Screening method, screening equipment and storage medium
By measuring the wetting contact angle of the cell electrode and cell parameters, qualified cells are screened out, solving the problem of incomplete cell screening in battery packs and improving the comprehensiveness and safety of cell screening.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- EVE ENERGY CO LTD
- Filing Date
- 2025-12-17
- Publication Date
- 2026-04-14
AI Technical Summary
In the current technology, the screening methods for battery pack cells are not comprehensive enough, resulting in unqualified cells entering the market and posing a risk of thermal runaway.
By measuring parameters such as the wetting contact angle of the cell electrode, the ratio of electrolyte retention to electrolyte injection, as well as the cell's capacity, internal resistance, and voltage, the qualification of the cell is comprehensively screened to ensure uniform electrolyte wetting and avoid thermal runaway.
This improves the comprehensiveness of cell screening, reduces the inflow of substandard cells, and enhances the uniformity and safety of the internal reaction of the cells.
Smart Images
Figure CN121847487A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of energy storage technology, specifically to a screening method, screening equipment, and storage medium. Background Technology
[0002] Currently, the selection of qualified battery cells for battery packs is related to their working status during use, such as the risk of thermal runaway in the battery pack. In existing technologies, the selection is mainly based on the capacity status after the cell manufacturing process is completed. There is a lack of a complete selection method from the cell manufacturing process to the completion of the cell, resulting in low comprehensiveness of the selection and causing unqualified cells to enter the market. Summary of the Invention
[0003] The purpose of this invention is to provide a screening method, screening equipment, and storage medium to improve the problem of low comprehensiveness in battery cell screening.
[0004] To achieve the objectives of this invention, the following technical solution is provided: In a first aspect, the present invention provides a screening method applied to a battery pack, the battery pack including an electrolyte and a plurality of battery cells, the screening method comprising: obtaining the wetting contact angle of the electrode of each of the plurality of battery cells; when the wetting contact angle of a first portion of the battery cells is greater than or equal to a first threshold and less than or equal to a second threshold, injecting the electrolyte into the first portion of the battery cells corresponding to the wetting contact angle; obtaining a first ratio of the electrolyte retention amount of the first portion of the battery cells to the electrolyte injection amount of the first portion of the battery cells; when the first ratio of a second portion of the battery cells is greater than or equal to a third threshold, obtaining a first parameter value of the second portion of the battery cells corresponding to the first ratio, the first parameter value including at least one of the battery cell capacity, the battery cell internal resistance, and the battery cell voltage; when the first parameter value of a third portion of the battery cells is less than or equal to a fourth threshold and greater than or equal to a fifth threshold, determining that the third portion of the battery cells is qualified.
[0005] It is understandable that limiting the wetting contact angle to between the first and second thresholds ensures that the electrode wettability to the electrolyte is moderate. By screening through the first ratio of the electrolyte retention amount to the electrolyte injection amount, cells with poor electrolyte storage capacity are excluded to avoid easy electrolyte loss and thermal runaway. Screening is performed using the first parameter value, the fourth threshold, and the fifth threshold. The first parameter value includes at least one of the cell's capacity, the cell's internal resistance, and the cell's voltage. This ensures the comprehensiveness of the screening from multiple perspectives, ensures uniform internal reaction of the cell, avoids local overcharging and over-discharging, and provides a complete screening method during and after the cell is manufactured, thus improving the comprehensiveness of the screening.
[0006] In one embodiment, obtaining the wetting contact angle of the electrode of each of the plurality of battery cells includes: For at least two distinct regions of each of the electrodes, multiple first sub-wetting contact angles are measured; The wetting contact angle is determined based on the arithmetic mean of multiple first sub-wetting contact angles.
[0007] It is understandable that multiple first sub-wetting contact angles are measured for at least two different regions of each electrode; the wetting contact angle is determined based on multiple first sub-wetting contact angles. The design of determining the wetting contact angle by measuring at least two different regions and using the first sub-wetting contact angles covers different parts of the electrode that may have defects, avoiding misjudgments caused by local deviations. The wetting contact angle is determined by comprehensively using multiple first sub-contact angles, reducing random errors in a single measurement and improving the accuracy of the measurement.
