Battery cell consistency dynamic screening method and system, electronic device, and storage medium

Abstract

The application relates to a battery cell consistency dynamic screening method and system, an electronic device and a storage medium. The battery cell consistency dynamic screening method calculates the reference pressure drop value after classifying each battery cell in a constant-temperature and constant-humidity charging and discharging environment, solves the voltage deviation problem caused by the traditional ignorance of the congenital differences of individual batteries, and greatly improves the accuracy and reliability of screening of pressure drop defective batteries.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to a method, system, electronic device, and storage medium for dynamic screening of cell consistency. Background Technology

[0002] Currently, after the battery cells are assembled and injected with electrolyte, they undergo multiple performance tests in the formation workshop. One of these tests is to calculate the absolute voltage drop rate by measuring the open-circuit voltage difference per unit time. This rate is then compared with the set process standards to screen out battery cells with excessive self-discharge, thereby improving the yield rate of battery cells.

[0003] However, environmental factors and differences in the battery itself can significantly interfere with the absolute voltage drop rate, which can easily lead to misjudgment and missed judgment, thus affecting the yield. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method, system, electronic device and storage medium for dynamic screening of battery cells with high self-discharge in a constant temperature and humidity charging and discharging environment, thereby improving the yield rate.

[0005] The objective of this invention is achieved through the following technical solution: The first aspect of this application provides a dynamic screening method for battery cell consistency, comprising: placing a plurality of charged battery cells in a constant temperature and humidity space and allowing them to stand; testing and screening the voltage of each charged battery cell to obtain a plurality of pre-processed battery cells; tracing the positive and negative electrode roll numbers corresponding to each pre-processed battery cell to obtain a plurality of battery combination roll codes; calculating the battery combination roll codes to obtain a battery cell sample quantity; classifying the battery cell sample quantity to obtain a first battery cell group or a second battery cell group; performing voltage drop calculation processing on each pre-processed battery cell in the first battery cell group to obtain a good battery cell; further classifying each pre-processed battery cell in the second battery cell group to obtain a first electrode roll group and a second electrode roll group; performing voltage drop calculation processing on each pre-processed battery cell in the first electrode roll group and the second electrode roll group to obtain the good battery cell.

[0006] The step of testing and screening the voltage of each charged battery cell to obtain a plurality of pre-treated battery cells includes placing each charged battery cell in a constant temperature and humidity space and letting it stand, testing the voltage of each charged battery cell to obtain a plurality of first voltage values, comparing each first voltage value with a first preset voltage value to obtain a plurality of initially screened battery cells; placing each initially screened battery cell in the constant temperature and humidity space and letting it stand, testing the voltage of each initially screened battery cell to obtain a second voltage value, comparing the second voltage value with a second preset voltage value to obtain a plurality of pre-treated battery cells.

[0007] The step of performing voltage drop calculations on each of the pre-processed cells in the second cell group to obtain good cells includes: calculating the number of all pre-processed cells in the first cell group; if the number is less than a preset threshold, merging the second cell group with the first electrode roll group and the second electrode roll group to obtain a first cell merge group and a second cell merge group; obtaining the first voltage value and the second voltage value corresponding to all the pre-processed cells in the first cell merge group; calculating a plurality of first voltage difference values ​​by comparing the first voltage value and the second voltage value; sorting the first voltage difference values ​​to obtain a first voltage difference median; and calculating the first voltage difference value with the first voltage difference median. A number of first dynamic reference voltage drop values ​​are obtained; the first voltage value and the second voltage value corresponding to all the pre-processed cells in the second cell merging group are obtained, and the first voltage value and the second voltage value are calculated to obtain a number of second voltage difference values; the second voltage difference values ​​are sorted to obtain the second voltage difference median; the second voltage difference value is calculated with the second voltage difference median to obtain a number of second dynamic reference voltage drop values; the first dynamic reference voltage drop value and the second dynamic reference voltage drop value corresponding to each pre-processed cell in the first cell group are compared to obtain the dynamic reference voltage drop extreme value corresponding to each pre-processed cell; the dynamic reference voltage drop extreme value is compared with the preset voltage drop value to obtain the good cell.

