Battery cell electrolyte infiltration distribution state evaluation method and device, electronic terminal

Abstract

This invention provides a method and apparatus for evaluating the electrolyte wetting distribution state of a battery cell, as well as an electronic terminal. The method involves evaluating the electrolyte wetting distribution state of a battery cell, where the battery cell includes a housing and an electrode assembly. The housing has a receiving cavity, and the electrode assembly is housed within the receiving cavity. A storage space for containing electrolyte exists between the electrode assembly and the inner wall of the receiving cavity. The method includes: acquiring attribute information of the battery cell, detection information of the electrolyte stored in the storage space, and charge / discharge conditions; determining the electrolyte wetting distribution state of the battery cell based on the attribute information of the battery cell, the detection information of the electrolyte stored in the storage space, and the charge / discharge conditions; the electrolyte wetting distribution state of the battery cell is defined as the saturation distribution of the electrolyte along the direction of gravity within the battery cell. This application improves the accuracy of evaluating the electrolyte wetting distribution state of the battery cell by combining the detection information of the electrolyte stored in the storage space and the charge / discharge conditions of the battery cell to determine the electrolyte wetting distribution state of the electrode assembly.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery technology, and in particular to a method and apparatus for evaluating the electrolyte wetting distribution state of battery cells, an electronic terminal, and a computer-readable storage medium. Background Technology

[0002] During the charge-discharge cycle, the negative electrode material expands, and the volume change of the electrode material leads to an increase in internal pressure. This causes the electrolyte to be squeezed out from the inside of the electrode material, resulting in local electrolyte loss. In severe cases, it may even cause lithium plating in the battery cell and a "water drop" phenomenon, affecting the battery's safety performance and service life. Summary of the Invention

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

[0004] In a first aspect, this application provides a method for evaluating the electrolyte wetting distribution state of a battery cell. The battery cell includes a housing and an electrode assembly. The housing has a receiving cavity, the electrode assembly is housed in the receiving cavity, and a liquid storage space for containing electrolyte is provided between the electrode assembly and the inner wall of the receiving cavity.

[0005] Acquire the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions;

[0006] The electrolyte wetting distribution state of the battery cell is determined based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions. The electrolyte wetting distribution state of the battery cell is the saturation distribution of the electrolyte along the direction of gravity in the battery cell.

[0007] In the technical solution of this application embodiment, the electrolyte wetting distribution state of the electrode assembly in the battery cell is determined by combining the detection information of the electrolyte stored in the storage space and the charging and discharging conditions of the battery cell, thereby improving the accuracy of the evaluation of the electrolyte wetting distribution state in the battery cell.

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

[0009] A control model is constructed, which includes a fluid permeation model and a multiphase flow motion model. The fluid permeation model is used to characterize the relationship between the pressure difference between the first and second end faces of the electrode assembly and the flow velocity of the electrolyte. The first and second end faces are the surfaces of the electrode assembly arranged along the direction of gravity. The multiphase flow motion model is used to characterize the relationship between the pressure of the first end face, the pressure of the second end face, fluid parameters, and electrolyte saturation under motion conditions of at least two different phases of fluid.

[0010] The electrolyte wetting distribution state of the battery cell is determined based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions, including:

[0011] The electrolyte wetting distribution of the battery cell is determined by a control model based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions.

[0012] In the technical solution of this application embodiment, considering that the electrode assembly is essentially composed of porous media and that there are two phase components in the electrode assembly, a control model is constructed by a fluid permeation model and a multiphase flow motion model in order to evaluate the electrolyte saturation distributed along the direction of gravity in the cell.

[0013] In some embodiments, the electrode assembly includes a first end face and a second end face arranged sequentially along the direction of gravity, with a sidewall surface disposed between the first end face and the second end face. The liquid storage space includes a first space and a second space that are interconnected. The first space is the gap between the second end face and the inner wall of the receiving cavity, and the second space is the gap between the sidewall surface of the electrode assembly and the inner wall of the receiving cavity. The liquid storage space has corresponding characteristic parameter information. The detection information of the electrolyte stored in the liquid storage space includes the detection height of the electrolyte in the second space.

[0014] The electrolyte wetting distribution state of the battery cell is determined based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions, including:

[0015] Based on the cell's attribute information, the detection height of the electrolyte in the second space, the characteristic parameter information corresponding to the second space and the first space, and the charging and discharging conditions, the electrolyte wetting distribution state of the cell is determined.

[0016] In the technical solution of this application embodiment, the electrolyte wetting distribution state of the electrode assembly in the battery cell is determined based on the electrolyte stored in the second space, by using the attribute information of the battery cell, the detection height of the electrolyte in the second space, the characteristic parameter information of the storage space, and the charging and discharging conditions, thereby improving the evaluation accuracy.

[0017] In some embodiments, the electrode assembly includes a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrode, wherein the end of the separator facing the first end face is higher than the end of the positive and / or negative electrode; the liquid storage space further includes a third space and a fourth space that are interconnected, wherein the third space is a space formed by the cooperation of the ends of adjacent separators and the intermediate positive and / or negative electrode facing the first end face; the fourth space is located on the side of the third space away from the electrode assembly, and the fourth space is used to connect the third space and the second space; the third space and the fourth space respectively have corresponding characteristic parameter information; the detection information of the electrolyte stored in the liquid storage space also includes the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space;

[0018] The electrolyte wetting distribution state of the battery cell is determined based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions, including:

[0019] Based on the cell's attribute information, the detection height of the electrolyte in the third space, the detection height of the electrolyte in the fourth space, the characteristic parameter information corresponding to the third and fourth spaces, and the charging and discharging conditions, the electrolyte wetting distribution state of the cell is determined.

