Battery material screening system, method, single battery and electric vehicle

Abstract

The embodiment of the application provides a battery material screening system, method, single battery and electric vehicle. It relates to the technical field of battery. The method comprises the following steps: determining the battery size of a battery to be optimized and determining a plurality of candidate batteries; controlling a pressure device to apply pressure to the candidate batteries; respectively performing charge-discharge tests on the candidate batteries by a test device; determining the comprehensive adaptation value of the candidate batteries according to the negative electrode interface of the candidate batteries; and determining the material system combination corresponding to the candidate battery with the maximum comprehensive adaptation value as the material system combination of the battery to be optimized. According to the above scheme, the pressure device applies pressure to the small-size candidate batteries to simulate the separation rule of the electrolyte in the large-size battery to be optimized, and the charge-discharge test and electrolyte infiltration effect analysis are performed on the candidate batteries, so that the optimal material system combination suitable for the battery to be optimized can be quickly matched, and the screening efficiency of the battery material is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery material screening system, method, single cell battery, and electric vehicle. Background Technology

[0002] With the rapid development of the new energy industry, the size of individual power batteries and energy storage batteries continues to increase to meet the demand for high energy density. However, large-size batteries face significant challenges in the manufacturing process due to poor electrolyte wetting.

[0003] In related technologies, the wetting effect is evaluated by disassembling large-size batteries and observing characteristics such as electrolyte distribution at the internal electrode interfaces, thereby optimizing battery materials for large-size batteries.

[0004] However, this method suffers from low efficiency. Summary of the Invention

[0005] This application provides a battery material screening system, method, single cell, and electric vehicle to improve the screening efficiency of battery materials.

[0006] In a first aspect, embodiments of this application provide a battery material screening system, which is used to simulate a battery to be optimized using candidate batteries and determine the material system combination of the battery to be optimized based on the screening results of the candidate batteries; the screening system includes a pressure device and a testing device;

[0007] The screening system is configured to perform the following steps:

[0008] The battery size of the battery to be optimized is determined and multiple candidate batteries are determined. Each candidate battery corresponds to a material system combination. The battery size of the battery to be optimized is larger than the battery size of any candidate battery.

[0009] For each candidate battery, the pressure corresponding to the battery size is determined, and the pressure device is controlled to apply the pressure to the candidate battery to reduce the gap between the electrode and the separator of the candidate battery. The electrolyte wetting rate and wetting path of the candidate battery after applying pressure are the same as those of the battery to be optimized.

[0010] The candidate battery is subjected to charge-discharge tests using the aforementioned testing equipment.

[0011] Based on the negative electrode interface of the candidate battery, the comprehensive fit value of the candidate battery is determined. The comprehensive fit value is used to characterize the comprehensive performance of the candidate battery in terms of electrochemical performance and electrolyte wetting.

[0012] Iterate through all candidate batteries to obtain the comprehensive fit value for each candidate battery. The candidate battery with the largest comprehensive fit value is determined as the target battery, and the material system combination corresponding to the target battery is determined as the material system combination of the battery to be optimized.

[0013] Secondly, embodiments of this application provide a method for screening battery materials, including:

[0014] The battery size of the battery to be optimized is determined and multiple candidate batteries are determined. Each candidate battery corresponds to a material system combination. The battery size of the battery to be optimized is larger than the battery size of any candidate battery.

[0015] For each candidate battery, the pressure corresponding to the battery size is determined, and the pressure device is controlled to apply the pressure to the candidate battery to reduce the gap between the electrode and the separator of the candidate battery. The electrolyte wetting rate and wetting path of the candidate battery after applying pressure are the same as those of the battery to be optimized.

[0016] The candidate batteries were subjected to charge-discharge tests using testing equipment.

[0017] Based on the negative electrode interface of the candidate battery, the comprehensive fit value of the candidate battery is determined. The comprehensive fit value is used to characterize the comprehensive performance of the candidate battery in terms of electrochemical performance and electrolyte wetting.

[0018] Iterate through all candidate batteries to obtain the comprehensive fit value for each candidate battery. The candidate battery with the largest comprehensive fit value is determined as the target battery, and the material system combination corresponding to the target battery is determined as the material system combination of the battery to be optimized.

[0019] Thirdly, embodiments of this application provide a single-cell battery, wherein the material system combination of the single-cell battery meets the preset wetting effect requirements;

[0020] The material system combination is determined based on the screening system described in the first aspect, which simulates large-size cells to be optimized, and the screening results of the cells to be selected.

[0021] Fourthly, embodiments of this application provide a battery pack comprising at least two individual cells as described in the third aspect, wherein each individual cell is electrically connected to the other.

[0022] Fifthly, embodiments of this application provide a battery pack, including a housing and at least two battery packs as described in the fourth aspect, each battery pack being disposed within the housing and electrically connected to each other.

[0023] Sixthly, embodiments of this application provide an electric vehicle that includes at least the battery pack described in the fifth aspect.

[0024] In a seventh aspect, embodiments of this application provide an electrical device that includes at least a single battery cell as described in the third aspect.

[0025] Eighthly, embodiments of this application provide a battery material screening device, comprising:

[0026] The preparation module determines the battery size of the battery to be optimized and identifies multiple candidate batteries. Each candidate battery corresponds to a material system combination, and the battery size of the battery to be optimized is larger than the battery size of any candidate battery.

[0027] The pressure control module is used to determine the pressure corresponding to the size of each candidate battery, control the pressure device to apply the pressure to the candidate battery respectively, so as to reduce the gap between the electrode and the separator of the candidate battery. The electrolyte wetting rate and wetting path of the candidate battery after applying pressure are the same as those of the battery to be optimized.

[0028] The test module is used to perform charge-discharge tests on the candidate battery using test equipment;

[0029] The detection module is used to determine the comprehensive fit value of the candidate battery based on the negative electrode interface of the candidate battery. The comprehensive fit value is used to characterize the comprehensive performance of the candidate battery in terms of electrochemical performance and electrolyte wetting.

[0030] The filtering module is used to traverse all candidate batteries, obtain the comprehensive fit value corresponding to each candidate battery, determine the candidate battery with the largest comprehensive fit value as the target battery, and determine the material system combination corresponding to the target battery as the material system combination of the battery to be optimized.

[0031] Ninthly, embodiments of this application provide an electronic device, including: a memory and a processor;

[0032] The memory stores computer-executed instructions;

[0033] The processor executes computer execution instructions stored in the memory, causing the processor to perform the implementation method described in the second aspect above.

[0034] In a tenth aspect, embodiments of this application provide a non-volatile computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the embodiments of the second aspect above.

[0035] Eleventhly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the implementation methods described in the second aspect above.

[0036] The battery material screening system, method, single cell, and electric vehicle provided in this application apply pressure to small-sized candidate batteries using a pressure device, actively controlling the separation of electrolyte components in the candidate batteries to simulate the separation law of electrolyte in large-sized candidate batteries. This allows for charge-discharge testing and electrolyte wetting effect analysis of the candidate batteries, avoiding repeated production and disassembly of large-sized candidate batteries. It enables rapid comparison and screening of the wetting effects of multiple material system combinations, quickly matching the optimal material system combination suitable for the candidate battery, thereby improving the screening efficiency of battery materials. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0038] Figure 1 This is a schematic diagram illustrating an application scenario of a battery material screening method provided in an embodiment of this application.

[0039] Figure 2 A flowchart illustrating a battery material screening method provided in this application embodiment;

[0040] Figure 3 A flowchart illustrating another battery material screening method provided in this application embodiment;

[0041] Figure 4 A schematic diagram illustrating the wetting effect of a large-size battery provided in an embodiment of this application;

[0042] Figure 5 A schematic diagram illustrating the principle of lithium intercalation defects in a wound battery provided in an embodiment of this application;

[0043] Figure 6 A schematic diagram illustrating the lithium intercalation defect principle of a stacked battery provided in an embodiment of this application;

[0044] Figure 7 A schematic diagram of a pressure device provided in an embodiment of this application;

[0045] Figure 8 A schematic diagram of a single battery cell provided in an embodiment of this application;

[0046] Figure 9 A schematic diagram of a battery pack provided in an embodiment of this application;

[0047] Figure 10 A schematic diagram of an electric vehicle provided in an embodiment of this application;

[0048] Figure 11This is a schematic diagram of the structure of a battery material screening device provided in an embodiment of this application;

[0049] Figure 12 This is a schematic diagram of the structure of another battery material screening device provided in an embodiment of this application;

[0050] Figure 13 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0051] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0052] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0053] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0054] It should be noted that the phrase "at...time" in the embodiments of this application can refer to the instant at which a certain situation occurs, or to a period of time after the occurrence of a certain situation; the embodiments of this application do not specifically limit this. Furthermore, the display interface provided in the embodiments of this application is merely an example, and the display interface may include more or less content.

