obtaining the temperature information of the corresponding pole group unit based on the coupling of the heat transfer model and the electrochemical model and the heat generation information of the single pole piece unit includes:

[0022] Obtaining the thermal conductivity of the electrode group unit material;

[0023] Based on the heat generation information of the single pole piece unit in the electrochemical model and the thermal conductivity of the pole group unit material, the heat generation information corresponding to the pole group unit is obtained.

[0024] In some embodiments, the thermal conductivity includes radial thermal conductivity and axonal thermal conductivity, and the axonal thermal conductivity and the radial thermal conductivity are determined by the following formula:

[0025]

[0026] k r ∑ i d i=∑ i k i d i ;

[0027] Among them, k r is the radial thermal conductivity, d i is the thickness of the i-th layer of the single pole sheet, k i is the thermal conductivity of the ith single-pole sheet, k z is the longitudinal thermal conductivity.

[0028] In some embodiments, the method further comprises:

[0029] Based on the deviation between the temperature information of the electrode group unit obtained by simulation and the measured temperature information, the parameters of the electrochemical model and the heat transfer model are adjusted until the deviation between the temperature information of the electrode group unit and the measured temperature information meets a preset condition.

[0030] A battery pole group temperature simulation device, comprising:

[0031] A first construction module is used to establish a monopole sheet geometric model and partition the monopole sheet geometric model to form a plurality of monopole sheet units;

[0032] A second building block is used to model the single-electrode unit to obtain an electrochemical model;

[0033] A calculation module, used for obtaining the heat generation information of the monopole unit based on the electrochemical model and the measured constant rate charge and discharge data information of the battery;

[0034] The third construction module is used to establish a geometric model of the pole group, partition the geometric model of the pole group to form a plurality of pole group units, and each pole group unit corresponds to a single pole piece unit, and model the pole group units to obtain a heat transfer model;

[0035] A coupling module is used to obtain temperature information corresponding to the pole group unit based on the coupling of the heat transfer model and the electrochemical model, as well as the heat generation information of the single pole piece unit.

[0036] Beneficial effect: The battery pole group temperature simulation method of the embodiment of the present application includes: establishing a single pole piece geometric model, partitioning the single pole piece geometric model to form a plurality of single pole piece units; modeling the single pole piece unit to obtain an electrochemical model; obtaining the heat generation information of the single pole piece unit based on the electrochemical model and the measured constant rate charge and discharge data information of the battery; establishing a pole group geometric model, partitioning the pole group geometric model to form a plurality of pole group units, and each pole group unit corresponds to a single pole piece unit, and modeling the pole group unit to obtain a heat transfer model; based on the coupling of the heat transfer model and the electrochemical model, and the heat generation information of the single pole piece unit, obtaining the temperature information of the corresponding pole group unit. By dividing a single pole piece into a plurality of single pole piece units, the heat generation information of the corresponding single pole piece unit can be obtained through the established electrochemical model, and then the pole group is divided into a plurality of pole group units corresponding to the single pole piece unit, a heat transfer model is established for the pole group unit, and the heat generation information is input into the heat transfer model to obtain the temperature information of the pole group unit; through this method, the heat generation and temperature changes corresponding to different positions of the battery pole group can be simulated more accurately, the temperature distribution law of the battery pole group can be described more accurately, and the error with the actual temperature can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 A schematic diagram of the steps of a battery electrode group temperature simulation method according to an embodiment of the present application;

[0039] Figure 2 This is a schematic diagram of the structure of a single-electrode battery model according to an embodiment of the present application;

[0040] Figure 3 This is a schematic diagram of the structure of a battery electrode group model according to an embodiment of the present application;

[0041] Figure 4 This is a schematic diagram of the structure of a battery according to an embodiment of the present application;

[0042] Figure 5 This is a schematic diagram comparing the 2C constant rate charging experimental results and the simulation results of Example 2 of the present application;

[0043] Figure 6 This is a schematic diagram comparing the 3C constant rate charging experimental results and the simulation results of the embodiment of the present application;

[0044] Figure numerals: 10 - single pole sheet; 11 - negative electrode collector; 12 - negative electrode; 13 - separator; 14 - positive electrode; 15 - positive electrode collector; 20 - pole group; 30 - first position; 40 - second position; X - length direction. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0046] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "plurality" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined.

