Reduced-order model electrochemical simulation method and device for multiple active substances

Abstract

The present application relates to a method and device for electrochemical simulation of a reduced-order model of multiple active substances, belonging to the field of battery simulation technology. The method comprises: simulating the placement of multiple particles in the positive and negative electrodes of a battery cell respectively, wherein the multiple particles include particles of different active substances and / or particles of different particle sizes; establishing a reduced-order model based on the particle parameters of the multiple particles to perform electrochemical simulation of the battery cell; the problem that the existing reduced-order model cannot consider the influence of multiple particles on electrochemical performance can be solved; and particles of multiple activities and / or multiple particle sizes can be added according to analysis requirements to improve the effect of electrochemical simulation.

Description

Technical Field

[0001] The present application relates to a reduced-order model electrochemical simulation method and device for multiple active substances, and belongs to the technical field of battery simulation. Background Art

[0002] Electrochemical simulation of batteries is a technology that uses mathematical and physical models to analyze the interaction of multiple physical fields such as electrochemical reactions, structural stress, and fluid heat transfer during battery operation. Generally, electrochemical simulation can be achieved through a reduced-order model, which refers to a method that reduces computing resource consumption by simplifying the complexity of the battery model while maintaining the basic characteristics of the original battery model.

[0003] Traditional reduced-order models include the Single Particle Model (SPM) and the Pseudo-Two-Dimensional Model (P2D). The single-particle model simplifies the positive and negative electrodes of the battery into representative single spherical particles instead of considering the complex structure of the entire electrode, that is, one active material particle is used at each of the positive and negative electrodes of the battery to approximate the state of the positive and negative electrodes. The quasi-two-dimensional model is between the one-dimensional model and the full two-dimensional model. It assumes uniformity within the electrode plane and considers spatial variations in the thickness direction of the electrode. Specifically, it is divided into multiple grids in the thickness direction of the positive and negative electrodes, and an active material particle is used on each grid to approximate the state of the local area.

[0004] Although the single particle model and the quasi-two-dimensional model can simplify the battery model, they can only perform electrochemical simulation on a battery cell composed of one active material, but cannot perform electrochemical simulation on a composite electrode composed of multiple active materials. On the other hand, the single particle model and the quasi-two-dimensional model use only one particle at the same electrode thickness position to represent the properties of the active material particles at that thickness position, and when there is only one particle, there is only one particle size. Therefore, it is impossible to consider the effect of the particle size distribution of the active material on the electrochemical performance. Summary of the invention

[0005] The present application provides a method, device and storage medium for electrochemical simulation of a reduced-order model of multiple active substances, which can solve the problem that the existing reduced-order model cannot consider the influence of multiple particles on electrochemical performance. The present application provides the following technical solutions:

[0006] In a first aspect, a reduced-order model electrochemical simulation method for multiple active materials is provided, the method comprising:

[0007] Simulating placing a plurality of particles in the positive and negative electrodes of the battery cell respectively, wherein the plurality of particles include particles of different active materials and / or particles of different particle sizes;

[0008] The reduced-order model is established based on the particle parameters of the plurality of particles to perform electrochemical simulation on the battery cell.

[0009] Optionally, establishing the reduced-order model based on the particle parameters of the plurality of particles to perform electrochemical simulation on the battery cell includes:

[0010] Modify the source term of the target key equation describing and simulating the electrochemical process inside the battery cell in the reduced-order model from the reaction current density of one particle to the sum of the reaction current densities of multiple particles; wherein the target key equation includes a solid phase potential equation, a liquid phase potential equation and an electrolyte lithium ion concentration equation;

[0011] The external circuit current in the reduced-order model is modified from the reaction current of one particle to the sum of the reaction currents of multiple particles;

[0012] Solving diffusion equations within the plurality of particles to determine lithium ion concentrations within the plurality of particles in the reduced-order model;

[0013] In the case where the plurality of particles include particles of different particle sizes, the volume fractions of particles of the plurality of particle sizes in the reduced-order model are determined by a probability density function of the particle size distribution.

[0014] Optionally, the volume fractions of the particles of various particle sizes are expressed by the following formula:

[0015] ;

[0016] Where i represents the index of the particle, i is a positive integer; The particle radius is r i The volume fraction of the i-th particle, P i The particle radius is r i The probability of the active substance particles appearing, is the volume fraction of various particles in the active material corresponding to the i-th particle in the electrode, which is a preset design parameter.

