Method and device for evaluating electrolyte wetting distribution state of battery cell, and electronic terminal

Abstract

The present invention provides a method and device for evaluating the electrolyte infiltration distribution state of a battery cell, and an electronic terminal. The method for evaluating the electrolyte infiltration distribution state of a battery cell includes: obtaining detection information of the battery cell and detection information of the electrolyte; the detection information of the battery cell includes the gas production rate of the battery cell; the detection information of the electrolyte includes the remaining amount of electrolyte and / or the electrolyte consumption rate; the electrolyte infiltration distribution state of the battery cell is determined based on the detection information of the battery cell and / or the detection information of the electrolyte; the electrolyte infiltration distribution state of the battery cell is the saturation distribution of the electrolyte along the gravity direction in the battery cell. The electrolyte saturation distributed in the battery cell along the gravity direction can be accurately evaluated by detecting the gas production rate of the battery cell, the remaining amount of electrolyte, and the electrolyte consumption rate, thereby characterizing the electrolyte infiltration distribution state of the battery cell.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, and in particular to a method and device for evaluating the electrolyte infiltration distribution state of a battery cell, an electronic terminal, and a computer-readable storage medium. Background Art

[0002] When the battery cell is undergoing a charge and discharge cycle, the negative electrode is embedded with lithium, which causes the lattice to change and the porosity of the material to change. This will cause the electrolyte in the battery cell to be "squeezed out", resulting in partial electrolyte loss, and in severe cases, it may even cause lithium deposition in the battery cell and a "diving" phenomenon. Summary of the invention

[0003] The main technical problem solved by the present invention is to provide a method and device for evaluating the electrolyte infiltration distribution state of a battery cell, an electronic terminal, and a computer-readable storage medium, which can accurately evaluate the electrolyte infiltration distribution state of the battery cell.

[0004] In a first aspect, the present application provides a method for evaluating the electrolyte wetting distribution state of a battery cell, comprising:

[0005] Obtaining detection information of the battery cell and detection information of the electrolyte; the detection information of the battery cell includes the gas generation rate of the battery cell; the detection information of the electrolyte includes the remaining amount of the electrolyte and / or the electrolyte consumption rate;

[0006] The electrolyte infiltration distribution state of the battery cell is determined based on the detection information of the battery cell and / or the detection information of the electrolyte; the electrolyte infiltration distribution state of the battery cell is the saturation distribution of the electrolyte along the gravity direction in the battery cell.

[0007] In the technical solution of the embodiment of the present application, taking into account that the electrolyte inside the battery cell will be consumed during the aging process of the battery cell, the local side reactions of the battery cell will be intensified and gas will be produced. By detecting the gas production rate of the battery cell, the remaining electrolyte amount and the electrolyte consumption rate, the electrolyte saturation of the battery cell distributed along the gravity direction can be accurately evaluated, thereby characterizing the electrolyte infiltration distribution state of the battery cell.

[0008] In some embodiments, the method further comprises:

[0009] Constructing an initial control model; the initial control model includes a fluid penetration model and a multiphase flow motion model;

[0010] The fluid permeation model is used to characterize the relationship between the pressure difference between the first surface and the second surface of the battery cell and the flow rate of the electrolyte. The first surface and the second surface are surfaces arranged along the gravity direction inside the battery cell.

[0011] The multiphase flow motion model is used to characterize the relationship between the pressure of the first surface, the pressure of the second surface, the fluid parameters and the electrolyte saturation when at least two fluids of different phases are in motion.

[0012] In one embodiment, the fluid penetration model is shown in the following formula:

[0013]

[0014]

[0015] Where: p c Indicates the capillary pressure of the battery cell; p ec Indicates the inlet capillary pressure of the battery cell; S W Indicates electrolyte saturation; R c represents the equivalent pore radius of the battery cell; σ represents the surface tension of the battery cell; θ represents the contact angle between the battery cell and the electrolyte.

[0016] In one embodiment, the multiphase flow motion model is shown in the following formula:

[0017]

[0018] Where: Indicates the porosity of the battery cell; Indicates the density of the component; represents the equivalent flux rate of the component; si represents the saturation of the component; t represents time.

[0019] In the technical solution of the embodiment of the present application, considering that the battery cell is essentially composed of porous media and there are two-phase components in the battery cell, an initial control model is constructed through a fluid permeation model and a multiphase flow motion model to facilitate the evaluation of the electrolyte saturation distributed in the battery cell along the gravity direction.

[0020] In some embodiments, determining the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and / or the detection information of the electrolyte includes:

[0021] Inputting detection information of the battery cell and / or detection information of the electrolyte into an initial control model;

[0022] The initial control model is modified based on the detection information of the battery cell and / or the detection information of the electrolyte to obtain an updated control model;

[0023] An updated control model is used to determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte.

[0024] In the technical solution of the embodiment of the present application, the boundary conditions under different states are determined by the detection information of the battery cell and the detection information of the electrolyte, and the initial control module is corrected based on the boundary conditions corresponding to the current state of the battery cell to obtain an updated control module, and then the updated control module is used to determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte, thereby improving the evaluation accuracy.

[0025] In some embodiments, the initial control model is modified based on the detection information of the battery cell and / or the detection information of the electrolyte to obtain an updated control model, including:

[0026] Determine the electrolyte absorption amount corresponding to the second surface based on the detection information of the battery cell and the detection information of the electrolyte;

[0027] The electrolyte intake amount is compared with the electrolyte remaining amount to determine the current boundary conditions; the current boundary conditions include the capillary pressure, gas phase pressure, liquid phase pressure corresponding to the battery cell, and the gas phase saturation and liquid phase saturation corresponding to the second surface of the battery cell, and the gas phase saturation and liquid phase saturation corresponding to the first surface;

[0028] An updated control model is constructed based on the initial control model and the current boundary conditions.

