Method, system and equipment for testing battery adhesive

Abstract

The invention discloses a battery adhesive testing method, system and equipment, and the method comprises the steps: constructing a multi-layer composite test sample containing a to-be-tested adhesive based on the structure position of the to-be-tested adhesive in a battery, and carrying out the tensile test and shear test of the multi-layer composite test sample, obtaining a tensile test force-displacement curve and a shear test force-displacement curve; obtaining a tensile property parameter of the adhesive to be tested according to the tensile test force-displacement curve, and obtaining a shear property parameter of the adhesive to be tested according to the shear test force-displacement curve; constructing a cohesive force model corresponding to the to-be-tested adhesive according to the tensile property parameters and the shear property parameters, and performing failure simulation on the to-be-tested adhesive according to the cohesive force model; the rigidity damage coefficient and the fracture energy of the to-be-tested adhesive are calculated according to the failure simulation, the failure test result of the to-be-tested adhesive is obtained according to the rigidity damage coefficient and the fracture energy, and the failure test accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a method, system and equipment for testing battery adhesive. Background Art

[0002] Adhesion is a common connection method used in battery production and manufacturing. Adhesives are typically used to bond aluminum-plastic films to the back of battery cells. Before using an adhesive, it's often necessary to assess its bond strength to ensure battery safety.

[0003] Prior art uses battery drop simulations or heavy object impact simulations to determine the adhesive performance of adhesives. During these failure simulations, prior art adhesives typically use linear elastic constitutive and double-sided binding methods to test and analyze adhesives.

[0004] However, when testing and analyzing the adhesive using the above method, the adhesive will experience tensile failure and shear failure in the thickness direction, which will affect the stress distribution and stiffness distribution of the adhered parts, causing unrealistic stress and deformation in the core copper and aluminum foil. It is impossible to truly simulate the shear slip phenomenon in the adhesive area, and the failure and shedding of the adhesive cannot be taken into account, and thus it is impossible to accurately obtain the test results of the adhesive. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention discloses a battery adhesive testing method, system and equipment for performing failure test evaluation on the adhesive, thereby improving the accuracy of adhesive testing.

[0006] To achieve the above objectives, in a first aspect, the present invention discloses a method for testing a battery adhesive, comprising:

[0007] Based on the structural position of the adhesive to be tested inside the battery, construct a multi-layer composite test sample containing the adhesive to be tested;

[0008] Performing a tensile test and a shear test on the multi-layer composite test sample respectively to obtain a tensile test force-displacement curve and a shear test force-displacement curve corresponding to the multi-layer composite test sample;

[0009] Obtaining the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and obtaining the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve;

[0010] constructing a cohesion model corresponding to the adhesive to be tested according to the tensile performance parameters and the shear performance parameters, and performing failure simulation on the adhesive to be tested according to the cohesion model;

[0011] The stiffness damage coefficient and the fracture energy of the adhesive to be tested are calculated according to the failure simulation, so as to obtain a failure test result of the adhesive to be tested according to the stiffness damage coefficient and the fracture energy.

[0012] The present invention discloses a method for testing battery adhesives. The method performs tensile and shear tests on a multi-layer composite test specimen containing the adhesive to be tested, thereby providing tensile performance parameters and the shear performance parameters for the cohesion model corresponding to the adhesive to be tested, thereby improving the accuracy of subsequent simulations and obtaining accurate failure test results. A multi-layer composite test specimen containing the adhesive to be tested is constructed based on the structural position of the adhesive to be tested inside the battery, so as to improve the accuracy of the test based on the multi-layer composite test specimen fitting the actual working conditions of the adhesive to be tested inside the battery. Subsequently, tensile and shear tests are performed on the multi-layer composite test specimen respectively, so as to construct the cohesion model corresponding to the adhesive to be tested based on the obtained tensile and shear performance parameters, thereby improving the accuracy of the cohesion model, improving the accuracy of the failure simulation based on the cohesion model, and improving the accuracy of the adhesive test. Finally, the stiffness damage coefficient and fracture energy calculated by simulation are used to perform a failure assessment on the adhesive to be tested, thereby improving the accuracy of the failure test of the adhesive to be tested.

[0013] As a preferred example, the method of constructing a multi-layer composite test sample containing the adhesive to be tested based on the structural position of the adhesive to be tested inside the battery includes:

[0014] Determining the structural position of the adhesive to be tested inside the battery according to the type of the adhesive to be tested;

[0015] When the adhesive to be tested is a hot melt adhesive, the aluminum-plastic film and the positive electrode current collector are cut from the battery cell shell, and the adhesive to be tested is applied to the bonding area of ​​the aluminum-plastic film and the positive electrode current collector to form a multi-layer composite test sample with a sandwich structure;

[0016] When the adhesive to be tested is a battery cell adhesive, the aluminum-plastic film is cut from the battery cell shell, and the adhesive to be tested is applied to the outer wall of the aluminum-plastic film to form the multi-layer composite test sample.

[0017] In the above scheme, the use position of the adhesive to be tested inside the battery is determined according to the type of the adhesive to be tested. For example, when the type of the adhesive to be tested is hot melt adhesive, it can be determined that the hot melt adhesive forms a sandwich structure with the aluminum-plastic film and the positive electrode current collector inside the battery, and then a multi-layer composite test sample with the same sandwich structure is constructed. When the type of the adhesive to be tested is the battery cell back glue, it can be determined that the battery cell back glue is bonded to the aluminum-plastic film inside the battery, and then the aluminum-plastic film and the adhesive to be tested are used to form a multi-layer composite test sample consistent with the internal structure of the battery, so as to improve the accuracy of the test by testing with a multi-layer composite test sample consistent with the actual working conditions of the battery.

[0018] As a preferred example, the performing of a tensile test and a shear test on the multi-layer composite test specimen respectively to obtain a tensile test force-displacement curve and a shear test force-displacement curve corresponding to the multi-layer composite test specimen includes:

[0019] Stretching the adhesive to be tested along the thickness direction of the adhesive to be tested according to a preset tensile test rate to obtain a tensile test force-displacement curve corresponding to the multi-layer composite test sample;

[0020] The adhesive to be tested is stretched along the extension direction of the adhesive to be tested according to the stretching test rate to obtain a shear test force-displacement curve corresponding to the multi-layer composite test sample.

[0021] In the above scheme, considering that the tensile failure and shear failure of the adhesive in the thickness direction will affect the stress distribution and stiffness distribution of the adhered parts, the multi-layer composite test specimen is subjected to a tensile test along the upper and lower ends of the adhesive at a constant tensile test rate to simulate the tensile failure, and the multi-layer composite test specimen is subjected to a shear test along the left and right ends of the adhesive at a constant tensile test rate to simulate the shear failure, thereby obtaining the tensile test force-displacement curve and the shear test force-displacement curve to provide accurate data for subsequent failure simulation, thereby improving the accuracy of the test.