[0008] In one embodiment, measuring multiple first sub-wetting contact angles for at least two distinct regions of each of the electrodes includes: The region includes the first region of the electrode, which is a circular region centered on the geometric center of the electrode and occupying a first proportion of the surface area of the electrode. Multiple first sub-wetting contact angles were measured over the circular region.
[0009] It can be understood that the region includes the first region of the electrode, which is a circular region centered on the geometric center of the electrode and occupying a first proportion of the surface area of the electrode. Multiple first sub-wetting contact angles are measured in the circular region, and the first region is defined geometrically, so that the measurement range of the first sub-wetting contact angle can be flexibly adjusted to adapt to different user needs. In one embodiment, measuring multiple first sub-wetting contact angles for at least two distinct regions of each of the electrodes further includes: The region includes the second region of the electrode, with the annular region within a second preset length range from the electrode tab of the electrode being the second region; Multiple first sub-wetting contact angles were measured over the annular region.
[0010] It can be understood that the region includes the second region of the electrode, which is the annular region within a second preset length range from the electrode tab of the electrode. Multiple first sub-wetting contact angles are measured in the annular region. By defining the second region and designing multiple first sub-wetting contact angles, the region near the electrode tab of the electrode is measured, which improves the comprehensiveness of the measurement and makes the measurement range of the first sub-wetting contact angles flexibly adjustable to adapt to different user needs.
[0011] In one embodiment, the first threshold is A, satisfying: 30°≤A≤60°; and / or, the first threshold is B, satisfying: 30°≤B≤60°.
[0012] It is understandable that the first threshold is set as A, satisfying: 30°≤A≤60°; and / or the first threshold is set as B, satisfying: 30°≤B≤60°. The first threshold A and the second threshold B are both limited to 30° to 60°, with 30° as the lower limit to avoid the selected battery cells spreading too quickly and generating air bubbles, and 60° as the upper limit to avoid insufficient immersion depth of the selected battery cells.
[0013] In one embodiment, injecting the electrolyte into the cell at the first portion corresponding to the wetting contact angle includes: Within a first preset time period, the electrolyte is injected into the first portion of the battery cells at a first injection volume per second; Within a second preset time period, the electrolyte is injected into the first portion of the battery cell at a second injection volume per second, wherein the first injection volume is greater than the second injection volume.
[0014] It is understandable that, within the first preset time period, electrolyte is injected into the first part of the battery cell at a first injection rate of one second; within the second preset time period, electrolyte is injected into the first part of the battery cell at a second injection rate of one second. The first injection rate is greater than the second injection rate. This fast-then-slow injection logic balances efficiency and quality. The large injection rate within the first preset time period quickly fills the internal space of the battery cell, improving injection efficiency. Within the second preset time period, the small injection rate is switched to slowly fill the remaining space, allowing sufficient time for air to escape and avoiding air bubble residue, thus providing accurate data for subsequent measurements. In one embodiment, the fourth threshold includes a first voltage value, and the fifth threshold includes a second voltage value. The step of determining that the third portion of the battery cell is qualified when the first parameter value of the third portion of the battery cell is less than or equal to the fourth threshold and greater than or equal to the fifth threshold includes: repeatedly measuring the first voltage of the third portion of the battery cell; determining the first parameter value based on the average of the multiple first voltages; and determining that the third portion of the battery cell is qualified when the first parameter value of the third portion of the battery cell is less than or equal to the first voltage value and greater than or equal to the second voltage value.
[0015] Multiple measurements of the first voltage of the third-part battery cell effectively avoid measurement deviations caused by occasional factors such as instrument instantaneous errors and environmental electromagnetic interference during a single voltage measurement. This filters out random errors, smooths data fluctuations, and makes the final voltage value more closely match the actual voltage state of the battery cell, improving the reliability and repeatability of the voltage detection results. A dual-threshold judgment range is set, with the first voltage value as the upper limit and the second voltage value as the lower limit. This range limits the first parameter value of the third-part battery cell to serve as the pass / fail criterion. The upper threshold (first voltage value) filters out unqualified products with excessively high voltage, overcharge risk, or abnormal internal electrochemical systems, preventing such cells from entering subsequent processes and causing safety hazards such as thermal runaway and sudden capacity drop. On the other hand, the lower threshold (second voltage value) eliminates cells with excessively low voltage, active material decay, or abnormal self-discharge, ensuring the basic energy output capacity and cycle life of the battery cell. Compared to a single threshold judgment standard, this dual-threshold judgment logic reduces the probability of misjudgment and missed judgment due to ambiguity in the judgment standard.