[0020] In the technical solution of this application embodiment, the electrolyte wetting distribution state of the electrode assembly in the battery cell is determined based on the electrolyte stored in each space in the storage space by using the attribute information of the battery cell, the detection height of the electrolyte in the second space, the detection height of the electrolyte in the third space, the detection height of the electrolyte in the fourth space, the characteristic parameter information of the storage space, and the charging and discharging conditions, thereby further improving the evaluation accuracy.

[0021] In some embodiments, the ratio between the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space is not less than 100.

[0022] In the technical solution of this application embodiment, by setting the ratio between the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space to be not less than 100, the detection height of the fourth space is made infinitely close to 0, thereby improving the evaluation accuracy of the electrolyte wetting distribution state of the battery cell and the robustness of the evaluation method.

[0023] In some embodiments, the characteristic parameter information includes at least one of capillary force, permeability in each preset direction, and porosity; the permeability of the second space in the horizontal direction is 0; the capillary force of the liquid storage space is less than the capillary force of the electrode assembly, and the porosity ranges from (0, 1).

[0024] In the technical solution of this application embodiment, the liquid storage space has corresponding characteristic parameter information, so as to determine the electrolyte wetting distribution state corresponding to the liquid storage space based on the characteristic parameter information of the liquid storage space.

[0025] In some embodiments, there is a positive correlation between the permeability in a preset direction and the hydraulic radius of the liquid storage space in the corresponding preset direction.

[0026] In the technical solution of this application embodiment, the permeability of the liquid storage space in the preset direction is determined by the hydraulic radius of the liquid storage space in the preset direction, thereby improving the accuracy of the permeability of the liquid storage space.

[0027] In some embodiments, the cell's attribute information includes electrode attributes and electrolyte attributes. The electrode attributes include at least one of electrode surface tension, electrode contact angle, and electrode porosity. The electrolyte attributes include at least one of electrolyte viscosity and electrolyte density. The charge / discharge conditions include charging rate or discharging rate.

[0028] In the technical solution of this application embodiment, by defining specific parameters of electrode properties and electrolyte properties, the performance of the battery under actual working conditions can be more accurately reflected.

[0029] Secondly, this application provides an electrolyte wetting distribution state assessment device for a battery cell. The battery cell includes a housing and an electrode assembly. The housing has a receiving cavity, the electrode assembly is housed in the receiving cavity, and a liquid storage space for containing electrolyte is provided between the electrode assembly and the inner wall of the receiving cavity.

[0030] The acquisition module is used to acquire the attribute information of the battery cell, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions;

[0031] The evaluation module is used to determine the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions; the electrolyte wetting distribution state of the battery cell is the saturation distribution of the electrolyte along the direction of gravity in the battery cell.

[0032] Thirdly, this application provides an electronic terminal, which includes a memory, a processor, and a computer program stored in the memory and running on the processor. 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 provided in the first aspect above.

[0033] Fourthly, this application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps in the method for evaluating the electrolyte wetting distribution state of a battery cell as described in the first aspect above.

[0034] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0035] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of a specific embodiment of the battery cell provided in this embodiment;

[0038] Figure 2 This is a flowchart illustrating the method for evaluating the electrolyte wetting distribution state of the battery cell provided in this application;

[0039] Figure 3 This is a schematic diagram of the contact angle of the gap between the separator and the negative electrode sheet in one embodiment of the method for evaluating the electrolyte wetting distribution state of the battery cell provided in this application;

[0040] Figure 4 This is a schematic diagram of the change curves of the liquid volume in the first space, second space, and third space over time in the electrolyte wetting distribution state evaluation method of the battery cell provided in this application.

[0041] Figure 5 This is a schematic diagram illustrating the evaluation results of electrolyte wetting distribution for cells of different heights provided in this application;

[0042] Figure 6 This is a schematic diagram of the framework of an embodiment of the electrolyte wetting distribution state evaluation device for battery cells provided in this application;

[0043] Figure 7 This is a schematic diagram of the framework of an embodiment of the electronic terminal provided in this application;

[0044] Figure 8 This is a schematic diagram of a framework of an embodiment of the computer-readable storage medium provided in this application.

[0045] Illustration: Battery cell 100; Electrode assembly 1; First end face 11; Second end face 12; Side wall 13; Liquid storage space 2; First space 21; Second space 22; Third space 23; Fourth space 24; Reception cavity 3. Detailed Implementation

[0046] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0048] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0049] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0050] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0051] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0052] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0053] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0054] Currently, during charge-discharge cycles, the negative electrode material expands, and this volume change increases internal pressure, causing the electrolyte to be squeezed out from the electrode material. This results in localized electrolyte loss, and in severe cases, may even lead to lithium plating and a "water plunge" phenomenon, affecting battery safety and lifespan. Therefore, it is necessary to monitor the electrolyte wetting status within the battery cell during cycling.

[0055] The Lagrange multiplier method can be used to construct boundary conditions for a battery cell where the bottom is in contact with the electrolyte along the direction of gravity, and the top is in contact with air. The Lagrange multiplier method is a mathematical method for solving the extrema of functions 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 can handle multiple constraints by introducing more Lagrange multipliers.

[0056] This scheme can realize the expansion law of the input graphite negative electrode and output as follows: Figure 1As shown, the distribution patterns of electrolyte in the cell under charging and discharging conditions help predict the electrolyte wetting performance of the cell during cycling. When determining the electrolyte distribution in the cell under discharging conditions, the free space at the top of the cell is not completely filled with air, but is under a complex changing process. As the cell's charging and discharging processes proceed, the boundary conditions at the top will undergo periodic and alternating changes such as saturation-half-saturation-deficient electrolyte.

