Battery electrode sheet deformation and damage testing method and apparatus

Abstract

The present application relates to the technical field of batteries, and discloses a battery electrode sheet deformation and damage testing method and apparatus. The battery electrode sheet deformation and damage testing method comprises: establishing a battery finite element model under a compression working condition, and layering an electrode assembly along the thickness direction on the basis of the battery finite element model, so as to form a plurality of unit electrode assemblies; performing composite material modeling on the unit electrode assemblies, so as to obtain a composite material model; acquiring stress-strain curve information of component materials in the unit electrode assemblies in a plurality of directions; and on the basis of the stress-strain curve information of the component materials in the unit electrode assemblies in the plurality of directions, the composite material model, and the battery finite element model, acquiring deformation contour maps of electrode sheets at different positions, so as to characterize deformation and damage of the electrode sheets by means of the deformation contour maps. The battery finite element model under the compression working condition and the composite material model are established to simulate a battery compression condition, and the deformation contour maps of the battery electrode sheets at different positions are calculated and outputted to characterize the deformation and damage conditions of the battery electrode sheets in real time.

Description

A method and apparatus for testing deformation and damage of battery electrodes

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. CN202410995066.2, filed on July 24, 2024, entitled "A Method and Apparatus for Testing Deformation and Damage of Battery Electrodes", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a method and apparatus for testing the deformation and damage of battery electrodes. Background Technology

[0004] During battery manufacturing and use, the electrodes are subjected to various external forces, such as compression, bending, and stretching. These forces can cause deformation and damage to the electrodes, thus affecting battery performance and safety. Current methods for calculating electrode deformation and damage primarily involve destructive testing of the battery followed by CT scans to determine the electrode deformation and damage. However, these methods have limitations; experimental measurement methods cannot provide real-time monitoring of electrode deformation and damage.

[0005] Application content

[0006] In view of this, the purpose of this application is to provide a method and apparatus for testing the deformation and damage of battery electrodes, which aims to overcome the technical problem of being unable to characterize the deformation and damage of battery electrodes in real time.

[0007] In a first aspect, this application provides a method for testing the deformation and damage of battery electrodes, including:

[0008] A finite element model of the battery under extrusion conditions is established, and the electrode assembly is layered along the thickness direction based on the finite element model of the battery to form multiple unit electrode assemblies.

[0009] The unit pole group is modeled as a composite material to obtain a composite material model;

[0010] Obtain stress-strain curve information of each component material in the unit pole group along multiple directions;

[0011] Based on the stress-strain curves of each component material in the unit electrode group along multiple directions, as well as the composite material model and the battery finite element model, deformation cloud maps of the electrode at different locations are obtained to characterize the deformation damage of the electrode through the deformation cloud maps.

[0012] Beneficial effects: By establishing a finite element model of the battery and a composite material model under extrusion conditions, the battery under pressure can be simulated, and deformation cloud maps at different positions of the battery electrode can be calculated and output, thus characterizing the deformation and damage of the battery electrode in real time.

[0013] In one optional implementation, the battery finite element model includes a cell model and an extrusion head model, wherein the extrusion head model is configured to simulate the extrusion conditions corresponding to the cell model.

[0014] In one optional implementation, the step of layering the electrode assembly along the thickness direction based on the battery finite element model to form multiple unit electrode assemblies includes:

[0015] Along the thickness direction, the pole group is divided into n equal parts, and each part is determined as a unit pole group, satisfying: n≥10.

[0016] In one optional implementation, the composite material modeling of the unit pole group to obtain a composite material model includes:

[0017] Obtain the distribution order, thickness, and name information of each component material in the unit pole group to input into the composite material model.

[0018] In one optional implementation, obtaining the stress-strain curve information of each component material in the unit pole group along multiple directions includes:

[0019] The component material is subjected to an extrusion test to obtain the extrusion force-displacement curve information of the component material;

[0020] Based on the extrusion pressure-displacement curve information, extrusion stress-strain curve information is obtained;

[0021] Tensile tests were performed on samples of the component material to obtain tensile force-displacement curve information of the component material;

[0022] Based on the tensile force-displacement curve information, tensile stress-strain curve information is obtained.