[0016] In one embodiment, the multiple measurements of the first sub-cell electrolyte volume in each of the first portions of the battery include: Measure the first mass of each of the cells in the first part; After the electrolyte is injected into each of the cells in the first part, the second mass of each of the cells in the first part after injection is obtained; The first sub-injection volume is determined based on the first mass and the second mass.
[0017] It is understandable that the first mass of each cell in the first part is measured; after the electrolyte is injected into each cell in the first part, the second mass of each cell in the first part after injection is obtained; the first sub-injection volume is determined based on the first mass and the second mass. The design of determining the injection volume by the first mass before injection and the second mass after injection makes the mass measurement unaffected by pipeline residues and volatilization, and can accurately obtain the actual amount of electrolyte entering the cell in the first part, thus improving the accuracy of obtaining the first sub-injection volume.
[0018] In a second aspect, embodiments of this application provide a screening device, including a processor, a memory, and at least one program, wherein the at least one program is stored in the memory and configured to be executed by the processor, the program including instructions for performing any of the methods in the first aspect.
[0019] Thirdly, embodiments of this application provide a computer-readable storage medium storing a computer program that causes a computer to execute to implement the method described in any one of the first aspects. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0021] Figure 1 This is a flowchart illustrating a screening method according to one embodiment; Figure 2 This is a schematic diagram of the structure of a screening device according to one embodiment.
[0022] Explanation of reference numerals in the attached figures: 200 - Screening device, 201 - Processor, 202 - Memory, 203 - Program. Detailed Implementation
[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0024] It should be noted that when a component is said to be "fixed" to another component, it can be directly on the other component or it can be in a middle component. When a component is said to be "connected" to another component, it can be directly connected to the other component or it may be in a middle component.
[0025] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used in this invention includes any and all combinations of one or more of the associated listed items.
[0026] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0027] Please see Figure 1 , Figure 1 This application provides a schematic flowchart of a screening method. For example... Figure 1As shown, the present invention provides a screening method applied to a battery pack, the battery pack including an electrolyte and multiple battery cells. The screening method includes the following steps S101-S105, wherein: S101: Obtain the wetting contact angle of the electrode of each of the multiple battery cells.
[0028] It should be noted that the wetting contact angle, as an important parameter characterizing the wettability of the electrode material surface in a battery cell, directly affects the wetting effect of the electrolyte on the electrode surface. If the wetting contact angle is too large, the electrolyte will not be able to effectively wet the electrode pore structure, resulting in obstructed lithium-ion transport paths and causing problems such as increased polarization and capacity decay. The size of the wetting contact angle between the electrode material and the electrolyte is determined by the surface chemical properties, microstructure, and electrolyte composition of the material. Optionally, the wetting contact angle can be accurately measured using an optical contact angle meter.
[0029] Alternatively, selection can be made using other material parameters of the electrode, such as surface tension and electrode porosity structure.
[0030] Optionally, the test method for the electrolyte wettability of the electrodes of the battery cell is not limited, and the test method includes the contact angle measurement method, the wetting time method, and the wetting height method, and is not limited here.
[0031] Optionally, the electrode material of the battery cell is not limited, and can be lithium cobalt oxide, lithium iron phosphate, ternary materials, graphite, silicon-based materials, lithium titanate, etc.
[0032] Optionally, in the lithium battery manufacturing process before electrolyte injection, i.e. after the cell is vacuum dried, the electrolyte used in this cell is dripped onto the cell's electrodes in a vacuum chamber environment, and the wetting contact angle of the electrolyte on the electrodes is measured using an optical contact angle meter. Optionally, the wetting contact angle at the same location on the electrodes of each cell is recorded.