[0029] In the technical solution of the embodiment of the present application, the current state of the battery cell is determined by comparing the amount of electrolyte absorbed corresponding to the second surface of the battery cell with the remaining amount of electrode liquid, and the capillary pressure, gas pressure, liquid pressure corresponding to the battery cell in the current boundary conditions and the gas saturation and liquid saturation corresponding to the second surface of the battery cell and the gas saturation and liquid saturation corresponding to the first surface are determined according to the current state of the battery cell, thereby improving the evaluation accuracy of the updated control model.

[0030] In some embodiments, the detection information of the battery cell also includes the battery cell size, the battery cell permeability, and the pressure difference between the two sides of the battery cell; the detection information of the electrolyte also includes the electrolyte viscosity and the electrolyte density;

[0031] Based on the detection information of the battery cell and the detection information of the electrolyte, determining the electrolyte absorption amount corresponding to the second surface includes:

[0032] Determine the flow rate of the electrolyte corresponding to the preset area of ​​the battery cell based on the battery cell permeability, the pressure difference between the two sides of the battery cell, the electrolyte density, and the electrolyte viscosity;

[0033] Based on the size of the battery cell and the flow rate of the electrolyte, the electrolyte absorption amount corresponding to the second surface is determined.

[0034] In some embodiments, the cell size includes the cell thickness and the cell width;

[0035] Based on the cell size and the flow rate of the electrolyte, the electrolyte absorption amount corresponding to the second surface is determined, including:

[0036] The flow velocity of the electrolyte is spatially integrated to obtain the total flow rate of the electrolyte;

[0037] The product of the thickness of the battery cell and the total flow rate of the electrolyte is integrated over time to obtain the electrolyte absorption amount corresponding to the second surface.

[0038] In some embodiments, based on the detection information of the battery cell and the detection information of the electrolyte, determining the electrolyte absorption amount corresponding to the second surface includes:

[0039] Determine the electrolyte absorption amount corresponding to the second surface based on the following formula;

[0040]

[0041]

[0042] Where: V el Indicates the amount of electrolyte inhaled; width indicates the thickness of the battery cell; l indicates the width of the battery cell; t indicates time; u el It represents the flow velocity of the electrolyte flowing through the second surface of the battery cell; k represents the permeability of the battery cell; μ represents the viscosity of the electrolyte; ▽p represents the pressure difference on both sides of the battery cell; ρ represents the density of the electrolyte; g represents the acceleration of gravity, which is 9.8m / s 2 .

[0043] In the technical solution of the embodiment of the present application, the electrolyte intake amount corresponding to the second surface of the battery cell is determined by the battery cell permeability, the pressure difference on both sides of the battery cell, the electrolyte density, and the electrolyte viscosity, thereby improving the accuracy of the electrolyte intake amount.

[0044] In some embodiments, comparing the electrolyte intake amount with the electrolyte remaining amount to determine the current boundary condition includes:

[0045] In response to the electrolyte absorption amount corresponding to the second surface of the battery cell being less than the electrolyte remaining amount, it is determined that the second surface of the battery cell is in contact with the electrolyte, the first surface of the battery cell is in contact with the gas, and the current boundary condition is the first boundary condition;

[0046] And / or, in response to the electrolyte absorption amount corresponding to the second surface of the battery cell being not less than the remaining electrolyte amount, it is determined that the first surface and the second surface corresponding to the battery cell are both in contact with the gas, and the current boundary condition is the second boundary condition; the first boundary condition is different from the second boundary condition.

[0047] In the technical solution of the embodiment of the present application, based on whether the amount of electrode liquid absorbed corresponding to the second surface of the battery cell is less than the remaining amount of electrolyte, it is determined whether the first surface and the second surface of the battery cell are in contact with the liquid phase or released from the gas phase, and then it is determined whether the current boundary condition is the first boundary condition or the second boundary condition, thereby improving the evaluation accuracy of the updated control model.

[0048] In some embodiments, the initial control model is modified based on the detection information of the battery cell and / or the detection information of the electrolyte to obtain an updated control model, including:

[0049] The multiphase flow motion model corresponding to the gas phase component in the initial control model is corrected based on the gas production rate of the battery cell to obtain a corrected gas phase flow motion model; the multiphase flow motion model corresponding to the liquid phase component in the initial control model is corrected based on the electrolyte consumption rate to obtain a corrected liquid phase flow motion model;

[0050] An updated control model is constructed based on the revised gas phase flow motion model, the revised liquid phase flow motion model and the fluid penetration model in the initial control model.

[0051] In the technical solution of the embodiment of the present application, the initial control model is corrected according to the gas production of the battery cell and the electrolyte consumption, thereby improving the evaluation accuracy of the updated control model.

[0052] In some embodiments, the multiphase flow motion model corresponding to the gas phase component in the initial control model is corrected based on the gas production rate of the battery cell to obtain a corrected gas phase flow motion model, including:

[0053] The corrected gas phase flow motion model is shown in the following formula:

[0054]

[0055] Where: Q air Indicates the gas production rate of the battery cell; Indicates the porosity of the battery cell; Indicates the density of the gas phase component; Indicates the saturation of gas phase components; represents the equivalent flux rate of gas phase components; t represents time;

[0056] And / or, based on the electrolyte consumption rate, the multiphase flow motion model corresponding to the liquid phase component in the initial control model is corrected to obtain a corrected liquid phase flow motion model, including:

[0057] The corrected liquid phase flow motion model is shown in the following formula:

[0058]

[0059] Where: Q elIndicates the electrolyte consumption rate; Indicates the density of the liquid component; Indicates the saturation of liquid components; represents the equivalent flux rate of the liquid phase component; t represents time.

[0060] In the technical solution of the embodiment of the present application, the multiphase flow motion model corresponding to the gas phase component in the initial control model is corrected according to the gas production rate of the battery cell; the multiphase flow motion equation corresponding to the liquid phase component is corrected according to the electrolyte consumption rate, so that the updated control model obtained can accurately evaluate the electrolyte wetting distribution state of the battery cell.