[0023] In one optional embodiment, the step of performing an extrusion test on the component material to obtain the extrusion pressure-displacement curve information of the component material includes:

[0024] Multiple identical component materials are stacked along the thickness direction, and an extruder is used to perform an extrusion test on the multiple identical component materials along the thickness direction to obtain the extrusion force displacement curve information.

[0025] In one optional implementation, obtaining the extrusion stress-strain curve information based on the extrusion pressure-displacement curve information includes:

[0026] The extrusion stress-strain curve information is obtained using the following formula:

[0027] ε1=Δt / t0;

[0028] σ1=F / S;

[0029] Wherein, t0 is the initial thickness of the component material before compression, Δt is the amount of compression deformation of the component material, ε1 is the extrusion strain of the component material, S is the area of ​​the component material under pressure, F is the extrusion force of the component material during the test, and σ1 is the extrusion stress per unit area of ​​the component material.

[0030] In one optional embodiment, the step of performing a tensile test on a sample of the component material to obtain the tensile-displacement curve information of the component material includes:

[0031] A sample of the component material is obtained, and the two ends of the sample are designated as clamping parts. The clamping parts are pulled to both sides along the length direction of the electrode assembly to perform a tensile test on the sample of the component material and obtain the tensile force-displacement curve information.

[0032] In one optional implementation, obtaining tensile stress-strain curve information based on the tensile displacement curve information includes:

[0033] The tensile stress-strain curve information is obtained through the following formulas: ε2=ΔL / L0; A=(h*a*L0) / (ΔL+L0);

[0034] σ² = T / A;

[0035] Wherein, L0 is the initial length of the sample before stretching, ΔL is the tensile displacement of the sample, ε2 is the tensile strain of the sample, h is the width of the sample, α is the thickness of a single sample, A is the cross-sectional area of ​​the sample during stretching, T is the tensile force during the test of the sample, and σ2 is the tensile stress of the sample.

[0036] Secondly, this application provides a battery electrode deformation damage testing device, comprising: a first construction module, used to establish a battery finite element model under extrusion conditions, and to layer the electrode assembly along the thickness direction based on the battery finite element model to form multiple unit electrode assemblies;

[0037] The second construction module is used to perform composite material modeling on the unit pole group to obtain a composite material model.

[0038] The stress-strain experimental module is used to obtain stress-strain curve information of each component material in the unit pole group along multiple directions;

[0039] The deformation damage testing module is used to obtain deformation cloud maps of the electrode sheets at different locations based on the stress-strain curve information of each component material in the unit electrode group along multiple directions, as well as the composite material model and the battery finite element model, so as to characterize the deformation damage of the electrode sheets through the deformation cloud maps. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 is a flowchart of the battery electrode deformation and damage test method according to an embodiment of this application;

[0042] Figure 2 is a schematic diagram of the structure of the cell model and the extrusion head model under the extrusion condition in an embodiment of this application;

[0043] Figure 3 is a schematic diagram of the polar component layered structure of an embodiment of this application;

[0044] Figure 4 is a schematic diagram of the structure of the unit pole group in an embodiment of this application;

[0045] Figure 5 is a schematic diagram of the structure of the positive electrode sheet during extrusion testing according to an embodiment of this application;

[0046] Figure 6 is a schematic diagram of the structure of the sample during tensile testing according to an embodiment of this application;

[0047] Figure 7 is a diagram of the extrusion stress-strain curves of each component material in the embodiments of this application;

[0048] Figure 8 is a tensile stress-strain curve of each component material in the embodiment of this application;

[0049] Figure 9 is a schematic diagram of the functional modules of the battery electrode deformation and damage testing device according to an embodiment of this application;

[0050] Reference numerals: 10-cell model; 20-extrusion head model; 30-electrode group; 31-unit electrode group; 311-diaphragm; 312-positive electrode sheet; 313-negative electrode sheet; 40-extrusion part; 50-sample; 51-clamping part; 52-testing part; X-thickness direction; Y-length direction. Detailed Implementation

[0051] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0052] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0053] With the rapid development of the electric vehicle market, the demand for batteries is increasing daily, and battery performance and safety have received widespread attention. Among these, the deformation and damage of battery electrodes are a crucial factor affecting battery performance and safety. During battery manufacturing and use, electrodes are subjected to various external forces, such as compression, bending, and stretching. These forces can lead to electrode deformation and damage, thus affecting battery performance and safety. Therefore, studying the deformation and damage of battery electrodes under various external forces is of great significance for improving battery performance and safety. Existing methods for calculating battery electrode deformation and damage mainly rely on testing. These methods primarily involve destructive testing of the battery followed by CT scans to determine the electrode deformation and damage. However, these methods have limitations: experimental measurement methods require numerous destructive tests, are costly, and cannot achieve real-time monitoring.

