Method, device, computer equipment and storage medium for simulating pinhole defects of pole pieces

Abstract

The present application relates to a pinhole defect simulation method, device, computer equipment and storage medium for a pole piece. The method includes: determining each pinhole defect information set for a target pole piece; each pinhole defect information is used to characterize different pinhole defects; simulating the charging and discharging conditions of the target pole piece when it has each pinhole defect, and obtaining the potential distribution information corresponding to each pinhole defect information; each potential distribution information is used to characterize the potential distribution of the target pole piece when it has each pinhole defect; fitting the potential distribution information corresponding to each pinhole defect information, and determining the pinhole defect information at the target potential based on the fitting result; according to the pinhole defect information at the target potential, determining the safety boundary of the target pole piece when a pinhole defect occurs. The use of the present application can improve efficiency.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method, device, computer equipment and storage medium for simulating pinhole defects of a pole piece. Background Art

[0002] With the rapid development of the energy storage industry, the output of energy storage batteries has continued to increase. Among them, energy storage batteries are mainly used for power energy storage or household energy storage. Compared with power batteries, energy storage batteries have higher requirements for cycle performance and safety and stability. However, in the production process of energy storage batteries, some abnormalities will occur in the pole pieces of energy storage batteries, such as pole piece wrinkles, lithium precipitation in the middle of the pole pieces, etc., which will cause pinhole defects in the pole pieces, thereby affecting the performance of the battery. At present, the pinhole defects of the pole pieces are mainly analyzed by manual disassembly of the battery. However, it is difficult to obtain an accurate quantitative relationship through the above method, and the efficiency is very low. Summary of the invention

[0003] Based on this, it is necessary to provide a pinhole defect simulation method, device, computer equipment, computer readable storage medium and computer program product for a pole piece to improve efficiency in response to the above technical problems.

[0004] In a first aspect, the present application provides a pinhole defect simulation method for a pole piece, comprising:

[0005] Determine each pinhole defect information set for the target pole piece; each pinhole defect information is used to characterize different pinhole defects;

[0006] Simulate the charging and discharging conditions of the target electrode when it has each pinhole defect, and obtain the potential distribution information corresponding to each pinhole defect information; each potential distribution information is used to characterize the potential distribution of the target electrode when it has each pinhole defect;

[0007] Fitting the potential distribution information corresponding to each pinhole defect information, and determining the pinhole defect information at the target potential based on the fitting result;

[0008] According to the pinhole defect information at the target potential, the safety margin of the target electrode when a pinhole defect occurs is determined.

[0009] In a second aspect, the present application provides a pinhole defect simulation device for a pole piece, comprising:

[0010] A defect information determination module is used to determine each pinhole defect information set for the target pole piece; each pinhole defect information is used to characterize different pinhole defects;

[0011] The pinhole defect simulation module is used to simulate the charging and discharging conditions of the target electrode when it has various pinhole defects, and obtain the potential distribution information corresponding to each pinhole defect information; each potential distribution information is used to characterize the potential distribution of the target electrode when it has various pinhole defects;

[0012] A fitting module, used to fit the potential distribution information corresponding to each pinhole defect information, and determine the pinhole defect information under the target potential based on the fitting result;

[0013] The safety boundary determination module is used to determine the safety boundary of the target electrode when a pinhole defect occurs based on the pinhole defect information at the target potential.

[0014] In some embodiments, the pinhole defect simulation module is also used to determine, for each pinhole defect information, a pole piece geometry model corresponding to the pinhole defect represented by the pinhole defect information; through the pole piece geometry model, the charging and discharging conditions of the target pole piece when it has a pinhole defect are simulated to obtain the potential distribution information corresponding to the pinhole defect information.

[0015] In some embodiments, the pole piece geometry model is selected from candidate pole piece geometry models. The pinhole defect simulation module is also used to draw a preliminary geometry model corresponding to the pinhole defect represented by the preset pinhole defect information; assign corresponding material properties to each pole piece region in the preliminary geometry model to obtain a candidate pole piece geometry model.

[0016] In some embodiments, the pinhole defect simulation module is also used to adopt constant power charging and discharging conditions to simulate the charging and discharging conditions of the target pole piece when it has a pinhole defect; by solving the control equations and boundary conditions that match the pole piece geometric model, the potential distribution of the physical field that matches the pole piece geometric model during the charging and discharging simulation process is calculated, and the potential distribution information corresponding to the pinhole defect information is obtained.

[0017] In some embodiments, the boundary conditions include dynamic current. The pinhole defect simulation module is also used to determine the constant power corresponding to the constant power charge and discharge condition; obtain the dynamic voltage of the target pole piece during the charge and discharge simulation process; and calculate the dynamic current corresponding to the target pole piece under constant power and dynamic voltage through the total differential equation corresponding to the target pole piece.

[0018] In some embodiments, each pinhole defect information includes each pinhole defect radius, and the pinhole defect information at the target potential includes the target pinhole defect radius. The fitting module is also used to determine the target negative electrode potential of the negative electrode defect-free area corresponding to each target electrode piece when the target electrode piece has a pinhole defect represented by each pinhole defect radius according to each potential distribution information; perform data fitting on the target negative electrode potential corresponding to each pinhole defect radius, and determine the target pinhole defect radius corresponding to the target electrode piece at the target potential based on the fitting result.