[0057] Therefore, this application provides a method for evaluating the electrolyte wetting distribution state of a battery cell. This method involves acquiring the battery cell's attribute information, detection information of the electrolyte stored in the storage space, and charge / discharge conditions. Based on these factors, the method determines the electrolyte wetting distribution state of the battery cell. The electrolyte wetting distribution state is defined as the saturation distribution of the electrolyte along the direction of gravity within the battery cell. By combining the detection information of the electrolyte stored in the storage space with the charge / discharge conditions of the battery cell, the method determines the electrolyte wetting distribution state of the electrode components within the battery cell. By considering the detection information of the electrolyte within the storage space of the battery cell, the method improves the accuracy of evaluating the electrolyte wetting distribution state within the battery cell.

[0058] Please see Figure 1 , Figure 1 This is a schematic diagram of a specific embodiment of the battery cell provided in this embodiment.

[0059] The battery cell 100 provided in this application includes a housing and an electrode assembly 1. The housing has a receiving cavity 3, and the electrode assembly 1 is housed in the receiving cavity 3. A liquid storage space 2 for containing electrolyte is provided between the electrode assembly 1 and the inner wall of the receiving cavity 3. The battery cell 100 has corresponding attribute information, including electrode properties and electrolyte properties. Electrode properties refer to the physical and chemical properties of the electrode sheets, including but not limited to at least one of electrode surface tension, electrode contact angle, electrode porosity, permeability, and conductivity. These properties affect the flow and reaction kinetics of the electrolyte in the electrode assembly 1. Electrolyte properties include at least one of electrolyte viscosity, electrolyte density, and conductivity. These parameters determine the flow properties and ion transport efficiency of the electrolyte. Charge and discharge conditions describe the operating conditions during battery charging, including at least one of charging current, voltage, temperature, charging rate, and discharging rate. Different charge and discharge conditions affect the flow and distribution of the electrolyte. The liquid storage space 2 has corresponding characteristic parameter information; the characteristic parameter information of the liquid storage space 2 includes at least one of capillary force, permeability in each preset direction and porosity.

[0060] The electrode assembly 1 includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The electrode assembly 1 is formed by winding the positive electrode, the separator, and the negative electrode.

[0061] The electrode assembly 1 includes a first end face 11 and a second end face 12 arranged sequentially along the direction of gravity. During the charging and discharging processes of the battery cell 100, the electrolyte in the storage space 2 is squeezed out or drawn back into the electrode assembly 1 through the first end face 11 and the second end face 12. A sidewall 13 is provided between the first end face 11 and the second end face 12 of the electrode assembly 1, preventing the electrolyte in the storage space 2 from being squeezed out or drawn back into the electrode assembly 1 through the sidewall 13.

[0062] In one embodiment, the liquid storage space 2 includes a first space 21 and a second space 22 that are interconnected. The first space 21 is the gap between the second end face 12 and the inner wall of the receiving cavity 3, and the second space 22 is the gap between the side wall surface 13 of the electrode assembly 1 and the inner wall of the receiving cavity 3. The first space 21 and the second space 22 each have corresponding characteristic parameter information.

[0063] In order to achieve effective insulation between the positive and negative electrodes, and considering the manufacturing process of the cell 100, the end of the separator between the positive and negative electrodes facing the first end face 11 is higher than the end of the positive and / or negative electrodes.

[0064] In one embodiment, the liquid storage space 2 further includes a third space 23 and a fourth space 24 that are interconnected. The third space 23 is a space formed by the cooperation of the adjacent separator and the ends of the positive electrode and / or negative electrode disposed in the middle facing the first end face 11. The fourth space 24 is located on the side of the third space 23 away from the electrode assembly 1, and the fourth space 24 is used to connect the third space 23 and the second space 22. The third space 23 and the fourth space 24 have corresponding characteristic parameter information.

[0065] Please see Figure 2 , Figure 2 This is a flowchart illustrating the method for evaluating the electrolyte wetting distribution state of the battery cell provided in this application.

[0066] This application provides a method for evaluating the electrolyte wetting distribution state of a battery cell, which is used to evaluate the electrolyte wetting distribution state of the battery cell provided above. Specifically, it includes the following steps.

[0067] S1: Obtain the attribute information of the battery cell, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions.

[0068] S2: Determine the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions; the electrolyte wetting distribution state of the battery cell is the saturation distribution of the electrolyte along the direction of gravity in the battery cell.

[0069] In the technical solution of this application embodiment, the electrolyte wetting distribution state of the electrode assembly in the battery cell is determined by combining the detection information of the electrolyte stored in the storage space and the charging and discharging conditions of the battery cell, thereby improving the accuracy of the evaluation of the electrolyte wetting distribution state in the battery cell.

[0070] In some embodiments, the method for evaluating the electrolyte wetting distribution state of the battery cell further includes: constructing a control model; the control model includes a fluid permeation model and a multiphase flow motion model.

[0071] Because the Reynolds number (Re) is relatively low during electrolyte movement within the battery cell, the influence of electrolyte turbulence can be ignored, and the overall electrolyte flow can be considered laminar. By modeling the controlled volume inside the cell, a fluid permeation model can be constructed based on Darcy's law. The Reynolds number (Re) is an important dimensionless number used to determine the type of fluid flow (laminar or turbulent). A low Reynolds number typically indicates laminar flow. Inside lithium-ion batteries (or other batteries), electrolyte flow is usually laminar due to the low Reynolds number.