[0022] As a preferred example, the method of obtaining the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and obtaining the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve includes:

[0023] Obtaining a maximum tensile traction force and a tensile displacement corresponding to the maximum tensile traction force from the tensile test force-displacement curve;

[0024] Obtaining a maximum shear traction force and a shear displacement corresponding to the maximum shear traction force from the shear test force-displacement curve;

[0025] Calculating the tensile initial damage stiffness, elastic modulus, and tensile fracture energy of the adhesive to be tested based on the maximum tensile traction force, the tensile displacement, and the thickness of the adhesive to be tested in the multi-layer composite test specimen;

[0026] The shear initial damage stiffness, shear modulus and shear fracture energy of the adhesive to be tested are calculated according to the maximum shear traction force, the shear displacement and the thickness of the adhesive to be tested in the multi-layer composite test specimen.

[0027] In the above scheme, the damage stiffness, elastic modulus, tensile fracture energy, shear modulus and shear fracture energy of the adhesive to be tested during the tensile process or shear process are calculated by the traction force and displacement in the test curve, so as to improve the accuracy and efficiency of obtaining the performance of the adhesive to be tested, thereby improving the efficiency and accuracy of adhesive testing.

[0028] As a preferred example, the method of obtaining the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and obtaining the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve includes:

[0029] The maximum tensile traction force and the tensile displacement or the maximum shear traction force and the maximum shear displacement are input into a pre-constructed initial damage stiffness calculation function to obtain the tensile initial damage stiffness or the shear initial damage stiffness; wherein, the calculation expression of the initial damage stiffness calculation function is:

[0030] σ=N / δ

[0031] Wherein, σ represents the output initial damage stiffness, which is the tensile initial damage stiffness or the shear initial damage stiffness; N represents the input traction force, which is the maximum tensile traction force or the maximum shear traction force; δ represents the input displacement, which is the tensile displacement or the shear displacement;

[0032] The initial tensile displacement in the tensile test force-displacement curve and the initial shear displacement in the shear test force-displacement curve are obtained, and the tensile initial damage stiffness, the initial tensile displacement, and the thickness or the shear initial damage stiffness, the initial shear displacement, and the thickness are input into a pre-established modulus calculation function to obtain the elastic modulus or the shear modulus; wherein the calculation expression of the modulus calculation function is:

[0033] E=σ / [(σ-δ min ) / h]

[0034] Wherein, the E represents the output modulus, which is the elastic modulus or the shear modulus; the δmin represents the input initial displacement, the initial displacement being the initial tensile displacement or the initial shear displacement; h represents the thickness;

[0035] The maximum tensile displacement in the tensile test force-displacement curve and the maximum shear displacement in the shear test force-displacement curve are obtained, and the maximum tensile displacement and the initial tensile displacement or the maximum shear displacement and the initial shear displacement are input into a pre-constructed fracture energy function to obtain the tensile fracture energy or the shear fracture energy; wherein the calculation expression of the fracture energy function is:

[0036] G=0.5*(δ max -δ min )

[0037] Wherein, G represents the output fracture energy, and the fracture energy is the tensile fracture energy or the shear fracture energy; max represents the maximum displacement of the input, where the maximum displacement is the maximum tensile displacement or the maximum shear displacement.

[0038] In the above scheme, by presetting various functions to realize the automatic acquisition of various performance parameters, such as tensile initial damage stiffness, elastic modulus, tensile fracture energy, etc., the accuracy and efficiency of parameter acquisition can be improved, thereby improving the efficiency and accuracy of the test.

[0039] As a preferred example, constructing a cohesion model corresponding to the adhesive to be tested according to the tensile performance parameters and the shear performance parameters, and performing failure simulation on the adhesive to be tested according to the cohesion model includes:

[0040] Constructing a cohesion constitutive model corresponding to the adhesive to be tested according to the tensile initial damage stiffness, the tensile fracture energy, the elastic modulus, the shear initial damage stiffness, the shear fracture energy and the shear modulus;

[0041] Establishing a double-sided binding contact relationship between the adhesive to be tested and the adherend, and establishing a multi-level simulation structure of the battery and a binding connection relationship between the simulation structures of two adjacent levels;

[0042] A cohesion model corresponding to the adhesive to be tested is constructed based on the cohesion constitutive model, the double-sided binding contact relationship, and the binding connection relationship at the multi-level simulation structure level, so as to perform failure simulation based on the cohesion model; wherein, the failure simulation includes drop simulation and heavy object impact simulation.

[0043] In the above scheme, the parameters of the adhesive cohesion model are fitted based on the various performance parameters obtained during the tensile test to improve the model's accuracy. By establishing the double-sided binding contact relationship between the adhesive and the adherend, as well as the binding connection relationship between various internal battery components such as the current collector, cell coating, and electrode, the accuracy of the ultimately constructed cohesion model is improved based on these parameters and connection relationships. This, in turn, improves the accuracy of failure simulations using this model.

[0044] As a preferred example, the calculating of the stiffness damage coefficient and the fracture energy of the adhesive to be tested according to the failure simulation, so as to obtain the failure test result of the adhesive to be tested according to the stiffness damage coefficient and the fracture energy, includes:

[0045] Obtaining a simulated displacement of the adhesive to be tested in the failure simulation;

[0046] Calculating the simulated stiffness damage coefficient and the simulated fracture energy of the adhesive to be tested according to the simulated displacement and the pre-constructed test curve; wherein the test curve is the tensile test force-displacement curve or the shear test force-displacement curve;

[0047] Calculating a simulated stiffness damage coefficient and a simulated fracture energy of the adhesive to be tested according to the test curve and the simulated displacement;

[0048] Obtaining a first comparison result of the simulated stiffness damage coefficient and a preset coefficient threshold and a second comparison result of the simulated fracture energy and a preset energy threshold;

[0049] The failure mode of the adhesive to be tested is determined according to the first comparison result and the second comparison result.

[0050] In the above scheme, the simulated displacement of the adhesive in each failure simulation is obtained, and the stiffness damage coefficient and simulated fracture energy of the adhesive in the current failure simulation are calculated based on the simulated displacement and the pre-constructed test curve, and then the failure mode of the adhesive to be tested is accurately evaluated based on the stiffness damage coefficient and simulated fracture energy.