[0008] The step of calculating the voltage drop of each pre-processed cell in the first electrode roll group and the second electrode roll group to obtain the good cell includes: obtaining the first voltage value and the second voltage value corresponding to all the pre-processed cells in the first electrode roll group; calculating the voltage drop between the first voltage value and the second voltage value of each pre-processed cell to obtain several third voltage difference values; sorting the third voltage difference values ​​to obtain the median of the third voltage difference; calculating the voltage drop between each third voltage difference value and the median of the third voltage difference to obtain several third dynamic reference voltage drop values; and sorting the third dynamic reference voltage drop values. The state reference voltage drop value is compared with the preset voltage drop value to obtain the good quality battery cell; the first voltage value and the second voltage value corresponding to all the pre-processed battery cells in the second electrode roll group are obtained, and the first voltage value and the second voltage value of each pre-processed battery cell are calculated to obtain a number of fourth voltage difference values. The fourth voltage difference values ​​are sorted to obtain the fourth voltage difference median; the fourth voltage difference value is calculated with the fourth voltage difference median to obtain a number of fourth dynamic reference voltage drop values; the fourth dynamic reference voltage drop value is compared with the preset voltage drop value to obtain the good quality battery cell.

[0009] A second aspect of this application provides a dynamic screening system for battery cell consistency, comprising: a primary screening module for placing several charged battery cells in a constant temperature and humidity space and allowing them to stand, and testing and screening the voltage of each charged battery cell to obtain several pre-processed battery cells; an encoding module for tracing the positive and negative electrode roll numbers corresponding to each pre-processed battery cell to obtain several battery combination roll codes; a statistics module for calculating the battery combination roll codes to obtain the battery cell sample size; and a secondary screening module for classifying the battery cells according to the battery cell sample size to obtain a first battery cell group or a second battery cell group, performing voltage drop calculation processing on each pre-processed battery cell in the first battery cell group to obtain a good battery cell; and performing secondary classification on each pre-processed battery cell in the second battery cell group to obtain a first electrode roll group, a second electrode roll group, and a third electrode roll group, performing voltage drop calculation processing on the first electrode roll group, the second electrode roll group, and the third electrode roll group to obtain the good battery cell.

[0010] The initial screening module is further configured to place each of the charged battery cells in a constant temperature and humidity space and let them stand, test the voltage of each charged battery cell to obtain several first voltage values, compare each of the first voltage values ​​with a first preset voltage value to obtain several initially screened battery cells; place each of the initially screened battery cells in the constant temperature and humidity space and let them stand, test the voltage of each initially screened battery cell to obtain a second voltage value, compare the second voltage value with a second preset voltage value to obtain several pre-treated battery cells.

[0011] The secondary screening module is further used to calculate the number of all pre-processed cells in the first cell group. If the number is less than a preset threshold, the first cell group is merged with the first electrode roll group and the second electrode roll group to obtain a first cell merge group and a second cell merge group. The module then obtains the first voltage value and the second voltage value corresponding to all pre-processed cells in the first cell merge group, calculates the first voltage value and the second voltage value to obtain several first voltage difference values, sorts the first voltage difference values ​​to obtain the first voltage difference median, and calculates several first dynamic reference voltage drop values ​​using the first voltage difference median for each first voltage difference value. Take the first voltage value and the second voltage value corresponding to all the pre-processed cells in the second cell merging group, calculate the first voltage value and the second voltage value to obtain a number of second voltage difference values; sort the second voltage difference values ​​to obtain the second voltage difference median; calculate the second voltage difference value and the second voltage difference median to obtain a number of second dynamic reference voltage drop values; compare the first dynamic reference voltage drop value and the second dynamic reference voltage drop value corresponding to each pre-processed cell in the first cell group to obtain the dynamic reference voltage drop extreme value corresponding to each pre-processed cell; compare each dynamic reference voltage drop extreme value with a preset voltage drop value to obtain the good cell.