[0019] In some embodiments, the safety boundary determination module is also used to calculate the safety pinhole defect range corresponding to the target electrode at the target potential according to the target pinhole defect radius, so as to determine the safety boundary according to the safety pinhole defect range.

[0020] In a third aspect, the present application provides a computer device, the computer device comprising a memory and a processor, the memory storing a computer program, and the processor implementing the steps in the above method when executing the computer program.

[0021] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the steps in the above method when executed by a processor.

[0022] In a fifth aspect, the present application provides a computer program product, which includes a computer program, and the computer program implements the steps in the above method when executed by a processor.

[0023] The pinhole defect simulation method, device, computer equipment, computer-readable storage medium and computer program product of the above-mentioned pole piece determine the pinhole defect information set for the target pole piece for characterizing different pinhole defects; simulate the charging and discharging conditions of the target pole piece when it has each pinhole defect, and obtain the potential distribution information corresponding to each pinhole defect information; each potential distribution information is used to characterize the potential distribution of the target pole piece when it has each pinhole defect; fit the potential distribution information corresponding to each pinhole defect information, and determine the pinhole defect information at the target potential based on the fitting result; determine the safety boundary of the target pole piece when a pinhole defect occurs based on the pinhole defect information at the target potential. In other words, the present application simulates the charging and discharging conditions of the target pole piece with different pinhole defects based on simulation means to determine the potential distribution information of the target pole piece when it has each pinhole defect. By fitting the potential distribution information and pinhole defect information, it is possible to perform qualitative and quantitative analysis of the pinhole defect and potential conditions of the target electrode. Through the pinhole defect information at the target potential, the safety boundary of the target electrode when a pinhole defect occurs can also be accurately determined. This is more efficient than manual battery disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a flow chart of a pinhole defect simulation method for a pole piece provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the structure of a pole piece geometric model provided in an embodiment of the present application;

[0026] Figure 3 A schematic diagram of electric potential distribution provided in an embodiment of the present application;

[0027] Figure 4 A potential change comparison diagram provided in an embodiment of the present application;

[0028] Figure 5 A schematic diagram of the lowest negative electrode potential corresponding to different pinhole defects provided in an embodiment of the present application;

[0029] Figure 6 A structural block diagram of a pinhole defect simulation device for a pole piece provided in an embodiment of the present application;

[0030] Figure 7 An internal structure diagram of a computer device provided in an embodiment of the present application;

[0031] Figure 8 An internal structure diagram of another computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0033] In some embodiments, Figure 1 As shown, a pinhole defect simulation method for a pole piece is provided. This embodiment uses the method applied to a computer device as an example. It can be understood that the computer device can be a server or a terminal, and the method can be implemented by the server or the terminal alone, or through the interaction between the server and the terminal. In this embodiment, the method includes the following steps:

[0034] S102, determining each pinhole defect information set for the target electrode.

[0035] The electrode is one of the important components of the battery. It is a thin film material that is conductive and responsible for collecting current. The electrode includes a positive electrode and a negative electrode. The target electrode refers to the electrode that needs to be simulated for pinhole defects.

[0036] Each pinhole defect information refers to the relevant information of the tiny holes or cracks that may exist in the target pole piece. In the embodiment of the present application, each pinhole defect information is used to characterize different pinhole defects, such as at least one of the specific position of the pinhole in the target pole piece, the number of pinholes on the surface of the target pole piece, the size of the pinhole, the distribution of the pinholes on the surface of the target pole piece, or the shape of the pinhole.

[0037] Specifically, the computer device determines each pinhole defect information set for the target pole piece, such as determining a pinhole defect radius that can characterize the target pole piece corresponding to different pinhole sizes.

[0038] S104, simulating the charging and discharging conditions of the target electrode when it has each pinhole defect, and obtaining the potential distribution information corresponding to each pinhole defect information.

[0039] Among them, each potential distribution information is used to characterize the potential distribution of each pole piece area when the target pole piece has each pinhole defect.

[0040] Specifically, the computer equipment performs numerical simulation or electrochemical simulation on the target electrode to simulate the charging and discharging conditions of the target electrode when it has various pinhole defects, such as simulating the electron and ion transmission and electrochemical reactions during the charging and discharging process, so as to determine the potential distribution of the target electrode when it has various pinhole defects according to the simulated charging and discharging conditions and obtain the potential distribution information.

[0041] S106, fitting the potential distribution information corresponding to each pinhole defect information, and determining the pinhole defect information at the target potential based on the fitting result.

[0042] Specifically, the computer device determines a suitable mathematical model to describe the relationship between the pinhole defect information and the potential distribution information. The computer device performs parameter fitting based on the selected mathematical model using each pinhole defect information and the potential distribution information corresponding to each pinhole defect information to obtain a fitting result. The computer device determines the pinhole defect information of the target electrode at any potential, such as at the target potential, based on the fitting result.