[0017] Optionally, the external circuit current is expressed by the following formula:

[0018] ;

[0019] ;

[0020] ;

[0021] Where i represents the index of the particle, i is a positive integer; J i is the reaction current density of each particle, dx is the length element in the thickness direction of the battery cell, and F is the Faraday constant; is the radius of the ith particle, is the volume fraction of the i-th particle, is the specific surface area of ​​the i-th particle; k i is the reaction rate constant of the ith particle, c l is the lithium ion concentration of the electrolyte, c l,ref is the lithium ion concentration of the reference electrolyte, α a +α c =1 is the transfer coefficient, c s,max,i is the maximum lithium ion concentration of each particle, c s,surf,i is the lithium ion concentration on the surface of each particle, R is the ideal gas constant, T is the temperature, is the overvoltage, where is the solid phase potential, is the liquid phase potential, is the equilibrium potential of various particles.

[0022] Optionally, the source term in the solid phase potential equation and the liquid phase potential equation is the total reaction current density of the multiple particles ;

[0023] The source term of the liquid phase lithium ion diffusion equation is the total reaction current density of various active material particles The corresponding lithium ion flux;

[0024] The solid phase lithium ion diffusion equation is solved in the sub-region corresponding to the particle, and the boundary flux is the reaction current density of the corresponding active material particle. .

[0025] In a second aspect, a reduced-order model electrochemical simulation device for multiple active substances is provided, the device comprising:

[0026] A particle setting module, used to simulate placing a plurality of particles in the positive and negative electrodes of the battery cell respectively, wherein the plurality of particles include particles of different active materials and / or particles of different particle sizes;

[0027] The model building module is used to build the reduced-order model based on the particle parameters of the multiple particles to perform electrochemical simulation on the battery cell.

[0028] Optionally, the model building module is used to:

[0029] Modify the source term of the target key equation describing and simulating the electrochemical process inside the battery cell in the reduced-order model from the reaction current density of one particle to the sum of the reaction current densities of multiple particles; wherein the target key equation includes a solid phase potential equation, a liquid phase potential equation and an electrolyte lithium ion concentration equation;

[0030] The external circuit current in the reduced-order model is modified from the reaction current of one particle to the sum of the reaction currents of multiple particles;

[0031] Solving diffusion equations within the plurality of particles to determine lithium ion concentrations within the plurality of particles in the reduced-order model;

[0032] In the case where the plurality of particles include particles of different particle sizes, the volume fractions of particles of the plurality of particle sizes in the reduced-order model are determined by a probability density function of the particle size distribution.

[0033] Optionally, the volume fractions of the particles of various particle sizes are expressed by the following formula:

[0034] ;

[0035] Where i represents the index of the particle, i is a positive integer; The particle radius is r i The volume fraction of the i-th particle, P i The particle radius is r i The probability of the active substance particles appearing, is the volume fraction of various particles in the active material corresponding to the i-th particle in the electrode, which is a preset design parameter.

[0036] Optionally, the external circuit current is expressed by the following formula:

[0037] ;

[0038] ;

[0039] ;

[0040] Where i represents the index of the particle, i is a positive integer; J i is the reaction current density of each particle, dx is the length element in the thickness direction of the battery cell, and F is the Faraday constant; is the radius of the ith particle, is the volume fraction of the i-th particle, is the specific surface area of ​​the i-th particle; k i is the reaction rate constant of the ith particle, c l is the lithium ion concentration of the electrolyte, c l,ref is the lithium ion concentration of the reference electrolyte, α a +α c =1 is the transfer coefficient, c s,max,i is the maximum lithium ion concentration of each particle, c s,surf,i is the lithium ion concentration on the surface of each particle, R is the ideal gas constant, T is the temperature, is the overvoltage, where is the solid phase potential, is the liquid phase potential, is the equilibrium potential of various particles.

[0041] Optionally, the source term in the solid phase potential equation and the liquid phase potential equation is the total reaction current density of the multiple particles ;

[0042] The source term of the liquid phase lithium ion diffusion equation is the total reaction current density of various active material particles The corresponding lithium ion flux;

[0043] The solid phase lithium ion diffusion equation is solved in the sub-region corresponding to the particle, and the boundary flux is the reaction current density of the corresponding active material particle. .

[0044] In a third aspect, a reduced-order model electrochemical simulation device for multiple active substances is provided, the device comprising a processor and a memory; a program is stored in the memory, and the program is loaded and executed by the processor to implement the reduced-order model electrochemical simulation method for multiple active substances described in the first aspect.