[0055] It should be noted that the battery material screening system, method, single cell, and electric vehicle of this application can be used in the field of battery technology, or in any field other than batteries. The application fields of the battery material screening system, method, single cell, and electric vehicle of this application are not limited.

[0056] Figure 1 This is a schematic diagram illustrating an application scenario of a battery material screening method provided in this application embodiment. An example is given based on the illustrated scenario: testing the electrolyte wetting effect of the battery and optimizing the battery material based on the wetting effect.

[0057] In the electrolyte injection process of battery production, when the multi-component electrolyte flows on the surface of the battery electrodes, the polar components (such as lithium salts) migrate at a lower rate than the non-polar components due to adsorption, resulting in an uneven distribution of electrolyte components inside the battery cell. This uneven distribution can lead to problems such as uneven formation film formation and interface defects, ultimately causing battery failures such as local lithium plating, capacity decay, and even thermal runaway during cycling.

[0058] This phenomenon is more pronounced in large-size batteries, thus the electrolyte wetting effect limits the performance of large-size batteries.

[0059] In related technologies, large-size batteries are disassembled to observe characteristics such as color difference and electrolyte distribution at their internal electrode interfaces, thereby evaluating the wetting effect and optimizing battery materials or other processes based on the wetting effect.

[0060] While this method is intuitive, it has significant drawbacks: high experimental costs (requiring the use of large equipment and raw materials) and long process adjustment cycles (requiring repeated manufacturing of large batteries).

[0061] The method for screening battery materials provided in this application aims to solve the above-mentioned technical problems in related technologies.

[0062] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0063] Figure 2 This is a flowchart illustrating a battery material screening method provided in an embodiment of this application. The method includes the following steps:

[0064] S201. Determine the battery size of the battery to be optimized and determine multiple candidate batteries. Each candidate battery corresponds to a material system combination. The battery size of the battery to be optimized is larger than the battery size of any candidate battery.

[0065] As an example, the implementing entity of this embodiment can be a battery material screening system. The screening system is used to simulate the battery to be optimized using candidate batteries and determine the material system combination of the battery to be optimized based on the screening results of the candidate batteries.

[0066] For example, the battery to be optimized can be a large-sized power battery or energy storage battery, whose dimensions include the length, width, thickness, etc.

[0067] For example, multiple candidate batteries are all small-sized batteries, smaller than the battery to be optimized. Each candidate battery corresponds to a different material system combination, which includes at least one of the following: positive electrode material type, negative electrode material type, separator type, and electrolyte type. For instance, several proven high-performance positive electrode materials, negative electrode materials, separators, and electrolytes can be combined to form the material system combination corresponding to each candidate battery.

[0068] Optional cathode materials include lithium cobalt oxide, ternary materials (lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide), lithium iron phosphate, lithium manganese oxide, lithium manganese iron phosphate, lithium-rich manganese-based materials, etc.

[0069] Anode materials include graphite, hard carbon, soft carbon, silicon-based materials, lithium titanate, etc.

[0070] Membrane materials, for example, can be based on polyethylene or polypropylene and can be coated with alumina, boehmite, aramid, etc.

[0071] The electrolyte is a solvent such as carbonate or carboxylic acid ester, and one or more lithium salts such as lithium hexafluorophosphate, lithium bisfluorosulfonylimide, and lithium bistrifluoromethylsulfonylimide are used as solutes. Various additives can also be added in small amounts to achieve various functions.

[0072] Optionally, the battery to be selected can be a pouch cell, which facilitates mass production and testing.

[0073] S202. For each candidate battery, determine the pressure corresponding to the battery size, and control the pressure device to apply pressure to the candidate battery to reduce the gap between the electrode and the separator of the candidate battery. The electrolyte wetting rate and wetting path of the candidate battery after applying pressure are the same as those of the battery to be optimized.

[0074] For example, a pressure device is used to apply a constant pressure to the battery candidate to simulate the internal pressure of a large-sized battery. The larger the battery size, the greater the pressure typically needs to be applied to simulate the compression state between the electrodes.

[0075] A uniquely matched pressure value is determined based on the size of the battery to be optimized. Then, the same pressure value is applied to all the candidate batteries using a pressure device to ensure that the candidate batteries differ only in the combination of material systems and to eliminate the interference of pressure factors.

[0076] Using scenario examples, pressure is applied to ensure the electrodes and separator inside the candidate battery adhere tightly, precisely controlling the gap size between them and preventing irregular displacement, excessively large local gaps, or over-compression. This stable gap constraint allows for controllable regulation of the electrolyte's wetting rate, path, and uniformity within the cell, improving the uncontrolled free diffusion of the electrolyte. Furthermore, it enhances the chromatographic separation of different components within the electrolyte, promoting differentiated distributions of solvents, lithium salts, and additives based on their physicochemical properties. Ultimately, this ensures that the spatial distribution characteristics of the electrolyte components within each candidate battery are consistent with the actual electrolyte component distribution characteristics within the optimized battery, achieving stable replication of the optimized battery's electrolyte distribution across multiple candidate batteries.

[0077] S203. Perform charge and discharge tests on the selected battery using testing equipment.

[0078] For example, the electrolyte wetting effect is related to charge-discharge cycles. By performing charge-discharge cycles, an electrolyte wetting effect that matches the actual use scenario of the battery can be obtained.

[0079] For example, the testing equipment may be a charge-discharge tester, which can perform charge-discharge operations on each candidate battery according to a preset charge-discharge strategy.

[0080] Optionally, charge-discharge testing includes processes such as formation, full charge, and discharge to a constant capacity, used to activate electrode materials and obtain the electrochemical performance parameters of the battery.

[0081] S204. Based on the negative electrode interface of the candidate battery, determine the comprehensive fit value of the candidate battery. The comprehensive fit value is used to characterize the electrochemical performance and electrolyte wetting performance of the candidate battery.

[0082] For example, after the charge-discharge test is completed, each candidate battery is disassembled and its negative electrode interface is observed.

[0083] Using a scenario example, the separation of electrolyte components can cause color differences at the negative electrode interface, with the degree of lithium intercalation in the central area being lower than in the peripheral areas, resulting in a color difference from the periphery to the center. By analyzing the degree of color difference, the wetting effect of the electrolyte in the electrode sheet can be evaluated.

[0084] For example, based on the electrolyte wetting effect, the comprehensive fit value of each candidate battery is determined in combination with the electrochemical performance of the candidate batteries. The comprehensive fit value combines electrochemical performance and electrolyte wetting effect to comprehensively evaluate the candidate batteries.

[0085] S205. Traverse all candidate batteries to obtain the comprehensive fit value corresponding to each candidate battery. Determine the candidate battery with the largest comprehensive fit value as the target battery, and determine the material system combination corresponding to the target battery as the material system combination of the battery to be optimized.

[0086] For example, the battery with the best overall fit value is selected as the target battery. The target battery has the best overall performance in terms of electrochemical performance and electrolyte wetting effect. Then, the material system combination corresponding to this battery is the material system combination that is most suitable for the battery to be optimized.

[0087] With the help of scenario examples, the better the wetting effect, the more uniform the electrolyte distribution can be obtained in the material system combination in large batteries, which is beneficial to extend battery life and improve performance.