[0051] As a preferred example, the calculating of the stiffness damage coefficient and fracture energy of the adhesive to be tested according to the failure simulation includes:

[0052] Obtaining the maximum displacement, initial displacement, maximum traction force, and displacement corresponding to the maximum traction force in the test curve;

[0053] The maximum displacement, the displacement corresponding to the maximum traction force, and the simulated displacement are input into a pre-constructed simulated stiffness damage coefficient function to obtain the simulated stiffness damage coefficient of the adhesive to be tested; wherein the calculation expression of the simulated stiffness damage coefficient function is:

[0054] D=[δ max *(δ new -δ s )] / [δ new *(δ max -δ s )]

[0055] Wherein, D represents the simulated stiffness damage coefficient; δ new represents the simulated displacement; the δ s represents the displacement corresponding to the maximum traction force;

[0056] The maximum displacement, the displacement corresponding to the maximum traction force, the simulated displacement, and the maximum traction force are input into a pre-constructed simulated fracture energy function to obtain the simulated fracture energy of the adhesive to be tested; wherein the calculation expression of the simulated fracture energy function is:

[0057] G IC =[δ new *(δ max -δ s )+δ max *(δ new -δ s )*N] / [2*(δ max -δ s )]

[0058] Among them, the G IC represents the simulated fracture energy.

[0059] In the above scheme, by presetting various functions to achieve automatic acquisition of simulation results, the accuracy and efficiency of simulation calculations can be improved, thereby improving the efficiency and accuracy of testing.

[0060] In a second aspect, the present invention discloses a battery adhesive testing system, including a sample building module, a tensile shear testing module, a performance extraction module, a failure simulation module, and a failure assessment module;

[0061] The sample building module is used to build a multi-layer composite test sample containing the adhesive to be tested based on the structural position of the adhesive to be tested inside the battery;

[0062] The tensile and shear test module is used to perform a tensile test and a shear test on the multi-layer composite test sample, respectively, to obtain a tensile test force-displacement curve and a shear test force-displacement curve corresponding to the multi-layer composite test sample;

[0063] The performance extraction module is used to obtain the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and to obtain the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve;

[0064] The failure simulation module is used to construct a cohesion model corresponding to the adhesive to be tested according to the tensile performance parameters and the shear performance parameters, and perform failure simulation on the adhesive to be tested according to the cohesion model;

[0065] The failure assessment module is used to calculate the stiffness damage coefficient and fracture energy of the adhesive to be tested according to the failure simulation, so as to obtain a failure test result of the adhesive to be tested according to the stiffness damage coefficient and fracture energy.

[0066] The present invention discloses a battery adhesive testing system that performs tensile and shear tests on a multi-layer composite test specimen containing the adhesive to be tested, thereby providing tensile performance parameters and the shear performance parameters for the cohesion model corresponding to the adhesive to be tested, thereby improving the accuracy of subsequent simulations and obtaining accurate failure test results. A multi-layer composite test specimen containing the adhesive to be tested is constructed based on the structural position of the adhesive to be tested inside the battery, so that the multi-layer composite test specimen is fitted to the actual working conditions of the adhesive to be tested inside the battery, thereby improving the accuracy of the test. Subsequently, tensile and shear tests are performed on the multi-layer composite test specimen, respectively, so that the cohesion model corresponding to the adhesive to be tested is constructed based on the obtained tensile and shear performance parameters, thereby improving the accuracy of the cohesion model, improving the accuracy of the failure simulation based on the cohesion model, and improving the accuracy of the adhesive test. Finally, the stiffness damage coefficient and fracture energy calculated by simulation are used to perform a failure assessment on the adhesive to be tested, thereby improving the accuracy of the failure test of the adhesive to be tested.

[0067] In a third aspect, the present invention discloses a terminal device comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a battery adhesive testing method as described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0069] Figure 1 1 is a flow chart of a method for testing a battery adhesive provided by an embodiment of the present invention;

[0070] Figure 2 1 is a schematic structural diagram of a battery adhesive testing system provided by an embodiment of the present invention;

[0071] Figure 3 1 is a flow chart of a method for testing a battery adhesive provided by another embodiment of the present invention;

[0072] Figure 4 is a schematic diagram of a tensile test based on a clamping tool provided by another embodiment of the present invention;

[0073] Figure 5 This is a schematic diagram of a shear test based on a clamping tool provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0074] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0075] Example 1

[0076] Reference Figure 1 To address the problem in the prior art of being unable to accurately test the failure of adhesives in batteries, this embodiment provides a battery adhesive testing method to accurately evaluate the failure mode of battery adhesives. Specifically, the testing method includes:

[0077] Step 101: Based on the structural position of the adhesive to be tested inside the battery, construct a multi-layer composite test sample containing the adhesive to be tested.

[0078] In this embodiment, this step mainly includes: determining the structural position of the adhesive to be tested inside the battery according to the type of the adhesive to be tested; when the adhesive to be tested is a hot melt adhesive, cutting the aluminum-plastic film and the positive electrode current collector from the battery cell shell, and applying the adhesive to be tested to the bonding area of ​​the aluminum-plastic film and the positive electrode current collector to form a multi-layer composite test sample with a sandwich structure; when the adhesive to be tested is a battery cell backing adhesive, cutting the aluminum-plastic film from the battery cell shell, and applying the adhesive to be tested to the outer wall of the aluminum-plastic film to form the multi-layer composite test sample.

[0079] In this embodiment, the above steps determine the usage position of the adhesive to be tested inside the battery according to the type of the adhesive to be tested. For example, when the type of the adhesive to be tested is hot melt adhesive, it can be determined that the hot melt adhesive forms a sandwich structure with the hot melt adhesive in the middle with the aluminum-plastic film and the positive electrode current collector inside the battery, and then a multi-layer composite test sample identical to the sandwich structure is constructed. When the type of the adhesive to be tested is the battery cell back glue, it can be determined that the battery cell back glue is bonded to the aluminum-plastic film inside the battery, and then the aluminum-plastic film and the adhesive to be tested are used to form a multi-layer composite test sample consistent with the internal structure of the battery, so as to improve the accuracy of the test by testing with a multi-layer composite test sample consistent with the actual operating conditions of the battery.

[0080] Step 102: performing a tensile test and a shear test on the multi-layer composite test specimen respectively to obtain a tensile test force-displacement curve and a shear test force-displacement curve corresponding to the multi-layer composite test specimen.

[0081] In this embodiment, this step mainly includes: stretching the adhesive to be tested along the thickness direction of the adhesive to be tested according to a preset tensile test rate to obtain a tensile test force-displacement curve corresponding to the multi-layer composite test sample; stretching the adhesive to be tested along the extension direction of the adhesive to be tested according to the tensile test rate to obtain a shear test force-displacement curve corresponding to the multi-layer composite test sample.