[0033] It should be noted that this step ensures consistent electrolyte wettability inside the cell, which helps optimize the electrolyte composition and electrode microstructure design to achieve rapid and complete wetting, reduce battery production costs, and improve product quality.
[0034] In one possible example, the wetting contact angle of the electrode of each of multiple battery cells is obtained, including: For at least two distinct regions of each electrode, multiple first sub-wetting contact angles were measured; The wetting contact angle is determined based on the arithmetic mean of multiple first sub-wetting contact angles.
[0035] It is understandable that the arithmetic mean of multiple first sub-wetting contact angles is calculated to obtain the wetting contact angle. The arithmetic mean makes the determination of the wetting contact angle more reliable, reduces the random error in obtaining the wetting contact angle, and improves the accuracy of determining the wetting contact angle.
[0036] It is understandable that multiple first sub-wetting contact angles are measured for at least two different regions of each electrode; the wetting contact angle is determined based on multiple first sub-wetting contact angles. The design of determining the wetting contact angle by measuring at least two different regions and using the first sub-wetting contact angles covers different parts of the electrode that may have defects, avoiding misjudgments caused by local deviations. The wetting contact angle is determined by comprehensively using multiple first sub-contact angles, reducing random errors in a single measurement and improving the accuracy of the measurement.
[0037] In one possible example, multiple first sub-wetting contact angles are measured for at least two distinct regions of each electrode, including: The region includes the first region of the electrode sheet, which is a circular region centered on the geometric center of the electrode sheet and occupying a first proportion of the surface area of the electrode sheet. Multiple first sub-wetting contact angles were measured over a circular region.
[0038] It can be understood that the region includes the first region of the electrode, which is a circular region centered on the geometric center of the electrode and occupying a first proportion of the surface area of the electrode. Multiple first sub-wetting contact angles are measured in the circular region, and the first region is defined geometrically, so that the measurement range of the first sub-wetting contact angle can be flexibly adjusted to adapt to different user needs. In one possible example, measuring multiple first sub-wetting contact angles for at least two distinct regions of each electrode also includes: The region includes the second region of the electrode, which is defined as the annular region within a second preset length range from the electrode tab of the electrode. Multiple first sub-wetting contact angles were measured in the annular region.
[0039] It can be understood that the region includes the second region of the electrode, which is the annular region within a second preset length range from the electrode tab of the electrode. Multiple first sub-wetting contact angles are measured in the annular region. By defining the second region and designing multiple first sub-wetting contact angles, the region near the electrode tab of the electrode is measured, which improves the comprehensiveness of the measurement and makes the measurement range of the first sub-wetting contact angles flexibly adjustable to adapt to different user needs.
[0040] S102: When the wetting contact angle of the first part of the cell is greater than or equal to the first threshold and less than or equal to the second threshold, electrolyte is injected into the first part of the cell corresponding to the wetting contact angle.
[0041] Optionally, the first part of the battery cell can be multiple cells. In one possible example, the first threshold is A, satisfying: 30°≤A≤60°; and / or, the first threshold is B, satisfying: 30°≤B≤60°.
[0042] It is understandable that the first threshold is set as A, satisfying: 30°≤A≤60°; and / or the first threshold is set as B, satisfying: 30°≤B≤60°. The first threshold A and the second threshold B are both limited to 30°-60°. Based on extensive experimental verification, 30° is the lower limit to avoid the selected cells spreading too quickly and generating bubbles, and 60° is the upper limit to avoid insufficient wetting depth of the selected cells.
[0043] In one possible example, injecting electrolyte into the cell at the first portion corresponding to the wetting contact angle includes: Within a first preset time period, electrolyte is injected into the first part of the battery cell at a first injection volume per second; Within a second preset time period, electrolyte is injected into the first part of the battery cell at a second injection volume per second, wherein the first injection volume is greater than the second injection volume.
[0044] It is understandable that, within the first preset time period, electrolyte is injected into the first part of the battery cell at a first injection rate of one second; within the second preset time period, electrolyte is injected into the first part of the battery cell at a second injection rate of one second. The first injection rate is greater than the second injection rate. This fast-then-slow injection logic balances efficiency and quality. The large injection rate within the first preset time period quickly fills the internal space of the battery cell, improving injection efficiency. Within the second preset time period, the small injection rate is switched to slowly fill the remaining space, allowing sufficient time for air to escape and avoiding air bubble residue, thus providing accurate data for subsequent measurements.