[0088] The battery material screening method provided in this application embodiment determines the battery size of the battery to be optimized and identifies multiple candidate batteries. Each candidate battery corresponds to a material system combination, and the battery size of the battery to be optimized is larger than the battery size of any candidate battery. For each candidate battery, the pressure corresponding to the battery size is determined, and a pressure device is used to apply pressure to the candidate batteries to reduce the gap between the electrode and the separator of the candidate battery. The electrolyte wetting rate and wetting path of the candidate battery after applying pressure are the same as those of the battery to be optimized. Charge and discharge tests are performed on the candidate batteries using a testing device. Based on the negative electrode interface of the candidate batteries, the comprehensive fit value of the candidate batteries is determined. The comprehensive fit value is used to characterize the electrochemical performance and electrolyte wetting performance of the candidate batteries. All candidate batteries are traversed to obtain the comprehensive fit value corresponding to each candidate battery. The candidate battery with the largest comprehensive fit value is determined as the target battery, and the material system combination corresponding to the target battery is determined as the material system combination of the battery to be optimized. By applying pressure to small-sized candidate batteries using pressure equipment, the separation of electrolyte components in the candidate batteries is actively controlled to simulate the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0089] Based on any of the above embodiments, the following, in conjunction with Figure 3 The detailed process of selecting battery materials is explained.

[0090] Figure 3 This is a schematic diagram illustrating the screening process for another battery material provided in an embodiment of this application. For example... Figure 3 As shown, the method includes:

[0091] S301. Determine the battery size of the battery to be optimized and determine multiple candidate batteries. Each candidate battery corresponds to a material system combination. The battery size of the battery to be optimized is larger than the battery size of any candidate battery.

[0092] For example, the battery to be optimized is a large-size battery, and the size of the large-size battery affects the wetting of the electrolyte.

[0093] Below, in conjunction with Figure 4 The wetting effect on large-size batteries is explained.

[0094] Figure 4 This is a schematic diagram illustrating the wetting effect of a large-size battery provided in an embodiment of this application. Figure 4 As shown, the large-size battery electrode has a large lateral width. When the electrolyte diffuses inside the electrode by its own wetting and capillary action, there is a natural limitation on the transmission distance. The electrolyte diffusion path in the middle region is long, and the electrolyte cannot reach the middle region sufficiently. Therefore, there is a defect of insufficient lithium intercalation in the middle region.

[0095] During the charging phase, the large-size battery lacks sufficient electrolyte in the middle as a lithium-ion transport medium. Free lithium ions cannot be successfully inserted into the graphite anode lattice and are deposited on the electrode surface in the form of metallic lithium, forming lithium plating. This causes the battery capacity and cycle life to decrease, and there is also a risk of internal short circuit and thermal runaway.

[0096] Below, in conjunction with Figure 5 The principle of lithium intercalation defects in wound batteries is explained.

[0097] Figure 5 This is a schematic diagram illustrating the principle of lithium intercalation defects in a wound battery provided in an embodiment of this application. Figure 5 As shown, the left and right sides of the wound battery are sealed by the winding and bending layer. Electrolyte has just been injected into the top and bottom edges of the wound battery. Initially, the electrolyte only penetrates linearly into the cell from the two injection edges and the electrode end faces. At this point, the electrolyte relies on capillary force to propagate unidirectionally along the electrode thickness direction, making it difficult for the electrolyte to fully reach the center, resulting in insufficient lithium intercalation in the central region.

[0098] After standing for a period of time, once the electrolyte has longitudinally penetrated and filled the surface electrode, it begins to diffuse laterally along the winding layer. Electrolytes from all the edges of the cell converge towards the center simultaneously. The electrolyte continues to contact the electrode and separator along more flow paths, and the highly polar lithium salt is continuously adsorbed and trapped along the way. The closer to the center, the more lithium salt is lost, and the area of ​​insufficient lithium intercalation in the center becomes smaller.

[0099] After standing for a period of time, the lateral path of the electrolyte continued to increase, and the lateral width of the region with insufficient lithium intercalation became narrower.

[0100] Below, in conjunction with Figure 6 The principle of lithium intercalation defects in stacked batteries is explained.

[0101] Figure 6 This is a schematic diagram illustrating the lithium intercalation defect principle of a stacked battery provided in an embodiment of this application. Figure 6 As shown, the exposed edges of the electrodes on all four sides of the stacked battery form a four-way synchronous wetting path, and the electrolyte can flow from the top, bottom, left and right sides of the cell to the center of the cell at the same time. Multiple flow channels share the lithium salt adsorption loss, the lithium salt concentration gradient is weak, and the area of ​​insufficient lithium intercalation defects is small.

[0102] One feasible implementation, the step of determining multiple candidate batteries, may include:

[0103] Obtain multiple pre-configured material system combinations, where the electrochemical performance of the battery corresponding to each material system combination is greater than or equal to the preset performance;

[0104] Based on multiple material system combinations, several candidate batteries are identified.

[0105] For example, multiple pre-configured material system combinations are provided, each defining the key material selection scheme used in cell construction. Basic electrochemical performance tests are conducted in advance for each material system combination. Material system combinations with corresponding battery electrochemical performance greater than or equal to preset performance indicators are screened and retained. Material combinations whose electrochemical performance does not meet the minimum usability requirements and lack research value are eliminated in advance. This prevents cell samples with fundamental performance defects from entering the subsequent wetting control, pressure loading, and electrolyte component distribution characterization processes, avoiding invalid experiments.

[0106] For example, each selected material system combination includes at least two of the following: positive electrode material type, negative electrode material type, separator type, and electrolyte type. No longer limited to a single material variable adjustment mode, it can flexibly achieve simultaneous changes in two, three, or even four types of key cell materials, adapting to multi-variable coupling research scenarios and facilitating the study of the coupled effects of synergistic changes in multiple materials on the electrolyte wetting behavior and component distribution state inside the cell.

[0107] In this feasible approach, by conducting pre-electrochemical performance screening of material system combinations, substandard material combinations can be eliminated from the source without the need for complex pressure wetting and characterization tests, thus reducing the investment in test materials and equipment time and improving the screening efficiency of battery materials.

[0108] One feasible approach is to combine materials into a system comprising positive electrode materials, negative electrode materials, membrane materials, and electrolyte materials.

[0109] The types of cathode materials are lithium cobalt oxide, ternary materials, lithium iron phosphate, lithium manganese oxide, lithium iron manganese phosphate, or lithium-rich manganese-based materials.

[0110] The types of anode materials are graphite, hard carbon, soft carbon, silicon-based materials, or lithium titanate;

[0111] The membrane material includes a substrate and a coating. The substrate is polyethylene or polypropylene; the coating is alumina, boehmite, aramid, or polyvinylidene fluoride.

[0112] The electrolyte material includes a solvent and a solute. The solvent is a carbonate or carboxylic acid ester; the solute is lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, or lithium bis(trifluoromethyl)sulfonyl)imide.

[0113] For example, the material system combination is any combination of the above materials, and both the positive electrode material and the negative electrode material are selected from the optional materials.

[0114] For example, the separator uses conventional base materials such as polyethylene and polypropylene to ensure basic cell isolation and mechanical stability. At the same time, it can be combined with different inorganic and organic coating materials such as alumina, boehmite, aramid, and polyvinylidene fluoride to meet diverse modification requirements such as high temperature resistance, high adhesion, low impedance, and high safety.

[0115] The electrolyte system allows for the selection and limitation of both the solvent system and the lithium salt solute. The solvent can be a single or compound system of carbonate or carboxylic acid ester to suit different viscosity, wettability, and oxidation resistance requirements. The lithium salt can be at least one of lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, or lithium bis(trifluoromethanesulfonyl)imide, which can achieve differentiated control of conductivity, thermal stability, hydrolytic stability, and interfacial film-forming characteristics.

[0116] By selecting and combining materials from multiple dimensions and categories, a large number of differentiated positive electrode, negative electrode, separator, and electrolyte coupling material systems can be constructed, providing a comprehensive material test sample library for systematically studying the effects of different material types and material combinations on electrolyte wetting rates.

[0117] In this feasible implementation, the rich range of material selection can fully simulate the actual material matching scenarios of large-size batteries of different systems, so that the material boundaries of small-size battery simulation tests are close to actual applications, thereby improving the accuracy of battery material selection.