[0061] In a second aspect, the present application provides a device for evaluating the electrolyte infiltration distribution state of a battery cell, comprising:

[0062] An acquisition module is used to acquire detection information of the battery cell and detection information of the electrolyte; the detection information of the battery cell includes the gas generation rate of the battery cell; the detection information of the electrolyte includes the remaining amount of the electrolyte and / or the consumption rate of the electrolyte;

[0063] The evaluation module is used to determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and / or the detection information of the electrolyte; the electrolyte infiltration distribution state of the battery cell is the saturation distribution of the electrolyte along the gravity direction in the battery cell.

[0064] In a third aspect, the present application provides an electronic terminal, which includes a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor is used to execute program data to implement the steps in the method for evaluating the electrolyte wetting distribution state of a battery cell as described in the first aspect above.

[0065] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the method for evaluating the electrolyte wetting distribution state of a battery cell in the first aspect described above.

[0066] It can be understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0067] 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, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0069] Figure 1 It is a schematic diagram of the distribution of electrolyte in the battery cell in the height direction of the battery cell over time during the charging and discharging process;

[0070] Figure 2 It is a schematic flow chart of a method for evaluating the electrolyte wetting distribution state of a battery cell provided in the present application;

[0071] Figure 3 yes Figure 2 A schematic flow chart of step S2 in a method for evaluating the electrolyte wetting distribution state of a battery cell is provided;

[0072] Figure 4 yes Figure 3 A schematic flow chart of a specific embodiment of step S22 in a method for evaluating electrolyte wetting distribution state of a battery cell is provided;

[0073] Figure 5 yes Figure 4 A schematic flow chart of step S2211 in the provided method for evaluating the electrolyte wetting distribution state of a battery cell;

[0074] Figure 6 yes Figure 3 A schematic flow chart of another specific embodiment of step S22 in the provided method for evaluating the electrolyte wetting distribution state of a battery cell;

[0075] Figure 7 It is a flow chart of a specific embodiment of a method for evaluating the electrolyte infiltration distribution state of a battery cell provided by the present application;

[0076] Figure 8 It is the curve of the amount of electrolyte absorbed by the battery cell per unit thickness changing with time;

[0077] Fig. 9 is a schematic diagram of the distribution of the electrolyte saturation of the battery cell along with the height of the battery cell at different times in one embodiment;

[0078] Fig.10 is a schematic diagram of the distribution of the electrolyte saturation of the battery cell along with the height of the battery cell at different times in another embodiment;

[0079] Fig.11 It is a schematic diagram of a framework of an embodiment of a device for evaluating the electrolyte infiltration distribution state of a battery cell provided by the present application;

[0080] Fig.12 It is a schematic diagram of the framework of an embodiment of an electronic terminal provided by the present application;

[0081] Fig.13 It is a schematic diagram of a framework of an embodiment of a computer-readable storage medium provided by the present application. DETAILED DESCRIPTION

[0082] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0083] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0084] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0085] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0086] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0087] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0088] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0089] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0090] As batteries move toward higher energy density, the thickness of the cell coating will also increase. Thicker porous electrode materials have problems with the liquid phase under fast charging conditions, so it is necessary to detect the electrolyte infiltration of the cell during the cell cycle.

[0091] The Lagrange multiplier method can be used to construct the model boundary conditions in which the bottom of the battery cell in the direction of gravity is in contact with the electrolyte and the top of the battery cell in the direction of gravity is in contact with the air. The Lagrange multiplier method is a mathematical method for solving the extreme value of a function under certain constraints. The core idea of ​​the Lagrange multiplier method is to transform the original constrained optimization problem into an unconstrained optimization problem by introducing new variables (i.e., Lagrange multipliers). This method is suitable for solving optimization problems with equality constraints, and multiple constraints can be handled by introducing more Lagrange multipliers.

[0092] See also Figure 1 , Figure 1 It is a schematic diagram of the distribution of electrolyte in the battery cell over time in the height direction of the battery cell during the charge and discharge process.

[0093] This scheme can realize the input of graphite negative electrode expansion law and output Figure 1The distribution of electrolyte with cell height and time shown helps predict the electrolyte wetting performance of the cell during the cycle. The current model boundary condition for testing the electrolyte wetting performance of the cell is that the bottom of the cell is in contact with the electrolyte and the top of the cell is in contact with the air. However, during the aging process of the cell, the boundary conditions of the cell will change. That is, when the cell is severely aged, both the bottom and top of the cell are in contact with the air. Therefore, the current model boundary conditions are not suitable for testing the electrolyte wetting performance of cells with severe cell aging.

[0094] See also Figure 2 , Figure 2 It is a flow chart of the method for evaluating the electrolyte wetting distribution state of a battery cell provided in the present application.

[0095] The present application provides a method for evaluating the electrolyte infiltration distribution state of a battery cell, which specifically includes the following steps.

[0096] S1: Acquire detection information of the battery cell and detection information of the electrolyte; the detection information of the battery cell includes the gas generation rate of the battery cell; the detection information of the electrolyte includes the remaining amount of the electrolyte and / or the electrolyte consumption rate.

[0097] S2: Determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and / or the detection information of the electrolyte; the electrolyte infiltration distribution state of the battery cell is the saturation distribution of the electrolyte along the gravity direction in the battery cell.

[0098] In the technical solution of the embodiment of the present application, taking into account that the electrolyte inside the battery cell will be consumed during the aging process of the battery cell, the local side reactions of the battery cell will be intensified and gas will be produced. By detecting the gas production rate of the battery cell, the remaining electrolyte amount and the electrolyte consumption rate, the electrolyte saturation of the battery cell distributed along the gravity direction can be accurately evaluated, thereby characterizing the electrolyte infiltration distribution state of the battery cell.

[0099] In some embodiments, the method for evaluating the electrolyte wetting distribution state of a battery cell further includes: constructing an initial control model; the initial control model includes a fluid penetration model and a multiphase flow motion model.