[0047] The temperature performance of lithium-ion batteries under different working conditions has a significant impact on the short-term performance and long-term life of the battery. The ability to more accurately monitor the internal temperature of the battery enables the battery management system (BMS) to more reasonably regulate the thermal management strategy, improve battery performance, and thus improve the performance of the vehicle, which plays an important role. Compared with traditional batteries, blade batteries have obvious changes in length scale. For example, the length of BYD's blade battery is about 960mm, which is about 9 times longer than that of conventional square batteries. At the same time, there are obvious differences in the position of blade battery poles. The positive and negative poles of traditional square batteries are located at the top of the battery, and most blade batteries are designed to be located on both sides of the thickness direction. The increase in the arrangement of blade battery poles and the length scale has a significant impact on the temperature distribution of the battery. In the battery, the current density flowing into and out of the current collector area is the largest. The Joule heat generated by the current passing through the current collector: Q = I^2 × R × t. Among them, Q is the heat generated, I is the current density, R is the resistance corresponding to the unit current collector length, and t is the time. Since the monopole is divided into n equal parts, the resistance corresponding to each current collector is R = ρ × L / S / n. Among them, ρ is the resistivity corresponding to the metal material, L is the total length of the current collector, and S is the flow area of ​​the current collector. According to Q=I^2×R×t, since the R of each equally divided current collector is the same, the main reason for the difference in heat generation at different positions of the current collector is the difference in current density. Therefore, the temperature of different areas on the single pole piece is also different. The traditional battery pole piece heat generation simulation method cannot accurately simulate the temperature distribution of different areas on the battery pole piece, and thus cannot accurately simulate the temperature distribution of different areas on the battery pole group. The error is large and not accurate enough.

[0048] In view of this, an embodiment of the present application provides a battery electrode group temperature simulation method to overcome at least one of the above-mentioned technical problems.

[0049] See also Figure 1 In an embodiment of the present application, the battery electrode group temperature simulation method includes:

[0050] S11: establishing a geometric model of the monopole sheet 10, and partitioning the geometric model of the monopole sheet 10 to form a plurality of monopole sheet units. The sizes of the plurality of monopole sheet units may be the same or different.

[0051] S12: Modeling of a single electrode unit to obtain an electrochemical model.

[0052] S13: Based on the electrochemical model and the measured constant rate charge and discharge data information of the battery, the heat generation information of the single pole piece unit is obtained.

[0053] S14: Establishing a geometric model of the pole group 20, partitioning the geometric model of the pole group 20 to form a plurality of pole group units, and each pole group unit corresponds to a single pole piece unit, and modeling the pole group units to obtain a heat transfer model.

[0054] S15: Based on the coupling of the heat transfer model and the electrochemical model, and the heat generation information of the single pole piece unit, the temperature information of the corresponding pole group unit is obtained.

[0055] The present application divides the monopole sheet 10 into a plurality of monopole sheet units, and then establishes an electrochemical model for the monopole sheet units. The heat generation information of the monopole sheet units at different positions on the monopole sheet 10 can be obtained through the established electrochemical model and the measured constant rate charge and discharge data information. Then the pole group 20 is divided into a plurality of pole group units corresponding to the monopole sheet units, a heat transfer model is established for the pole group units, the heat transfer model is coupled with the electrochemical model, and the heat generation information is input into the coupled heat transfer model, so that the temperature information of the pole group unit can be obtained. Through this method, the heat generation and temperature changes corresponding to different positions of the battery pole group 20 can be simulated more accurately, the temperature on the pole group 20 can be simulated more finely, the temperature distribution law of the battery pole group 20 can be described more accurately, the error with the actual temperature can be reduced, and it is beneficial to manage the internal temperature of the battery.

[0056] See also Figure 2 In some embodiments, a geometric model of the monopole sheet 10 is established, and the geometric model of the monopole sheet 10 is partitioned to form a plurality of monopole sheet units, including: along the length direction X of the geometric model of the monopole sheet 10, based on the current density of the monopole sheet 10, the geometric model of the monopole sheet 10 is divided into a plurality of regions, and each region of the monopole sheet 10 is determined as a monopole sheet unit. The length direction X of the geometric model of the monopole sheet 10 is the direction of current transmission. Since the density distribution of the current is different during the transmission process, the heat generation distribution on the monopole sheet 10 is also different. Therefore, in the direction of current transmission, the monopole sheet 10 is divided into a plurality of monopole sheet units. The heat generation on different monopole sheet units can better reflect the heat generation situation at different positions on the monopole sheet 10.