[0118] S302. For each candidate battery, determine the pressure corresponding to the battery size, and control the pressure device to apply pressure to the candidate battery to reduce the gap between the candidate battery electrode and the separator. The electrolyte wetting rate and wetting path of the candidate battery after applying pressure are the same as those of the battery to be optimized.

[0119] One feasible approach is to determine the pressure corresponding to the battery size by: determining a pre-trained pressure prediction model, which is obtained by training the model based on the sample size of multiple sample batteries and the sample pressure corresponding to each sample size; inputting the battery size into the pressure prediction model to obtain the pressure output by the pressure prediction model.

[0120] For example, a large number of sample batteries (such as large batteries of different sizes) can be collected in advance. By measuring the amount of sample pressure applied to small-sized batteries using pressure sensors, the electrolyte separation law of the sample batteries can be simulated, resulting in multiple sample sizes and the sample pressure corresponding to each sample size, thus constructing sample data.

[0121] Optionally, the sample data can be trained using a linear regression model, a neural network model, or a support vector regression model to obtain the mapping relationship between size and pressure.

[0122] With the example scenario, after inputting the battery size to be optimized, the model automatically outputs the corresponding pressure value. For example, when the battery thickness is 10mm, the model outputs a pressure of 0.3MPa; when the battery thickness is 20mm, the output pressure is 0.6MPa.

[0123] Optionally, the training process of the pressure prediction model can use mean squared error as the loss function and optimize the model parameters through gradient descent to minimize the error between the predicted pressure and the measured pressure.

[0124] In this feasible implementation, the pressure is automatically determined by a pressure prediction model, avoiding errors from manual experience estimation, improving the efficiency of pressure setting, and thus enhancing the screening efficiency of battery materials.

[0125] One feasible implementation includes a pressure device comprising a clamping plate, a buffer pad, and multiple elastic pressure-applying components. Each elastic pressure-applying component includes a screw, a nut, and a spring. The spring is fitted onto the shank of the screw, which passes through the clamping plate. The nut is fitted to the end of the screw. The multiple elastic pressure-applying components are located at the corners of the clamping plate. The buffer pad is positioned between the battery to be selected and the clamping plate, and between the multiple batteries to be selected. The step of controlling the pressure device to apply pressure to the batteries to be selected may include: clamping the battery to be selected using the clamping plate; determining the target spring compression corresponding to the pressure; and adjusting the spring compression of each of the multiple elastic pressure-applying components to the target spring compression.

[0126] Below, in conjunction with Figure 7 The pressure equipment is described.

[0127] Figure 7 This is a schematic diagram of a pressure device provided in an embodiment of this application. Figure 7As shown, two clamping plates act as the pressure-bearing structure, evenly transmitting pressure to the battery in the middle, simulating the electrolyte decomposition process in a large battery. The screws and nuts at the four corners of the clamping plates are pressure adjustment mechanisms; by turning the nuts, the distance between the two clamping plates is changed, thereby adjusting the pressure. Springs fitted around the screws absorb the volume expansion during battery charging and discharging, preventing rigid pressure from crushing the electrode plates and maintaining stable pressure over a long period. Buffer pads compensate for minor flatness errors on the battery surface, disperse localized stress, and prevent damage from hard contact.

[0128] For example, the clamps are rigid metal plates used to hold multiple stacked candidate batteries. Cushioning pads (such as silicone pads) are located between the batteries and the clamps, and between adjacent batteries, to cushion pressure and distribute it evenly.

[0129] The elastic pressure application assembly is located at the corner of the clamping plate, and the spring is compressed by tightening the nut. For example, if a pressure of 0.5 MPa is required and the total effective area of ​​the springs is 10 cm², the spring pressure should be 500 N. If the spring constant is 100 N / mm, the target spring compression is 5 mm. During adjustment, ensure that the compression of the four springs is consistent to maintain balanced clamping pressure.

[0130] Optionally, when adjusting the spring compression, a vernier caliper can be used to measure the free length and compressed length of each spring to calculate the actual compression. If the compression deviation of any spring exceeds the deviation threshold, the nuts are readjusted until the difference in compression of the four springs is less than the deviation threshold. This precisely controls the pressure applied to the battery and ensures that the pressure remains constant throughout the test.

[0131] Optionally, the buffer pad can be made of silicone, which can absorb the minute deformation caused by the expansion of the electrode during charging and discharging, thereby maintaining pressure stability.

[0132] In this feasible implementation, the elastic pressure component can precisely control and maintain a constant pressure, and the buffer pad can absorb the volume changes of the electrode during the charging and discharging process to ensure pressure stability, thereby accurately simulating the confinement state of a large battery and improving the screening efficiency of battery materials.

[0133] S303. Perform charge and discharge tests on the selected battery using testing equipment.

[0134] One feasible approach is to conduct charge-discharge tests to determine the application scenario of the battery to be optimized; based on the application scenario, determine the corresponding test temperature range, test humidity range, and charge-discharge strategy; based on the test temperature range and test humidity range, adjust the temperature and humidity of the test environment using a temperature and humidity control device; until the temperature and humidity of the test environment are within the test temperature range and the humidity is within the test humidity range, and then conduct charge-discharge tests on the selected battery using a test device according to the charge-discharge strategy.

[0135] The screening system also includes temperature and humidity control equipment, such as a constant temperature and humidity chamber.

[0136] For example, different application scenarios correspond to different battery operating temperature and humidity ranges. The test temperature and humidity ranges are selected according to the application scenario, and then the charge and discharge strategies (such as voltage and current rates) are set.

[0137] The temperature and humidity control equipment first adjusts the environment, and only after the temperature and humidity stabilize within the range does the charge and discharge test begin, in order to ensure consistent test conditions and eliminate environmental interference.

[0138] In this feasible approach, a specific temperature and humidity range is matched according to the actual application scenario of the battery to be optimized, rather than using a uniform fixed temperature and humidity for testing. This can replicate the electrolyte wetting and ion transport behavior under the real working environment of the battery, avoid the performance deviation caused by conventional room temperature standard testing, and thus improve the accuracy of battery material selection.

[0139] One feasible implementation method is to perform charge-discharge testing by: injecting electrolyte into the selected batteries using an injection device; allowing the batteries to stand for a preset time, and then vacuum sealing them using a sealing device; and performing charge-discharge testing on the selected batteries using a testing device according to a charge-discharge strategy.

[0140] The screening system also includes injection equipment and sealing equipment;

[0141] For example, the injection device is a micro-syringe or an automatic liquid injector. In a low-humidity environment, the side seal of the battery gas bag is cut open, and electrolyte slightly higher than the critical injection volume is injected (for example, if the critical injection volume is 2 mL, then 2.2 mL is injected).

[0142] After allowing the electrolyte to be fully absorbed, let it stand for a preset time (e.g., 10 minutes) and then vacuum seal it (using a vacuum sealer and needle to create a vacuum) to eliminate any residual air in the air bag and prevent air from affecting the wetting process. Finally, perform a charge-discharge test.

[0143] With a scenario example, during charge-discharge cycles, the electrodes undergo slight expansion and contraction, and the pores continuously consume electrolyte. If only the critical electrolyte injection volume is added, the electrode pores will be filled with electrolyte under pressure, leaving no free electrolyte inside the cell. This prevents electrolyte component stratification and segregation phenomena such as electrolyte deficiency in the center. A small amount of excess electrolyte will form a free liquid phase inside the cell. Under uniform pressure from the clamping plates, the electrolyte will flow laterally along the electrodes, causing regional separation of the high-lithium salt concentration electrolyte and solvent. This replicates the wetting phenomenon of abundant electrolyte at the edges and scarce electrolyte in the center of large-size batteries.

[0144] This feasible implementation integrates automated functions such as liquid injection, sealing, temperature and humidity control, and charging and discharging. While simulating the separation law of large-size batteries, it shortens the test cycle and improves the efficiency of battery material screening.

[0145] One feasible approach involves conducting charge-discharge tests on multiple candidate batteries using the following method: determining the corresponding characteristic state of charge (SOC) based on the material system combination of the candidate batteries, where the characteristic SOC is the SOC where the negative electrode interface of the battery exhibits a color difference due to wetting; adjusting the charging cutoff capacity in the charge-discharge strategy based on the characteristic SOC to obtain the target charge-discharge strategy; and conducting charge-discharge tests on the candidate batteries using testing equipment based on the target charge-discharge strategy.