[0045] S103: Obtain the first ratio of the liquid retention amount of the first part of the battery cell to the liquid injection amount of the first part of the battery cell.
[0046] In one possible example, the first sub-cell electrolyte volume of each cell in the first section is measured multiple times, including: Measure the first mass of each cell in the first section; After the electrolyte is injected into each cell of the first part, the second mass of each cell of the first part after injection is obtained; The first sub-injection volume is determined based on the first mass and the second mass.
[0047] It is understandable that the first mass of each cell in the first part is measured; after the electrolyte is injected into each cell in the first part, the second mass of each cell in the first part after injection is obtained; the first sub-injection volume is determined based on the first mass and the second mass. The design of determining the injection volume by the first mass before injection and the second mass after injection makes the mass measurement unaffected by pipeline residues and volatilization, and can accurately obtain the actual amount of electrolyte entering the cell in the first part, thus improving the accuracy of obtaining the first sub-injection volume.
[0048] S104: When the first ratio of the second part of the battery cells is greater than or equal to the third threshold, obtain the first parameter value of the second part of the battery cells corresponding to the first ratio. The first parameter value includes at least one of the battery cell capacity, battery cell internal resistance and battery cell voltage.
[0049] Optionally, the second part can consist of multiple battery cells.
[0050] S105: When the first parameter value of a cell in the third part is less than or equal to the fourth threshold and greater than or equal to the fifth threshold, the cell in the third part is deemed qualified.
[0051] The fourth threshold includes the first voltage value, and the fifth threshold includes the second voltage value. When the first parameter value of a cell in the third part is less than or equal to the fourth threshold and greater than or equal to the fifth threshold, the cell in the third part is judged to be qualified. This includes: measuring the first voltage of the cell in the third part multiple times; determining the first parameter value based on the average value of multiple first voltages; and judging the cell in the third part to be qualified when the first parameter value of a cell in the third part is less than or equal to the first voltage value and greater than or equal to the second voltage value.
[0052] Optionally, under specified conditions (typically 25 degrees Celsius), if the first parameter value of the cell in the third part is less than or equal to 5 millivolts and greater than or equal to 3 millivolts, the cell in the third part is deemed qualified.
[0053] Optionally, the first parameter value further includes the self-discharge parameter, thickness, and temperature rise of the battery cell. Optionally, under a specified environment (usually 25°C), when the battery cell is left standing for a preset number of days and the capacity attenuation ratio is less than or equal to the fourth threshold and greater than or equal to the fifth threshold, it is determined that the battery cells in the third part are qualified. Optionally, under the condition of a constant temperature and humidity environment, with the test temperature around 25°C, when the battery cell is charged from 0% to the specified state of charge of 100%, if the temperature of the battery cell is less than or equal to the fourth threshold (e.g., 32°C) and greater than or equal to the fifth threshold (e.g., 25°C), it is determined that the battery cells in the third part are qualified. Optionally, measure the thickness of the battery cell. When the thickness of the battery cell is less than or equal to the fourth threshold (e.g., 71.8 mm) and greater than or equal to the fifth threshold (e.g., 71.2 mm), it is determined that the battery cells in the third part are qualified. Optionally, measure the capacity of the battery cell. When the capacity of the battery cell is less than or equal to the fourth threshold (5 Ah) and greater than or equal to the fifth threshold (3 Ah), it is determined that the battery cells in the third part are qualified. Optionally, measure the internal resistance of the battery cell. When the internal resistance of the battery cell is less than or equal to the fourth threshold (0.1 mΩ) and greater than or equal to the fifth threshold (2 mΩ), it is determined that the battery cells in the third part are qualified.