[0057] See also Figure 3 In some embodiments, a geometric model of the pole group 20 is established, and the geometric model of the pole group 20 is partitioned to form a plurality of pole group units, including: the pole group 20 includes a plurality of monopole sheets 10, and along the length direction X of the geometric model of the monopole sheet 10, the geometric model of the pole group 20 is divided into a plurality of regions based on the region of the geometric model of the monopole sheet 10, and each region of the pole group 20 is determined as a pole group unit. A battery pole group 20 can be formed by a plurality of monopole sheets 10, and the pole group 20 is partitioned along the length direction X into a plurality of pole group units corresponding to the monopole sheet units, so that the heat generation on the corresponding pole group unit can be reflected by the monopole sheet unit. Since it is more convenient to actually detect the temperature of the pole group 20 on the battery than the temperature on the monopole sheet 10, it is convenient to compare with the measured temperature by simulating the temperature on the pole group unit.

[0058] See also Figure 2 In some embodiments, the monopolar sheet unit is modeled to obtain an electrochemical model, including: defining the material basic parameters of the material domain of the electrochemical model, the material domain includes the negative current collector 11, the negative electrode 12, the separator 13, the positive electrode 14, and the positive current collector 15. Defining the material basic parameters of each material domain of the electrochemical model may specifically include: defining the positive and negative electrode domains: the materials in the domain are linked to the properties of the positive and negative active materials, and the particle size of the positive and negative active particles, the exchange current density in the electrochemical reaction, the volume fraction of the positive and negative active materials, and the diffusion coefficient and ion conductivity of the electrolyte in the porous electrode are set. Define the diaphragm domain: the materials in the domain are linked to the electrolyte material properties, and the electrolyte conductivity and diffusion coefficient in the diaphragm domain are set. Define the positive and negative foil domains: the materials in the domain are linked to the copper and aluminum foil material properties of the electrode properties. The specific parameters of these material properties can be directly entered in the simulation software. In addition to defining the parameters of each material in the electrochemical model, boundary conditions such as the electrical grounding position and the electrode current density acquisition position need to be set. The electrical grounding position is set to the surface where the end of the negative electrode tab is located, and the electrode current density acquisition position is set to the surface where the end of the positive electrode current collector 15 is located.

[0059] Define the variables in the electrochemical model. The variables in the electrochemical model include at least the battery voltage, the state of charge of the positive electrode material, the state of charge of the negative electrode material and the initial temperature of the battery. Define the variables in the electrochemical module, which may include at least: the solid potential of the surface where the end of the positive electrode current collector 15 is located is the battery voltage. The ratio of the average lithium ion concentration on the surface of the negative electrode 12 particles to the maximum lithium ion concentration of the negative electrode is the state of charge of the negative electrode material. The ratio of the average lithium ion concentration on the surface of the positive electrode 14 particles to the maximum lithium ion concentration of the positive electrode is the state of charge of the positive electrode material. Define the initial temperature of the battery. The initial temperature of the battery comes from the heat transfer model. The temperature is assigned to each material domain to achieve the coupling of the heat transfer model and the electrochemical model.

[0060] Define variable probes in the electrochemical model, and the variable probes are used to monitor the battery voltage and battery temperature. The variable probes may include a first probe and a second probe, and the first probe variable may be defined as Ecell, and the first probe is used to monitor the voltage change of the monopolar sheet 10 during the battery charging and discharging process. The second probe variable may be defined as T, and the second probe monitors the temperature change of the monopolar sheet 10 during the battery charging and discharging process.

[0061] In some embodiments, the monopolar sheet unit is modeled to obtain an electrochemical model, and further includes: the electrical grounding position is set to the surface where the end of the negative electrode tab is located, and the electrode current density acquisition position is set to the surface where the end of the positive electrode current collector 15 is located. In the electrochemical modeling, the electrical grounding position refers to using the surface where the end of the negative electrode tab is located as the grounding point, and the electrode current density acquisition position refers to using the surface where the end of the positive electrode current collector 15 is located as the position for obtaining the electrode current density. The setting of these position information can improve the establishment of the model, which is conducive to obtaining heat generation information through the model.

[0062] In some embodiments, the electrochemical model is characterized by a control equation. The heat generated by the monopolar unit includes reversible heat and irreversible heat: irreversible heat includes ohmic heat and polarization heat, and reversible heat includes electrochemical reaction heat. The control equation includes solid-phase Ohm's law, liquid-phase Ohm's law, solid-phase ion diffusion, liquid-phase ion diffusion, and electrochemical reaction equations.

[0063] Ohm's law in solid state:

[0064]

[0065] Ohm's law in liquid phase:

[0066]

[0067] Solid phase ion diffusion:

[0068]

[0069] Liquid phase ion diffusion:

[0070]

[0071] Electrochemical reaction equation (BV equation):

[0072]

[0073] The meanings of the symbols in the above equations are shown in the following table:

[0074]

[0075]

[0076] The heat generation information can be obtained through the above control equations and related parameter information.