[0146] For example, under a characteristic state of charge, the negative electrode interface of the battery can produce a stable, quantifiable color difference due to uneven electrolyte wetting.

[0147] For example, the characteristic state of charge can be predetermined through a gradient charging experiment. Batteries with the same material system combination are charged to different states of charge, and the negative electrode interface is disassembled and observed. The state of charge when the color contrast is most distinct is taken as the characteristic state of charge.

[0148] For example, for graphite anodes, the characteristic state of charge is approximately 63%. In this state of charge, the region with insufficient lithium intercalation appears purplish-red, while the region with sufficient lithium intercalation appears yellow, showing the most obvious color difference.

[0149] After obtaining the characteristic state of charge, the cutoff capacity of the constant current charging in the last step of the charge-discharge strategy is set to the total discharge capacity multiplied by the characteristic state of charge, so that the candidate battery will eventually stop at the characteristic state of charge after the charge-discharge cycle, which is convenient for observing color difference.

[0150] In this feasible implementation, a unique characteristic state of charge is individually calibrated based on the material system combination, and the charging cutoff capacity is adaptively adjusted to the color development critical range. This allows the difference in lithium intercalation degree caused by uneven electrolyte distribution to be directly converted into a stable and clear negative electrode partition color difference, thereby improving the accuracy of electrode material selection.

[0151] One feasible implementation method is to perform charge-discharge testing as follows: determine the cutoff capacity in the target charge-discharge strategy; according to the target charge-discharge strategy, perform target operations on the selected battery until the cutoff capacity is reached to complete the charge-discharge test. The target operations include: formation, full charge, discharge to capacity setting, and charging. Adjacent operations in the target operations include a resting operation.

[0152] The target operation is illustrated in Table 1 below:

[0153] Table 1

[0154]

[0155] Referring to Table 1, the cutoff capacity is... The target operation sequence is as follows: rest for 1 minute, form and charge, rest for 5 minutes, fully charge, rest for 5 minutes, discharge to set capacity, rest for 5 minutes, charge to cut-off capacity, and rest for 15 minutes.

[0156] Allowing the battery to reach electrochemical equilibrium during resting prevents polarization from affecting test results. Charging with a high current (0.5C) generates a large overpotential, further highlighting the differences in lithium intercalation.

[0157] To illustrate with a scenario example, taking the lithium iron phosphate-graphite material system as an example, with a characteristic state of charge of 63% and a discharge capacity X of 1000mAh, the cutoff capacity is 630mAh. Under 0.5C (500mA) constant current charging, it takes approximately 76 minutes to reach 630mAh.

[0158] In this feasible implementation, formation, full charge, discharge to capacity, and charging are performed sequentially, with a resting step between each process, completely replicating the standardized activation process of the battery. The formation process generates a uniform and stable passivation film on the negative electrode surface, eliminating interference caused by inconsistent electrochemical activity within the new cell; full charge allows the electrolyte inside the cell to fully wet the pores of the electrode; discharge to capacity accurately calibrates the true usable capacity of each candidate battery, using this as a benchmark for calculating the cutoff capacity corresponding to the characteristic state of charge, avoiding distortion of state of charge control due to initial capacity deviation of the cell; the resting operation between adjacent processes allows sufficient time for electrolyte diffusion and ion distribution to stabilize, eliminating temporary color differences caused by instantaneous concentration differences during charging and discharging, ensuring that the final interface color difference is determined only by the long-term wetting performance differences of the material system combination, thereby improving the accuracy of battery material selection.

[0159] S304. Using the outer area of ​​the negative electrode interface of the battery to be selected as the reference color, the color of the central area is detected by a colorimeter to obtain the color detection result of the battery to be selected. The color result includes at least one of the following: color uniformity, color difference range, and color difference depth.

[0160] The screening system also includes a colorimeter.

[0161] For example, a colorimeter is a precision color measurement device capable of quantitatively detecting color difference values. It uses the color of the outer region of the negative electrode interface (electrolyte-rich area) as a standard reference to measure the color difference in the central region (electrolyte-deficient area).

[0162] For example, after the battery has undergone charge and discharge testing, it is disassembled, and the negative electrode is removed for color testing. Color uniformity refers to the color consistency of the entire negative electrode interface, color difference range refers to the color difference value between the center and the periphery, and color difference depth refers to the specific value of the color difference.

[0163] Optionally, color uniformity can be obtained by calculating the standard deviation of the chromaticity values ​​of multiple sampling points (e.g., 9 points) across the entire negative electrode interface. The smaller the standard deviation, the higher the color uniformity.

[0164] In this feasible implementation method, a colorimeter is used to replace subjective judgment by the human eye, realizing quantitative detection of the wetting effect, thereby improving the accuracy of battery material screening.

[0165] S305. Based on the color detection results of the candidate batteries, determine the electrolyte wetting effect value of the candidate batteries.

[0166] For example, if the overall color uniformity of the negative electrode center area is high, it means that the electrolyte supply in the center is stable, there is no local liquid phase deficiency after pressure, and the electrolyte wetting effect is excellent; if the color of the center area is messy and the uniformity is poor, it means that the electrolyte is distributed randomly in the electrode, there is liquid deficiency in many places, and the wetting effect is poor.

[0167] For example, if only a very small area shows a color deviation that is inconsistent with the surrounding reference color, the defect range of electrolyte loss and segregation is small, and the wetting performance is better; if there is a large area of ​​discolored area, it means that there is a large area of ​​electrolyte separation and lack of liquid in the middle of the cell, and the wetting effect is poor.

[0168] For example, if the color difference between the central area and the outer reference color is slight, it indicates that the degree of lithium intercalation in the two areas is similar, the electrolyte supply difference is small, and the wetting uniformity is good; if the color difference is significant, it indicates that the electrolyte supply in the center is seriously insufficient and the wetting defects are serious.

[0169] For example, at least one of the test results—color uniformity, color difference range, and color difference depth—is converted into a unique, comparable, and quantifiable electrolyte wetting effect value. This places the wetting performance of all candidate batteries under the same evaluation scale.

[0170] Based on the above implementation methods, the wetting effect value can be quickly determined according to the color contrast relationship between the inner and outer areas of the same battery. The determination logic is simple and intuitive, thereby improving the screening efficiency of battery materials.

[0171] S306. Determine the electrochemical performance, wetting effect weight, and electrochemical performance weight of the candidate batteries.

[0172] For example, electrochemical performance includes at least one of the following: capacity retention, internal resistance, rate performance, etc., obtained by charge-discharge testing.

[0173] For example, the system synchronously collects the electrochemical performance data of each candidate battery obtained from the actual test in the entire standardized charge and discharge test process.

[0174] Two types of independent adjustable parameters are set: wetting effect weight and electrochemical performance weight. These two weights are used to define the important proportion of electrolyte wetting index and electrochemical performance index in the material screening and judgment process, respectively.

[0175] S307. Based on the wetting effect weight and the electrochemical performance weight, the electrolyte wetting effect value of the battery to be selected and the electrochemical performance value of the battery to be selected are weighted and summed to obtain the comprehensive suitability value of the battery to be selected.

[0176] For example, the overall fit value is calculated as follows: Overall fit value = wetting effect value × wetting effect weight + electrochemical performance score × electrochemical performance weight.

[0177] For example, if battery A has a wetting effect value of 80 and an electrochemical performance score of 90, with weights of 0.4 and 0.6 respectively, then the overall fit value = 80 × 0.4 + 90 × 0.6 = 86; if battery B has a wetting effect value of 70 and an electrochemical performance score of 95, then the overall fit value = 70 × 0.4 + 95 × 0.6 = 85.

[0178] For example, the two types of core performance indicators are integrated for evaluation, taking into account both the electrolyte wetting ability of the material system combination and the electrochemical performance under actual working conditions, thereby comprehensively evaluating the material system combination.

[0179] S308. Traverse all candidate batteries to obtain the comprehensive fit value corresponding to each candidate battery. Determine the candidate battery with the largest comprehensive fit value as the target battery, and determine the material system combination corresponding to the target battery as the material system combination of the battery to be optimized.