[0054] Measure the first voltage of the battery cells in the third part multiple times, which can effectively avoid measurement deviations caused by accidental factors such as instrument instantaneous errors and environmental electromagnetic interference during the single voltage measurement process, filter random errors, smooth data fluctuations, make the finally obtained voltage value more conform to the true voltage state of the battery cell, and improve the reliability and repeatability of the voltage detection result. Set a double-threshold determination interval with the first voltage value as the upper limit and the second voltage value as the lower limit, and limit the first parameter value of the battery cells in the third part within this interval as the qualified determination basis. Through the upper limit threshold (the first voltage value), unqualified products with too high voltage, overcharge risk or abnormal internal electrochemical system of the battery cell can be screened out, avoiding potential safety hazards such as thermal runaway and sudden capacity drop caused by such battery cells entering the subsequent processes. On the other hand, through the lower limit threshold (the second voltage value), battery cells with too low voltage, active material attenuation or abnormal self-discharge can be eliminated, ensuring the basic energy output ability and cycle life of the battery cell. The determination logic of this double-threshold interval reduces the probability of misjudgment and missed judgment caused by fuzzy determination criteria compared with the single-threshold determination standard.
[0055] Optionally, the battery cells in the third part can be multiple battery cells. Optionally, conventional parameter screening is also carried out. For example, when the capacity of the battery cells in the third part is greater than or equal to the fifth threshold, it is determined that the battery cells in the third part are qualified. This conventional parameter can also be parameters such as internal resistance, self-discharge, temperature rise, and thickness to determine whether they are qualified, or screening and matching are carried out.
[0056] Optionally, screening for consistency at the raw material level is crucial for improving the performance, manufacturing quality, and preventing failures of battery cells, thereby ensuring the efficient and safe operation of battery cells in actual applications.
[0057] It is understandable that limiting the wetting contact angle to between the first and second thresholds ensures that the electrode wettability to the electrolyte is moderate. By screening through the first ratio of electrolyte retention to electrolyte injection, cells with poor electrolyte storage capacity are excluded to avoid easy electrolyte loss and thermal runaway. Screening is carried out using the first parameter value, the fourth threshold, and the fifth threshold. The first parameter value includes at least one of the cell's capacity, internal resistance, and voltage. This ensures the comprehensiveness of the screening from multiple perspectives, guarantees uniform internal reaction of the cell, avoids local overcharging and over-discharging, and provides a complete screening method during and after the cell is manufactured, thus improving the comprehensiveness of the screening.
[0058] Please see Figure 2 , Figure 2 This is a schematic diagram of the structure of a screening device provided in an embodiment of this application. For example... Figure 2 As shown, the screening device 200 includes a processor 201, a memory 202, and at least one program 203, wherein the at least one program 203 is stored in the memory 202 and configured to be executed by the processor 201, which is used to invoke computer instructions to perform the following steps: Obtain the wetting contact angle of the electrode of each of the multiple battery cells.
[0059] When the wetting contact angle of the first part of the cell is greater than or equal to the first threshold and less than or equal to the second threshold, electrolyte is injected into the first part of the cell corresponding to the wetting contact angle.
[0060] Obtain a first ratio between the liquid retention volume of the first part of the battery cell and the liquid injection volume of the first part of the battery cell.
[0061] Obtain the first parameter value of the second part of the battery cell corresponding to the first ratio. The first parameter value includes at least one of the battery cell's capacity, internal resistance, and voltage.
[0062] When the first parameter value of a cell in the third part is less than or equal to the fourth threshold and greater than or equal to the fifth threshold, the cell in the third part is deemed qualified.
[0063] In one possible example, processor 201 is used to measure multiple first sub-wetting contact angles for at least two different regions of each electrode; processor 201 is used to determine the wetting contact angle based on the multiple first sub-wetting contact angles.
[0064] In one possible example, the region includes a first region of the electrode, which is a circular region centered on the geometric center of the electrode and occupying a first proportion of the surface area of the electrode; the processor 201 is used to measure a plurality of first sub-wetting contact angles over the circular region.
[0065] In one possible example, the region includes a second region of the electrode, with an annular region within a second preset length range from the electrode tab of the electrode as the second region. The processor 201 is used to measure multiple first sub-wetting contact angles in the annular region. The processor 201 is used to calculate the arithmetic mean of the multiple second sub-wetting contact angles to obtain the wetting contact angle.