[0043] S108, determining the safety margin of the target electrode when a pinhole defect occurs according to the pinhole defect information at the target potential.

[0044] The safety margin refers to the maximum allowable size of a pinhole defect.

[0045] Specifically, the computer device determines the maximum allowable size of the target electrode when a pinhole defect occurs based on the pinhole defect information at the target potential, and obtains the safety margin. By determining the safety margin of the target electrode, serious safety problems can be prevented during normal operation and use of the battery, ensuring the reliability and safety of the battery.

[0046] The pinhole defect simulation method of the above-mentioned pole piece determines each pinhole defect information set for the target pole piece for characterizing different pinhole defects; simulates the charging and discharging conditions of the target pole piece when it has each pinhole defect, and obtains the potential distribution information corresponding to each pinhole defect information; each potential distribution information is used to characterize the potential distribution of the target pole piece when it has each pinhole defect; fits the potential distribution information corresponding to each pinhole defect information, and determines the pinhole defect information at the target potential based on the fitting result; and determines the safety boundary of the target pole piece when the pinhole defect occurs based on the pinhole defect information at the target potential. In other words, the present application simulates the charging and discharging conditions of the target pole piece with different pinhole defects based on simulation means to determine the potential distribution information of the target pole piece when it has each pinhole defect. By fitting the potential distribution information and pinhole defect information, it is possible to qualitatively and quantitatively analyze the pinhole defect and potential of the target pole piece. Through the pinhole defect information at the target potential, the safety boundary of the target pole piece when a pinhole defect occurs can be accurately determined, which is more efficient than manual battery disassembly. In addition, through simulation analysis, it is also possible to predict and evaluate the impact of different pinhole defect sizes and locations on battery performance and safety during actual use of the target pole piece, providing a basis for battery safety design and control.

[0047] In some embodiments, S104 specifically includes but is not limited to: for each pinhole defect information, determining a pole piece geometry model corresponding to the pinhole defect represented by the pinhole defect information; through the pole piece geometry model, simulating the charging and discharging conditions of the target pole piece when it has a pinhole defect, and obtaining the potential distribution information corresponding to the pinhole defect information.

[0048] The pole piece geometric model refers to the geometric model obtained by drawing the pole piece structure.

[0049] Specifically, the computer device determines, for each pinhole defect information, from the candidate pole piece geometric models, the corresponding pole piece geometric model when the target pole piece has the pinhole defect represented by the pinhole defect information. The computer device simulates the charging and discharging conditions of the target pole piece when it has the pinhole defect through the determined pole piece geometric model to obtain the potential distribution information corresponding to the pinhole defect information.

[0050] It can be seen that in this embodiment, the geometric structure of the target pole piece when it has a pinhole defect represented by the pinhole defect information can be simulated by drawing a pole piece geometric model in advance, so that the charging and discharging simulation processing of the target pole piece can be directly performed using the pole piece geometric model, which is more efficient than directly disassembling the battery.

[0051] In some embodiments, after determining the pinhole defect information specifically corresponding to the target pole piece, the pole piece structure can be drawn according to the determined pinhole defect information to obtain a corresponding pole piece geometric model, so as to simulate the charging and discharging of the target pole piece through the drawn pole piece geometric model.

[0052] In some embodiments, the cell design information of the target electrode can also be converted into parameters required in the model, such as electrode parameters and model variable parameters. The electrode parameters include at least one of the solid phase volume fraction, liquid phase volume fraction, porosity, capacity, or positive and negative electrode stoichiometric ratio, and the model variable parameters include at least one of the dynamic current i_app or the dynamic voltage E_cell.

[0053] In some embodiments, the pole piece geometry model is selected from the candidate pole piece geometry models. Before the step of "for each pinhole defect information, determining the pole piece geometry model corresponding to the pinhole defect represented by the pinhole defect information", the pinhole defect simulation method of the pole piece of the embodiment of the present application also includes but is not limited to: drawing a preliminary geometry model corresponding to the pinhole defect represented by the preset pinhole defect information; assigning corresponding material properties to each pole piece region in the preliminary geometry model to obtain a candidate pole piece geometry model.

[0054] The preliminary geometric model refers to a geometric model that draws the structure of the pole piece according to the preset pinhole defect information. The preset pinhole defect information refers to the pre-set pinhole defect information.

[0055] The candidate pole piece geometric model refers to a geometric model obtained after setting corresponding material properties for each pole piece region of the preliminary set model on the basis of the preliminary geometric model.

[0056] Each pole piece region refers to some specific areas in the pole piece.

[0057] In some embodiments, each electrode region includes at least one of a positive electrode current collector, a positive electrode porous electrode, a separator, a negative electrode current collector, a negative electrode porous electrode, or a pinhole defect region. The pinhole defect region is determined according to preset pinhole defect information, such as a preset pinhole defect radius. In practical applications, the structure of the preliminary geometric model drawn based on the positive electrode current collector, the positive electrode porous electrode, the separator, the negative electrode current collector, the negative electrode porous electrode, and the pinhole defect region can be as follows: Figure 2 shown.