[0180] For example, the battery with the highest overall fit value is selected as the target battery. If battery A has an overall fit value of 86 and battery B has 85, then battery A is selected. Then, the material system combination corresponding to battery A is determined as the material system combination of the battery to be optimized.

[0181] In this feasible approach, by integrating the wetting effect and electrochemical performance through a comprehensive fit value, the overall applicability of the material system combination can be evaluated from multiple perspectives. This avoids the problem that material selection based solely on the wetting effect may lead to insufficient electrochemical performance, thereby selecting the material system combination with the best overall performance to improve the overall performance of the battery to be optimized.

[0182] This application provides a single-cell battery, wherein the material system combination of the single-cell battery meets the preset wetting effect requirements;

[0183] The material system combination is determined by the battery material screening system, which uses small-sized batteries to simulate large-sized batteries to be optimized, and then determines the combination based on the screening results of the small-sized batteries.

[0184] This application does not impose any special limitation on the geometry of the single cell 400, which can be cylindrical, square, or any other arbitrary shape. For example, Figure 8 The image shows a single-cell battery 400 with a square structure.

[0185] A single battery cell 400 typically includes a housing 410, a cell 430, and a cover assembly 420. The housing 410 is used to house the cell 430, and the cover assembly has at least one positive electrode post and at least one negative electrode post. The cell 430 includes one or more electrode assemblies, which are formed by stacking or winding positive electrode sheets, negative electrode sheets, and separators.

[0186] The single cell 400 is the basic unit that constitutes a battery. It can store chemical energy and controllably convert chemical energy into electrical energy. In a recyclable single cell, the active materials can be activated by charging after discharge, allowing it to continue to be used. The single cells 400 can be further combined into a battery pack. The number of single cells contained in the battery pack can be adjusted according to the actual application scenario and capacity requirements.

[0187] Based on the above implementation method, pressure is applied to small-sized candidate batteries using pressure equipment to actively control the separation of electrolyte components in the candidate batteries, thereby simulating the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0188] This application provides a battery pack comprising at least two of the above-described individual cells, each of which is electrically connected to the other.

[0189] Based on the above implementation method, pressure is applied to small-sized candidate batteries using pressure equipment to actively control the separation of electrolyte components in the candidate batteries, thereby simulating the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0190] This application provides a battery pack, including a housing and at least two battery packs as described above, each battery pack being disposed within the housing and electrically connected to each other.

[0191] See Figure 9 , Figure 9A schematic diagram of the battery pack structure is shown in some embodiments of this application. The battery pack 200 is disposed inside the electric vehicle and can be installed at the bottom, front, or rear of the electric vehicle. The battery pack 200 can provide power support to the electric vehicle, for example, acting as the operating power source for the electric vehicle. The electric vehicle may also be equipped with a controller and a motor. The controller is used to schedule the battery pack to deliver electrical energy to the motor to meet the power needs of the electric vehicle during starting, navigation, and driving.

[0192] The battery pack 200, as a rechargeable battery, is the power source for new energy vehicles. The battery pack includes a housing 210 and multiple individual battery cells housed within the housing 210. The housing 210 provides space for the individual battery cells and other components, while also providing dustproof, waterproof, and protective functions to the internal components, thereby reducing the adverse effects of external liquids or foreign objects on the effectiveness and performance of the individual battery cells and other components, effectively extending the battery pack's lifespan. The shape of the housing is not limited; for example, it can be a cuboid, cylinder, etc. The material of the housing can also be flexibly selected; for example, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic are all suitable.

[0193] The battery pack 200 in this embodiment includes multiple battery groups 230, with one battery group 230 disposed in each sub-accommodating space. Each battery group 230 includes multiple stacked individual cells, and the stacking direction of the individual cells can be parallel to the plane of the base plate. The battery pack 200 also includes a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (casing, brackets, etc.), and protective components, etc., and the above components are placed in the housing 210 and sealed by the cover plate 220 to form a complete functional unit that can directly output electrical energy.

[0194] The battery management system (BMS) is used to detect the operating status of the battery pack and its individual cells, and to manage the battery module and its individual cells. The BMS includes a Battery Management Unit (BMU), a Cell Measurement Circuit (CMC), sensors, and various electronic control devices. The BMS includes at least one processor and a memory. The memory can be built into the BMS or externally located, and can also be remotely configured and connected to the BMS via a network.

[0195] Based on the above implementation method, pressure is applied to small-sized candidate batteries using pressure equipment to actively control the separation of electrolyte components in the candidate batteries, thereby simulating the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0196] This application provides an electric vehicle that includes at least the aforementioned battery pack.

[0197] The following example uses an electric vehicle as a specific example of an electrical device. See [link / reference] Figure 10 , Figure 10 The diagram illustrates the structure of an electric vehicle in some embodiments of this application. This electric vehicle can be a new energy vehicle, encompassing various types such as pure electric vehicles, hybrid electric vehicles, and range-extended electric vehicles. The battery device 500 can be located at the bottom, front, or rear of the electric vehicle 100, providing power support to the electric vehicle, for example, acting as its operating power source. Furthermore, the electric vehicle 100 typically also includes a controller 300, which manages the discharge process of the battery device 500 to cover various power needs during vehicle startup, navigation, and operation.

[0198] In some embodiments, the battery device 500 comprises one or more battery packs, which can be connected in series, parallel, or a hybrid configuration. A hybrid configuration refers to the simultaneous presence of series and parallel connections in the connection of multiple battery packs. In other embodiments, the battery device 500 is a cluster-level battery architecture composed of multiple battery packs connected in series, wherein the number of battery packs in each cluster is strictly configured according to voltage and capacity requirements. More specifically, the battery unit of the battery device 500 includes multiple batteries, some of which are connected in series to form a cluster that meets a preset power supply voltage requirement, and at least one spare battery among the multiple batteries is bypassed.

[0199] Based on the above implementation method, pressure is applied to small-sized candidate batteries using pressure equipment to actively control the separation of electrolyte components in the candidate batteries, thereby simulating the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0200] This application provides an electrical device that includes at least the aforementioned single battery cell.

[0201] Based on the above implementation method, pressure is applied to small-sized candidate batteries using pressure equipment to actively control the separation of electrolyte components in the candidate batteries, thereby simulating the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0202] Figure 11 This is a schematic diagram of a battery material screening device provided in an embodiment of this application. Figure 11 As shown, the battery material screening device 110 may include: a preparation module 111, a pressure control module 112, a testing module 113, a detection module 114, and a screening module 115.

[0203] Preparation module 111 is used to determine the battery size of the battery to be optimized and to determine multiple candidate batteries. Each candidate battery corresponds to a material system combination, and the battery size of the battery to be optimized is larger than the battery size of any candidate battery.

[0204] The pressure control module 112 is used to determine the pressure corresponding to the size of each candidate battery, control the pressure device to apply pressure to the candidate batteries respectively, so as to reduce the gap between the candidate battery electrode and the separator. The electrolyte wetting rate and wetting path of the candidate battery after applying pressure are the same as those of the battery to be optimized.

[0205] Test module 113 is used to perform charge and discharge tests on the battery to be tested using test equipment.

[0206] The detection module 114 is used to determine the comprehensive fit value of the candidate battery based on the negative electrode interface of the candidate battery. The comprehensive fit value is used to characterize the comprehensive performance of the candidate battery in terms of electrochemical performance and electrolyte wetting.

[0207] The filtering module 115 is used to traverse all candidate batteries, obtain the comprehensive fit value corresponding to each candidate battery, determine the candidate battery with the largest comprehensive fit value as the target battery, and determine the material system combination corresponding to the target battery as the material system combination of the battery to be optimized.

[0208] Optionally, preparation module 111 can be executed. Figure 2 S201 in the embodiment.

[0209] Optionally, the pressure control module 112 can perform... Figure 2 S202 in the embodiment.

[0210] Optionally, test module 113 can be executed. Figure 2 S203 in the embodiment.

[0211] Optionally, the detection module 114 can perform... Figure 2 S204 in the embodiment.

[0212] Optionally, the filtering module 115 can perform... Figure 2 S205 in the embodiment.