[0066] In one possible example, processor 201 is used to process the following formula: Calculate the arithmetic mean of multiple first sub-wetting contact angles to obtain the wetting contact angle.
[0067] In one possible example, processor 201 is used to process the following formula: The first threshold is A, satisfying: 30°≤A≤60°; and / or, the first threshold is B, satisfying: 30°≤B≤60°.
[0068] In one possible example, during a first preset duration, the processor 201 injects electrolyte into the first portion of the battery cell at a first injection volume per second; during a second preset duration, the processor 201 injects electrolyte into the first portion of the battery cell at a second injection volume per second, wherein the first injection volume is greater than the second injection volume.
[0069] In one possible example, the processor 201 is used to measure the first voltage of the battery cell in the third part multiple times; determine a first parameter value based on the average of the multiple first voltages; and determine that the battery cell in the third part is qualified when the first parameter value of the battery cell in the third part is less than or equal to the first voltage value and greater than or equal to the second voltage value.
[0070] In one possible example, processor 201 is used to measure a first mass of each cell in the first part; after the electrolyte injection is completed for each cell in the first part, processor 201 is used to obtain a second mass of each cell in the first part after injection; processor 201 is used to determine a first sub-injection volume based on the first mass and the second mass.
[0071] Those skilled in the art will understand that there may be multiple processors 201 and memory 202. The memory 202 may also be referred to as a storage medium or storage device, etc. The embodiments of this application do not limit this.
[0072] It should be understood that in this application, the processor 201 may be a central processing unit (CPU), or it may be other general-purpose processors 201, digital signal processors 201 (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 201 may also be a general-purpose microprocessor 201, a graphics processing unit 201 (GPU), or one or more integrated circuits to execute the relevant program 203 to achieve the functions required by the embodiments of this application.
[0073] The processor 201 can also be an integrated circuit chip with signal processing capabilities. In implementation, each step of this application can be completed by the integrated logic circuitry in the hardware of the processor 201 or by instructions in software form. The processor 201 described above can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The steps of the methods disclosed in the embodiments of this application can be directly manifested as being executed by the hardware decoding processor 201, or executed by a combination of hardware and software modules in the decoding processor 201. The software modules can be located in random access memory 202, flash memory and read-only memory 202, programmable read-only memory 202 or electrically erasable programmable memory 202, registers, and other mature storage media in the art. The storage medium is located in memory 202, and the processor 201 reads the information in memory 202 and, in conjunction with its hardware, completes the functions required by the units included in the methods, apparatus, and storage media of the embodiments of this application.
[0074] It should also be understood that the memory 202 mentioned in the embodiments of this application can be volatile memory 202 or non-volatile memory 202, or may include both volatile and non-volatile memory 202. The non-volatile memory 202 can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory 202 can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DR RAM). The memory 202 can also be a Compact Disc Read-Only Memory (CD-ROM) or other optical disc storage, optical disk storage (including compressed optical disks, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media, or other magnetic storage devices, or any other medium capable of carrying or storing the desired program 203 code in the form of instructions or data structures and accessible by a computer, but is not limited thereto. The memory 202 can exist independently and be connected to the processor 201 via a bus. The memory 202 can also be integrated with the processor 201. The memory 202 can store the program 203. When the program 203 stored in the memory 202 is executed by the processor 201, the processor 201 performs the various steps of the method determined in the above embodiments of this application.
[0075] It should be noted that when the processor 201 is a general-purpose processor 201, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory 202 (memory module) is integrated into the processor 201. It should be noted that the memory 202 described herein is intended to include, but is not limited to, these and any other suitable types of memory 202.
[0076] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0077] In implementation, each step of the above method can be completed by the integrated logic circuitry of the hardware in the processor 201 or by instructions in software form. The steps of the method disclosed in the embodiments of this application can be directly manifested as execution by the hardware processor 201, or execution by a combination of hardware and software modules in the processor 201. The software modules can reside in mature storage media in the art, such as random access memory 202, flash memory, read-only memory 202, programmable read-only memory 202, electrically erasable programmable memory 202, registers, etc. This storage medium is located in memory 202. The processor 201 reads information from memory 202 and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, these steps will not be described in detail here.