[0045] In a fourth aspect, a computer-readable storage medium is provided, wherein a program is stored in the storage medium, and the program is loaded and executed by the processor to implement the reduced-order model electrochemical simulation method of multiple active materials described in the first aspect.

[0046] The beneficial effects of the present application are as follows: by simulating the placement of multiple particles in the positive and negative electrodes of the battery cell respectively, the multiple particles include particles of different active materials and / or particles of different particle sizes; a reduced-order model is established based on the particle parameters of the multiple particles to perform electrochemical simulation of the battery cell; the problem that the existing reduced-order model cannot consider the influence of multiple particles on electrochemical performance can be solved; and particles of multiple activities and / or multiple particle sizes can be added according to analysis requirements to improve the effect of electrochemical simulation.

[0047] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a flow chart of a reduced-order model electrochemical simulation method for multiple active substances provided by an embodiment of the present application;

[0049] Figure 2 It is a block diagram of a reduced-order model electrochemical simulation device for multiple active substances provided by one embodiment of the present application. DETAILED DESCRIPTION

[0050] The specific implementation methods of the present application are further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but are not intended to limit the scope of the present application.

[0051] Figure 1 This is a flow chart of a reduced-order model electrochemical simulation method for multiple active substances provided in one embodiment of the present application. This embodiment is described by taking the method applied to an electronic device as an example. The electronic device may be a user terminal or server with computing capabilities. This embodiment does not limit the implementation of the electronic device. The method includes at least the following steps:

[0052] Step 101 , simulating the placement of a plurality of particles in the positive and negative electrodes of the battery cell, respectively. The plurality of particles include particles of different active materials and / or particles of different particle sizes.

[0053] According to the above, the existing single-particle model uses one active material particle at each positive and negative electrode to approximate the state of the positive and negative electrodes. The quasi-two-dimensional model is divided into multiple grids in the thickness direction of the positive and negative electrodes, and one active material particle is used on each grid to approximate the state of the local area. At this time, it is impossible to consider the impact of multiple particles on electrochemical performance. Based on this, in this embodiment, one particle in the single-particle model and the quasi-two-dimensional model is modified to place multiple particles, and the multiple particles can be particles of different active materials and / or particles of different particle sizes.

[0054] Step 102 : establishing a reduced-order model based on particle parameters of the various particles to perform electrochemical simulation on the battery cell.

[0055] In one example, a reduced-order model is established based on particle parameters of multiple particles to perform electrochemical simulation of a battery cell, including: modifying the source term of the target key equation that describes and simulates the electrochemical process inside the battery cell in the reduced-order model from the reaction current density of one particle to the sum of the reaction current densities of multiple particles; wherein the target key equation includes the solid phase potential equation, the liquid phase potential equation and the electrolyte lithium ion concentration equation; modifying the external circuit current in the reduced-order model from the reaction current of one particle to the sum of the reaction currents of multiple particles; solving the diffusion equation in the multiple particles to determine the lithium ion concentration in the multiple particles in the reduced-order model; and in the case where the multiple particles include particles of different particle sizes, determining the volume fractions of particles of various particle sizes in the reduced-order model through the probability density function of the particle size distribution.

[0056] In the electrochemical simulation of batteries, the external circuit current, solid lithium ion concentration equation, solid phase potential equation, liquid phase potential equation, electrolyte lithium ion concentration equation, etc. are all key equations and parameters used to describe and simulate the electrochemical process inside the battery. Among them, the external circuit current refers to the current flowing through the external circuit during the charge and discharge process of the battery. It is an input parameter in battery simulation, which directly affects the charge and discharge rate of the battery. The external circuit current determines the working state of the battery and is a bridge connecting the internal electrochemical process of the battery and external applications. Lithium ion concentration refers to the number of lithium ions in the electrolyte and active materials inside the battery. Changes in lithium ion concentration affect the electrochemical reaction rate of the battery and the equilibrium potential of the electrode. In the simulation, the distribution and changes of lithium ion concentration are described by the diffusion equation. The diffusion equation is a mathematical equation used to describe the diffusion process of lithium ions in the electrolyte and electrode materials. It is based on Fick's law and takes into account the concentration gradient and diffusion coefficient of lithium ions. Solving the diffusion equation can predict the migration behavior of lithium ions inside the battery, which is crucial to understanding the charge and discharge performance of the battery. The solid phase potential equation is an equation used to describe the potential distribution inside the electrode material. It takes into account the conduction of electrons in the electrode material and the charge transfer generated by the electrochemical reaction. Solving the solid phase potential equation helps to understand the electrochemical behavior of the electrode material and the internal resistance of the battery. The liquid phase potential equation is an equation used to describe the potential distribution inside the electrolyte. It takes into account the ion migration and electrochemical reactions in the electrolyte. Solving the liquid phase potential equation helps to understand the electrochemical behavior of the electrolyte and the internal resistance of the battery. The electrolyte lithium ion concentration equation is an equation used to describe the variation of lithium ion concentration in the electrolyte with time and space. It takes into account the diffusion, electromigration and electrochemical reactions of lithium ions. Solving the electrolyte lithium ion concentration equation helps to predict the distribution of lithium ions in the electrolyte, which is very important for understanding the charge and discharge performance of the battery and the stability of the electrolyte.