[0077] In some embodiments, based on the coupling of the heat transfer model and the electrochemical model, and the heat generation information of the single pole piece unit, the temperature information of the corresponding pole group unit is obtained, including: obtaining the thermal conductivity of the pole group unit material. Based on the heat generation information of the single pole piece unit in the electrochemical model and the thermal conductivity of the pole group unit material, the heat generation information of the corresponding pole group unit is obtained. In other words, the heat transfer model and the electrochemical model are coupled to comprehensively consider the effects of heat transfer and electrochemical reactions on the system temperature. The heat transfer model is used to describe the transfer and distribution of heat in the battery, while the electrochemical model is used to describe the electrochemical reaction and current distribution. By coupling these two models, the temperature distribution in the battery can be more accurately predicted. In this coupled model, the heat generation information of the single pole piece unit is an important input parameter. By obtaining the heat generation information of the single pole piece unit, the heat released by the unit in the battery system can be understood. Based on the heat generation information of the single pole piece unit in the electrochemical model and the thermal conductivity of the pole group unit material (thermal conductivity is a physical property of the material, which describes the strength of the thermal conductivity of the material), the temperature information of the corresponding pole group unit can be obtained. By understanding the thermal conductivity of the electrode unit material, the temperature distribution of the battery under the corresponding heat generation can be inferred.

[0078] In some embodiments, the thermal conductivity of the electrode unit material can be obtained by the following formula, where the thermal conductivity includes radial thermal conductivity and axonal thermal conductivity;

[0079] Radial thermal conductivity:

[0080]

[0081] Among them, d i is the thickness of the i-th monopole sheet 10, k i is the thermal conductivity of the i-th layer of the monopole sheet 10, k z is the longitudinal thermal conductivity.

[0082] Axial thermal conductivity:

[0083] k r ∑ i d i =∑ i k i d i ;

[0084] Among them, k r is the radial thermal conductivity, d i is the thickness of the i-th monopole sheet 10, k i is the thermal conductivity of the i-th monopole sheet 10.

[0085] Based on the heat generation information of the single pole piece unit in the electrochemical model and the thermal conductivity of the pole group unit material, the heat generation information of the corresponding pole group unit is obtained. After obtaining the heat generation of the single pole piece unit, the heat generation information of the pole group unit corresponding to the single pole piece unit can be obtained by converting the thermal conductivity.

[0086] See also Figure 4 , Figure 5 and Figure 6 , in some embodiments, the battery pole group temperature simulation method further includes: adjusting the parameters of the electrochemical model and the heat transfer model based on the deviation between the temperature information of the pole group unit obtained by simulation and the measured temperature information, until the deviation between the temperature information of the pole group unit and the measured temperature information meets the preset conditions. In order to verify the accuracy of the simulation model, the battery adiabatic ARC test 2C and 3C constant rate charging experimental results are compared with the simulation results. Compare the differences between the simulation and actual tests of the temperature sensing points at the first position 30 and the second position 40. It can be seen from the figure that the maximum temperature difference is about 5°C. In summary, this method can more accurately describe the temperature distribution of the battery at different positions, and can explain the temperature distribution law of long batteries, which can provide a reference for optimizing battery design.

[0087] A battery pole group temperature simulation device comprises: a first building module, a second building module, a calculation module, a third building module and a coupling module.

[0088] The first construction module is used to establish a geometric model of the monopole sheet 10, and partition the geometric model of the monopole sheet 10 to form a plurality of monopole sheet units. The second construction module is used to model the monopole sheet unit to obtain an electrochemical model. The calculation module is used to obtain the heat generation information of the monopole sheet unit based on the electrochemical model and the measured constant rate charge and discharge data information of the battery. The third construction module is used to establish a geometric model of the pole group 20, partition the geometric model of the pole group 20 to form a plurality of pole group units, and each pole group unit corresponds to a monopole sheet unit, and model the pole group unit to obtain a heat transfer model. The coupling module is used to obtain the temperature information of the corresponding pole group unit based on the coupling of the heat transfer model and the electrochemical model, as well as the heat generation information of the monopole sheet unit.