[0078] Those skilled in the art will recognize that the various illustrative logical blocks (ILBs) and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.
[0079] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented entirely or partially as a computer-programmed program 203 product. The program 203 product includes one or more computer instructions. When the program 203 instructions are loaded and executed on the processor 201, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic) or wireless (e.g., infrared, wireless, microwave, etc.) means, or from one website, computer, server, or data center to the mobile phone processor 201 via a wired means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives).
[0080] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.
Claims
1. A screening method, characterized by, The screening method is applied to a battery pack, the battery pack including an electrolyte and multiple battery cells, and the screening method includes: Obtain the wetting contact angle of the electrode of each of the plurality of battery cells; When the wetting contact angle of the first portion of the battery cell is greater than or equal to a first threshold and less than or equal to a second threshold, the electrolyte is injected into the first portion of the battery cell corresponding to the wetting contact angle. Obtain a first ratio between the liquid retention amount of the first portion of the battery cell and the liquid injection amount of the first portion of the battery cell; When the first ratio of the second part of the battery cells is greater than or equal to the third threshold, the first parameter value of the second part of the battery cells corresponding to the first ratio is obtained. The first parameter value includes at least one of the battery cell capacity, the battery cell internal resistance, and the battery cell voltage. When the first parameter value of a cell in the third part is less than or equal to the fourth threshold and greater than or equal to the fifth threshold, the cell in the third part is deemed qualified.
2. The screening method according to claim 1, characterized in that, The step of obtaining the wetting contact angle of the electrode of each of the plurality of battery cells includes: For at least two distinct regions of each of the electrodes, multiple first sub-wetting contact angles are measured; The wetting contact angle is determined based on the arithmetic mean of multiple first sub-wetting contact angles.
3. The screening method according to claim 2, characterized in that, Measuring multiple first sub-wetting contact angles in at least two distinct regions of each of the electrodes includes: The region includes the first region of the electrode, which is a circular region centered on the geometric center of the electrode and occupying a first proportion of the surface area of the electrode. Multiple first sub-wetting contact angles were measured over the circular region.
4. The screening method according to claim 2, characterized by, Measuring multiple first sub-wetting contact angles in at least two distinct regions of each of the electrodes further includes: The region includes the second region of the electrode, with the annular region within a second preset length range from the electrode tab of the electrode being the second region; Multiple first sub-wetting contact angles were measured over the annular region.
5. The screening method according to any one of claims 1 to 4, characterized in that, The first threshold is A, satisfying: 30°≤A≤60°; and / or, the second threshold is B, satisfying: 30°≤B≤60°.
6. The screening method according to any one of claims 1 to 4, characterized in that, The process of injecting the electrolyte into the first portion of the cell corresponding to the wetting contact angle includes: Within a first preset time period, the electrolyte is injected into the first portion of the battery cells at a first injection volume per second; Within a second preset time period, the electrolyte is injected into the first portion of the battery cell at a second injection volume per second, wherein the first injection volume is greater than the second injection volume.
7. The screening method according to any one of claims 1 to 4, characterized in that, The step of obtaining a first ratio of the liquid retention volume of the first portion of the battery cells to the liquid injection volume of the first portion of the battery cells includes: The first sub-injection volume of each cell in the first part was measured multiple times; The injection volume is determined based on multiple first sub-injection volumes.
8. The screening method according to any one of claims 1 to 4, characterized in that, The fourth threshold includes a first voltage value, and the fifth threshold includes a second voltage value. The step of determining that the third portion of the battery cells is qualified when the first parameter value of any of the third portion of the cells is less than or equal to the fourth threshold and greater than or equal to the fifth threshold includes: The first voltage of the battery cell in the third part was measured multiple times; The first parameter value is determined based on the average value of multiple first voltages; When the first parameter value of a cell in the third part is less than or equal to the first voltage value and greater than or equal to the second voltage value, the cell in the third part is deemed to be qualified.
9. A screening device, characterized in that, The method includes a processor, a memory, and at least one program, wherein the at least one program is stored in the memory and configured to be executed by the processor, the program including instructions for performing the method of any one of claims 1 to 8.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that causes a computer to perform the method according to any one of claims 1 to 8.