[0100] Since the Re number of the electrolyte movement process inside the battery cell is small, the effect of electrolyte turbulence in the battery cell can be ignored, and the overall flow of the electrolyte can be regarded as laminar flow. After modeling the control body inside the battery cell, a fluid permeation model can be constructed according to Darcy's law. Among them, the Reynolds number (Re) is an important dimensionless number used to determine the type of fluid flow (laminar or turbulent). When the Reynolds number is small, it usually indicates that the flow is in a laminar state. Inside lithium-ion batteries (or other batteries), the flow of electrolyte is usually in a laminar state because the Reynolds number is small.

[0101] Among them, the fluid permeation model is used to characterize the relationship between the pressure difference between the first surface and the second surface of the battery cell and the flow rate of the electrolyte. The first surface and the second surface are surfaces arranged along the direction of gravity inside the battery cell.

[0102] In a specific embodiment, the fluid penetration model is shown in the following formula.

[0103] (Formula 1)

[0104] (Formula 2)

[0105] Where: p c Indicates the capillary pressure of the battery cell; p ec Indicates the inlet capillary pressure of the battery cell; S W Indicates electrolyte saturation; R c represents the equivalent pore radius of the battery cell; σ represents the surface tension of the battery cell; θ represents the contact angle between the battery cell and the electrolyte.

[0106] The multiphase flow motion model is used to characterize the relationship between the pressure of the first surface, the pressure of the second surface, the fluid parameters and the electrolyte saturation when at least two fluids of different phases are in motion.

[0107] Since the battery cell problem is a type of multiphase flow problem, its driving force is the extrusion and reabsorption of electrode liquid caused by the change in porosity of the porous medium in the battery cell. Multiphase flow problem refers to the flow phenomenon in which two or more immiscible fluids (such as liquid and gas, oil and water, etc.) exist simultaneously in a system. Specifically, the multiphase flow motion model is constructed through the multiphase flow equation.

[0108] In a specific embodiment, the multiphase flow motion model is shown in the following formula.

[0109] (Formula 3)

[0110] Where: Indicates the porosity of the battery cell; Indicates the density of the component; represents the equivalent flux rate of the component; si represents the saturation of the component; t represents time.

[0111] Specifically, the multiphase flow motion model corresponding to the gas phase component is shown in the following formula.

[0112] (Formula 4)

[0113] Specifically, the multiphase flow motion model corresponding to the liquid phase component is shown in the following formula.

[0114] (Formula 5)

[0115] In the technical solution of the embodiment of the present application, considering that the battery cell is essentially composed of porous media and there are two-phase components in the battery cell, an initial control model is constructed through a fluid permeation model and a multiphase flow motion model to facilitate the evaluation of the electrolyte saturation distributed in the battery cell along the gravity direction.

[0116] In some embodiments, the step of acquiring detection information of the battery cell and detection information of the electrolyte in step S1 includes the following specific implementation methods.

[0117] Specifically, the detection information of the battery cell and the detection information of the electrolyte can be detected in real time, and offline data can also be obtained. The offline data includes the detection information of the battery cell and the detection information of the electrolyte. The battery cell includes a positive electrode and a negative electrode and a separator arranged between the positive electrode and the negative electrode. Among them, the material of the negative electrode can be graphite.

[0118] The detection information of the battery cell includes the battery cell size, battery cell permeability, and pressure difference on both sides of the battery cell. Among them, the battery cell size includes the battery cell thickness, battery cell width and battery cell length. The battery cell is curled along the length direction. The detection information of the battery cell also includes the battery cell gas production area and the battery cell gas production rate corresponding to the battery cell gas production area. The detection information of the battery cell also includes the graphite expansion and contraction curves.

[0119] The detection information of the electrolyte includes the remaining amount of the electrolyte and / or the electrolyte consumption rate. The detection information of the electrolyte also includes the electrolyte viscosity and the electrolyte density.

[0120] In some embodiments, the step of determining the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and / or the detection information of the electrolyte in step S2 includes the following specific implementation methods.

[0121] See also Figure 3 , Figure 3 yes Figure 2 A schematic flow chart of step S2 in a method for evaluating the electrolyte wetting distribution state of a battery cell is provided.

[0122] S21: Inputting the detection information of the battery cell and / or the detection information of the electrolyte into the initial control model.

[0123] Specifically, the graphite expansion and contraction curve of the battery cell, the battery cell height, the electrolyte viscosity, the electrolyte density, the remaining amount of electrolyte in the battery cell, the electrolyte consumption rate, the battery cell gas generation position and the battery cell gas generation rate are input into the initial control model.

[0124] S22: Modifying the initial control model based on the detection information of the battery cell and / or the detection information of the electrolyte to obtain an updated control model.

[0125] In some embodiments, the initial control model is modified according to the consumption of the electrolyte to obtain an updated control model.

[0126] See also Figure 4 , Figure 4 yes Figure 3 A flowchart of a specific embodiment of step S22 in a method for evaluating the electrolyte wetting distribution state of a battery cell is provided.

[0127] S2211: Determine the electrolyte absorption amount corresponding to the second surface based on the detection information of the battery cell and the detection information of the electrolyte.

[0128] See also Figure 5 , Figure 5 yes Figure 4 A schematic flow chart of step S2211 in a method for evaluating the electrolyte wetting distribution state of a battery cell is provided.

[0129] S2211a: Determine the flow rate of the electrolyte corresponding to the preset area of ​​the battery cell based on the permeability of the battery cell, the pressure difference on both sides of the battery cell, the electrolyte density, and the electrolyte viscosity.

[0130] Specifically, the flow rate of the electrolyte corresponding to the preset area of ​​the battery cell is determined based on the following formula.

[0131] (Formula 6)

[0132] Where: u el It represents the flow rate of the electrolyte flowing through the preset area of ​​the battery cell; k represents the permeability of the battery cell; μ represents the viscosity of the electrolyte; ▽p represents the pressure difference on both sides of the battery cell; ρ represents the density of the electrolyte; g represents the acceleration of gravity, which is 9.8m / s 2 .