[0012] The secondary screening module is further configured to: acquire the first voltage value and the second voltage value corresponding to all the pre-processed cells in the first electrode roll group; calculate the first voltage value and the second voltage value of each pre-processed cell to obtain several third voltage difference values; sort the third voltage difference values ​​to obtain the third voltage difference median; calculate the third voltage difference value and the third voltage difference median to obtain several third dynamic reference voltage drop values; compare each third dynamic reference voltage drop value with a preset voltage drop value to obtain the good cell; acquire the first voltage value and the second voltage value corresponding to all the pre-processed cells in the second electrode roll group; calculate the first voltage value and the second voltage value of each pre-processed cell to obtain several fourth voltage difference values; sort the fourth voltage difference values ​​to obtain the fourth voltage difference median; calculate the fourth voltage difference value and the fourth voltage difference median to obtain several fourth dynamic reference voltage drop values; compare each fourth dynamic reference voltage drop value with a preset voltage drop value to obtain the good cell.

[0013] A third aspect of this application provides an electronic device, comprising: Processor; and A memory that stores executable code, which, when executed by the processor, causes the processor to perform the method described above.

[0014] A fourth aspect of this application provides a computer-readable storage medium having executable code stored thereon, which, when executed by a processor of an electronic device, causes the processor to perform the method described above.

[0015] Compared with the prior art, the present invention has at least the following advantages: This application solves the problem of voltage deviation caused by ignoring the inherent differences of individual batteries in traditional methods by classifying each cell and calculating the reference voltage drop value under a constant temperature and humidity charging and discharging environment, which greatly improves the accuracy and reliability of screening out batteries with poor voltage drop. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below.

[0017] Figure 1 This is a flowchart of a cell consistency dynamic screening method according to an embodiment of the present invention; Figure 2 This is a functional block diagram of a cell consistency dynamic screening system according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0018] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0019] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0020] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] Currently, after assembly and electrolyte injection, battery cells undergo multiple performance tests in the formation workshop. One of these tests involves calculating the absolute voltage drop rate by measuring the open-circuit voltage difference per unit time. This rate is then compared with established process standards to screen out cells with excessive self-discharge, thereby improving the yield rate. However, environmental factors and differences in the battery itself significantly interfere with the absolute voltage drop rate, potentially leading to misjudgments and missed judgments, thus affecting the yield rate.

[0022] To address the aforementioned issues, this application provides a method, system, electronic device, and storage medium for dynamic screening of battery cells to ensure consistency. This method can accurately screen out battery cells with excessive self-discharge under constant temperature and humidity charging and discharging conditions, thereby improving the yield rate.

[0023] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0024] Figure 1 This is a flowchart illustrating a dynamic screening method for battery cell consistency according to an embodiment of this application.

[0025] See Figure 1 A dynamic screening method for battery cell consistency includes: Step S101: Place several charged battery cells in a constant temperature and humidity space and let them stand. Test and screen the voltage of each charged battery cell to obtain several pre-processed battery cells.

[0026] It should be noted that after the battery cells complete pre-formation and a specific period of settling, they are charged to the specified voltage and capacity in a customized constant temperature and humidity chamber. The charged battery cells are then transferred to a constant temperature and humidity room and settling at a specified temperature in stages for a specific period of time. The voltage of the battery cells is then measured using an OCV tester, and a number of pre-treated battery cells are selected.

[0027] Specifically, each of the charged cells is placed in a constant temperature and humidity space and left to stand. The voltage of each charged cell is tested to obtain several first voltage values. Each first voltage value is compared with a first preset voltage value to obtain several initial screened cells. Each of the pre-screened cells is placed in the constant temperature and humidity space and left to stand. The voltage of the pre-screened cells is tested to obtain a second voltage value. The second voltage value is compared with a second preset voltage value to obtain a number of pre-treated cells.

[0028] It should be noted that the charged battery cells are transferred to a constant temperature and humidity chamber and left to stand at a specified temperature for a specific period of time. An OCV tester is used to measure the first voltage value (OCVA1) of the battery cells. If the voltage does not meet the first preset voltage value, the cells will be rejected, resulting in several pre-screened cells that temporarily meet the standards. Next, the pre-screened cells are transferred back to the constant temperature and humidity chamber and left to stand at a specified temperature for a specific period of time. An OCV tester is used to measure the second voltage value (OCV2). If the voltage does not meet the second preset voltage value, the cells will be rejected, resulting in several pre-treated cells.