[0058] Specifically, the computer device determines the pinhole defect area for the pinhole defect represented by the preset pinhole defect information. The computer device draws the geometric structure of the pinhole defect area, the positive current collector, the positive porous electrode, the separator, the negative current collector, the negative porous electrode and the pinhole defect area to obtain a preliminary geometric model. The computer device assigns material properties of different materials to the positive current collector, the positive porous electrode, the separator, the negative current collector, the negative porous electrode and the pinhole defect area to obtain a candidate electrode piece geometric model.

[0059] It can be seen that in this embodiment, by assigning different material properties to different electrode areas in the electrode, the behavior of different materials in the actual environment is simulated in a targeted manner to simulate the charge and discharge process of the electrode, thereby predicting battery performance and optimizing the design to improve battery reliability.

[0060] In some embodiments, the material properties include at least one of aluminum (Al) properties, lithium iron phosphate material properties, porosity properties, copper (Cu) properties, graphite properties, and electrolyte material properties. In practical applications, the positive current collector can be given Al properties, the positive porous electrode can be given lithium iron phosphate material properties, the diaphragm can be given porosity properties, the negative current collector can be given Cu properties, the negative porous electrode can be given graphite properties, and the pinhole defect area can be given electrolyte material properties. Among them, the porosity of the diaphragm refers to the proportion of pores in the diaphragm.

[0061] In some embodiments, the step of "using a pole piece geometry model to simulate the charging and discharging conditions of a target pole piece when it has a pinhole defect, and obtain potential distribution information corresponding to the pinhole defect information" specifically includes but is not limited to: using a constant power charging and discharging condition to simulate the charging and discharging conditions of a target pole piece when it has a pinhole defect; calculating the potential distribution of a physical field that matches the pole piece geometry model during the charging and discharging simulation process by solving control equations and boundary conditions that match the pole piece geometry model, and obtaining potential distribution information corresponding to the pinhole defect information.

[0062] Among them, the constant power charging and discharging condition is a charging and discharging test condition. Under the constant power charging condition, the battery is charged at a constant power.

[0063] In the electrode simulation, the control equations can describe the behavior of electrodes, electrolytes, and battery materials. Boundary conditions describe the physical phenomena that occur at the boundaries of the simulation area, such as current, potential, temperature, or mass flow. The physical field is the physical quantity involved in the simulation process. Common physical fields include current, potential, temperature, concentration, etc. It can be understood that by solving the control equations and applying appropriate boundary conditions, the distribution and changes of these physical fields can be obtained.

[0064] Specifically, the computer equipment uses constant power charging and discharging conditions, such as controlling the battery at a constant 0.25P or 0.5P, to simulate the charging and discharging of the target battery electrode with a pinhole defect. The computer equipment calculates the potential distribution of the physical field matching the electrode geometry model during the charging and discharging simulation process by solving the control equations and boundary conditions matching the electrode geometry model, and obtains the potential distribution information corresponding to the pinhole defect information.

[0065] It can be seen that in this embodiment, by performing charge and discharge simulation through physical fields, boundary conditions and control equations, the impact of each pinhole defect on the performance of the electrode can be evaluated, the impact of the pinhole defect can be minimized, and the performance and reliability of the battery can be improved, thereby extending its service life.

[0066] In some embodiments, the electrode geometry model of the present application is based on the porous electrode theory and the concentrated solution theory. In order to more intuitively display the potential distribution in the thickness direction of the entire electrode, a two-dimensional model can be used. It should be noted that the battery charging and discharging process mainly includes mass transfer and reaction processes, and its main control equations are as follows:

[0067] 1. Solid phase charge conservation. During the charge and discharge process of lithium-ion batteries, the charge conservation relationship conforms to Ohm's law. The corresponding control equation is shown in formula (1):

[0068]

[0069] Among them, δ eff is the solid phase effective conductivity, φ s is the solid phase potential, and j is the local current density.

[0070] 2. Liquid phase charge conservation, the corresponding control equations are shown in formula (2) and formula (3):

[0071]

[0072]

[0073] Among them, κ eff is the effective conductivity of the liquid phase, φ e is the liquid phase potential, is the effective diffusion ion conductivity, j is the lithium ion current density, is the ion migration number, C e is the liquid phase lithium ion concentration, is the activity correlation, F is the Faraday constant, R is the ideal gas state constant, and T is the temperature.

[0074] 3. Conservation of solid matter mainly reflects the solid phase diffusion process. It characterizes the process of lithium ions diffusing from the center of the particle to the surface of the particle. The area where this process occurs is the positive and negative porous electrodes. Using Fick's second law, the corresponding control equation is shown in formula (4):

[0075]

[0076] Wherein, Cs is the solid phase lithium ion concentration, r is the particle ion radius, and Ds is the solid phase diffusion coefficient.

[0077] 4. Liquid phase material conservation, the corresponding control equation is shown in formula (5):

[0078]

[0079] Among them, ε e is the liquid volume fraction, is the effective diffusion of liquid phase, c e is the electrolyte concentration.