[0072] The fluid permeation model is used to characterize the relationship between the pressure difference between the first and second end faces of the electrode assembly and the flow velocity of the electrolyte. The first and second end faces are the surfaces inside the battery cell arranged along the direction of gravity.

[0073] To improve the accuracy of electrolyte wetting distribution assessment in battery cells, boundary conditions are applied to the control model to ensure that the assessed electrolyte wetting distribution does not exceed the physical limits of the battery cell. Charge / discharge conditions include either charging rate or discharging rate. If the charge / discharge condition is at the charging rate, the electrolyte wetting distribution is in the charging process; if it's at the discharging rate, the electrolyte wetting distribution is in the discharging process. The charging process has a corresponding first boundary condition, and the discharging process has a corresponding second boundary condition. For example, when the charge / discharge condition is at the charging rate, the first boundary condition is used; when it's at the discharging rate, the second boundary condition is used. This distinction makes the simulation process more consistent with actual usage, improving simulation accuracy. Furthermore, considering the symmetry of the wound battery cell, only one corner region of the cell is calculated, and the result is then extended to the entire cell through symmetry. This method significantly reduces computational load and increases simulation speed. Using the Darcy equation combined with the porous medium equation as the control model allows for a more accurate description of fluid flow in porous media. This combination of equations takes into account the pore structure and permeability of the medium, making the evaluation results more reliable.

[0074] The charging rate refers to the ratio of the current required to charge a battery cell to its rated capacity within a specified time to the battery's rated capacity. It is usually represented by "C," where "1C" represents the current required to fully charge the cell in one hour. For example, a 2000mAh battery cell charged at a 1C charging rate means it requires 2000mA of current to fully charge in one hour. The charging rate can be calculated using the following formula: Charging Rate = Charging Current / Battery Capacity. For example, if a battery cell has a capacity of 2000mAh and is charged with a current of 4000mA, then the charging rate is: Charging Rate = 4000mA / 2000mAh = 2C. This means the cell will be fully charged in 30 minutes; that is, a 2C charging rate means it will be fully charged in 1 / 2 hour.

[0075] To improve the accuracy of electrolyte evaluation under charge and discharge conditions, the upper and lower boundaries of the fluid permeation model are determined to be capillary pressure boundary conditions. During the simulation, the upper and lower boundaries of the cell will be subjected to capillary pressure, which will affect the flow and distribution of the electrolyte in the electrode assembly. The upper boundary of the multiphase flow motion model is determined to be an air boundary condition. During the simulation, the upper boundary of the cell will be in contact with air, and the influence of air on electrolyte flow needs to be considered. The lower boundary of the multiphase flow motion model is determined to be an electrolyte boundary condition. During the simulation, the lower boundary of the cell will be filled with electrolyte, and the influence of the electrolyte's physical properties on the flow needs to be considered.

[0076] For ease of understanding, the following examples are provided, but are not intended to limit this application. As an example, the fluid permeation model uses Darcy's equation, and the multiphase flow motion model uses the porous medium multiphase flow equation. Therefore, if the charging / discharging conditions determine that the process is in discharge, then in Darcy's equation, the upper and lower surfaces of the cell are subject to capillary pressure boundary conditions. In the multiphase flow motion model, the upper surface of the cell is subject to air boundary conditions, and the lower surface is subject to electrolyte boundary conditions. If the charging / discharging conditions determine that the process is in charge, then in Darcy's equation, the upper and lower surfaces of the cell are subject to ambient pressure boundary conditions. In the multiphase flow motion model, the upper surface of the cell is subject to flow rate boundary conditions; the lower surface is still considered to be in contact with the electrolyte, and electrolyte boundary conditions are selected.

[0077] By selecting appropriate boundary conditions based on different charging and discharging conditions, and by combining fluid permeation model and multiphase flow motion model in the control model, the control model has more suitable simulation boundary conditions under each charging and discharging condition, thereby improving the accuracy of electrolyte flow simulation.

[0078] In one specific embodiment, the fluid permeation model is shown in the following formula.

[0079]

[0080] p ec=2*σ*cos(θ / )R c (Formula 2)

[0081] In the formula: p c p represents capillary pressure; ec Indicates the inlet capillary pressure; S W Indicates electrolyte saturation; R c σ represents the equivalent pore radius; σ represents the surface tension; θ represents the contact angle between the electrode assembly and the electrolyte.

[0082] Among them, the multiphase flow motion model is used to characterize the relationship between the pressure at the first end face, the pressure at the second end face, fluid parameters and electrolyte saturation in motion of at least two different phase fluids.

[0083] Since the cell problem is a type of multiphase flow problem, its driving force is the extrusion and reabsorption of electrode liquid caused by changes in the porosity of the porous medium within the cell. Multiphase flow problems refer to the flow phenomena where two or more immiscible fluids (such as liquid and gas, oil and water) coexist in a system. Specifically, a multiphase flow motion model is constructed using multiphase flow equations.

[0084] In one specific embodiment, the multiphase flow motion model is shown in the following formula.

[0085]

[0086] Where: ε p Represents porosity; ρ si Indicates the density of the component; s air Indicates the saturation degree of the component; u si The equivalent flux rate of a component is represented by si; the component saturation is represented by si.

[0087] Specifically, the multiphase flow motion model corresponding to the gas phase components is shown in the following formula.

[0088]

[0089] Specifically, the multiphase flow motion model corresponding to the liquid phase component is shown in the following formula.

[0090]

[0091] In the technical solution of this application embodiment, considering that the electrode assembly is essentially composed of porous media and that there are two phase components in the electrode assembly, an initial control model is constructed by a fluid permeation model and a multiphase flow motion model in order to evaluate the electrolyte saturation distributed along the direction of gravity in the cell.