[0029] Step S102: Trace the positive and negative electrode roll numbers corresponding to each pre-processed cell to obtain several battery combination roll codes.

[0030] It should be noted that by tracing the positive and negative electrode roll numbers corresponding to each pre-processed cell, the battery pack roll code can be obtained, such as positive electrode A and negative electrode B.

[0031] Step S103: Calculate the roll code of each battery combination to obtain the sample number of battery cells.

[0032] It is understandable that this step involves counting all battery pack codes to obtain the cell sample size n.

[0033] Step S104: Classify the battery cell samples to obtain a first battery cell group or a second battery cell group. Perform voltage drop calculation on each pre-processed battery cell in the first battery cell group to obtain a good battery cell. Perform secondary classification on each pre-processed battery cell in the second battery cell group to obtain a first electrode roll group and a second electrode roll group. Perform voltage drop calculation on each pre-processed battery cell in the first electrode roll group and the second electrode roll group to obtain a good battery cell.

[0034] It should be noted that, assuming a preset quantity threshold n min If the sample size of the battery cells is 500, and the sample size n is greater than or equal to n... min If the sample size n is less than n0, then the pre-processed cells are recorded as the second cell group, and the combination code of the second cell group is positive A + negative B, or positive D + negative C. minAt that time, the pre-processed cells in this group were recorded as the first cell group, and the combined roll code of the cells in the second cell group was positive A + negative C. Further, the pre-processed cells in the second cell group were further classified into a first pole roll group and a second pole roll group. The combined roll code of the first pole roll group was positive A + negative B. The combined roll code of the second pole roll group was positive D + negative C. Then, voltage drop calculations were performed on all pre-processed cells in each pole roll group to select the good cells.

[0035] Specifically, each pre-processed cell in the first cell group undergoes voltage drop calculation to obtain a good cell, including: Calculate the number of all pre-processed cells in the first cell group. If the number is less than a preset threshold, merge the second cell group with the first electrode roll group and the second electrode roll group respectively to obtain a first cell merge group and a second cell merge group. Obtain the first voltage value and second voltage value corresponding to all pre-processed cells in the first cell merge group. Calculate the first voltage value and second voltage value to obtain several first voltage difference values. Sort the first voltage difference values ​​to obtain the first voltage difference median. Calculate the first voltage difference value with the first voltage difference median to obtain several first dynamic reference voltage drop values. Obtain the second cell... The first voltage value and the second voltage value corresponding to all pre-processed cells in the cell merging group are used to calculate several second voltage difference values. The second voltage difference values ​​are sorted to obtain the median of the second voltage difference. Each second voltage difference value is calculated with the median of the second voltage difference to obtain several second dynamic reference voltage drop values. The first dynamic reference voltage drop value and the second dynamic reference voltage drop value corresponding to each pre-processed cell in the first cell group are compared to obtain the extreme value of the dynamic reference voltage drop corresponding to each pre-processed cell. Each extreme value of the dynamic reference voltage drop is compared with the preset voltage drop value to obtain the good cell.

[0036] It should be noted that if the total number of pre-processed cells in the first cell group is less than the preset threshold n... min To prevent randomness in the results, the voltage drop calculation method involves merging the first cell group and the first electrode roll group separately, and merging the first cell group and the second electrode roll group separately, resulting in a first cell merged group and a second cell merged group. Then, the dynamic reference voltage drop of all pre-processed cells in the first cell merged group is calculated to obtain the first dynamic reference voltage drop value; the dynamic reference voltage drop of all pre-processed cells in the second cell merged group is calculated to obtain the second dynamic reference voltage drop value. Next, the first and second dynamic reference voltage drops for each pre-processed cell in the first cell group are compared, and the one with the larger absolute value is selected as the dynamic reference voltage drop value, i.e., the extreme value of the dynamic reference voltage drop. Finally, the extreme value of the dynamic reference voltage drop for each pre-processed cell is compared with the preset voltage drop value to select good cells; otherwise, they are discarded.