[0080] 5. Interface reaction is used to describe the relationship between the redox reaction rate and current density on the electrode surface. The corresponding control equations are shown in formulas (6) to (9):

[0081]

[0082]

[0083] η=φ s -φ e -Uj•R set (8)

[0084] j=a•i (9)

[0085] Where i is the local current density, i0 is the exchange current density, α a Anode transfer coefficient, α c is the cathode transfer coefficient, η is the overpotential, F is the Faraday constant, R is the ideal gas state constant, φ s is the solid phase potential, φ e is the liquid phase potential, R set is the membrane resistance, a is the active specific surface area, T is the temperature, j is the lithium ion current density, C e is the liquid phase lithium ion concentration, k is the reaction rate constant, C s,max is the maximum lithium ion concentration, C s,surf is the lithium ion concentration on the particle surface, U is the equilibrium potential, R set For film resistance.

[0086] In some embodiments, the simulation model can realize the characterization of mass transfer and electrochemical reaction processes based on the above equation framework, and the specific physical field settings are as follows: add positive and negative porous electrodes, and set the corresponding electrode parameters; add a diaphragm, set the corresponding diaphragm parameters; set the initial electrolyte concentration; add electrode boundaries, and select the positive and negative collector domains; add an initial charge distribution interface to define the initial state of the battery; add an electrode current boundary; add a ground boundary; create a new component to add a heat transfer module.

[0087] In some embodiments, the setting of boundary conditions includes: applying a dynamic current i_app at the positive electrode tab of the battery; controlling the negative electrode of the battery to be grounded; setting the initial state of charge and defining the initial voltage V_init; defining the initial capacity of the battery Q_init; setting coupling variables and defining thermal parameters to complete the bidirectional coupling of the electrochemical module and the thermal module.

[0088] In some embodiments, the model needs to be meshed, and the meshing process includes: using a triangular boundary mesh to divide the pinhole area and encrypting the mesh; sweeping the pole piece area to complete the meshing of the entire pole piece thickness area; and meshing the pole ear separately. Through meshing, the regional geometry can be discretized to solve the changes in variables in different regions.

[0089] In some embodiments, in order to improve computational efficiency and enhance model convergence, a two-dimensional model can be used when performing meshing, that is, a two-dimensional thick electrode pinhole model is used, taking part of the length of the real electrode and keeping the electrode thickness dimension unchanged.

[0090] In some embodiments, the boundary condition includes a dynamic current i_app. The pinhole defect simulation method of the pole piece of the embodiment of the present application also includes but is not limited to: determining the constant power corresponding to the constant power charging and discharging condition; obtaining the dynamic voltage of the target pole piece during the charging and discharging simulation process; and calculating the dynamic current corresponding to the target pole piece under constant power and dynamic voltage through the total differential equation corresponding to the target pole piece.

[0091] Among them, the total differential equation is an equation that describes the differentiation of multivariate functions.

[0092] Specifically, the computer device determines the constant power corresponding to the constant power charge and discharge condition. The computer device obtains the dynamic voltage of the battery to which the target pole piece belongs during the charge and discharge simulation process through the probe. The computer device calculates the dynamic current corresponding to the target pole piece under constant power and dynamic voltage through the total differential equation corresponding to the target pole piece.

[0093] It can be seen that in the embodiments of the present application, simulating the charge and discharge conditions of the target electrode through constant power charge and discharge conditions can provide detailed electrode behavior information, optimize electrode design and material selection, save time and cost, and predict and optimize the performance and behavior of the entire battery system.

[0094] In some embodiments, the battery to which the target electrode belongs is an energy storage battery, which generally adopts a constant power charging and discharging condition, such as 0.25P, 0.5P. Where 1P = V ave *i_1C,V ave is the voltage platform, i_1C is the 1C current of the battery cell, and the nominal capacity of the battery is equal in value. In the actual constant power discharge process, the voltage and current are constantly changing, so the global ordinary differential is used here to realize the changing current. Add a global differential equation, define the dynamic current as i_app, and the global ordinary differential expression is i_app=i_app-P / E_cell. The initial value of i_app is 0. In the initial case, i_app=P / E_cell. Among them, P is a constant value and E_cell is the dynamic voltage.

[0095] In some embodiments, each pinhole defect information includes each pinhole defect radius, and the pinhole defect information at the target potential includes the target pinhole defect radius. S106 specifically includes but is not limited to: determining, based on each potential distribution information, the target negative electrode potentials of the negative electrode defect-free regions corresponding to the target electrode piece when the target electrode piece has pinhole defects represented by each pinhole defect radius; performing data fitting on the target negative electrode potentials corresponding to each pinhole defect radius, and determining the target pinhole defect radius corresponding to the target electrode piece at the target potential based on the fitting result.

[0096] Among them, the pinhole defect radius is the distance from the circular edge of the pinhole defect to its center, which can also be understood as the radius of the pinhole defect. The pinhole defect radius is an important indicator for evaluating pole piece defects.

[0097] Negative electrode defect-free area refers to the area without defects in the negative electrode material of the battery. In the battery, the negative electrode refers to the location of the negative electrode active material, such as graphite in lithium-ion batteries. The negative electrode defect-free area is the place in the battery responsible for releasing and absorbing electrons.