[0092] In some embodiments, the steps of obtaining the attribute information of the battery cell, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions in step S1 include the following specific implementations.

[0093] Specifically, it can detect the cell's attribute information, the electrolyte stored in the storage space, and the charging and discharging conditions in real time, and can also acquire offline data. Offline data includes the cell's attribute information, the electrolyte stored in the storage space, and the charging and discharging conditions.

[0094] In one embodiment, user input parameters and / or preset parameters can also be used as the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions.

[0095] The cell's attribute information includes electrode attributes and electrolyte attributes. Electrode attributes include at least one of electrode surface tension, electrode contact angle, and electrode porosity. Electrolyte attributes include at least one of electrolyte viscosity and electrolyte density. Charge / discharge conditions include charge rate or discharge rate. Electrode attributes also include electrode size, electrode permeability, and pressure difference across the electrode. Electrode size includes the height and width of the electrode assembly. Electrode attributes also include graphite expansion and contraction curves.

[0096] In the technical solution of this application embodiment, by defining specific parameters of electrode properties and electrolyte properties, the performance of the battery under actual working conditions can be more accurately reflected.

[0097] In one embodiment, the detection information of the electrolyte stored in the storage space includes the detection height of the electrolyte in the second space.

[0098] In one embodiment, the detection information of the electrolyte stored in the storage space also includes the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space.

[0099] When the electrolyte in the electrode assembly is squeezed out, the electrolyte squeezed out through the first end face does not immediately flow to the first and second storage spaces, but is first stored in the third space. When the electrolyte is drawn back into the first end face of the electrode assembly, the first end face of the electrode assembly first contacts the electrolyte stored in the third space. Only when the electrolyte stored in the third space is completely drawn back into the electrode assembly will the first end face of the electrode assembly switch back to contact with air.

[0100] In one embodiment, the characteristic parameter information corresponding to the liquid storage space is determined based on the characteristic parameter information of the porous medium.

[0101] Specifically, the porosity of a porous medium is defined as the proportion of vacant space in the material. Since the liquid storage space is entirely vacant, its porosity can be 1. The porosity can range from (0, 1], and the specific value can be set according to the actual situation.

[0102] Specifically, the permeability of porous media is defined as the ability of rock to allow fluid to pass through under a certain pressure difference; it is a parameter characterizing the soil or rock's ability to conduct liquids. Since the reservoir space is entirely composed of voids and contains no particles, the permeability of the reservoir space in the conductive direction can be 100 millidarcy. Because the reservoir space in a battery cell is a complex structure, its characteristic length can be on the order of centimeters. The permeability calculated at this scale is a very large value relative to the porous electrode. A permeability of 100 millidarcy in the conductive direction of the reservoir space is sufficient to meet the requirements.

[0103] In one embodiment, there is a positive correlation between the permeability in the preset direction and the hydraulic radius of the liquid storage space in the corresponding preset direction.

[0104] In one specific embodiment, the permeability of the liquid storage space in a preset direction can be determined using the following formula.

[0105]

[0106] In the formula: K represents the permeability in the preset direction; R represents the hydraulic radius in the preset direction.

[0107] In one specific embodiment, the hydraulic radius in a preset direction can be determined using the following formula.

[0108]

[0109] In the formula: D dl Indicates the characteristic length; A represents the wetting area; P represents the wetting perimeter; for example, the wetting area of ​​a circle with diameter D is... The wetting perimeter is πD; the wetting area of ​​a square with side length D is D. 2 The wetting perimeter is 4D; the wetting area of ​​an infinitely long plate with a spacing of D is DL, and the wetting perimeter is 2L.

[0110] In the technical solution of this application embodiment, the permeability of the liquid storage space in the preset direction is determined by the hydraulic radius of the liquid storage space in the preset direction, thereby improving the accuracy of the permeability of the liquid storage space.

[0111] Please see Figure 3 , Figure 3 This is a schematic diagram of the contact angle between the separator and the negative electrode sheet in one embodiment of the method for evaluating the electrolyte wetting distribution state of the battery cell provided in this application.

[0112] Specifically, the calculation method for the capillary force in the liquid storage space is similar to that in a capillary tube. The calculation of the capillary force in the liquid storage space requires consideration of the two adjacent interfaces. The formula for calculating the capillary force (PEC) in the liquid storage space is shown below.

[0113] pec=πRcos(θ neg )γ neg +πRcos(θ sep )γ sep (Formula 9)

[0114] Reference Figure 3 In the above formula, θ neg θ sep These are the contact angles of the negative electrode and the separator side, respectively, γ. neg γ sep Let be the surface tensions of the negative electrode and the separator, respectively, and R be the equivalent pore radius of the reservoir space. We substitute this parameter R in cm and compare it with the capillary force of the negative electrode. The capillary force in the reservoir space is less than that of the electrode assembly. The calculated capillary force in the reservoir space is much smaller than that in the negative electrode region. Therefore, in numerical calculations, the capillary force in the reservoir space can be taken as a small value, i.e., pec = 0.

[0115] In one specific embodiment, the characteristic parameter information of each space in the liquid storage space can be as shown in Table 1.

[0116] Table 1

[0117]

[0118] In some embodiments, the step of determining the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions in step S2 includes the following specific implementations.

[0119] In one embodiment, a control model is used to determine the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions.

[0120] In the technical solution of this application embodiment, considering that the electrode assembly is essentially composed of porous media and that there are two phase components in the electrode assembly, a control model is constructed by a fluid permeation model and a multiphase flow motion model in order to evaluate the electrolyte saturation distributed along the direction of gravity in the cell.