[0057] The volume fraction of particles of various sizes is expressed by the following formula:

[0058] ;

[0059] Where i represents the index of the particle, i is a positive integer; The particle radius is r i The volume fraction of the i-th particle, P i The particle radius is r i The probability of the active substance particles appearing, is the volume fraction of various particles in the electrode in the active material corresponding to the i-th particle, which is a preset design parameter. For example, the positive electrode includes two active materials, NCM and LFP, and each active material includes particles of three sizes; if the active material corresponding to the i-th particle is NCM, then is the total volume fraction of particles of three particle sizes corresponding to NCM; if the active material corresponding to the i-th particle is LFP, then is the total volume fraction of particles of three particle sizes corresponding to LFP.

[0060] The external circuit current is expressed by the following formula:

[0061] ;

[0062] ;

[0063] ;

[0064] Where i represents the index of the particle, i is a positive integer; J i is the reaction current density of each particle, dx is the length element in the thickness direction of the battery cell, and F is the Faraday constant; is the radius of the ith particle, is the volume fraction of the i-th particle, is the specific surface area of ​​the i-th particle; k i is the reaction rate constant of the ith particle, c l is the lithium ion concentration of the electrolyte, c l,ref is the lithium ion concentration of the reference electrolyte, α a +α c =1 is the transmission coefficient. Schematically, in this embodiment, α a =α c =0.5 is used as an example. In other embodiments, α a and α c The value of can also be other values. This embodiment does not a and α c The value of c is limited. s,max,i is the maximum lithium ion concentration of each particle, c s,surf,i is the lithium ion concentration on the surface of each particle, R is the ideal gas constant, T is the temperature, is the overvoltage, where is the solid phase potential, is the liquid phase potential, is the equilibrium potential of various particles.

[0065] in, Enter the equation, By solving the liquid phase lithium ion diffusion equation, we can obtain: Enter the equation, Enter the equation, It is obtained by solving the solid phase lithium ion diffusion equation, and T is obtained by solving the heat transfer equation. By solving the solid phase potential equation, we can obtain: By solving the liquid phase potential equation, we can obtain: Enter the equation.

[0066] Correspondingly, the source term in the solid phase potential equation and the liquid phase potential equation is the total reaction current density of multiple particles The source term of the liquid phase lithium ion diffusion equation is the total reaction current density of various active material particles Corresponding lithium ion flux. Solve the solid phase lithium ion diffusion equation in the sub-region corresponding to the particle, and the boundary flux is the reaction current density of the corresponding active material particle. .

[0067] In one example, the multiple particles of the positive electrode include two active material particles with the same particle size, such as: the positive electrode is a composite electrode of two active particles of ternary lithium (Nickel Cobalt Manganese Lithium Oxide, NCM) and lithium iron phosphate (Lithium Iron Phosphate, LFP), the radius of the NCM particle is 5 microns, the radius of the LFP particle is 0.5 microns, the volume fraction of NCM is 0.24, and the volume fraction of LFP is also 0.24. If 10 grids are divided in the thickness direction of the positive electrode, two active material particle sub-areas are set on each grid, representing NCM particles and LFP particles respectively, and the geometric size of each sub-area is set to the size of the corresponding particle.