[0054] In view of the above, this application provides a method for testing the deformation and damage of battery electrodes to overcome at least one of the above-mentioned technical problems.

[0055] Referring to Figure 1, in this embodiment of the application, the battery electrode deformation damage testing method includes: establishing a finite element model of the battery under extrusion conditions, and dividing the battery electrode assembly 30 into multiple unit electrode assemblies 31 along the thickness direction X based on the battery finite element model. This step can be performed using finite element analysis software to establish a geometric model of the battery in a computer and convert it into a finite element mesh. Based on the extrusion conditions, the electrode assembly 30 is divided into multiple unit electrode assemblies 31 along the thickness direction X in the battery finite element model; by analyzing each unit electrode assembly 31 in this layered manner, the deformation of the electrode sheet under extrusion conditions can be simulated more accurately.

[0056] Composite material modeling is performed on unit electrode group 31 to obtain composite material model. Composite material modeling is performed for each unit electrode group 31. Composite material modeling can consider the lamination composition of different materials, such as electrodes, diaphragms, etc., and the performance parameters of these materials can be defined.

[0057] The stress-strain curves of each component material in unit electrode assembly 31 along multiple directions are obtained. In other words, by performing finite element analysis on each component material in unit electrode assembly 31 along multiple directions, stress-strain curves of each component material along multiple directions can be obtained. This data helps to understand the deformation and stress distribution of the battery electrode in different directions.

[0058] Based on the stress-strain curves of each component material in unit electrode group 31 along multiple directions, as well as the composite material model and the battery finite element model. Specifically, the stress-strain curve information is input as parameters into the composite material model, and then the composite material model and the battery finite element model are jointly input into the finite element analysis software. Through the analysis and calculation of the software, the battery under pressure can be simulated, thereby obtaining deformation cloud maps at different locations of the electrode. These deformation cloud maps can characterize the deformation and damage of the electrode.

[0059] Referring to Figures 1 and 2, in some embodiments, the battery finite element model includes a cell model 10 and an extrusion head model 20. The extrusion head model 20 is configured to simulate the extrusion conditions corresponding to the cell model 10. The cell model 10 and extrusion head model 20 are built in finite element simulation software. The cell model 10 represents the main body of the battery. The cell model 10 can be established by importing the battery geometry into the finite element software and setting the correct material parameters and constraints. The extrusion head model 20 is established to simulate the deformation of the cell model 10 under extrusion conditions. Its geometry corresponds to that of the cell model 10 and can be selected according to actual conditions and the force and stress distribution applied to the cell during the extrusion process. The extrusion head model 20 can be established using the part assembly function in the finite element software. The extrusion condition is established by extruding the cell model 10 using the extrusion head model 20, facilitating the characterization of battery electrode deformation and damage under extrusion load through modeling and software calculations.

[0060] Referring to Figure 3, in some embodiments, the electrode assembly 30 can be simplified as a homogeneous cuboid. The total thickness of the electrode assembly 30 is defined as t. Based on the battery finite element model, the electrode assembly 30 is layered along the thickness direction X to form multiple unit electrode assemblies 31. This includes: dividing the electrode assembly 30 into n equal parts along the thickness direction X, with each part defined as a unit electrode assembly 31, satisfying n≥10. The thickness of each unit electrode assembly 31 is then t / n. Here, n can be as large as possible based on the computer's computing power to make the calculation and analysis results more accurate.