[0121] In one embodiment, the electrolyte wetting distribution state of the battery cell is determined based on the cell's attribute information, the detection height of the electrolyte in the second space, the characteristic parameter information corresponding to the second space and the first space, and the charging and discharging conditions.

[0122] In the technical solution of this application embodiment, the electrolyte wetting distribution state of the electrode assembly in the battery cell is determined based on the electrolyte stored in the second space, by using the attribute information of the battery cell, the detection height of the electrolyte in the second space, the characteristic parameter information of the storage space, and the charging and discharging conditions, thereby improving the evaluation accuracy.

[0123] In one embodiment, the electrolyte wetting distribution state of the battery cell is determined based on the cell's attribute information, the detection height of the electrolyte in the third space, the detection height of the electrolyte in the fourth space, the characteristic parameter information corresponding to the third space and the fourth space, and the charging and discharging conditions.

[0124] In the technical solution of this application embodiment, the electrolyte wetting distribution state of the electrode assembly in the battery cell is determined based on the electrolyte stored in each space in the storage space by using the attribute information of the battery cell, the detection height of the electrolyte in the second space, the detection height of the electrolyte in the third space, the detection height of the electrolyte in the fourth space, the characteristic parameter information of the storage space, and the charging and discharging conditions, thereby further improving the evaluation accuracy.

[0125] In some embodiments, the ratio between the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space is not less than 100. For example, the ratio between the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space can be 100, 120, or 150.

[0126] In the technical solution of this application embodiment, by setting the ratio between the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space to be not less than 100, the detection height of the fourth space is made infinitely close to 0, thereby improving the evaluation accuracy of the electrolyte wetting distribution state of the battery cell and the robustness of the evaluation method.

[0127] By detecting the detection height of the electrolyte in the second and third spaces, the boundary conditions of the first and second end faces of the electrode material are determined. This allows the control model to determine the electrolyte wetting distribution state of the battery cell based on the cell's property information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions, thereby improving prediction accuracy.

[0128] Please see Figure 4 , Figure 4 This is a schematic diagram of the change curves of the electrolyte storage volume in the first space, second space, and third space over time in the electrolyte wetting distribution state evaluation method of the battery cell provided in this application.

[0129] Taking a single charge-discharge cycle of a battery cell as an example, during the charging process, the electrolyte in the electrode assembly is squeezed out and overflows into the storage space. The battery cell's attribute information and the detection height of the electrolyte stored in the second, third, and fourth spaces can be collected at a preset frequency to determine the corresponding storage volume of each space based on the detection height. The electrolyte wetting distribution state of the battery cell during charging is determined based on the battery cell's attribute information and the detection height of the electrolyte stored in the second, third, and fourth spaces. During the discharging process, the electrode assembly draws the electrolyte back into the storage space. The battery cell's attribute information and the detection height of the electrolyte stored in the second, third, and fourth spaces can be collected at a preset frequency to determine the corresponding storage volume of each space based on the detection height. The electrolyte wetting distribution state of the battery cell during discharging is determined based on the battery cell's attribute information and the detection height of the electrolyte stored in the second, third, and fourth spaces.

[0130] For example, during one charge-discharge cycle, the volumes of electrolyte stored in the first, second, and third spaces of the battery cell are as follows: Figure 4 As shown.

[0131] pass Figure 4 It can be seen that the liquid volume in the first space remains constant. This is because the first space is completely immersed in the electrolyte during the charging and discharging process, so its liquid volume is always equal to its maximum liquid volume.

[0132] During the charging process, at a sampling time of 0.3 hours, the third space was completely filled with the electrolyte squeezed out from the electrode assembly. Afterward, the volume remained unchanged. During the discharge phase, the electrode assembly reabsorbed the electrolyte from the third space, and the electrolyte storage volume in the third space decreased again.

[0133] During charging, the electrolyte in the electrode assembly is squeezed out. Before the sampling time is 0.3 hours, the second space receives the electrolyte squeezed out from the second end face of the electrode assembly, and the rate of change of the electrolyte volume in the second space is consistent with that in the third space. From 0.3 hours to 0.5 hours, the second space receives both the electrolyte squeezed out from the second end face of the electrode assembly and the electrolyte overflowing from the third space, and the rate of change of the electrolyte volume in the second space is twice that before the sampling time is 0.3 hours. During the discharging phase, the electrode assembly draws back electrolyte from the storage space, and the electrolyte volume in the second space gradually decreases again.

[0134] For ease of understanding, the following examples are provided, but are not intended to limit this application. As an example, taking a lithium-ion battery, the positive electrode material is LiCoO2, the separator material is polyethylene, and the negative electrode material is graphite with a thickness of 50 μm and a porosity of 0.3. The electrolyte is an organic solvent containing LiPF6, with a viscosity of 1.2 mPa·s and a density of 1.1 g / cm³. The charging current is set to 1C, the charging voltage to 4.2V, and the temperature to 25℃. The inlet flow rate is set to 0.1 m / s, the outlet pressure to atmospheric pressure, and the wall conditions to be non-slip. These parameters are used as the cell's attribute information and substituted into the control model.

[0135] Please see Figure 5 , Figure 5 This is a schematic diagram illustrating the evaluation results of electrolyte wetting distribution for cells of different heights provided in this application.

[0136] The above implementation method allows for the prediction of electrolyte wetting distribution in battery cells of different heights, as the cell height is directly proportional to the electrode assembly height. As shown in the figure, when the amount of electrolyte in different cells is the same, the higher the cell, the larger the area of ​​poor wetting of the electrode assembly. Therefore, for taller cells, more accurate prediction of electrolyte distribution is needed.