[0098] In some embodiments, the target cathode potential is a minimum cathode potential.

[0099] Specifically, the computer device determines the target negative electrode potential of the negative electrode defect-free area corresponding to each pinhole defect represented by each pinhole defect radius according to each potential distribution information. The computer device performs data fitting on the target negative electrode potential corresponding to each pinhole defect radius to obtain a fitting result that can characterize the correspondence between different pinhole defect radii and different negative electrode potentials. Based on the fitting result, the computer device determines the pinhole defect radius corresponding to the target potential and obtains the target pinhole defect radius.

[0100] It can be seen that in the embodiment of the present application, by fitting the target negative electrode potential and the pinhole defect radius, it is possible to perform qualitative and quantitative analysis of the pinhole defect and potential condition of the target electrode piece, which is efficient and quick.

[0101] In some embodiments, S108 specifically includes but is not limited to: calculating the safe pinhole defect range corresponding to the target electrode at the target potential according to the target pinhole defect radius, so as to determine the safety boundary according to the safe pinhole defect range.

[0102] The safe pinhole defect range refers to the range of size and number of electrode pinhole defects allowed to exist during the battery manufacturing process.

[0103] Specifically, the computer device calculates the safe pinhole defect range corresponding to the target electrode at the target potential according to the target pinhole defect radius, so as to determine the safety boundary according to the safe pinhole defect range.

[0104] It can be seen that in this embodiment, by determining the safety boundary of the target electrode, the quality control and safety performance in the battery manufacturing process can be ensured. That is, by obtaining the actual pinhole defect radius of the battery electrode in the battery manufacturing process, it is possible to know whether the quality and performance of the battery meet the requirements, and prevent the occurrence of excessive pinhole defects, thereby ensuring stable battery performance.

[0105] It should be noted that pinhole defects can cause lithium ions in the positive electrode active material to leak to the negative electrode, forming a lithium deposition boundary phenomenon. At this time, an oxidation reaction will occur on the surface of the negative electrode, and a reduction reaction will occur at the lithium deposition boundary. The reaction at the boundary will affect the operation and cycle life of the battery. When the negative electrode potential of the electrode is zero, it means that the electrode is in an open circuit state, that is, no current passes through. This may be because an electrolysis reaction occurs at the pinhole defect of the electrode, resulting in a potential loss. In other words, a negative electrode potential of zero may affect the performance and stability of the battery. Therefore, the target potential can be set to zero to obtain the pinhole defect radius corresponding to the target electrode when the negative electrode potential is zero, and then determine the safety boundary of the target electrode.

[0106] In some embodiments, the computer device can obtain the negative electrode potential distribution of the target electrode at the corresponding pinhole defect radius based on the simulation model, identify the electrode lithium deposition risk area, and explain the mechanism. Among them, the negative electrode potential distribution corresponding to the target electrode at 0.1mm can be as follows Figure 3 As shown in the figure, it can be seen that the lowest point of the negative electrode potential is concentrated in the active material area on the inner wall of the pinhole. In addition, the average negative electrode potential of the negative electrode defect-free area corresponding to the target electrode at different pinhole defect radii can be obtained through geometric parametric scanning. Figure 4 As shown in the figure, it can be seen that as the radius of the pinhole defect increases, the polarization of the negative electrode surface gradually increases. In addition, the lowest potential of the negative electrode corresponding to different pinhole defect radii can also be obtained at the same time, and the following is obtained through data fitting: Figure 5 The relationship between different pinhole defect radii and the lowest potential of the negative electrode is shown, so as to obtain the pinhole defect radius corresponding to when the lowest potential of the electrode is zero, and then obtain the safety boundary of the target electrode when a pinhole defect occurs.

[0107] In some embodiments, the pinhole defect simulation method of the pole piece of the embodiment of the present application further includes but is not limited to the following steps:

[0108] (1) Draw a preliminary geometric model corresponding to the pinhole defect represented by a preset pinhole defect radius.

[0109] (2) Assign corresponding material properties to each pole piece region in the preliminary geometric model to obtain a candidate pole piece geometric model.

[0110] (3) Determine the radius of each pinhole defect set for the target electrode.

[0111] (4) For each pinhole defect radius, determine the pole piece geometric model corresponding to the pinhole defect represented by the pinhole defect information from the candidate pole piece geometric models.

[0112] (5) Using constant power charging and discharging conditions, simulate the charging and discharging conditions of the target electrode when it has a pinhole defect.

[0113] (6) By solving the control equations and boundary conditions that match the electrode geometry model, the potential distribution of the physical field that matches the electrode geometry model during the charge and discharge simulation process is calculated to obtain the potential distribution information corresponding to the pinhole defect information.

[0114] (7) According to each potential distribution information, the target negative electrode potential of the negative electrode defect-free area corresponding to the target electrode piece is determined when the target electrode piece has a pinhole defect represented by each pinhole defect radius.

[0115] (8) Perform data fitting on the target negative electrode potential corresponding to each pinhole defect radius, and determine the target pinhole defect radius corresponding to the target electrode at the target potential based on the fitting results.