[0068] In the process of building the reduced-order model, ensure Satisfy the external circuit current equation:

[0069] ;

[0070] Where i represents NCM or LFP:

[0071] ;

[0072] ;

[0073] In the positive electrode region, the source term in the solid phase potential equation and the liquid phase potential equation is the total reaction current density of the two active material particles. In the positive electrode region, the source term of the liquid phase lithium ion diffusion equation is the total reaction current density of the two active material particles Corresponding lithium ion flux. Solve the solid phase lithium ion diffusion equation in the two active material particle regions, and the boundary flux is the reaction current density of the corresponding active material particle. . Solve all electrochemical equations.

[0074] In another example, the multiple particles in the positive electrode include: two active material particles with the same particle size, and the same active material particles have multiple particles with different particle sizes. For example: the positive electrode is a composite electrode mixed with two active materials NCM and LFP. The NCM particles satisfy the normal distribution, the radius mean is 5 microns, the standard deviation is 1 micron, the LFP particles satisfy the normal distribution, the radius mean is 0.5 microns, the standard deviation is 0.1 microns, the volume fraction of NCM is 0.24, and the volume fraction of LFP is also 0.24. If 10 grids are divided in the thickness direction of the positive electrode, 6 active material particle sub-regions are set on each grid, representing NCM particles and LFP particles, respectively, with 3 active material particles each. The radius of the NCM sub-region is set to 3 microns, 5 microns, and 7 microns, recorded as NCM sub-region 1, NCM sub-region 2, and NCM sub-region 3, and the radius of the LFP sub-region is set to 0.3 microns, 0.5 microns, and 0.7 microns, recorded as LFP sub-region 1, LFP sub-region 2, and LFP sub-region 3. The particles with NCM particle size of (0,4] μm are represented by particles in sub-region 1, the particles with NCM particle size of (4,6] μm are represented by particles in sub-region 2, and the particles with NCM particle size of (6,+∞) μm are represented by particles in sub-region 3. The probabilities of occurrence of particles represented by particles in NCM sub-regions 1, 2, and 3 are 0.1587, 0.6826, and 0.1587, respectively, and the corresponding volume fractions are:

[0075] ;

[0076] ;

[0077] ;

[0078] Therefore, the volume fractions of the three LFP particles can be obtained as follows: , , .

[0079] In the process of building the reduced-order model, ensure Satisfy the external circuit current equation:

[0080] ;

[0081] Among them, i represents any one of the six particles,

[0082] ;

[0083] ;

[0084] ;

[0085] ;

[0086] ;

[0087] ;

[0088] In the positive electrode region, the source term in the solid phase potential equation and the liquid phase potential equation is the total reaction current density of the six active material particles. In the positive electrode region, the source term of the liquid phase lithium ion diffusion equation is the total reaction current density of the six active material particles Corresponding lithium ion flux. Solve the solid phase lithium ion diffusion equation in each active material particle sub-region, and the boundary flux is the reaction current density of the corresponding active material particle. . Solve all electrochemical equations.

[0089] In summary, the reduced-order model electrochemical simulation method for multiple active substances provided in this embodiment simulates the placement of multiple particles in the positive and negative electrodes of the battery cell, respectively, and the multiple particles include particles of different active substances and / or particles of different particle sizes; a reduced-order model is established based on the particle parameters of the multiple particles to perform electrochemical simulation of the battery cell; the problem that the existing reduced-order model cannot consider the influence of multiple particles on the electrochemical performance can be solved; and particles of multiple activities and / or multiple particle sizes can be added according to analysis requirements to improve the effect of electrochemical simulation.

[0090] Figure 2 1 is a block diagram of a reduced-order model electrochemical simulation device for multiple active materials provided in one embodiment of the present application. The device comprises at least the following modules: a particle setting module 210 and a model building module 220 .

[0091] A particle setting module 210 is used to simulate placing a plurality of particles in the positive and negative electrodes of the battery cell, respectively, wherein the plurality of particles include particles of different active materials and / or particles of different particle sizes;

[0092] The model building module 220 is used to build the reduced-order model based on the particle parameters of the multiple particles to perform electrochemical simulation on the battery cell.

[0093] Optionally, the model building module 220 is used to:

[0094] Modify the source term of the target key equation describing and simulating the electrochemical process inside the battery cell in the reduced-order model from the reaction current density of one particle to the sum of the reaction current densities of multiple particles; wherein the target key equation includes a solid phase potential equation, a liquid phase potential equation and an electrolyte lithium ion concentration equation;

[0095] The external circuit current in the reduced-order model is modified from the reaction current of one particle to the sum of the reaction currents of multiple particles;

[0096] Solving diffusion equations within the plurality of particles to determine lithium ion concentrations within the plurality of particles in the reduced-order model;

[0097] In the case where the plurality of particles include particles of different particle sizes, the volume fractions of particles of the plurality of particle sizes in the reduced-order model are determined by a probability density function of the particle size distribution.