[0037] In another embodiment, taking the first cell merging group as an example, the number of pre-processed cells in the first electrode roll group is much greater than n. min If this happens, the sample size will be unbalanced. Therefore, to ensure the accuracy of the results: extract the sample size of preprocessed cells from the first cell group by subtracting the preset threshold and the total number of preprocessed cells in the first cell group. Mix the sample size of preprocessed cells with the first cell group to obtain the third cell group. Obtain the first voltage value and the second voltage value corresponding to all preprocessed cells in the third cell group. Calculate the first voltage value and the second voltage value to obtain several fifth voltage difference values. Sort the fifth voltage difference values ​​to obtain the median of the first voltage difference. Calculate the fifth voltage difference value with the median of the fifth voltage difference to obtain several fifth dynamic reference voltage drop values. Compare the fifth dynamic reference voltage drop value and the second dynamic reference voltage drop value corresponding to each preprocessed cell in the first cell group to obtain the extreme value of the dynamic reference voltage drop corresponding to each preprocessed cell. Compare each extreme value of the dynamic reference voltage drop with the preset voltage drop value to obtain the good cells.

[0038] Specifically, the first voltage value and the second voltage value corresponding to all pre-processed cells in the first electrode roll group are obtained. The first voltage value and the second voltage value of each pre-processed cell are calculated to obtain several third voltage difference values. The third voltage difference values ​​are sorted to obtain the median of the third voltage difference. Each third voltage difference value is calculated with the median of the third voltage difference to obtain several third dynamic reference voltage drop values. Each third dynamic reference voltage drop value is compared with the preset voltage drop value to obtain a good cell. It should be noted that all pre-processed cells in the first electrode roll group have positive electrode A and negative electrode B. Then, the first and second voltage values ​​corresponding to all pre-processed cells in the first electrode roll group are calculated one by one to obtain multiple third voltage difference values ​​for the pre-processed cells. These third voltage difference values ​​are then sorted, and the median of the third voltage difference is found. Finally, the difference between the third voltage difference value of each pre-processed cell and the median of the third voltage difference is calculated to obtain several third dynamic reference voltage drop values. The third dynamic reference voltage drop value corresponding to each pre-processed cell is compared with a preset voltage drop value. If they match, the pre-processed cell is considered a good cell; otherwise, it is discarded.

[0039] Specifically, the first voltage value and the second voltage value corresponding to all pre-processed cells in the second electrode roll group are obtained. The first voltage value and the second voltage value of each pre-processed cell are calculated to obtain several fourth voltage difference values. The fourth voltage difference values ​​are sorted to obtain the median of the fourth voltage difference. The fourth voltage difference values ​​are calculated with the median of the fourth voltage difference to obtain several fourth dynamic reference voltage drop values. The third dynamic reference voltage drop values ​​are compared with the preset voltage drop values ​​to obtain good cells. It should be noted that all pre-processed cells in the second electrode roll group have positive (D) and negative (C) electrodes. Then, the first and second voltage values ​​corresponding to all pre-processed cells in the second electrode roll group are calculated one by one to obtain multiple fourth voltage difference values ​​for the pre-processed cells. These fourth voltage difference values ​​are then sorted, and the median of the fourth voltage difference is found. Finally, the difference between the fourth voltage difference value of each pre-processed cell and the median of the fourth voltage difference is calculated to obtain several fourth dynamic reference voltage drop values. The fourth dynamic reference voltage drop value corresponding to each pre-processed cell is compared with a preset voltage drop value. If they match, the pre-processed cell is considered a good cell; otherwise, it is discarded.