[0082] In this embodiment, the above steps take into account that the tensile failure and shear failure of the adhesive in the thickness direction will affect the stress distribution and stiffness distribution of the adhered parts. Therefore, the multi-layer composite test specimen is subjected to a tensile test along the upper and lower ends of the adhesive at a constant tensile test rate to simulate the tensile failure, and the multi-layer composite test specimen is subjected to a shear test along the left and right ends of the adhesive at the constant tensile test rate to simulate the shear failure, thereby obtaining a tensile test force-displacement curve and a shear test force-displacement curve to provide accurate data for subsequent failure simulation, thereby improving the accuracy of the test.

[0083] Step 103: obtaining the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and obtaining the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve.

[0084] In this embodiment, this step mainly includes: obtaining the maximum tensile traction and the tensile displacement corresponding to the maximum tensile traction from the tensile test force-displacement curve; obtaining the maximum shear traction and the shear displacement corresponding to the maximum shear traction from the shear test force-displacement curve; calculating the tensile initial damage stiffness, elastic modulus and tensile fracture energy of the adhesive to be tested based on the maximum tensile traction, the tensile displacement and the thickness of the adhesive to be tested in the multi-layer composite test specimen; calculating the shear initial damage stiffness, shear modulus and shear fracture energy of the adhesive to be tested based on the maximum shear traction, the shear displacement and the thickness of the adhesive to be tested in the multi-layer composite test specimen.

[0085] The maximum tensile traction force and the tensile displacement or the maximum shear traction force and the maximum shear displacement are input into a pre-constructed initial damage stiffness calculation function to obtain the tensile initial damage stiffness or the shear initial damage stiffness; wherein the calculation expression of the initial damage stiffness calculation function is:

[0086] σ=N / δ

[0087] Wherein, σ represents the output initial damage stiffness, which is the tensile initial damage stiffness or the shear initial damage stiffness; N represents the input traction force, which is the maximum tensile traction force or the maximum shear traction force; δ represents the input displacement, which is the tensile displacement or the shear displacement;

[0088] The initial tensile displacement in the tensile test force-displacement curve and the initial shear displacement in the shear test force-displacement curve are obtained, and the tensile initial damage stiffness, the initial tensile displacement, and the thickness or the shear initial damage stiffness, the initial shear displacement, and the thickness are input into a pre-established modulus calculation function to obtain the elastic modulus or the shear modulus; wherein the calculation expression of the modulus calculation function is:

[0089] E=σ / [(σ-δ min ) / h]

[0090] Wherein, the E represents the output modulus, which is the elastic modulus or the shear modulus; the δ min represents the input initial displacement, the initial displacement being the initial tensile displacement or the initial shear displacement; h represents the thickness;

[0091] The maximum tensile displacement in the tensile test force-displacement curve and the maximum shear displacement in the shear test force-displacement curve are obtained, and the maximum tensile displacement and the initial tensile displacement or the maximum shear displacement and the initial shear displacement are input into a pre-constructed fracture energy function to obtain the tensile fracture energy or the shear fracture energy; wherein the calculation expression of the fracture energy function is:

[0092] G=0.5*(δ max -δ min )

[0093] Wherein, G represents the output fracture energy, and the fracture energy is the tensile fracture energy or the shear fracture energy; max represents the maximum displacement of the input, where the maximum displacement is the maximum tensile displacement or the maximum shear displacement.

[0094] In this embodiment, the above steps calculate the damage stiffness, elastic modulus, tensile fracture energy, shear modulus, and shear fracture energy of the adhesive under test during the tensile or shear process using the traction force and displacement in the test curve, thereby improving the accuracy and efficiency of obtaining the properties of the adhesive under test, thereby improving the efficiency and accuracy of adhesive testing. Specifically, by presetting various functions to automatically obtain various performance parameters, such as tensile initial damage stiffness, elastic modulus, and tensile fracture energy, the accuracy and efficiency of parameter acquisition can be improved, thereby improving the efficiency and accuracy of testing.

[0095] Step 104: constructing a cohesion model corresponding to the adhesive to be tested according to the tensile performance parameters and the shear performance parameters, and performing failure simulation on the adhesive to be tested according to the cohesion model.

[0096] In this embodiment, this step mainly includes: constructing a cohesion constitutive model corresponding to the adhesive to be tested based on the tensile initial damage stiffness, the tensile fracture energy, the elastic modulus, the shear initial damage stiffness, the shear fracture energy and the shear modulus; establishing a double-sided binding contact relationship between the adhesive to be tested and the adhered part, and establishing a multi-level simulation structure of the battery and a binding connection relationship between the simulation structures at two adjacent levels; constructing a cohesion model corresponding to the adhesive to be tested based on the cohesion constitutive model, the double-sided binding contact relationship, and the binding connection relationship at the multi-level simulation structure level, so as to perform failure simulation according to the cohesion model; wherein, the failure simulation includes drop simulation and heavy object impact simulation.

[0097] In this embodiment, the above steps fit the parameters of the adhesive cohesion model based on the various performance parameters obtained during the tensile test to improve the model's accuracy. By establishing the double-sided binding contact relationship between the adhesive and the adherend, as well as the binding connection relationship between various internal battery components such as the current collector, cell coating, and electrode, the accuracy of the ultimately constructed cohesion model is improved based on these parameters and connection relationships. This, in turn, improves the accuracy of failure simulations using this model.

[0098] Step 105: Calculate the stiffness damage coefficient and fracture energy of the adhesive to be tested according to the failure simulation, so as to obtain a failure test result of the adhesive to be tested according to the stiffness damage coefficient and fracture energy.

[0099] In this embodiment, this step mainly includes: obtaining the simulated displacement of the adhesive to be tested in the failure simulation; calculating the simulated stiffness damage coefficient and simulated fracture energy of the adhesive to be tested based on the simulated displacement and the pre-constructed test curve; wherein, the test curve is the tensile test force-displacement curve or the shear test force-displacement curve; calculating the simulated stiffness damage coefficient and simulated fracture energy of the adhesive to be tested based on the test curve and the simulated displacement; obtaining a first comparison result of the simulated stiffness damage coefficient and a preset coefficient threshold and a second comparison result of the simulated fracture energy and a preset energy threshold; determining the failure mode of the adhesive to be tested based on the first comparison result and the second comparison result.