[0116] (9) According to the target pinhole defect radius, the safe pinhole defect range corresponding to the target electrode at the target potential is calculated to determine the safety boundary according to the safe pinhole defect range.

[0117] It should be understood that, although the steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indications of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear description in this article, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0118] Based on the same inventive concept, the embodiment of the present application also provides a pinhole defect simulation device for a pole piece. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of the pinhole defect simulation device for one or more pole pieces provided below can refer to the limitations of the pinhole defect simulation method for pole pieces above, and will not be repeated here.

[0119] like Figure 6 As shown, the embodiment of the present application provides a pinhole defect simulation device for a pole piece, comprising:

[0120] The defect information determination module 602 is used to determine each pinhole defect information set for the target electrode; each pinhole defect information is used to characterize different pinhole defects;

[0121] The pinhole defect simulation module 604 is used to simulate the charging and discharging conditions of the target electrode when it has each pinhole defect, and obtain the potential distribution information corresponding to each pinhole defect information; each potential distribution information is used to characterize the potential distribution of the target electrode when it has each pinhole defect;

[0122] A fitting module 606 is used to fit the potential distribution information corresponding to each pinhole defect information, and determine the pinhole defect information at the target potential based on the fitting result;

[0123] The safety margin determination module 608 is used to determine the safety margin of the target electrode when a pinhole defect occurs according to the pinhole defect information at the target potential.

[0124] The pinhole defect simulation device of the above-mentioned pole piece determines each pinhole defect information set for the target pole piece for characterizing different pinhole defects; simulates the charging and discharging conditions of the target pole piece when it has each pinhole defect, and obtains the potential distribution information corresponding to each pinhole defect information; each potential distribution information is used to characterize the potential distribution of the target pole piece when it has each pinhole defect; fits the potential distribution information corresponding to each pinhole defect information, and determines the pinhole defect information at the target potential based on the fitting result; and determines the safety boundary of the target pole piece when the pinhole defect occurs according to the pinhole defect information at the target potential. In other words, the present application simulates the charging and discharging conditions of the target pole piece with different pinhole defects based on simulation means to determine the potential distribution information of the target pole piece when it has each pinhole defect. By fitting the potential distribution information and pinhole defect information, it is possible to perform qualitative and quantitative analysis of the pinhole defect and potential conditions of the target electrode. Through the pinhole defect information at the target potential, the safety boundary of the target electrode when a pinhole defect occurs can also be accurately determined. This is more efficient than manual battery disassembly.

[0125] In some embodiments, the pinhole defect simulation module 604 is also used to determine, for each pinhole defect information, a pole piece geometry model corresponding to the pinhole defect represented by the pinhole defect information; through the pole piece geometry model, the charging and discharging conditions of the target pole piece when it has a pinhole defect are simulated to obtain the potential distribution information corresponding to the pinhole defect information.

[0126] In some embodiments, the pole piece geometry model is selected from candidate pole piece geometry models. The pinhole defect simulation module 604 is also used to draw a preliminary geometry model corresponding to the pinhole defect represented by the preset pinhole defect information; assign corresponding material properties to each pole piece region in the preliminary geometry model to obtain a candidate pole piece geometry model.

[0127] In some embodiments, the pinhole defect simulation module 604 is also used to adopt constant power charging and discharging conditions to simulate the charging and discharging conditions of the target pole piece when it has a pinhole defect; by solving the control equations and boundary conditions that match the pole piece geometric model, the potential distribution of the physical field that matches the pole piece geometric model during the charging and discharging simulation process is calculated, and the potential distribution information corresponding to the pinhole defect information is obtained.

[0128] In some embodiments, the boundary condition includes a dynamic current. The pinhole defect simulation module 604 is also used to determine the constant power corresponding to the constant power charge and discharge condition; obtain the dynamic voltage of the target pole piece during the charge and discharge simulation process; and calculate the dynamic current corresponding to the target pole piece under constant power and dynamic voltage through the total differential equation corresponding to the target pole piece.

[0129] In some embodiments, each pinhole defect information includes each pinhole defect radius, and the pinhole defect information at the target potential includes the target pinhole defect radius. The fitting module 606 is also used to determine the target negative electrode potential of the negative electrode defect-free area corresponding to the target electrode piece when the target electrode piece has a pinhole defect represented by each pinhole defect radius according to each potential distribution information; perform data fitting on the target negative electrode potential corresponding to each pinhole defect radius, and determine the target pinhole defect radius corresponding to the target electrode piece at the target potential based on the fitting result.

[0130] In some embodiments, the safety boundary determination module 608 is further used to calculate the safety pinhole defect range corresponding to the target electrode at the target potential according to the target pinhole defect radius, so as to determine the safety boundary according to the safety pinhole defect range.

[0131] In some embodiments, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 7 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data related to the pinhole defect simulation of the pole piece. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the steps in the above-mentioned pinhole defect simulation method of the pole piece are implemented.

[0132] In some embodiments, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Figure 8As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, the steps in the pinhole defect simulation method of the above-mentioned pole piece are implemented. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen; the input device of the computer device can be a touch layer covering the display screen, or a key, trackball or touchpad provided on the computer device housing, or an external keyboard, touchpad or mouse, etc.