[0040] In another embodiment, when a pre-processed cell uses two different positive or negative electrode rolls, the roll with the larger number of sheets used is selected as one of the combined roll codes, and the above steps are then used for calculation. For example, in the production process of positive electrode roll A + negative electrode roll B, after using 30 sheets of positive electrode roll A in one of the pre-processed cells, the material is exhausted, and then positive electrode roll F is used until the pre-processed cell is completed, with positive electrode roll F using 25 sheets. According to the previous settings, positive electrode roll A is used as one of the combined roll codes for calculation. Furthermore, when a pre-processed cell uses two different positive or negative electrode rolls, the roll with the larger number of sheets used is selected as one of the combined roll codes, and the above steps are then used for calculation. For example, in the production process of positive electrode roll A + negative electrode roll B, after using 25 sheets of positive electrode roll A in one of the pre-processed cells, the material is exhausted, and then positive electrode roll F is used until the pre-processed cell is completed, with positive electrode roll F also using 25 sheets. At this point, it is necessary to calculate the dynamic reference voltage drop of the pre-processed cell separately for the two combined roll codes, namely, the positive roll A + negative roll B and the positive roll F + negative roll B respectively. The larger absolute value between the two is selected as the dynamic reference voltage drop value of the pre-processed cell.

[0041] In summary, unlike conventional fixed grouping, this application calculates dynamic reference voltage drop based on the battery pack electrode roll code as the baseline group under a rigorous constant temperature and humidity formation environment, achieving the lowest possible differentiation of battery self-discharge levels based on process and material errors. Furthermore, to address the dynamic changes in different battery electrode roll code groups, this application develops a multi-level dynamic reference voltage drop calculation decision scheme based on the actual process conditions, ensuring the rationality of the output results.

[0042] Corresponding to the aforementioned application function implementation method embodiments, this application also provides a cell consistency dynamic screening system, electronic device, and corresponding embodiments.

[0043] Figure 2 This is a functional block diagram of the cell consistency dynamic screening system shown in the embodiments of this application.

[0044] See Figure 2 A dynamic screening system for battery cell consistency includes a primary screening module 100 for placing several charged battery cells in a constant temperature and humidity space and allowing them to stand, and testing and screening the voltage of each charged battery cell to obtain several pre-processed battery cells; an encoding module 200 for tracing the positive and negative electrode roll numbers corresponding to each pre-processed battery cell to obtain several battery combination roll codes; a statistics module 300 for calculating the battery combination roll codes to obtain the battery cell sample quantity; a secondary screening module 400 for classifying the battery cell sample quantity to obtain a first battery cell group or a second battery cell group, performing voltage drop calculation on each pre-processed battery cell in the first battery cell group to obtain good battery cells; and performing secondary classification on each pre-processed battery cell in the second battery cell group to obtain a first electrode roll group and a second electrode roll group, performing voltage drop calculation on each pre-processed battery cell in the first electrode roll group and the second electrode roll group to obtain good battery cells.

[0045] The primary screening module 100 is also used to place each charged battery cell in a constant temperature and humidity space and let it stand, test the voltage of each charged battery cell to obtain several first voltage values, compare each first voltage value with a first preset voltage value to obtain several primary screened battery cells; place each primary screened battery cell in a constant temperature and humidity space and let it stand, test the voltage of each primary screened battery cell to obtain a second voltage value, compare the second voltage value with a second preset voltage value to obtain several pre-processed battery cells.

[0046] In one embodiment, the secondary screening module 400 is further configured to calculate the number of all pre-processed cells in the first cell group; if the number is less than a preset threshold, the first cell group is merged with the first electrode roll group and the second electrode roll group respectively to obtain a first cell merge group and a second cell merge group; the first voltage value and the second voltage value corresponding to all pre-processed cells in the first cell merge group are obtained; the first voltage value and the second voltage value are calculated to obtain a plurality of first voltage difference values; the first voltage difference values ​​are sorted to obtain the first voltage difference median; and the first voltage difference values ​​are calculated with the first voltage difference median to obtain a plurality of first dynamic base values. The process involves: obtaining the first and second voltage values ​​corresponding to all pre-processed cells in the second cell merging group; calculating the first and second voltage values ​​to obtain several second voltage difference values; sorting the second voltage difference values ​​to obtain the median of the second voltage difference; calculating the second voltage difference value with the median of the second voltage difference to obtain several second dynamic reference voltage drop values; comparing the first and second dynamic reference voltage drop values ​​corresponding to each pre-processed cell in the first cell group to obtain the extreme value of the dynamic reference voltage drop for each pre-processed cell; and comparing each extreme value of the dynamic reference voltage drop with a preset voltage drop value to obtain a good cell.