[0137] Please see Figure 6 , Figure 6 This is a schematic diagram of a framework of an embodiment of the electrolyte wetting distribution state evaluation device for battery cells provided in this application.

[0138] This embodiment provides a battery cell electrolyte wetting distribution state evaluation device 60, which includes an acquisition module 61 and an evaluation module 62.

[0139] The acquisition module 61 is used to acquire the attribute information of the battery cell, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions.

[0140] The evaluation module 62 is used to determine the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions; the electrolyte wetting distribution state of the battery cell is the saturation distribution of the electrolyte along the direction of gravity in the battery cell.

[0141] In the technical solution of this application embodiment, the electrolyte wetting distribution state of the electrode assembly in the battery cell is determined by combining the detection information of the electrolyte stored in the storage space and the charging and discharging conditions of the battery cell, thereby improving the accuracy of the evaluation of the electrolyte wetting distribution state in the battery cell.

[0142] In one embodiment, the electrolyte wetting distribution state evaluation device 60 for the battery cell further includes a construction module 63. The construction module 63 is used to construct a control model; the 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 end face and the second end face of the electrode assembly and the flow velocity of the electrolyte, and the first end face and the second end face are the surfaces of the electrode assembly arranged along the direction of gravity; the multiphase flow motion model is used to characterize the relationship between the pressure of the first end face, the pressure of the second end face, fluid parameters and electrolyte saturation under the motion state of at least two different phases of fluid.

[0143] The evaluation module 62 is also used to determine the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the storage space, and the charging and discharging conditions using a control model.

[0144] In the technical solution of this application embodiment, considering that the electrode assembly is essentially composed of porous media and that there are two phase components in the electrode assembly, a control model is constructed by a fluid permeation model and a multiphase flow motion model in order to evaluate the electrolyte saturation distributed along the direction of gravity in the cell.

[0145] The evaluation module 62 is also used to determine the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection height of the electrolyte in the second space, the characteristic parameter information corresponding to the second space and the first space, and the charging and discharging conditions. The permeability of the second space in the horizontal direction is 0; the capillary force of the liquid storage space is less than that of the electrode assembly, and the porosity ranges from (0, 1).

[0146] In the technical solution of this application embodiment, the liquid storage space has corresponding characteristic parameter information, so as to determine the electrolyte wetting distribution state corresponding to the liquid storage space based on the characteristic parameter information of the liquid storage space.

[0147] In some embodiments, there is a positive correlation between the permeability in a preset direction and the hydraulic radius of the liquid storage space in the corresponding preset direction.

[0148] In the technical solution of this application embodiment, the permeability of the liquid storage space in the preset direction is determined by the hydraulic radius of the liquid storage space in the preset direction, thereby improving the accuracy of the permeability of the liquid storage space.

[0149] In the technical solution of this application embodiment, the electrolyte wetting distribution state of the electrode assembly in the battery cell is determined based on the electrolyte stored in the second space, by using the attribute information of the battery cell, the detection height of the electrolyte in the second space, the characteristic parameter information of the storage space, and the charging and discharging conditions, thereby improving the evaluation accuracy.

[0150] The evaluation module 62 is also used to determine the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection height of the electrolyte in the third space, the detection height of the electrolyte in the fourth space, the characteristic parameter information corresponding to the third space and the fourth space, and the charging and discharging conditions.

[0151] In one embodiment, the ratio between the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space is not less than 100.

[0152] In the technical solution of this application embodiment, by setting the ratio between the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space to be not less than 100, the detection height of the fourth space is made infinitely close to 0, thereby improving the evaluation accuracy of the electrolyte wetting distribution state of the battery cell and the robustness of the evaluation method.

[0153] In the technical solution of this application embodiment, the electrolyte wetting distribution state of the electrode assembly in the battery cell is determined based on the electrolyte stored in each space in the storage space by using the attribute information of the battery cell, the detection height of the electrolyte in the second space, the detection height of the electrolyte in the third space, the detection height of the electrolyte in the fourth space, the characteristic parameter information of the storage space, and the charging and discharging conditions, thereby further improving the evaluation accuracy.

[0154] Please see Figure 7 , Figure 7 This is a schematic diagram of the framework of an embodiment of the electronic terminal provided in this application.

[0155] The electronic terminal 80 includes a memory 81 and a processor 82 coupled to each other. The processor 82 is used to execute program instructions stored in the memory 81 to implement the steps of the above-described embodiment of the method for evaluating the electrolyte wetting distribution state of any of the battery cells. In a specific implementation scenario, the electronic terminal 80 may include, but is not limited to, a microcomputer or a server. In addition, the electronic terminal 80 may also include mobile devices such as laptops and tablets, which are not limited here.

[0156] Specifically, processor 82 controls itself and memory 81 to implement the steps of the embodiment of the method for evaluating the electrolyte wetting distribution state of any of the aforementioned battery cells. Processor 82 can also be referred to as a CPU (Central Processing Unit). Processor 82 may be an integrated circuit chip with signal processing capabilities. Processor 82 can also be a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor can be a microprocessor or any conventional processor. Furthermore, processor 82 can be implemented using integrated circuit chips.

[0157] Please see Figure 8 , Figure 8 This is a schematic diagram of a framework of an embodiment of the computer-readable storage medium provided in this application.

[0158] The computer-readable storage medium 90 stores program instructions 901 that can be executed by a processor. The program instructions 901 are used to implement the steps of the embodiment of the method for evaluating the electrolyte wetting distribution state of any of the above-described battery cells.