[0133] Those skilled in the art will understand that Figure 7 or Figure 8 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0134] In some embodiments, a computer device is provided. The computer device includes a memory and a processor. The memory stores a computer program. When the processor executes the computer program, the steps in the above method embodiments are implemented.

[0135] In some embodiments, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0136] In some embodiments, a computer program product is provided. The computer program product includes a computer program. When the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0137] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions.

[0138] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0139] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0140] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A pinhole defect simulation method for a pole piece, characterized in that: include: Determine each pinhole defect information set for the target pole piece; Each of the pinhole defect information is used to characterize different pinhole defects; For each pinhole defect information, determine the pole piece geometry model corresponding to the pinhole defect represented by the pinhole defect information, simulate the charging and discharging conditions of the target pole piece when it has the pinhole defect, calculate the potential distribution of the physical field matching the pole piece geometry model during the charging and discharging simulation process by solving the boundary conditions of the control equation matching the pole piece geometry model, and obtain the potential distribution information corresponding to the pinhole defect information; each of the potential distribution information is used to characterize the potential distribution of the target pole piece when it has each of the pinhole defects; Fitting the potential distribution information corresponding to each of the pinhole defect information, and determining the pinhole defect information at the target potential based on the fitting result; According to the pinhole defect information at the target potential, a safety margin of the target electrode when a pinhole defect occurs is determined.

2. The method according to claim 1, characterized in that The step of determining, for each pinhole defect information, a pole piece geometric model corresponding to the pinhole defect represented by the pinhole defect information comprises: For each pinhole defect information, the pole piece geometric model corresponding to the target pole piece when it has the pinhole defect represented by the pinhole defect information is determined from the candidate pole piece geometric models, and the pole piece geometric model corresponding to the pinhole defect represented by the pinhole defect information is obtained.

3. The method according to claim 1, characterized in that The pole piece geometric model is selected from candidate pole piece geometric models; before determining the pole piece geometric model corresponding to the pinhole defect represented by the pinhole defect information for each pinhole defect information, the method further includes: Drawing a preliminary geometric model corresponding to a pinhole defect represented by preset pinhole defect information; Corresponding material properties are assigned to each pole piece region in the preliminary geometric model to obtain a candidate pole piece geometric model.

4. The method according to claim 1, characterized in that: The simulating the charging and discharging condition of the target electrode when it has the pinhole defect includes: A constant power charge and discharge condition is adopted to simulate the charge and discharge condition of the target electrode when it has the pinhole defect.

5. The method according to claim 4, characterized in that The boundary condition includes a dynamic current; the method further includes: Determine the constant power corresponding to the constant power charging and discharging condition; Obtaining the dynamic voltage of the target electrode during the charge and discharge simulation process; The dynamic current corresponding to the target pole piece under the constant power and the dynamic voltage is calculated by the total differential equation corresponding to the target pole piece.

6. The method according to any one of claims 1 to 5, characterized in that: Each of the pinhole defect information includes each pinhole defect radius; the pinhole defect information at the target potential includes a target pinhole defect radius; The step of fitting the potential distribution information corresponding to each of the pinhole defect information, and determining the pinhole defect information at the target potential based on the fitting result, includes: According to each of the potential distribution information, determine the target negative electrode potential of the negative electrode defect-free area corresponding to each of the target electrode pieces when the target electrode piece has a pinhole defect represented by each of the pinhole defect radii; Data fitting is performed on the target negative electrode potential corresponding to each of the pinhole defect radii, and the target pinhole defect radius corresponding to the target electrode piece at the target potential is determined based on the fitting result.

7. The method according to claim 6, characterized in that Determining the safety margin of the target electrode when a pinhole defect occurs according to the pinhole defect information at the target potential includes: According to the target pinhole defect radius, the safe pinhole defect range corresponding to the target electrode at the target potential is calculated, so as to determine the safety boundary according to the safe pinhole defect range.

8. A pinhole defect simulation device for a pole piece, characterized in that: include: A defect information determination module, used to determine each pinhole defect information set for the target pole piece; Each of the pinhole defect information is used to characterize different pinhole defects; A pinhole defect simulation module is used to determine, for each pinhole defect information, a pole piece geometry model corresponding to the pinhole defect represented by the pinhole defect information, simulate the charge and discharge conditions of the target pole piece when it has the pinhole defect, calculate the potential distribution of the physical field matching the pole piece geometry model during the charge and discharge simulation process by solving the boundary conditions of the control equation matching the pole piece geometry model, and obtain the potential distribution information corresponding to the pinhole defect information; each of the potential distribution information is used to characterize the potential distribution of the target pole piece when it has each of the pinhole defects; A fitting module, used for fitting the potential distribution information corresponding to each of the pinhole defect information, and determining the pinhole defect information at the target potential based on the fitting result; The safety boundary determination module is used to determine the safety boundary of the target electrode when a pinhole defect occurs according to the pinhole defect information at the target potential.

9. A computer device, comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

Images