[0213] It should be noted that the battery material screening device shown in the embodiments of this application can perform the technical solution shown in the above method embodiments, and its implementation principle and beneficial effects are similar, so they will not be described again here.

[0214] Based on the above implementation method, pressure is applied to small-sized candidate batteries using pressure equipment to actively control the separation of electrolyte components in the candidate batteries, thereby simulating the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0215] In one possible implementation, the pressure control module 112 is specifically used for:

[0216] The pre-trained stress prediction model is determined. The stress prediction model is obtained by training the model based on the sample size of multiple sample batteries and the sample stress corresponding to each sample size.

[0217] Input the battery size into the pressure prediction model to obtain the pressure output by the pressure prediction model.

[0218] In one possible implementation, the pressure device includes a clamping plate, a buffer pad, and multiple elastic pressure-applying components. Each elastic pressure-applying component includes a screw, a nut, and a spring. The spring is fitted onto the shank of the screw, which passes through the clamping plate. The nut is fitted to the end of the screw. The multiple elastic pressure-applying components are located at the corners of the clamping plate. The buffer pad is positioned between the battery to be selected and the clamping plate, and between the multiple batteries to be selected. The pressure control module 112 is specifically used for:

[0219] The selected battery is held in place by clamping the clamps;

[0220] Determine the target spring compression corresponding to the pressure;

[0221] The compression of the springs in the multiple elastic compression components is adjusted to the target spring compression.

[0222] In one possible implementation, the screening system further includes a temperature and humidity control device; the testing module 113 is specifically used for:

[0223] Identify the application scenarios for the battery to be optimized;

[0224] Based on the application scenario, determine the corresponding test temperature range, test humidity range, and charge / discharge strategy;

[0225] Based on the test temperature range and test humidity range, the temperature and humidity of the test environment are adjusted using temperature and humidity control equipment;

[0226] Until the temperature and humidity of the test environment are within the test temperature range and the humidity is within the test humidity range, the selected battery is charged and discharged using the test equipment according to the charge and discharge strategy.

[0227] In one possible implementation, the screening system further includes an injection device and a sealing device; the testing module 113 is specifically used for:

[0228] Electrolyte is injected into the selected battery using an injection device;

[0229] After a preset set time, the selected battery is vacuum-sealed using a sealing device.

[0230] According to the charging and discharging strategy, the selected battery is charged and discharged using testing equipment.

[0231] In one possible implementation, test module 113 is specifically used for:

[0232] Based on the material system combination of the candidate battery, the corresponding characteristic state of charge is determined. The characteristic state of charge is the state of charge in which the negative electrode interface of the battery produces a color difference due to the wetting effect.

[0233] Based on the characteristic state of charge, the charging cutoff capacity in the charging and discharging strategy is adjusted to obtain the target charging and discharging strategy.

[0234] Based on the target charge / discharge strategy, charge / discharge tests are conducted on the selected battery using testing equipment.

[0235] In one possible implementation, test module 113 is specifically used for:

[0236] Determine the cutoff capacity in the target charge / discharge strategy;

[0237] According to the target charge and discharge strategy, target operations are performed on the selected battery until the cutoff capacity is reached to complete the charge and discharge test. Target operations include: formation, full charge, discharge to capacity and charging. There are rest operations between adjacent operations in the target operations.

[0238] Figure 12This is a schematic diagram of another battery material screening device provided in an embodiment of this application. Figure 11 Based on the illustrated embodiments, as Figure 12 As shown, the battery material screening device 110 also includes a calculation module 116 and an acquisition module 117.

[0239] Calculation module 116 is used for:

[0240] Using the outer area of ​​the negative electrode interface of the battery to be selected as the reference color, the color of the central area is detected by a colorimeter to obtain the color detection result of the battery to be selected. The color result includes at least one of the following: color uniformity, color difference range, and color difference depth.

[0241] Based on the color detection results of the candidate batteries, determine the electrolyte wetting effect value of the candidate batteries;

[0242] The overall suitability value of the candidate battery is determined based on the electrolyte wetting effect value.

[0243] In one possible implementation, the computing module 116 is specifically used for:

[0244] Determine the electrochemical performance, wetting effect weight, and electrochemical performance weight of the candidate batteries;

[0245] Based on the wetting effect weight and the electrochemical performance weight, the electrolyte wetting effect value of the battery to be selected and the electrochemical performance value of the battery to be selected are weighted and summed to obtain the comprehensive suitability value of the battery to be selected.

[0246] Module 117 is used for:

[0247] Obtain multiple pre-configured material system combinations, where the electrochemical performance of the battery corresponding to each material system combination is greater than or equal to the preset performance;

[0248] Based on multiple material system combinations, several candidate batteries are identified.

[0249] Figure 13 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application, such as... Figure 13 As shown, the electronic device includes:

[0250] The electronic device includes a processor 291 and a memory 292; it may also include a communication interface 293 and a bus 294. The processor 291, memory 292, and communication interface 293 can communicate with each other via the bus 294. The communication interface 293 can be used for information transmission. The processor 291 can invoke logical instructions stored in the memory 292 to execute the methods of the above embodiments.

[0251] Furthermore, the logic instructions in the aforementioned memory 292 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0252] The memory 292, as a non-volatile computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this application. The processor 291 executes functional applications and data processing by running the software programs, instructions, and modules stored in the memory 292, that is, it implements the methods in the above-described method embodiments.

[0253] The memory 292 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 292 may include high-speed random access memory and may also include non-volatile memory.

[0254] Based on the above implementation method, pressure is applied to small-sized candidate batteries using pressure equipment to actively control the separation of electrolyte components in the candidate batteries, thereby simulating the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0255] This application provides a non-volatile computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method as described in the foregoing embodiments.

[0256] Based on the above implementation method, pressure is applied to small-sized candidate batteries using pressure equipment to actively control the separation of electrolyte components in the candidate batteries, thereby simulating the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0257] This application provides a computer program product, including a computer program that, when executed by a processor, implements the method as described in the foregoing embodiments.

[0258] Based on the above implementation method, pressure is applied to small-sized candidate batteries using pressure equipment to actively control the separation of electrolyte components in the candidate batteries, thereby simulating the separation law of electrolyte in large-sized candidate batteries. Charge-discharge tests and electrolyte wetting effect analysis are then performed on the candidate batteries. This avoids the need for repeated production and disassembly of large-sized candidate batteries, and allows for rapid comparison and screening of the wetting effect of multiple material system combinations. The optimal material system combination suitable for the candidate battery can be quickly matched, thereby improving the screening efficiency of battery materials.

[0259] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0260] It should be further noted that although the steps in the flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps; they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages, which do not necessarily complete at the same time but can be executed at different times. The execution order of these sub-steps or stages is also not necessarily sequential but can be alternated or carried out in turn with other steps or at least some of the sub-steps or stages of other steps.

[0261] It should be understood that the above-described device embodiments are merely illustrative, and the device of this application can also be implemented in other ways. For example, the division of units / modules in the above embodiments is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units, modules, or components may be combined, or integrated into another system, or some features may be ignored or not executed.

[0262] Furthermore, unless otherwise specified, the functional units / modules in the various embodiments of this application can be integrated into one unit / module, or each unit / module can exist physically separately, or two or more units / modules can be integrated together. The integrated units / modules described above can be implemented in hardware or as software program modules.

[0263] When integrated units / modules are implemented in hardware, the hardware can be digital circuits, analog circuits, etc. The physical implementation of the hardware structure includes, but is not limited to, transistors, memristors, etc. The processor can be any suitable hardware processor, such as CPU, GPU, FPGA, DSP, and ASIC. The storage unit can be any suitable magnetic or magneto-optical storage medium, such as Resistive Random Access Memory (RRAM), Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), Enhanced Dynamic Random Access Memory (EDRAM), High-Bandwidth Memory (HBM), Hybrid Memory Cube (HMC), etc.