[0089] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0090] The battery electrode group temperature simulation method and device provided in the embodiments of the present application are introduced in detail above, and the principles and implementation methods of the present application are explained by using specific examples. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application; ordinary technicians in this field should understand that: they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery electrode group temperature simulation method, characterized in that: include: Establishing a monopole sheet geometric model, and partitioning the monopole sheet geometric model to form a plurality of monopole sheet units; Modeling the monopole unit to obtain an electrochemical model; Based on the electrochemical model and the measured constant rate charge and discharge data information of the battery, obtaining the heat generation information of the monopole unit; Establishing a geometric model of the pole group, partitioning the geometric model of the pole group to form a plurality of pole group units, each of which corresponds to a single pole piece unit, and modeling the pole group units to obtain a heat transfer model; Based on the coupling of the heat transfer model and the electrochemical model, and the heat generation information of the single pole piece unit, the temperature information corresponding to the pole group unit is obtained.

2. The battery electrode group temperature simulation method according to claim 1, characterized in that: The step of establishing a monopole sheet geometric model and partitioning the monopole sheet geometric model to form a plurality of monopole sheet units includes: Along the length direction of the monopole sheet geometric model, the monopole sheet geometric model is divided into a plurality of regions based on the current density of the monopole sheet, and each region of the monopole sheet is determined as a monopole sheet unit.

3. The battery electrode group temperature simulation method according to claim 2, characterized in that: The step of establishing a geometric model of a pole group and partitioning the geometric model of the pole group to form a plurality of pole group units includes: The pole group includes a plurality of monopole sheets. Along the length direction of the monopole sheet geometric model, the pole group geometric model is divided into a plurality of regions based on the regions of the monopole sheet geometric model. Each region of the pole group is determined as a pole group unit.

4. The battery electrode group temperature simulation method according to claim 1, characterized in that: The step of modeling the monopole unit to obtain an electrochemical model includes: Defining material basis parameters of a material domain of the electrochemical model, wherein the material domain includes a negative current collector, a negative electrode, a separator, a positive electrode, and a positive current collector; Defining variables in the electrochemical model, wherein the variables in the electrochemical model at least include battery voltage, positive electrode material charge state, negative electrode material charge state and battery initial temperature; A variable probe in the electrochemical model is defined, where the variable probe is used to monitor the battery voltage and the battery temperature.

5. The battery electrode group temperature simulation method according to claim 1, characterized in that: The modeling of the monopole unit to obtain an electrochemical model further includes: The electrical grounding position is set to the surface where the end of the negative electrode tab is located, and the electrode current density acquisition position is set to the surface where the end of the positive electrode current collector is located.

6. The battery electrode group temperature simulation method according to claim 1, characterized in that: The electrochemical model is characterized by a control equation, which includes solid-phase Ohm's law, liquid-phase Ohm's law, solid-phase ion diffusion, liquid-phase ion diffusion and an electrochemical reaction equation.

7. The battery electrode group temperature simulation method according to claim 1, characterized in that: The step of obtaining the temperature information of the corresponding pole group unit based on the coupling of the heat transfer model and the electrochemical model and the heat generation information of the single pole piece unit includes: Obtaining the thermal conductivity of the electrode group unit material; Based on the heat generation information of the single pole piece unit in the electrochemical model and the thermal conductivity of the pole group unit material, the heat generation information corresponding to the pole group unit is obtained.

8. The battery electrode group temperature simulation method according to claim 7, characterized in that: The thermal conductivity includes radial thermal conductivity and abaxial thermal conductivity, and the abaxial thermal conductivity and the radial thermal conductivity are determined by the following formula: k r ∑ i d i =∑ i k i d i ; Among them, k r is the radial thermal conductivity, d i is the thickness of the i-th layer of the single pole sheet, k i is the thermal conductivity of the ith single-pole sheet, k z is the longitudinal thermal conductivity.

9. The battery electrode group temperature simulation method according to claim 1, characterized in that: The method further comprises: Based on the deviation between the temperature information of the electrode group unit obtained by simulation and the measured temperature information, the parameters of the electrochemical model and the heat transfer model are adjusted until the deviation between the temperature information of the electrode group unit and the measured temperature information meets a preset condition.

10. A battery pole group temperature simulation device, characterized in that: include: A first construction module is used to establish a monopole sheet geometric model and partition the monopole sheet geometric model to form a plurality of monopole sheet units; A second building block is used to model the single-electrode unit to obtain an electrochemical model; A calculation module, used for obtaining the heat generation information of the monopole unit based on the electrochemical model and the measured constant rate charge and discharge data information of the battery; The third construction module is used to establish a geometric model of the pole group, partition the geometric model of the pole group to form a plurality of pole group units, each of which corresponds to a single pole piece unit, and model the pole group units to obtain a heat transfer model; A coupling module is used to obtain temperature information corresponding to the pole group unit based on the coupling of the heat transfer model and the electrochemical model, as well as the heat generation information of the single pole piece unit.

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