[0133] S2211b: Based on the size of the battery cell and the flow rate of the electrolyte, determine the electrolyte absorption amount corresponding to the second surface.

[0134] In some embodiments, the flow velocity of the electrolyte is spatially integrated to obtain the total flow rate of the electrolyte; the product of the thickness of the battery cell and the total flow rate of the electrolyte is temporally integrated to obtain the electrolyte absorption amount corresponding to the second surface.

[0135] Specifically, the electrolyte absorption amount corresponding to the second surface is determined based on the following formula.

[0136] (Formula 7)

[0137] Where: V el Indicates the amount of electrolyte inhaled; width indicates the thickness of the battery cell; l indicates the width of the battery cell; t indicates time; u elIndicates the flow rate of the electrolyte flowing through the second surface of the battery cell.

[0138] In the technical solution of the embodiment of the present application, the electrolyte intake amount corresponding to the second surface of the battery cell is determined by the battery cell permeability, the pressure difference on both sides of the battery cell, the electrolyte density, and the electrolyte viscosity, thereby improving the accuracy of the electrolyte intake amount.

[0139] S2212: Compare the amount of electrolyte inhaled with the remaining amount of electrolyte to determine the current boundary conditions; the current boundary conditions include the capillary pressure, gas pressure, liquid pressure corresponding to the battery cell, and the gas saturation and liquid saturation corresponding to the second surface of the battery cell, and the gas saturation and liquid saturation corresponding to the first surface.

[0140] The gas phase pressure P air is the capillary pressure P of the battery cell c and liquid pressure P el The difference, that is, P air =P c -P el .

[0141] In some embodiments, in response to the electrolyte absorption amount corresponding to the second surface of the battery cell being less than the electrolyte remaining amount, it is determined that the second surface of the battery cell is in contact with the electrolyte and the first surface of the battery cell is in contact with the gas, and the current boundary condition is the first boundary condition. The first boundary condition is that the capillary pressure, gas phase pressure and liquid phase pressure of the battery cell are all zero, that is, P air =0,P c =0,P el = 0. The gas phase saturation corresponding to the second surface of the battery cell is 0, and the liquid phase saturation is 1, and the gas phase saturation corresponding to the first surface of the battery cell is 1, and the liquid phase saturation is 0.

[0142] The updated control model constructed by using the initial control model and the first boundary condition evaluates the wetting state of the battery cell according to the detection information of the battery cell and the detection information of the electrolyte. In the wetting state of the battery cell, the saturation of the electrolyte distributed near the first surface of the battery cell is less than the saturation of the electrolyte distributed near the second surface of the battery cell.

[0143] In a specific embodiment, the aging process of the battery cell is accompanied by the consumption of electrolyte. In fact, after the battery cell has been charged and discharged for about 200 cycles, the electrolyte inside the battery cell has been consumed. Specifically, it refers to the electrolyte outside after the free electrolyte is consumed and the electrode is completely absorbed. At this time, when the battery cell absorbs liquid again, the second surface of the battery cell will change from "electrolyte environment" to "no electrolyte environment". Therefore, it is necessary to improve the boundary conditions of the initial control model.

[0144] In some embodiments, in response to the electrolyte absorption amount corresponding to the second surface of the battery cell being not less than the electrolyte remaining amount, it is determined that both the first surface and the second surface corresponding to the battery cell are in contact with the gas, and the current boundary condition is the second boundary condition; the first boundary condition is different from the second boundary condition. The second boundary condition is that the gas phase pressure is zero and the capillary pressure of the battery cell is the inlet capillary pressure of the battery cell, that is, P air =0,P c =P ec , P el =-P ec The gas phase saturation corresponding to the second surface of the battery cell is 1, and the liquid phase saturation is 0. The gas phase saturation corresponding to the first surface of the battery cell is 1, and the liquid phase saturation is 0.

[0145] The updated control model constructed by using the initial control model and the second boundary condition evaluates the wetting state of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte. In the wetting state of the battery cell, the electrolyte saturation distributed near the first surface of the battery cell and the electrolyte saturation distributed near the second surface of the battery cell are both less than the electrolyte saturation distributed in the middle of the battery cell, and the electrolyte saturation gradually increases when the second surface of the battery cell points to the middle of the battery cell; the electrolyte saturation gradually increases when the first surface of the battery cell points to the middle of the battery cell.

[0146] In the technical solution of the embodiment of the present application, based on whether the amount of electrode liquid absorbed corresponding to the second surface of the battery cell is less than the remaining amount of electrolyte, it is determined whether the first surface and the second surface of the battery cell are in contact with the liquid phase or released from the gas phase, and then it is determined whether the current boundary condition is the first boundary condition or the second boundary condition, thereby improving the evaluation accuracy of the updated control model.

[0147] S2213: Construct an updated control model based on the initial control model and current boundary conditions.

[0148] In the technical solution of the embodiment of the present application, the current state of the battery cell is determined by comparing the amount of electrolyte absorbed corresponding to the second surface of the battery cell with the remaining amount of electrode liquid, and the capillary pressure, gas pressure, liquid pressure corresponding to the battery cell in the current boundary conditions and the gas saturation and liquid saturation corresponding to the second surface of the battery cell and the gas saturation and liquid saturation corresponding to the first surface are determined according to the current state of the battery cell, thereby improving the evaluation accuracy of the updated control model.

[0149] In some embodiments, the initial control model is modified according to the gas generation condition of the battery cell to obtain an updated control model.

[0150] See also Figure 6 , Figure 6 yes Figure 3A schematic flow chart of another specific embodiment of step S22 in the method for evaluating the electrolyte wetting distribution state of a battery cell is provided.

[0151] Specifically, the gas generation rate of the battery cell and the electrolyte consumption rate are both detected from the gas generation area of ​​the battery cell. Both the gas generation rate of the battery cell and the electrolyte consumption rate are positive numbers.