[0047] In one embodiment, the secondary screening module 400 is further configured to acquire the first voltage value and the second voltage value corresponding to all pre-processed cells in the first electrode roll group, calculate the first voltage value and the second voltage value of each pre-processed cell to obtain several third voltage difference values, sort the third voltage difference values ​​to obtain the median of the third voltage difference; calculate the third voltage difference value and the median of the third voltage difference to obtain several third dynamic reference voltage drop values; compare each third dynamic reference voltage drop value with a preset voltage drop value to obtain a good cell; acquire the first voltage value and the second voltage value corresponding to all pre-processed cells in the second electrode roll group, calculate the first voltage value and the second voltage value of each pre-processed cell to obtain several fourth voltage difference values, sort the fourth voltage difference values ​​to obtain the median of the fourth voltage difference; calculate the fourth voltage difference value and the median of the fourth voltage difference to obtain several fourth dynamic reference voltage drop values; compare each fourth dynamic reference voltage drop value with a preset voltage drop value to obtain a good cell.

[0048] Regarding the system in the above embodiments, the specific ways in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated further here.

[0049] Figure 3 This is a schematic diagram of the structure of an electronic device shown in an embodiment of this application.

[0050] See Figure 3 The electronic device 1000 includes a memory 1010 and a processor 1020.

[0051] The processor 1020 can be a central processing unit (CPU), or it can be an integrated circuit composed of other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be any conventional processor that can run the Linux kernel.

[0052] Memory 1010 may include various types of storage units, such as system memory, read-only memory (ROM), and permanent storage devices. ROM may store static data or instructions required by processor 1020 or other modules of the computer. Permanent storage devices may be read-write storage devices. Permanent storage devices may be non-volatile storage devices that retain stored instructions and data even when the computer is powered off. In some embodiments, permanent storage devices use mass storage devices (e.g., magnetic or optical disks, flash memory) as permanent storage devices. In other embodiments, permanent storage devices may be removable storage devices (e.g., floppy disks, optical drives). System memory may be a read-write storage device or a volatile read-write storage device, such as dynamic random access memory. System memory may store some or all of the instructions and data required by the processor during operation. Furthermore, memory 1010 may include any combination of computer-readable storage media, including various types of semiconductor memory chips (e.g., DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and disks and / or optical disks may also be used. In some embodiments, the memory 1010 may include a removable storage device that is readable and / or writable, such as a laser disc (CD), a read-only digital multifunction optical disc (e.g., DVD-ROM, dual-layer DVD-ROM), a read-only Blu-ray disc, an ultra-high density optical disc, a flash memory card (e.g., SD card, mini SD card, Micro-SD card, etc.), a magnetic floppy disk, etc. Computer-readable storage media do not contain carrier waves or transient electronic signals transmitted wirelessly or via wired connections.

[0053] The memory 1010 stores executable code, which, when processed by the processor 1020, can cause the processor 1020 to execute part or all of the methods described above.

[0054] Furthermore, the method according to this application can also be implemented as a computer program or computer program product, which includes computer program code instructions for performing some or all of the steps in the method described above.

[0055] Alternatively, this application may be implemented as a computer-readable storage medium (or a non-transitory machine-readable storage medium or a machine-readable storage medium) storing executable code (or computer program or computer instruction code) thereon, which, when executed by a processor of an electronic device (or server, etc.), causes the processor to perform part or all of the steps of the methods described above according to this application.

[0056] The solution of this application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of each embodiment have different focuses; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. Those skilled in the art should also understand that the actions and modules involved in the specification are not necessarily essential to this application. Furthermore, it is understood that the steps in the method of this application embodiment can be adjusted, combined, and deleted according to actual needs, and the modules in the device of this application embodiment can be combined, divided, and deleted according to actual needs.