[0264] If the integrated unit / module is implemented as a software program module and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to related technologies, 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 memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0265] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0266] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0267] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery material screening system, characterized in that, The screening system is used to simulate the battery to be optimized using candidate batteries, and to determine the material system combination of the battery to be optimized based on the screening results of the candidate batteries; the screening system includes pressure equipment and testing equipment; The screening system is configured to perform the following steps: The battery size of the battery to be optimized is determined and multiple candidate batteries are determined. Each candidate battery corresponds to a material system combination. The battery size of the battery to be optimized is larger than the battery size of any candidate battery. For each candidate battery, the pressure corresponding to the battery size is determined, and the pressure device is controlled to apply the pressure to the candidate battery to reduce the gap between the electrode and the separator of the candidate battery. The electrolyte wetting rate and wetting path of the candidate battery after applying pressure are the same as those of the battery to be optimized. The candidate battery is subjected to charge-discharge tests using the aforementioned testing equipment. Based on the negative electrode interface of the candidate battery, the comprehensive fit value of the candidate battery is determined. The comprehensive fit value is used to characterize the comprehensive performance of the candidate battery in terms of electrochemical performance and electrolyte wetting. Iterate through all candidate batteries to obtain the comprehensive fit value for each candidate battery. The candidate battery with the largest comprehensive fit value is determined as the target battery, and the material system combination corresponding to the target battery is determined as the material system combination of the battery to be optimized.

2. The system according to claim 1, characterized in that, The step of determining the pressure corresponding to the battery size specifically includes: A pre-trained stress prediction model is determined, which is obtained by training the model based on the sample size of multiple sample batteries and the sample stress corresponding to each sample size. The battery size is input into the pressure prediction model to obtain the pressure output by the pressure prediction model.

3. The system according to claim 2, characterized in that, The pressure device includes a clamping plate, a buffer pad, and multiple elastic pressure components. Each elastic pressure component includes a screw, a nut, and a spring. The spring is fitted onto the shank of the screw, the screw passes through the clamping plate, and the nut is fitted to the end of the screw. The multiple elastic pressure components are located at the corners of the clamping plate, and the buffer pad is disposed between the candidate battery and the clamping plate, as well as between the multiple candidate batteries. The step of controlling the pressure device to apply the pressure to the candidate batteries specifically includes: The battery to be selected is held by the clamping plate; Determine the target spring compression corresponding to the pressure; The compression of the springs in the plurality of elastic compression components is adjusted to the target spring compression.

4. The system according to claim 1, characterized in that, The screening system further includes a temperature and humidity control device; the step of performing charge-discharge tests on the candidate batteries using the testing device specifically includes: Determine the application scenarios for the battery to be optimized; Based on the application scenario, determine the corresponding test temperature range, test humidity range, and charge / discharge strategy; Based on the test temperature range and the test humidity range, the test environment is regulated by the temperature and humidity control device. Until the temperature and humidity of the test environment are within the test temperature range and the humidity is within the test humidity range, the candidate battery is charged and discharged using the test equipment according to the charge and discharge strategy.

5. The system according to claim 4, characterized in that, The screening system further includes an injection device and a sealing device; the step of performing charge-discharge tests on the candidate batteries using the testing device according to the charge-discharge strategy specifically includes: Electrolyte is injected into the battery to be selected using the injection device; After a preset time of settling, the selected battery is vacuum-sealed using the sealing device. According to the charging and discharging strategy, the candidate battery is charged and discharged using the testing equipment.

6. The system according to claim 5, characterized in that, The step of performing charge-discharge tests on the candidate battery using the testing equipment according to the charge-discharge strategy specifically includes: Based on the material system combination of the candidate batteries, the corresponding characteristic state of charge is determined. The characteristic state of charge is the state of charge in which the negative electrode interface of the battery produces a color difference due to the wetting effect. Based on the characteristic state of charge, the charging cutoff capacity in the charging and discharging strategy is adjusted to obtain the target charging and discharging strategy. According to the target charge / discharge strategy, the candidate battery is subjected to charge / discharge tests using the test equipment.

7. The system according to claim 6, characterized in that, The step of performing charge-discharge tests on the candidate battery using the testing equipment according to the target charge-discharge strategy specifically includes: Determine the cutoff capacity in the target charge / discharge strategy; According to the target charge and discharge strategy, target operations are performed on the candidate battery until the cutoff capacity is reached to complete the charge and discharge test. The target operations include: formation, full charge, discharge to capacity setting and charging. Adjacent operations in the target operations include a resting operation.

8. The system according to any one of claims 1-7, characterized in that, The screening system also includes a colorimeter; the step of determining the comprehensive compatibility value of the candidate battery based on the negative electrode interface of the candidate battery specifically includes: Using the outer area of ​​the negative electrode interface of the battery to be selected as the reference color, the color of the central area is detected by the colorimeter to obtain the color detection result of the battery to be selected. The color result includes at least one of the following: color uniformity, color difference range, and color difference depth. Based on the color detection results of the candidate batteries, the electrolyte wetting effect value of the candidate batteries is determined; The overall suitability value of the candidate battery is determined based on the electrolyte wetting effect value of the candidate battery.

9. The system according to claim 8, characterized in that, The step of determining the comprehensive suitability value of the candidate battery based on the electrolyte wetting effect value of the candidate battery specifically includes: Determine the electrochemical performance, wetting effect weight, and electrochemical performance weight of the candidate batteries; Based on the wetting effect weight and the electrochemical performance weight, the electrolyte wetting effect value and the electrochemical performance of the candidate battery are weighted and summed to obtain the comprehensive suitability value of the candidate battery.

10. The system according to any one of claims 1-7, characterized in that, The step of determining multiple candidate batteries specifically includes: Obtain multiple pre-configured material system combinations, where the electrochemical performance of the battery corresponding to each material system combination is greater than or equal to the preset performance; Based on the combination of the multiple material systems, the corresponding multiple candidate batteries are determined.

11. The system according to claim 10, characterized in that, The material system combination includes a combination of positive electrode material, negative electrode material, separator material and electrolyte material; The cathode material is of the type of lithium cobalt oxide, ternary material, lithium iron phosphate, lithium manganese oxide, lithium iron manganese phosphate, or lithium-rich manganese-based material. The type of negative electrode material is graphite, hard carbon, soft carbon, silicon-based material or lithium titanate; The membrane material includes a substrate and a coating, wherein the substrate is polyethylene or polypropylene; and the coating is alumina, boehmite, aramid, or polyvinylidene fluoride. The electrolyte material includes a solvent and a solute, wherein the solvent is a carbonate or a carboxylic acid ester; and the solute is lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, or lithium bis(trifluoromethyl)sulfonyl)imide.

12. A method for screening battery materials, characterized in that, include: The battery size of the battery to be optimized is determined and multiple candidate batteries are determined. Each candidate battery corresponds to a material system combination. The battery size of the battery to be optimized is larger than the battery size of any candidate battery. For each candidate battery, the pressure corresponding to the battery size is determined, and the pressure device is controlled to apply the pressure to the candidate battery to reduce the gap between the electrode and the separator of the candidate battery. The electrolyte wetting rate and wetting path of the candidate battery after applying pressure are the same as those of the battery to be optimized. The candidate batteries were subjected to charge-discharge tests using testing equipment. Based on the negative electrode interface of the candidate battery, the comprehensive fit value of the candidate battery is determined. The comprehensive fit value is used to characterize the comprehensive performance of the candidate battery in terms of electrochemical performance and electrolyte wetting. Iterate through all candidate batteries to obtain the comprehensive fit value for each candidate battery. The candidate battery with the largest comprehensive fit value is determined as the target battery, and the material system combination corresponding to the target battery is determined as the material system combination of the battery to be optimized.

13. A single-cell battery, characterized in that, The material system combination of the individual battery cells meets the preset wetting effect requirements; The material system combination is determined based on the screening results of the candidate batteries, using a large-size candidate battery simulation system according to any one of claims 1-11.

14. A battery pack, characterized in that, It includes at least two individual cells as described in claim 13, each of which is electrically connected to the other.

15. A battery pack, characterized in that, It includes a housing and at least two battery packs as described in claim 14, each of the battery packs being disposed within the housing and electrically connected to each other.

16. An electric vehicle, characterized in that, It includes at least the battery pack as described in claim 15.

17. An electrical appliance, characterized in that, It includes at least the single cell as described in claim 13.

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