[0152] S2221: Based on the gas production rate of the battery cell, the multiphase flow motion model corresponding to the gas phase components in the initial control model is corrected to obtain a corrected gas phase flow motion model.

[0153] In some embodiments, the modified gas phase flow motion model is shown in the following formula:

[0154] (Formula 8)

[0155] Where: Q air Indicates the gas production rate of the battery cell; Indicates the porosity of the battery cell; Indicates the density of the gas phase component; Indicates the saturation of gas phase components; represents the equivalent flux rate of gas phase components; t represents time.

[0156] S2222: Based on the electrolyte consumption rate, the multiphase flow motion model corresponding to the liquid phase component in the initial control model is corrected to obtain a corrected liquid phase flow motion model.

[0157] In some embodiments, the modified liquid phase flow motion model is shown in the following formula:

[0158] (Formula 9)

[0159] Where: Q el Indicates the electrolyte consumption rate; Indicates the density of the liquid component; Indicates the saturation of liquid components; represents the equivalent flux rate of the liquid phase component; t represents time.

[0160] In the technical solution of the embodiment of the present application, the multiphase flow motion model corresponding to the gas phase component in the initial control model is corrected according to the gas production rate of the battery cell; the multiphase flow motion equation corresponding to the liquid phase component is corrected according to the electrolyte consumption rate, so that the updated control model obtained can accurately evaluate the electrolyte wetting distribution state of the battery cell.

[0161] S2223: An updated control model is constructed based on the corrected gas phase flow motion model, the corrected liquid phase flow motion model and the fluid penetration model in the initial control model.

[0162] Specifically, an update control model is used to evaluate the wetting state of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte; the wetting state of the battery cell is that the electrolyte saturation corresponding to the gas production area of ​​the battery cell is less than the electrolyte saturation corresponding to other areas of the battery cell except the gas production area.

[0163] In the technical solution of the embodiment of the present application, the initial control model is corrected according to the gas production of the battery cell and the electrolyte consumption, thereby improving the evaluation accuracy of the updated control model.

[0164] S23: Determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte using the updated control model.

[0165] In the technical solution of the embodiment of the present application, the boundary conditions under different states are determined by the detection information of the battery cell and the detection information of the electrolyte, and the initial control module is corrected based on the boundary conditions corresponding to the current state of the battery cell to obtain an updated control module, and then the updated control module is used to determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte, thereby improving the evaluation accuracy.

[0166] See also Figure 7 , Figure 7 It is a flow chart of a specific embodiment of a method for evaluating the electrolyte wetting distribution state of a battery cell provided in the present application.

[0167] During the charge and discharge process of the battery, start collecting the detection information of the battery cell and the detection information of the electrolyte, and determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte. Determine whether the evaluation of the electrolyte infiltration distribution state of the battery cell is completed. If the evaluation is completed, there is no need to collect the detection information of the battery cell and the detection information of the electrolyte. If the evaluation of the electrolyte infiltration distribution state of the battery cell has not yet ended, determine the electrolyte suction amount corresponding to the second surface of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte. If the electrode liquid suction amount corresponding to the second surface of the battery cell is less than the remaining amount of the electrolyte, then build an updated control model based on the first boundary condition and the initial control model to evaluate the electrolyte infiltration distribution state of the battery cell. If the electrode liquid suction amount corresponding to the second surface of the battery cell is not less than the remaining amount of the electrolyte, switch the boundary conditions, and build an updated control model based on the second boundary condition and the initial control model to evaluate the electrolyte infiltration distribution state of the battery cell.

[0168] Based on the update control model in the above embodiment, the electrolyte wetting performance of the battery cells with different viscosity, height, capillary pressure and other parameters throughout the life cycle can be evaluated.

[0169] See also Figure 8 and Fig. 9 , Figure 8It is the curve of the amount of electrolyte absorbed by the battery cell per unit thickness changing with time; Fig. 9 It is a schematic diagram of the distribution of the electrolyte saturation of the battery cell along with the height of the battery cell at different times in an embodiment.

[0170] In a specific embodiment, during the charge and discharge process of the battery cell, the detection information of the battery cell and the detection information of the electrolyte corresponding to each time within 600s are continuously collected. The detection information of the battery cell includes the battery cell size, the battery cell permeability, and the pressure difference on both sides of the battery cell. Among them, the battery cell size includes the battery cell thickness, the battery cell width and the battery cell length. The detection information of the battery cell also includes the graphite expansion and contraction curves. The detection information of the electrolyte includes the remaining electrolyte, the electrolyte viscosity and the electrolyte density. Based on the battery cell permeability, the pressure difference on both sides of the battery cell, the electrolyte density and the electrolyte viscosity, the flow rate of the electrolyte corresponding to the preset area of ​​the battery cell is determined. Based on the battery cell size and the flow rate of the electrolyte, the amount of electrolyte absorbed by the second surface corresponding to the second surface is determined. The amount of electrolyte absorbed by the unit thickness of the specific battery cell within the 600s period is as follows: Figure 8 When the electrolyte retention per unit thickness inside the battery cell is 0.00027m 2 When the electrolyte suction amount is not less than the electrolyte remaining amount, the battery cell stops sucking electrolyte, and the current boundary condition in the update control model is switched from the first boundary condition to the second boundary condition to evaluate the electrolyte infiltration distribution state of the battery cell.

[0171] like Fig. 9 It can be seen that the time period for the current boundary condition in the updated control model to switch from the first boundary condition to the second boundary condition is within the range of 250s~350s. At 200s, the second surface of the battery cell is still in contact with a sufficient amount of electrolyte. Therefore, the electrode liquid saturation corresponding to the second surface of the battery cell is 1. In the infiltration state of the battery cell, the electrolyte saturation distributed near the first surface of the battery cell is less than the electrolyte saturation distributed near the second surface of the battery cell. At 400s, the electrolyte inhalation amount is not less than the electrolyte remaining amount, the second surface of the battery cell has been in contact with the air, and the second surface of the battery cell has been poorly infiltrated. In the infiltration state of the battery cell, the electrolyte saturation distributed near the first surface of the battery cell and the electrolyte saturation distributed near the second surface of the battery cell are both less than the electrolyte saturation distributed in the middle of the battery cell, and the second surface of the battery cell points to the middle direction of the battery cell, and the electrolyte saturation gradually increases; the first surface of the battery cell points to the middle direction of the battery cell, and the electrolyte saturation gradually increases.