[0159] In some embodiments, the functions or modules of the apparatus provided in this disclosure can be used to perform the methods described in the above method embodiments. The specific implementation can be referred to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0160] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0161] In the several embodiments provided in this application, it should be understood that the disclosed methods and apparatus can be implemented in other ways. For example, the apparatus implementations described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0162] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0163] If the integrated unit is implemented as 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 this application, in essence, 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. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods of various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0164] The above are merely embodiments of the present invention and do not limit the scope of patent protection of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for evaluating the electrolyte wetting distribution state of a battery cell, characterized in that, The battery cell includes a housing and an electrode assembly. The housing has a receiving cavity, and the electrode assembly is housed in the receiving cavity. A liquid storage space for containing electrolyte is provided between the electrode assembly and the inner wall of the receiving cavity. The system acquires the attribute information of the battery cell, the detection information of the electrolyte stored in the electrolyte storage space, and the charging and discharging conditions. The electrolyte wetting distribution state of the battery cell is determined based on the attribute information of the battery cell, the detection information of the electrolyte stored in the electrolyte storage space, and the charging and discharging conditions; the electrolyte wetting distribution state of the battery cell is the saturation distribution of the electrolyte along the direction of gravity in the battery cell.

2. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 1, characterized in that, The method further includes: A control model is constructed, comprising a fluid permeation model and a multiphase flow motion model. The fluid permeation model characterizes the relationship between the pressure difference between the first and second end faces of the electrode assembly and the flow velocity of the electrolyte, wherein the first and second end faces are the surfaces of the electrode assembly arranged along the direction of gravity. The multiphase flow motion model characterizes the relationship between the pressure at the first end face, the pressure at the second end face, fluid parameters, and electrolyte saturation under motion conditions involving at least two different phases of fluid. The determination of the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the electrolyte storage space, and the charging and discharging conditions includes: The control model is used to determine the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the electrolyte storage space, and the charging and discharging conditions.

3. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 1, characterized in that, The electrode assembly includes a first end face and a second end face arranged sequentially along the direction of gravity. A side wall is provided between the first end face and the second end face. The liquid storage space includes a first space and a second space that are interconnected. The first space is the gap between the second end face and the inner wall of the receiving cavity, and the second space is the gap between the side wall of the electrode assembly and the inner wall of the receiving cavity. The liquid storage space has corresponding characteristic parameter information. The detection information of the electrolyte stored in the storage space includes the detection height of the electrolyte in the second space; The determination of the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the electrolyte storage space, and the charging and discharging conditions includes: Based on the attribute information of the battery cell, the detection height of the electrolyte in the second space, the characteristic parameter information corresponding to the second space and the first space respectively, and the charging and discharging conditions, the electrolyte wetting distribution state of the battery cell is determined.

4. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 3, characterized in that, The electrode assembly includes a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrode. The end of the separator facing the first end face is higher than the end of the positive and / or negative electrode. The liquid storage space further includes a third space and a fourth space that are interconnected. The third space is formed by the adjacent separator and the ends of the positive and / or negative electrode disposed in the middle facing the first end face. The fourth space is located on the side of the third space away from the electrode assembly and is used to connect the third space and the second space. The third space and the fourth space each have corresponding characteristic parameter information. The detection information of the electrolyte stored in the storage space also includes the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space; The ratio between the detection height of the electrolyte in the third space and the detection height of the electrolyte in the fourth space is not less than 100. The determination of the electrolyte wetting distribution state of the battery cell based on the cell's attribute information, the detection information of the electrolyte stored in the electrolyte storage space, and the charging and discharging conditions includes: Based on the cell's attribute information, the detection height of the electrolyte in the third space, the detection height of the electrolyte in the fourth space, the characteristic parameter information corresponding to the third space and the fourth space respectively, and the charging and discharging conditions, the electrolyte wetting distribution state of the cell is determined.

5. The method for evaluating the electrolyte wetting distribution state of a battery cell according to any one of claims 3 to 4, characterized in that, The characteristic parameter information includes at least one of capillary force, permeability in each preset direction, and porosity; the permeability of the second space in the horizontal direction is 0; the capillary force of the liquid storage space is less than the capillary force of the electrode assembly, and the porosity ranges from (0, 1).

6. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 5, characterized in that, The permeability in each of the preset directions is positively correlated with the hydraulic radius of the liquid storage space in the corresponding preset direction.

7. The method for evaluating the electrolyte wetting distribution state of a battery cell according to claim 1, characterized in that, The cell's attribute information includes electrode attributes and electrolyte attributes. The electrode attributes include at least one of electrode surface tension, electrode contact angle, and electrode porosity. The electrolyte attributes include at least one of electrolyte viscosity and electrolyte density. The charge / discharge conditions include charging rate or discharging rate.

8. A device for evaluating the electrolyte wetting distribution state of a battery cell, characterized in that, The battery cell includes a housing and an electrode assembly. The housing has a receiving cavity, and the electrode assembly is housed in the receiving cavity. A liquid storage space for containing electrolyte is provided between the electrode assembly and the inner wall of the receiving cavity. The acquisition module is used to acquire the attribute information of the battery cell, the detection information of the electrolyte stored in the electrolyte storage space, and the charging and discharging conditions; An evaluation module is used to determine the electrolyte wetting distribution state of the battery cell based on the attribute information of the battery cell, the detection information of the electrolyte stored in the electrolyte storage space, and the charging and discharging conditions; the electrolyte wetting distribution state of the battery cell is the saturation distribution of the electrolyte along the direction of gravity in the battery cell.

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. The processor is used to execute program data 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 that, when executed by a processor, implements the steps in the method for evaluating the electrolyte wetting distribution state of a battery cell as described in any one of claims 1 to 7.

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