[0061] Referring to Figure 4, in some embodiments, composite material modeling is performed on the unit electrode group 31 to obtain a composite material model, including: obtaining the distribution order, thickness, and name information of each component material in the unit electrode group 31, and inputting it into the composite material model. Here, the composite material model refers to a method of setting material properties for a structure composed of multiple stacked materials in finite element software. After establishing the composite material model, it is necessary to input the distribution order, thickness, material name, and stress-strain curves of each component material in each direction, inputting specific parameter information into the composite material model to facilitate analysis and calculation by the finite element analysis software. The unit electrode group 31 can determine the top-to-bottom layering information of the corresponding component materials based on the thickness ratio of the positive and negative electrode plates and the separator. The following table is a schematic diagram of the input parameter information for the composite material model of the unit electrode group 31:

[0062] Where c is the thickness of the separator 311, a is the thickness of the positive electrode 312, and b is the thickness of the negative electrode 313. The number of layers in a single electrode group 31 is not limited to four; only a schematic table is provided here. The order, thickness, and material name of the component materials can be entered according to the actual situation. The sum of the thicknesses of all separators 311, positive electrode 312, and negative electrode 313 in a single electrode group 31 is t / n.

[0063] Referring to Figures 5, 6, 7, and 8, in some embodiments, obtaining stress-strain curve information of each component material in unit pole group 31 along multiple directions includes: performing an extrusion test on the component material to obtain the extrusion pressure-displacement curve information of the component material. The extrusion test is a common material performance testing method used to evaluate the performance of materials under extrusion loading. In the extrusion test, a force perpendicular to the surface of the component material is applied to cause extrusion deformation in the thickness direction X, and the changes in extrusion pressure and displacement are recorded. This data can be used to plot the extrusion pressure-displacement curve to understand the material's extrusion behavior. Based on the extrusion pressure-displacement curve information, extrusion stress-strain curve information can be obtained. Based on the extrusion pressure-displacement curve information, the extrusion stress-strain curve information can be further solved. The extrusion stress is given by the ratio of the material's extrusion pressure to the area under force, while the extrusion strain is given by the ratio of the material's displacement to its initial size. By plotting the relationship between extrusion stress (exptrusion pressure divided by area under force) and extrusion strain (displacement divided by initial size), the extrusion stress-strain curve information can be obtained.

[0064] A tensile test is performed on sample 50 of the component material to obtain the tensile-displacement curve information of the component material. Tensile testing is a common material performance testing method used to evaluate the performance of materials under tensile loading. In the tensile test, two clamps apply tensile force to sample 50, causing it to be stretched and deformed. The tensile test obtains the tensile-displacement curve information by recording the changes in tensile force and displacement. Based on the tensile-displacement curve information, the tensile stress-strain curve information is obtained. Tensile stress can be given by the ratio of tensile force to the cross-sectional area under force, while tensile strain can be given by the ratio of displacement to the initial size. By plotting the relationship between tensile stress (tensile force divided by cross-sectional area under force) and tensile strain (displacement divided by initial size), the tensile stress-strain curve information can be obtained.

[0065] Referring to Figures 5 and 7, in some embodiments, an extrusion test is performed on the component materials to obtain the extrusion pressure-displacement curve information of the component materials. This includes: stacking multiple identical component materials along the thickness direction X, and using an extruder 40 to extrude the multiple identical component materials along the thickness direction X to obtain the extrusion pressure-displacement curve information. Alternatively, a multi-layered component material can be placed on one of the extruders 40, and another extruder 40 can be used to extrude the multi-layered component material along the thickness direction X. The extrusion pressure-displacement curve reflects the mechanical behavior of the entire stacked material under extrusion loading. In the experiment, a synchronous measurement method can be used, by installing appropriate force sensors and displacement sensors on the extruder 40 to record the extrusion pressure and corresponding displacement data of the multi-layered component material in real time during the extrusion process. The extrusion pressure is gradually increased, and the changes in extrusion pressure and displacement are observed and recorded to obtain the extrusion pressure-displacement curve information.

[0066] In the test, a synchronous measurement method can be used. By installing appropriate force and displacement sensors on the extruder 40, the extrusion pressure and corresponding displacement data of the laminated material during the extrusion process can be recorded in real time. The extrusion pressure is gradually increased, and the changes in extrusion pressure and displacement are observed and recorded to obtain extrusion pressure-displacement curve information.

[0067] Please refer to Figures 5 and 7. In some embodiments, the extrusion stress-strain curve information is obtained based on the extrusion pressure-displacement curve information, including obtaining the extrusion stress-strain curve information using the following formula:

[0068] ε1=Δt / t0;

[0069] σ1=F / S;

[0070] Where t0 is the initial thickness of the component material before compression, Δt is the compression deformation of the component material, ε1 is the extrusion strain of the component material, S is the pressure area of ​​the component material, F is the extrusion force during the test, and σ1 is the extrusion stress per unit area of ​​the component material. By substituting the extrusion force-displacement curve information into the formula for calculation, the extrusion stress-strain curve information can be obtained.