[0098] Optionally, the volume fractions of the particles of various particle sizes are expressed by the following formula:

[0099] ;

[0100] Where i represents the index of the particle, i is a positive integer; The particle radius is r i The volume fraction of the i-th particle, P i The particle radius is r i The probability of the active substance particles appearing, is the volume fraction of various particles in the active material corresponding to the i-th particle in the electrode, which is a preset design parameter.

[0101] Optionally, the external circuit current is expressed by the following formula:

[0102] ;

[0103] ;

[0104] ;

[0105] Where i represents the index of the particle, i is a positive integer; J i is the reaction current density of each particle, dx is the length element in the thickness direction of the battery cell, and F is the Faraday constant; is the radius of the ith particle, is the volume fraction of the i-th particle, is the specific surface area of ​​the i-th particle; k i is the reaction rate constant of the ith particle, c l is the lithium ion concentration of the electrolyte, c l,ref is the lithium ion concentration of the reference electrolyte, α a +α c =1 is the transfer coefficient, c s,max,i is the maximum lithium ion concentration of each particle, c s,surf,i is the lithium ion concentration on the surface of each particle, R is the ideal gas constant, T is the temperature, is the overvoltage, where is the solid phase potential, is the liquid phase potential, is the equilibrium potential of various particles.

[0106] Optionally, the source term in the solid phase potential equation and the liquid phase potential equation is the total reaction current density of the multiple particles ;

[0107] The source term of the liquid phase lithium ion diffusion equation is the total reaction current density of multiple active material particles The corresponding lithium ion flux;

[0108] The solid phase lithium ion diffusion equation is solved in the sub-region, and the boundary flux is the reaction current density of the corresponding active material particles. .

[0109] For relevant details, refer to the above method embodiment.

[0110] It should be noted that: the electrochemical simulation device for reduced-order models of multiple active substances provided in the above embodiments only uses the division of the above-mentioned functional modules as an example when performing electrochemical simulation of reduced-order models of multiple active substances. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the electrochemical simulation device for reduced-order models of multiple active substances is divided into different functional modules to complete all or part of the functions described above. In addition, the electrochemical simulation device for reduced-order models of multiple active substances provided in the above embodiments and the electrochemical simulation method embodiment for reduced-order models of multiple active substances belong to the same concept. The specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0111] Optionally, the present application also provides a computer-readable storage medium, in which a program is stored, and the program is loaded and executed by a processor to implement the reduced-order model electrochemical simulation method of multiple active substances in the above method embodiment.

[0112] Optionally, the present application also provides a computer product, which includes a computer-readable storage medium, in which a program is stored, and the program is loaded and executed by a processor to implement the reduced-order model electrochemical simulation method of multiple active substances in the above method embodiment.

[0113] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0114] The above-mentioned 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 invention patent. 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 patent of the present application shall be subject to the attached claims.

Claims

1. A reduced-order model electrochemical simulation method for multiple active materials, characterized in that: The method comprises: Simulating placing a plurality of particles in the positive and negative electrodes of the battery cell respectively, wherein the plurality of particles include particles of different active materials and / or particles of different particle sizes; The reduced-order model is established based on the particle parameters of the multiple particles to perform electrochemical simulation on the battery cell, including: modifying the source term of the target key equation that describes and simulates the electrochemical process inside the battery cell in the reduced-order model from the reaction current density of one particle to the sum of the reaction current densities of multiple particles; wherein the target key equation includes a solid phase potential equation, a liquid phase potential equation and an electrolyte lithium ion concentration equation; modifying the external circuit current in the reduced-order model from the reaction current of one particle to the sum of the reaction currents of multiple particles; solving the diffusion equation in the multiple particles to determine the lithium ion concentration in the multiple particles in the reduced-order model; when the multiple particles include particles of different particle sizes, determining the volume fraction of particles of multiple particle sizes in the reduced-order model through the probability density function of the particle size distribution; The volume fractions of the particles of various particle sizes are expressed by the following formula: Where i represents the index of the particle, i is a positive integer; ε s，i The particle radius is r i The volume fraction of the i-th particle, P i The particle radius is r i The probability of the active material particles appearing, ε s is the volume fraction of various particles in the active material corresponding to the i-th particle in the electrode, which is a preset design parameter.