[0100] wherein, obtaining the maximum displacement, initial displacement, maximum traction force and the displacement corresponding to the maximum traction force in the test curve;

[0101] The maximum displacement, the displacement corresponding to the maximum traction force, and the simulated displacement are input into a pre-constructed simulated stiffness damage coefficient function to obtain the simulated stiffness damage coefficient of the adhesive to be tested; wherein the calculation expression of the simulated stiffness damage coefficient function is:

[0102] D=[δ max *(δ new -δ s )] / [δ new *(δ max -δ s )]

[0103] Wherein, D represents the simulated stiffness damage coefficient; δ new represents the simulated displacement; the δ s represents the displacement corresponding to the maximum traction force;

[0104] The maximum displacement, the displacement corresponding to the maximum traction force, the simulated displacement, and the maximum traction force are input into a pre-constructed simulated fracture energy function to obtain the simulated fracture energy of the adhesive to be tested; wherein the calculation expression of the simulated fracture energy function is:

[0105] G IC =[δ new *(δ max -δ s )+δ max *(δ new -δ s )*N] / [2*(δ max -δ s )]

[0106] Among them, the G IC represents the simulated fracture energy.

[0107] In this embodiment, the above steps obtain the simulated displacement of the adhesive in each failure simulation, and then calculate the stiffness damage coefficient and simulated fracture energy of the adhesive in the current failure simulation based on the simulated displacement and pre-constructed test curves. The stiffness damage coefficient and simulated fracture energy are then used to accurately assess the failure mode of the adhesive under test. By presetting various functions to automatically obtain simulation results, the accuracy and efficiency of simulation calculations can be improved, thereby improving the efficiency and accuracy of testing.

[0108] Reference Figure 2 Based on the above method embodiment, a corresponding device embodiment is provided; this embodiment provides a battery adhesive testing system, including a sample building module 201, a tensile shear test module 202, a performance extraction module 203, a failure simulation module 204 and a failure assessment module 205.

[0109] The sample building module 201 is used to build a multi-layer composite test sample containing the adhesive to be tested based on the structural position of the adhesive to be tested inside the battery.

[0110] The tensile and shear testing module 202 is used to perform a tensile test and a shear test on the multi-layer composite test specimen, respectively, to obtain a tensile test force-displacement curve and a shear test force-displacement curve corresponding to the multi-layer composite test specimen.

[0111] The performance extraction module 203 is configured to obtain the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and to obtain the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve.

[0112] The failure simulation module 204 is configured to construct a cohesion model corresponding to the adhesive to be tested according to the tensile performance parameters and the shear performance parameters, and perform failure simulation on the adhesive to be tested according to the cohesion model.

[0113] The failure assessment module 205 is configured to calculate the stiffness damage coefficient and the fracture energy of the adhesive to be tested according to the failure simulation, so as to obtain a failure test result of the adhesive to be tested according to the stiffness damage coefficient and the fracture energy.

[0114] It can be understood that the above-mentioned device embodiment corresponds to the method embodiment, and it can implement a battery adhesive testing method provided by any of the above-mentioned method embodiments.

[0115] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. Furthermore, in the drawings of the device embodiments provided in this embodiment, the connection relationship between modules indicates that they have a communication connection, which may be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement the present invention without inventive effort.

[0116] Based on the above-mentioned embodiment of a battery adhesive testing method, this embodiment also provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a battery adhesive testing method described in any of the above-mentioned method embodiments.

[0117] For example, in this embodiment, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to implement the battery adhesive testing method provided in this embodiment. The one or more modules may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0118] The terminal device may be a computing device such as a desktop computer, a notebook computer, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0119] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, connecting various parts of the entire terminal device using various interfaces and lines.

[0120] The present embodiment discloses a battery adhesive testing method, system, and device. By performing tensile and shear tests on a multi-layer composite test specimen containing the adhesive to be tested, tensile performance parameters and shear performance parameters are provided for the cohesion model corresponding to the adhesive to be tested, thereby improving the accuracy of subsequent simulations and obtaining accurate failure test results. A multi-layer composite test specimen containing the adhesive to be tested is constructed based on the structural position of the adhesive to be tested within the battery, so that the multi-layer composite test specimen is fitted to the actual working conditions of the adhesive to be tested within the battery, thereby improving the accuracy of the test. Subsequently, tensile and shear tests are performed on the multi-layer composite test specimen, respectively, to construct a cohesion model corresponding to the adhesive to be tested based on the obtained tensile and shear performance parameters, thereby improving the accuracy of the cohesion model, improving the accuracy of failure simulations performed based on the cohesion model, and improving the accuracy of adhesive testing. Finally, the stiffness damage coefficient and fracture energy calculated by simulation are used to perform a failure assessment on the adhesive to be tested, thereby improving the accuracy of the failure test of the adhesive to be tested.

[0121] Example 2

[0122] Batteries typically use adhesives to bond the aluminum-plastic film to the back of the cell. In existing battery cell drop simulations or heavy object impacts, the adhesive is typically calculated using a linear elastic constitutive model, with double-sided binding analysis performed. However, this approach rarely considers adhesive failure and shear failure. Adhesives can experience tensile and shear failure in the thickness direction, affecting the stress and stiffness distribution of the bonded parts. This can lead to unrealistic stress and deformation in the core copper and aluminum foil, and cannot accurately simulate shear slip in the adhesive area.

[0123] In order to solve the technical problem that the existing technology cannot evaluate the failure of adhesives, Figure 3This embodiment provides a battery adhesive testing method that can accurately assess the failure mode of the adhesive itself and the interface failure mode between the adhesive and the adherend, thereby improving the accuracy of drop simulation or heavy object impact simulation and achieving accurate assessment of battery component material failure. Specifically, the testing method includes:

[0124] Step 301: construct a multi-layer composite test specimen including the adhesive to be tested, and perform a tensile test and a shear test on the multi-layer composite test specimen using a preset test fixture to obtain a dynamic tensile test force-displacement curve and a dynamic shear test force-displacement curve.

[0125] In this embodiment, before conducting tensile tests and shear tests on the adhesive to be tested, in order to make the test results fit the actual working conditions of the adhesive in the battery, a multi-layer composite test sample where the adhesive to be tested is located can be constructed according to the type of adhesive to be tested and the spatial structural position of the adhesive to be tested in the battery.

[0126] It should be noted that before constructing the multilayer composite test specimen, the adhesive to be tested must be immersed in the electrolyte for a period of time to simulate the impact of the electrolyte inside the battery cell on the performance of the adhesive to be tested. Preferably, the immersion time is set based on the actual working conditions of the adhesive; generally, to ensure effective testing, a 24-hour immersion period is recommended.

[0127] In one embodiment of this embodiment, when the adhesive to be tested is a hot melt adhesive consistent with the hot melt adhesive in the battery, a multi-layer composite test sample is constructed with a sandwich structure including an aluminum-plastic film, a hot melt adhesive and a positive electrode current collector; wherein, in the multi-layer composite test sample, the hot melt adhesive is located between the aluminum-plastic film and the positive electrode current collector, and the aluminum-plastic film and the positive electrode current collector are bonded together by the hot melt adhesive.