[0071] Referring to Figures 6 and 8, in some embodiments, a tensile test is performed on a sample 50 of the component material to obtain the tensile-displacement curve information of the component material. This includes: acquiring the sample 50 of the component material, calibrating both ends of the sample 50 as clamping portions 51, and pulling the clamping portions 51 to both sides along the length direction Y of the electrode assembly 30 to perform a tensile test on the sample 50 of the component material, detecting the deformation and tensile force of the testing portion 52, and obtaining the tensile-displacement curve information of the testing portion 52. A tensile clamp can be connected to the corresponding clamping portion 51 to ensure that the sample 50 remains stable during the test and does not fall off. During the test, the clamping portions 51 can be positioned at both ends of the sample 50, and then a tensile force is applied to induce the extension and deformation of the sample 50. Simultaneously, force sensors and displacement sensors can be installed on the clamp for data acquisition. The tensile force can be gradually increased, and the tensile force and displacement data of the sample 50 are recorded. This allows the acquisition of tensile-displacement curve information, thereby understanding the mechanical behavior and performance characteristics of the sample 50 under tensile loading.

[0072] Please refer to Figures 6 and 8. In some embodiments, tensile stress-strain curve information is obtained based on tensile displacement curve information, including obtaining tensile stress-strain curve information through the following formulas: ε2=ΔL / L0; A=(h*a*L0) / (ΔL+L0); σ2=T / A;

[0073] Where L0 is the initial length of sample 50 before stretching, ΔL is the tensile displacement of sample 50, ε2 is the tensile strain of sample 50, h is the width of sample 50, α is the thickness of a single sample 50, A is the cross-sectional area of ​​sample 50 during stretching, T is the tensile force of sample 50 during testing, and σ2 is the tensile stress of sample 50.

[0074] By substituting the tensile force-displacement curve information into the formula for calculation, the tensile stress-strain curve information can be obtained.

[0075] Referring to Figure 4, in some embodiments, the components of the unit electrode assembly 31 include a positive electrode 312, a negative electrode 313, and a separator 311, with the separator 311 positioned between the positive electrode 312 and the negative electrode 313. The separator 311 serves to isolate the ion transport between the positive electrode 312 and the negative electrode 313. The separator 311 is typically made of an electrolyte-impregnated polymer material or a ceramic material, which can prevent short circuits between the positive and negative electrodes while promoting ion transport in the battery and maintaining stable battery operation. Of course, the components of each unit electrode assembly 31 may not only include these three materials; other materials may also be present. When establishing a composite material model, the parameter information of other materials needs to be included.

[0076] Please refer to Figure 9. A battery electrode deformation damage testing device includes a first building module, a second building module, a stress-strain experiment module, and a deformation damage testing module. The first building module is used to establish a finite element model of the battery under extrusion conditions, and based on the battery finite element model, the electrode assembly 30 is layered along the thickness direction X to form multiple unit electrode assemblies 31. The second building module is connected to the first building module and is used to perform composite material modeling on the unit electrode assemblies 31 in the first building module to obtain a composite material model. The stress-strain experiment module is connected to the second building module and is used to obtain stress-strain curve information of each component material in the unit electrode assembly 31 along multiple directions. The deformation damage testing module is connected to the first building module, the second building module, and the stress-strain experiment module respectively, and is used to obtain deformation cloud maps of the electrode at different locations based on the stress-strain curve information of each component material in the unit electrode assembly 31 along multiple directions, as well as the composite material model and the battery finite element model, so as to characterize the deformation damage of the electrode through the deformation cloud maps.

[0077] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0078] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents. Industrial applicability

[0079] This application establishes a finite element model of the battery and a composite material model under extrusion conditions, which can simulate the battery under pressure, calculate and output deformation cloud maps at different positions of the battery electrode, and characterize the deformation and damage of the battery electrode in real time.