2. The method according to claim 1, characterized in that The external circuit current is expressed by the following formula: I=∑ i ∫J i β i dx; Where i represents the index of the particle, i is a positive integer; J i is the reaction current density of each particle, dx is the length element in the thickness direction of the battery cell, and F is the Faraday constant; r i is the radius of the ith particle, ε s，i is the volume fraction of the i-th particle, β i is the specific surface area of ​​the i-th particle; k i is the reaction rate constant of the i-th particle, c1 is the lithium ion concentration of the electrolyte, c l，ref is the lithium ion concentration of the reference electrolyte, α a +α c =1 is the transfer coefficient, c s,max，i is the maximum lithium ion concentration of each particle, c S，surf，i is the lithium ion concentration on the surface of each particle, R is the ideal gas constant, T is the temperature, η i =φ s -φ l -E eq，i is the overvoltage, where φ s is the solid phase potential, φ l is the liquid phase potential, E eq，i is the equilibrium potential of various particles.

3. The method according to claim 2, characterized in that The source term in the solid phase potential equation and the liquid phase potential equation is the total reaction current density ∑ i J i ; The source term of the liquid phase lithium ion diffusion equation is the total reaction current density of various active material particles ∑ i J i The corresponding lithium ion flux; The solid phase lithium ion diffusion equation is solved in the sub-region corresponding to the particle, and the boundary flux is the reaction current density J corresponding to the active material particle. i .

4. A reduced-order model electrochemical simulation device for multiple active substances, characterized in that: The device comprises: A particle setting module, used to simulate placing a plurality of particles in the positive and negative electrodes of the battery cell respectively, wherein the plurality of particles include particles of different active materials and / or particles of different particle sizes; A model building module is used to build the reduced-order model based on the particle parameters of the multiple particles to perform electrochemical simulation on the battery cell, including: modifying the source term of the target key equation that describes and simulates the electrochemical process inside the battery cell in the reduced-order model from the reaction current density of one particle to the sum of the reaction current densities of multiple particles; wherein the target key equation includes a solid phase potential equation, a liquid phase potential equation and an electrolyte lithium ion concentration equation; modifying the external circuit current in the reduced-order model from the reaction current of one particle to the sum of the reaction currents of multiple particles; solving the diffusion equation in the multiple particles to determine the lithium ion concentration in the multiple particles in the reduced-order model; when the multiple particles include particles of different particle sizes, determining the volume fraction of particles of multiple particle sizes in the reduced-order model through the probability density function of the particle size distribution; The volume fractions of the particles of various particle sizes are expressed by the following formula: Where i represents the index of the particle, i is a positive integer; ε s，i The particle radius is r i The volume fraction of the i-th particle, P i The particle radius is r i The probability of the active material particles appearing, ε s is the volume fraction of various particles in the active material corresponding to the i-th particle in the electrode, which is a preset design parameter.

5. The device according to claim 4, characterized in that The external circuit current is expressed by the following formula: I=∑ i ∫J i β i dx; Where i represents the index of the particle, i is a positive integer; J i is the reaction current density of each particle, dx is the length element in the thickness direction of the battery cell, and F is the Faraday constant; r i is the radius of the ith particle, ε s，i is the volume fraction of the i-th particle, β i is the specific surface area of ​​the i-th particle; k i is the reaction rate constant of the i-th particle, c1 is the lithium ion concentration of the electrolyte, c 1，ref is the lithium ion concentration of the reference electrolyte, α a +α c =1 is the transfer coefficient, c s,max，i is the maximum lithium ion concentration of each particle, c S,surf，i is the lithium ion concentration on the surface of each particle, R is the ideal gas constant, T is the temperature, η i =φ s -φ l -E eq，i is the overvoltage, where φ s is the solid phase potential, φ l is the liquid phase potential, E eq,i is the equilibrium potential of various particles.

6. The device according to claim 5, characterized in that The source term in the solid phase potential equation and the liquid phase potential equation is the total reaction current density ∑ i J i ; The source term of the liquid phase lithium ion diffusion equation is the total reaction current density of various active material particles ∑ i J i The corresponding lithium ion flux; The solid phase lithium ion diffusion equation is solved in the sub-region corresponding to the particle, and the boundary flux is the reaction current density J corresponding to the active material particle. i .

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