[0128] In another embodiment of this embodiment, when the adhesive to be tested is a cell adhesive that is consistent with the cell adhesive in the battery, a multi-layer composite test sample is constructed with a two-layer structure including an aluminum-plastic film and a cell adhesive; wherein, in the multi-layer composite test sample, the cell adhesive is applied to one side of the aluminum-plastic film.

[0129] It should be noted that in order to ensure that the test results are consistent with the results of testing the battery itself, the thickness of the adhesive to be tested in the multi-layer composite test sample must be consistent with the actual design plan, and the curing method must also be fixed.

[0130] After constructing the multi-layer composite test specimen, in order to perform a tensile test and a shear test on the multi-layer composite test specimen, the multi-layer composite test specimen can be fixed on a pre-constructed fixture so that the multi-layer composite test specimen can be stretched along both ends of the thickness direction of the adhesive to be tested by the fixture to perform a tensile test, or the multi-layer composite test specimen can be stretched along both ends of the extension direction of the adhesive to be tested by the fixture to perform a shear test.

[0131] In one embodiment of the present invention, a tooling fixture is provided; wherein, the tooling fixture includes an upper fixture and a lower fixture; the upper fixture and the lower fixture both include a rotatably connected clamping end and an end plate; wherein, in order to simulate the internal structure of a battery, the end plate is made of a metal material.

[0132] The upper and lower ends of the multi-layer composite test sample are bonded to the end plates of the upper fixture and the lower fixture respectively. Since the end plates are made of thinner metal parts to fit the composition of the battery, thicker raw materials can be used or strong glue can be used to bond the multi-layer composite test sample to the end plates. Specifically, Figure 4 As shown, when the multi-layer composite test specimen is a sandwich structure, one side of the aluminum-plastic film in the multi-layer composite test specimen is bonded to the end plate of the upper fixture by a strong glue, one side of the aluminum-plastic film is bonded to one side of the aluminum foil current collector, i.e., the positive electrode current collector, by the adhesive to be tested, and the other side of the positive electrode current collector is bonded to the end plate of the lower fixture by the strong glue.

[0133] Reference Figure 4 During the tensile test, the clamping end is rotated so that the clamping end is vertically connected to the end plate, and is fixed to the clamping end of the upper clamp and the clamping end of the lower clamp through the tensile testing machine to apply traction forces in opposite directions to the upper and lower ends of the multi-layer composite test specimen, and the tensile traction force applied by the tensile testing machine to the multi-layer composite test specimen at each moment and the corresponding displacement of the adhesive to be tested in the multi-layer composite test specimen at each moment are obtained, so as to construct a dynamic tensile test force-displacement curve of the multi-layer composite test specimen according to the tensile traction force and the displacement until the tensile test is completed.

[0134] Similarly, refer to Figure 5During the shear test, the clamping end is rotated so that the clamping end is connected parallel to the end plate, and is fixed to the clamping end of the upper clamp and the chuck clamping end of the lower clamp through the tensile testing machine to apply traction forces in opposite directions to the left and right ends of the multi-layer composite test specimen, that is, along the extension direction of the adhesive to be tested, and the shear traction force applied by the tensile testing machine to the multi-layer composite test specimen at each moment and the corresponding displacement of the adhesive to be tested in the multi-layer composite test specimen at each moment are obtained, so as to construct a dynamic shear test force-displacement curve of the multi-layer composite test specimen according to the shear traction force and the displacement until the shear test is completed.

[0135] Step 302: Calculate the tensile performance parameters and shear performance parameters corresponding to the adhesive to be tested based on the dynamic tensile test force-displacement curve and the dynamic shear test force-displacement curve; wherein the tensile performance parameters include tensile initial damage stiffness, elastic modulus and tensile fracture energy; and the shear performance parameters include shear initial damage stiffness, shear modulus and shear fracture energy.

[0136] In this embodiment, the tensile displacement corresponding to each tensile force is obtained based on the dynamic tensile test force-displacement curve. Specifically, the maximum tensile force of the adhesive to be tested, the tensile displacement corresponding to the maximum tensile force, the maximum tensile displacement in the dynamic tensile test force-displacement curve, and the initial tensile displacement are obtained based on the dynamic tensile test force-displacement curve.

[0137] Similarly, the shear displacement corresponding to each shear traction force is obtained based on the dynamic shear test force-displacement curve. Specifically, the maximum shear traction force of the adhesive under test, the shear displacement corresponding to the maximum shear traction force, the maximum shear displacement in the dynamic shear test force-displacement curve, and the initial shear displacement are obtained based on the dynamic shear test force-displacement curve.

[0138] The maximum tensile traction force and the tensile displacement or the maximum shear traction force and the maximum shear displacement are input into a pre-constructed initial damage stiffness calculation function to obtain the tensile initial damage stiffness or the shear initial damage stiffness; wherein, the calculation expression of the initial damage stiffness calculation function is:

[0139] σ1=N1 / δ

[0140] Wherein, σ represents the output initial damage stiffness, which is the tensile initial damage stiffness or the shear initial damage stiffness; N represents the input traction force, which is the maximum tensile traction force or the maximum shear traction force; δ represents the input displacement, which is the tensile displacement or the shear displacement;

[0141] The initial tensile displacement in the tensile test force-displacement curve and the initial shear displacement in the shear test force-displacement curve are obtained, and the tensile initial damage stiffness, the initial tensile displacement, and the thickness or the shear initial damage stiffness, the initial shear displacement, and the thickness are input into a pre-established modulus calculation function to obtain the elastic modulus or the shear modulus; wherein the calculation expression of the modulus calculation function is:

[0142] E=σ / [(σ-δ min ) / h]

[0143] Wherein, the E represents the output modulus, which is the elastic modulus or the shear modulus; the δ min represents the input initial displacement, the initial displacement being the initial tensile displacement or the initial shear displacement; h represents the thickness;

[0144] The maximum tensile displacement in the tensile test force-displacement curve and the maximum shear displacement in the shear test force-displacement curve are obtained, and the maximum tensile displacement and the initial tensile displacement or the maximum shear displacement and the initial shear displacement are input into a pre-constructed fracture energy function to obtain the tensile fracture energy or the shear fracture energy; wherein the calculation expression of the fracture energy function is:

[0145] G=0.5*(δ max -δ min )

[0146] Wherein, G represents the output fracture energy, and the fracture energy is the tensile fracture energy or the shear fracture energy; max represents the maximum displacement of the input, where the maximum displacement is the maximum tensile displacement or the maximum shear displacement.

[0147] Step 303: constructing a cohesion model corresponding to the adhesive to be tested according to the tensile performance parameters and the shear performance parameters, and performing a drop simulation or a heavy object impact simulation according to the cohesion model.