Claims

1. A method for testing deformation damage of a battery electrode sheet, characterized by, include: A finite element model of the battery under extrusion conditions is established, and the electrode assembly is layered along the thickness direction based on the finite element model of the battery to form multiple unit electrode assemblies. The unit pole group is modeled as a composite material to obtain a composite material model; Obtain stress-strain curve information of each component material in the unit pole group along multiple directions; Based on the stress-strain curves of each component material in the unit electrode group along multiple directions, as well as the composite material model and the battery finite element model, deformation cloud maps of the electrode at different locations are obtained to characterize the deformation damage of the electrode through the deformation cloud maps.

2. The battery electrode sheet deformation damage test method according to claim 1, characterized by, The battery finite element model includes a cell model and an extrusion head model, wherein the extrusion head model is configured to simulate the extrusion conditions corresponding to the cell model.

3. The battery electrode sheet deformation damage test method according to claim 1, characterized by, The method of layering the electrode assembly along the thickness direction based on the battery finite element model to form multiple unit electrode assemblies includes: Along the thickness direction, the pole group is divided into n equal parts, and each part is determined as a unit pole group, satisfying: n≥10.

4. The battery electrode sheet deformation damage test method according to claim 1, characterized by, The step of performing composite material modeling on the unit pole group to obtain a composite material model includes: Obtain the distribution order, thickness, and name information of each component material in the unit pole group to input into the composite material model.

5. The battery electrode sheet distortion damage test method according to claim 1, characterized by, The step of obtaining stress-strain curve information of each component material in the unit pole group along multiple directions includes: The component material is subjected to an extrusion test to obtain the extrusion force-displacement curve information of the component material; Based on the extrusion pressure-displacement curve information, extrusion stress-strain curve information is obtained; Tensile tests were performed on samples of the component material to obtain tensile force-displacement curve information of the component material; Based on the tensile force-displacement curve information, tensile stress-strain curve information is obtained.

6. The battery electrode sheet deformation damage test method according to claim 5, characterized by, The step of performing an extrusion test on the component material to obtain the extrusion pressure-displacement curve information of the component material includes: Multiple identical component materials are stacked along the thickness direction, and an extruder is used to perform an extrusion test on the multiple identical component materials along the thickness direction to obtain the extrusion force displacement curve information.

7. The battery electrode sheet deformation damage test method according to claim 5, characterized by, The step of obtaining the extrusion stress-strain curve information based on the extrusion pressure-displacement curve information includes: The extrusion stress-strain curve information is obtained using the following formula: ε1=Δt / t0; σ1=F / S; Wherein, t0 is the initial thickness of the component material before compression, Δt is the amount of compression deformation of the component material, ε1 is the extrusion strain of the component material, S is the area of ​​the component material under pressure, F is the extrusion force of the component material during the test, and σ1 is the extrusion stress per unit area of ​​the component material.

8. The battery electrode sheet deformation damage test method according to claim 5, characterized by, The step of performing a tensile test on a sample of the component material to obtain the tensile-displacement curve information of the component material includes: A sample of the component material is obtained, and the two ends of the sample are designated as clamping parts. The clamping parts are pulled to both sides along the length direction of the electrode assembly to perform a tensile test on the sample of the component material and obtain the tensile force-displacement curve information.

9. The battery electrode sheet distortion damage test method according to claim 5, characterized by, The step of obtaining tensile stress-strain curve information based on the tensile displacement curve information includes: The tensile stress-strain curve information is obtained by the following formula: ε2=ΔL / L0; A=(h*a*L0) / (ΔL+L0); σ2=T / A; Wherein, L0 is the initial length of the sample before stretching, ΔL is the stretching displacement of the sample, ε2 is the tensile strain of the sample, h is the width of the sample, ɑ is the thickness of a single sample, A is the cross-sectional area during the stretching of the sample, T is the tension during the testing of the sample, and σ2 is the tensile stress of the sample.

10. A battery electrode sheet deformation damage testing device characterized by, Comprise: A first construction module for establishing a battery finite element model under extrusion conditions, and layering the pole group along the thickness direction based on the battery finite element model to form a plurality of unit pole groups; A second construction module for modeling the unit pole group as a composite material to obtain a composite material model; A stress-strain experiment module for obtaining stress-strain curve information of each component material in the unit pole group along multiple directions; A deformation damage testing module for obtaining a deformation cloud map of the pole piece at different positions based on the stress-strain curve information of each component material in the unit pole group along multiple directions, and the composite material model and the battery finite element model, so as to characterize the deformation damage of the pole piece through the deformation cloud map.

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