[0172] See also Fig.10 , Fig.10 Schematic diagram of the distribution of electrolyte saturation of a battery cell along with the height of the battery cell at different times in another embodiment.

[0173] In a specific embodiment, during the charge and discharge process of the battery cell, the detection information of the battery cell and the detection information of the electrolyte corresponding to each time within 600s are continuously collected. The detection information of the battery cell includes the battery cell size, the battery cell permeability, and the pressure difference on both sides of the battery cell. Among them, the battery cell size includes the battery cell thickness, the battery cell width and the battery cell length. The detection information of the battery cell also includes the gas production area of ​​the battery cell and the gas production rate of the battery cell corresponding to the gas production area of ​​the battery cell. The gas production area of ​​the battery cell is the middle of the battery cell, and the gas production rate of the battery cell is 0.005m 3 The detection information of the battery cell also includes the graphite expansion and contraction curves. The detection information of the electrolyte includes the remaining amount of electrolyte and / or the electrolyte consumption rate. The detection information of the electrolyte also includes the electrolyte viscosity and electrolyte density.

[0174] Since there is a side reaction area in the middle of the battery cell, the gas production area, which continuously produces gas, even if the second surface of the battery cell is in contact with a sufficient amount of electrolyte, the electrolyte saturation in the middle will decrease, resulting in poor wetting. The electrolyte saturation corresponding to the gas production area of ​​the battery cell is less than the electrolyte saturation corresponding to other areas except the gas production area of ​​the battery cell.

[0175] See also Fig.11 , Fig.11 It is a schematic diagram of the framework of an embodiment of a device for evaluating the electrolyte wetting distribution state of a battery cell provided in the present application.

[0176] This embodiment provides an electrolyte infiltration distribution state evaluation device 60 for a battery cell. The electrolyte infiltration distribution state evaluation device 60 for a battery cell includes an acquisition module 61 and an evaluation module 62 .

[0177] The acquisition module 61 is used to acquire detection information of the battery cell and detection information of the electrolyte; the detection information of the battery cell includes the gas generation rate of the battery cell; the detection information of the electrolyte includes the remaining amount of the electrolyte and / or the electrolyte consumption rate.

[0178] The evaluation module 62 is used to determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and / or the detection information of the electrolyte; the electrolyte infiltration distribution state of the battery cell is the saturation distribution of the electrolyte along the gravity direction in the battery cell.

[0179] In the technical solution of the embodiment of the present application, taking into account that the electrolyte inside the battery cell will be consumed during the aging process of the battery cell, the local side reactions of the battery cell will be intensified and gas will be produced. By detecting the gas production rate of the battery cell, the remaining electrolyte amount and the electrolyte consumption rate, the electrolyte saturation of the battery cell distributed along the gravity direction can be accurately evaluated, thereby characterizing the electrolyte infiltration distribution state of the battery cell.

[0180] See also Fig.12 , Fig.12 It is a schematic diagram of the framework of an embodiment of an electronic terminal provided by the present application.

[0181] The electronic terminal 80 includes a memory 81 and a processor 82 coupled to each other, and the processor 82 is used to execute program instructions stored in the memory 81 to implement the steps of the embodiment of the electrolyte infiltration distribution state evaluation method of any battery cell described above. In a specific implementation scenario, the electronic terminal 80 may include but is not limited to: a microcomputer, a server, and in addition, the electronic terminal 80 may also include a mobile device such as a laptop computer and a tablet computer, which is not limited here.

[0182] Specifically, the processor 82 is used to control itself and the memory 81 to implement the steps of the embodiment of the electrolyte infiltration distribution state evaluation method for any of the above-mentioned batteries. The processor 82 can also be called a CPU (Central Processing Unit). The processor 82 may be an integrated circuit chip with signal processing capabilities. The processor 82 can also be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field-programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. In addition, the processor 82 can be implemented by an integrated circuit chip.

[0183] See also Fig.13 , Fig.13 It is a schematic diagram of a framework of an embodiment of a computer-readable storage medium provided by the present application.

[0184] The computer-readable storage medium 90 stores program instructions 901 that can be executed by a processor, and the program instructions 901 are used to implement the steps of any of the above-mentioned embodiments of the method for evaluating the electrolyte wetting distribution state of a battery cell.

[0185] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0186] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0187] In the several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation described above is only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation, such as units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0188] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0189] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of each implementation method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

[0190] The above are only implementation modes of the present invention, and are not intended to limit the patent protection scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for evaluating the electrolyte infiltration distribution state of a battery cell, characterized in that: include: Constructing an initial control model; Acquire detection information of the battery cell and detection information of the electrolyte; the detection information of the battery cell includes the gas generation rate of the battery cell; the detection information of the electrolyte includes the remaining amount of electrolyte and / or the consumption rate of electrolyte; Determining the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and / or the detection information of the electrolyte; the electrolyte infiltration distribution state of the battery cell is the saturation distribution of the electrolyte along the gravity direction in the battery cell; The determining the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and / or the detection information of the electrolyte includes: Inputting the detection information of the battery cell and / or the detection information of the electrolyte into the initial control model; Modifying the initial control model based on the detection information of the battery cell and / or the detection information of the electrolyte to obtain an updated control model; Determining the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte using the update control model; Among them, the initial control model includes a fluid permeation model and a multiphase flow motion model; wherein the fluid permeation model is used to characterize the relationship between the pressure difference between the first surface and the second surface of the battery cell and the flow velocity of the electrolyte, and the first surface and the second surface are surfaces arranged inside the battery cell along the direction of gravity; the multiphase flow motion model is used to characterize the relationship between the pressure of the first surface, the pressure of the second surface, the fluid parameters and the electrolyte saturation when at least two fluids in different phases are in motion.

2. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 1, characterized in that: The modifying the initial control model based on the detection information of the battery cell and / or the detection information of the electrolyte to obtain an updated control model includes: Determining an electrolyte absorption amount corresponding to the second surface based on the detection information of the battery cell and the detection information of the electrolyte; Compare the electrolyte intake amount with the electrolyte remaining amount to determine the current boundary conditions; the current boundary conditions include the capillary pressure, gas phase pressure, liquid phase pressure corresponding to the battery cell, and the gas phase saturation and liquid phase saturation corresponding to the second surface of the battery cell, and the gas phase saturation and liquid phase saturation corresponding to the first surface; The updated control model is constructed based on the initial control model and the current boundary conditions.

3. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 2, characterized in that: The detection information of the battery cell also includes the battery cell size, the battery cell permeability, and the pressure difference between the two sides of the battery cell; the detection information of the electrolyte also includes the electrolyte viscosity and the electrolyte density; The determining, based on the detection information of the battery cell and the detection information of the electrolyte, the electrolyte absorption amount corresponding to the second surface includes: Determining a flow rate of the electrolyte corresponding to a preset area of ​​the battery cell based on the battery cell permeability, the pressure difference between the two sides of the battery cell, the electrolyte density, and the electrolyte viscosity; The electrolyte absorption amount corresponding to the second surface is determined based on the size of the battery cell and the flow rate of the electrolyte.

4. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 3, characterized in that: The battery cell size includes battery cell thickness and battery cell width; The determining, based on the size of the battery cell and the flow rate of the electrolyte, the amount of electrolyte absorbed by the second surface corresponding to the second surface includes: Performing spatial integration on the flow velocity of the electrolyte to obtain the total flow rate of the electrolyte; The product of the thickness of the battery core and the total flow rate of the electrolyte is time-integrated to obtain the electrolyte absorption amount corresponding to the second surface.

5. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 2, characterized in that: The comparing the electrolyte intake amount with the electrolyte remaining amount to determine the current boundary condition includes: In response to the electrolyte absorption amount corresponding to the second surface of the battery cell being less than the electrolyte remaining amount, it is determined that the second surface of the battery cell is in contact with the electrolyte, the first surface of the battery cell is in contact with the gas, and the current boundary condition is the first boundary condition; And / or, in response to the electrolyte absorption amount corresponding to the second surface of the battery cell being not less than the remaining electrolyte amount, it is determined that the first surface and the second surface corresponding to the battery cell are both in contact with the gas, and the current boundary condition is the second boundary condition; the first boundary condition is different from the second boundary condition.

6. The method for evaluating the electrolyte infiltration distribution state of a battery cell according to any one of claims 2 to 5, characterized in that: The modifying the initial control model based on the detection information of the battery cell and / or the detection information of the electrolyte to obtain an updated control model includes: Based on the gas production rate of the battery cell, the multiphase flow motion model corresponding to the gas phase component in the initial control model is corrected to obtain a corrected gas phase flow motion model; based on the electrolyte consumption rate, the multiphase flow motion model corresponding to the liquid phase component in the initial control model is corrected to obtain a corrected liquid phase flow motion model; The updated control model is constructed based on the modified gas phase flow motion model, the modified liquid phase flow motion model and the fluid penetration model in the initial control model.

7. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 6, characterized in that: The multiphase flow motion model corresponding to the gas phase component in the initial control model is corrected based on the gas production rate of the battery cell to obtain a corrected gas phase flow motion model, including: The modified gas phase flow motion model is shown in the following formula: Where: Indicates the gas generation rate of the battery cell; represents the porosity of the battery cell; represents the density of the gas phase component; represents the saturation of the gas phase component; represents the equivalent flux rate of the gas phase component; t represents time; And / or, the multiphase flow motion model corresponding to the liquid phase component in the initial control model is corrected based on the electrolyte consumption rate to obtain a corrected liquid phase flow motion model, including: The modified liquid phase flow motion model is shown in the following formula: Where: Q el represents the electrolyte consumption rate; represents the density of the liquid phase component; Indicates the saturation of the liquid phase component; represents the equivalent flux rate of the liquid phase component; t represents time.

8. A device for evaluating the electrolyte infiltration distribution state of a battery cell, characterized in that: include: An acquisition module, used to acquire detection information of the battery cell and detection information of the electrolyte; the detection information of the battery cell includes a gas generation rate of the battery cell; The detection information of the electrolyte includes the remaining amount of electrolyte and / or the consumption rate of electrolyte; An evaluation module, used to determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and / or the detection information of the electrolyte; the electrolyte infiltration distribution state of the battery cell is the saturation distribution of the electrolyte along the gravity direction in the battery cell; and is also used to input the detection information of the battery cell and / or the detection information of the electrolyte into an initial control model; based on the detection information of the battery cell and / or the detection information of the electrolyte, the initial control model is corrected to obtain an updated control model; The updated control model is used to determine the electrolyte infiltration distribution state of the battery cell based on the detection information of the battery cell and the detection information of the electrolyte; wherein the initial control model includes a fluid permeation model and a multiphase flow motion model; wherein the fluid permeation model is used to characterize the relationship between the pressure difference between the first surface and the second surface of the battery cell and the flow velocity of the electrolyte, and the first surface and the second surface are surfaces arranged inside the battery cell along the direction of gravity; the multiphase flow motion model is used to characterize the relationship between the pressure of the first surface, the pressure of the second surface, fluid parameters and the electrolyte saturation when at least two fluids in different phases are in motion.

9. An electronic terminal, characterized in that: The electronic terminal includes a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor is used to execute the program to implement the steps in the method for evaluating the electrolyte wetting distribution state of the battery cell as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the steps in the method for evaluating the electrolyte wetting distribution state of the battery cell as claimed in any one of claims 1 to 7 are implemented.

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