[0148] In this embodiment, the cohesion model constitutive model of the adhesive to be tested is defined according to the tensile initial damage stiffness and tensile fracture energy and the shear initial damage stiffness and shear fracture energy, and then the elastic modulus and shear modulus of the cohesion model constitutive model are set according to the elastic modulus and the shear modulus.

[0149] Select the quadratic nominal stress criterion and establish a double-sided binding contact relationship between the adherend and the adhesive material. Build simulation components corresponding to each internal battery component, such as the current collector, cell coating, and electrode, and use binding connections to obtain the cohesion model corresponding to the adhesive to be tested. Then, perform drop simulation or heavy object impact simulation based on the cohesion model.

[0150] Step 304: Obtain the simulated displacement of the adhesive to be tested in the drop simulation or heavy object impact simulation, and calculate the simulated stiffness damage coefficient and simulated fracture energy of the adhesive to be tested based on the simulated displacement combined with the dynamic tensile test force-displacement curve and the dynamic shear test force-displacement curve to obtain the failure test result of the adhesive to be tested.

[0151] In this embodiment, based on the simulated displacement obtained in the drop simulation or heavy object impact simulation, combined with the maximum displacement, initial displacement, maximum traction force and the displacement corresponding to the maximum traction force in the test curve, the simulated stiffness damage coefficient and simulated fracture energy of the adhesive to be tested are calculated; wherein, the test curve is the dynamic tensile test force-displacement curve or the dynamic shear test force-displacement curve.

[0152] Specifically, the maximum displacement, the displacement, and the simulated displacement are input into a pre-constructed simulated stiffness damage coefficient function to obtain the simulated stiffness damage coefficient of the adhesive to be tested; wherein the calculation expression of the simulated stiffness damage coefficient function is:

[0153] D=[δ max *(δ new -δ s )] / [δ new *(δ max -δ s )]

[0154] Wherein, D represents the simulated stiffness damage coefficient; δ new represents the simulated displacement; the δ s represents the displacement corresponding to the maximum traction force;

[0155] The maximum displacement, the displacement, the simulated displacement, and the maximum traction force are input into a pre-constructed simulated fracture energy function to obtain the simulated fracture energy of the adhesive to be tested; wherein the calculation expression of the simulated fracture energy function is:

[0156] G IC =[δ new *(δ max -δ s )+δ max *(δ new -δ s )*N] / [2*(δmax -δ s )]

[0157] Among them, the G IC represents the simulated fracture energy.

[0158] After obtaining the simulated stiffness damage coefficient and the simulated fracture energy, the simulated stiffness damage coefficient is compared with a preset coefficient threshold, the simulated displacement is compared with the displacement corresponding to the maximum traction force in the test curve, and the simulated fracture energy is compared with a preset simulated fracture energy threshold to obtain the failure test result of the adhesive to be tested.

[0159] Specifically, when the simulated displacement is greater than or equal to the displacement corresponding to the maximum traction force and the simulated stiffness damage coefficient is greater than or equal to 0, it means that the adhesive bonding is damaged; and when the simulated fracture energy is greater than or equal to the preset simulated fracture energy threshold, it means that the adhesive to be tested is fractured.

[0160] This embodiment discloses a method for testing battery adhesives. By establishing a material constitutive model for adhesives such as hot melt adhesives or adhesive backing for battery cells, and by using cohesion units or cohesion contacts to implement failure assessment of the adhesive, the damage evolution law of the adhesive is taken into account, the failure mode of the battery cell adhesive is realistically simulated, and corresponding pull-out shear test methods and sample devices are defined. This can improve the analysis accuracy of working conditions such as battery cell drop simulation and heavy object impact simulation, and can more accurately assess the stress and deformation of the bonded surfaces - aluminum-plastic film and aluminum foil, which is conducive to the development and verification of new hot melt adhesives, adhesive backings, and PAS adhesives. In addition, the defined test methods and devices can also better fit the cohesion constitutive model of the adhesive, facilitating subsequent material simulation parameter processing and failure assessment.

[0161] The specific embodiments described above further illustrate the objectives, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A battery adhesive testing method, characterized in that: include: Based on the structural position of the adhesive to be tested inside the battery, construct a multi-layer composite test sample containing the adhesive to be tested; Performing a tensile test and a shear test on the multi-layer composite test sample respectively to obtain a tensile test force-displacement curve and a shear test force-displacement curve corresponding to the multi-layer composite test sample; Obtaining the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and obtaining the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve; constructing a cohesion model corresponding to the adhesive to be tested according to the tensile performance parameters and the shear performance parameters, and performing failure simulation on the adhesive to be tested according to the cohesion model; The stiffness damage coefficient and the fracture energy of the adhesive to be tested are calculated according to the failure simulation, so as to obtain a failure test result of the adhesive to be tested according to the stiffness damage coefficient and the fracture energy.

2. A battery adhesive testing method according to claim 1, characterized in that: The method comprises constructing a multi-layer composite test sample containing the adhesive to be tested based on the structural position of the adhesive to be tested inside the battery, including: Determining the structural position of the adhesive to be tested inside the battery according to the type of the adhesive to be tested; When the adhesive to be tested is a hot melt adhesive, the aluminum-plastic film and the positive electrode current collector are cut from the battery cell shell, and the adhesive to be tested is applied to the bonding area of ​​the aluminum-plastic film and the positive electrode current collector to form a multi-layer composite test sample with a sandwich structure; When the adhesive to be tested is a battery cell adhesive, the aluminum-plastic film is cut from the battery cell shell, and the adhesive to be tested is applied to the outer wall of the aluminum-plastic film to form the multi-layer composite test sample.

3. The battery adhesive testing method according to claim 2, characterized in that: The step of performing a tensile test and a shear test on the multi-layer composite test specimen to obtain a tensile test force-displacement curve and a shear test force-displacement curve corresponding to the multi-layer composite test specimen comprises: Stretching the adhesive to be tested along the thickness direction of the adhesive to be tested according to a preset tensile test rate to obtain a tensile test force-displacement curve corresponding to the multi-layer composite test sample; The adhesive to be tested is stretched along the extension direction of the adhesive to be tested according to the stretching test rate to obtain a shear test force-displacement curve corresponding to the multi-layer composite test sample.

4. A battery adhesive testing method according to claim 3, characterized in that: The method of obtaining the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and obtaining the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve includes: Obtaining a maximum tensile traction force and a tensile displacement corresponding to the maximum tensile traction force from the tensile test force-displacement curve; Obtaining a maximum shear traction force and a shear displacement corresponding to the maximum shear traction force from the shear test force-displacement curve; Calculating the tensile initial damage stiffness, elastic modulus, and tensile fracture energy of the adhesive to be tested based on the maximum tensile traction force, the tensile displacement, and the thickness of the adhesive to be tested in the multi-layer composite test specimen; The shear initial damage stiffness, shear modulus and shear fracture energy of the adhesive to be tested are calculated according to the maximum shear traction force, the shear displacement and the thickness of the adhesive to be tested in the multi-layer composite test specimen.

5. The battery adhesive testing method according to claim 4, characterized in that: The method of obtaining the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and obtaining the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve includes: The maximum tensile traction force and the tensile displacement or the maximum shear traction force and the maximum shear displacement are input into a pre-constructed initial damage stiffness calculation function to obtain the tensile initial damage stiffness or the shear initial damage stiffness; wherein, the calculation expression of the initial damage stiffness calculation function is: σ=N / δ Wherein, σ represents the output initial damage stiffness, which is the tensile initial damage stiffness or the shear initial damage stiffness; N represents the input traction force, which is the maximum tensile traction force or the maximum shear traction force; δ represents the input displacement, which is the tensile displacement or the shear displacement; The initial tensile displacement in the tensile test force-displacement curve and the initial shear displacement in the shear test force-displacement curve are obtained, and the tensile initial damage stiffness, the initial tensile displacement, and the thickness or the shear initial damage stiffness, the initial shear displacement, and the thickness are input into a pre-established modulus calculation function to obtain the elastic modulus or the shear modulus; wherein the calculation expression of the modulus calculation function is: E=σ / [(σ-δ min ) / h] Wherein, the E represents the output modulus, which is the elastic modulus or the shear modulus; the δ min represents the input initial displacement, the initial displacement being the initial tensile displacement or the initial shear displacement; h represents the thickness; The maximum tensile displacement in the tensile test force-displacement curve and the maximum shear displacement in the shear test force-displacement curve are obtained, and the maximum tensile displacement and the initial tensile displacement or the maximum shear displacement and the initial shear displacement are input into a pre-constructed fracture energy function to obtain the tensile fracture energy or the shear fracture energy; wherein the calculation expression of the fracture energy function is: G=0.5*(δ max -d min ) Wherein, G represents the output fracture energy, and the fracture energy is the tensile fracture energy or the shear fracture energy; max represents the maximum displacement of the input, where the maximum displacement is the maximum tensile displacement or the maximum shear displacement.

6. The battery adhesive testing method according to claim 4, characterized in that: The step of constructing a cohesion model corresponding to the adhesive to be tested according to the tensile performance parameters and the shear performance parameters, and performing failure simulation on the adhesive to be tested according to the cohesion model, includes: Constructing a cohesion constitutive model corresponding to the adhesive to be tested according to the tensile initial damage stiffness, the tensile fracture energy, the elastic modulus, the shear initial damage stiffness, the shear fracture energy and the shear modulus; Establishing a double-sided binding contact relationship between the adhesive to be tested and the adherend, and establishing a multi-level simulation structure of the battery and a binding connection relationship between the simulation structures of two adjacent levels; A cohesion model corresponding to the adhesive to be tested is constructed based on the cohesion constitutive model, the double-sided binding contact relationship, and the binding connection relationship at the multi-level simulation structure level, so as to perform failure simulation based on the cohesion model; wherein, the failure simulation includes drop simulation and heavy object impact simulation.

7. A battery adhesive testing method according to claim 6, characterized in that: Calculating the stiffness damage coefficient and the fracture energy of the adhesive to be tested according to the failure simulation to obtain a failure test result of the adhesive to be tested according to the stiffness damage coefficient and the fracture energy includes: Obtaining a simulated displacement of the adhesive to be tested in the failure simulation; Calculating the simulated stiffness damage coefficient and the simulated fracture energy of the adhesive to be tested according to the simulated displacement and the pre-constructed test curve; wherein the test curve is the tensile test force-displacement curve or the shear test force-displacement curve; Calculating a simulated stiffness damage coefficient and a simulated fracture energy of the adhesive to be tested according to the test curve and the simulated displacement; Obtaining a first comparison result of the simulated stiffness damage coefficient and a preset coefficient threshold and a second comparison result of the simulated fracture energy and a preset energy threshold; The failure mode of the adhesive to be tested is determined according to the first comparison result and the second comparison result.

8. The battery adhesive testing method according to claim 7, characterized in that: Calculating the stiffness damage coefficient and fracture energy of the adhesive to be tested according to the failure simulation includes: Obtaining the maximum displacement, initial displacement, maximum traction force, and displacement corresponding to the maximum traction force in the test curve; The maximum displacement, the displacement corresponding to the maximum traction force, and the simulated displacement are input into a pre-constructed simulated stiffness damage coefficient function to obtain the simulated stiffness damage coefficient of the adhesive to be tested; wherein the calculation expression of the simulated stiffness damage coefficient function is: D=[δ max *(d new -d s )] / [d new *(d max -d s )] Wherein, D represents the simulated stiffness damage coefficient; δ new represents the simulated displacement; the δ s represents the displacement corresponding to the maximum traction force; The maximum displacement, the displacement corresponding to the maximum traction force, the simulated displacement, and the maximum traction force are input into a pre-constructed simulated fracture energy function to obtain the simulated fracture energy of the adhesive to be tested; wherein the calculation expression of the simulated fracture energy function is: G IC =[δ new *(d max -d s )+d max *(d new -d s )*N] / [2*(δ max -d s )] Among them, the G IC represents the simulated fracture energy.

9. A battery adhesive testing system, characterized in that: It includes sample construction module, tensile shear test module, performance extraction module, failure simulation module and failure assessment module; The sample building module is used to build a multi-layer composite test sample containing the adhesive to be tested based on the structural position of the adhesive to be tested inside the battery; The tensile and shear test module is used to perform a tensile test and a shear test on the multi-layer composite test sample, respectively, to obtain a tensile test force-displacement curve and a shear test force-displacement curve corresponding to the multi-layer composite test sample; The performance extraction module is used to obtain the tensile performance parameters of the adhesive to be tested according to the tensile test force-displacement curve and to obtain the shear performance parameters of the adhesive to be tested according to the shear test force-displacement curve; The failure simulation module is used to construct a cohesion model corresponding to the adhesive to be tested according to the tensile performance parameters and the shear performance parameters, and perform failure simulation on the adhesive to be tested according to the cohesion model; The failure assessment module is used to calculate the stiffness damage coefficient and fracture energy of the adhesive to be tested according to the failure simulation, so as to obtain a failure test result of the adhesive to be tested according to the stiffness damage coefficient and fracture energy.

10. A terminal device, characterized in that: The invention comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, a battery adhesive testing method according to any one of claims 1 to 8 is implemented.

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