[0057] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A dynamic screening method for battery cell consistency, characterized in that, include: Several charged battery cells were placed in a constant temperature and humidity space and left to stand. The voltage of each charged battery cell was tested and screened to obtain several pre-treated battery cells. By tracing the positive and negative electrode roll numbers corresponding to each pre-treated cell, several battery combination roll codes are obtained. The number of battery cells is obtained by calculating the roll code of each battery assembly. The battery cell samples are classified to obtain a first battery cell group or a second battery cell group. The voltage drop of each pre-processed battery cell in the first battery cell group is calculated to obtain a good battery cell. The pre-processed cells in the second cell group are further classified to obtain a first electrode roll group and a second electrode roll group. Voltage drop calculation is performed on each pre-processed cell in the first electrode roll group and the second electrode roll group to obtain the good quality cells.

2. The cell consistency dynamic screening method according to claim 1, characterized in that, The voltage of each charged battery cell is tested and screened to obtain several pre-processed battery cells, including: Each of the charged cells is placed in a constant temperature and humidity space and left to stand. The voltage of each charged cell is tested to obtain several first voltage values. Each first voltage value is compared with a first preset voltage value to obtain several initial screened cells. Each of the pre-screened cells is placed in the constant temperature and humidity space and left to stand. The voltage of the pre-screened cells is tested to obtain a second voltage value. The second voltage value is compared with a second preset voltage value to obtain a number of pre-treated cells.

3. The cell consistency dynamic screening method according to claim 2, characterized in that, The step of performing voltage drop calculations on each of the pre-processed cells in the first cell group to obtain a good cell includes: Calculate the number of all pre-processed cells in the first cell group. If the number is less than a preset threshold, merge the first cell group with the first electrode roll group and the second electrode roll group to obtain the first cell merge group and the second cell merge group. Obtain the first voltage value and the second voltage value corresponding to all the pre-processed cells in the first cell merging group; calculate the first voltage value and the second voltage value to obtain a plurality of first voltage difference values; sort the first voltage difference values ​​to obtain the first voltage difference median; calculate the first voltage difference value and the first voltage difference median to obtain a plurality of first dynamic reference voltage drop values. Obtain the first voltage value and the second voltage value corresponding to all the pre-processed cells in the second cell merging group; calculate the first voltage value and the second voltage value to obtain a number of second voltage difference values; sort the second voltage difference values ​​to obtain the second voltage difference median; calculate the second voltage difference value and the second voltage difference median to obtain a number of second dynamic reference voltage drop values. The first dynamic reference voltage drop value and the second dynamic reference voltage drop value corresponding to each pre-processed cell in the first cell group are compared to obtain the extreme value of the dynamic reference voltage drop corresponding to each pre-processed cell; The extreme values ​​of each dynamic reference voltage drop are compared with the preset voltage drop values ​​to obtain the good quality battery cells.

4. The cell consistency dynamic screening method according to claim 2, characterized in that, The step of performing voltage drop calculations on each of the pre-processed cells in the first and second electrode winding groups to obtain the good cells includes: Obtain the first voltage value and the second voltage value corresponding to all the pre-processed cells in the first electrode roll group. Calculate the first voltage value and the second voltage value of each pre-processed cell to obtain several third voltage difference values. Sort the third voltage difference values ​​to obtain the median of the third voltage difference. Calculate several third dynamic reference voltage drop values ​​by comparing each third voltage difference value with the median of the third voltage difference. Compare each third dynamic reference voltage drop value with a preset voltage drop value to obtain the good cell. Obtain the first voltage value and the second voltage value corresponding to all the pre-processed cells in the second electrode roll group. Calculate the first voltage value and the second voltage value of each pre-processed cell to obtain several fourth voltage difference values. Sort the fourth voltage difference values ​​to obtain the fourth voltage difference median. Calculate the fourth voltage difference value with the fourth voltage difference median to obtain several fourth dynamic reference voltage drop values. Compare each fourth dynamic reference voltage drop value with a preset voltage drop value to obtain the good cell.

5. A dynamic screening system for battery cell consistency, characterized in that, include: The initial screening module is used to place several charged battery cells in a constant temperature and humidity space and let them stand still, and to test and screen the voltage of each charged battery cell to obtain several pre-processed battery cells. The coding module is used to trace the positive and negative electrode roll numbers corresponding to each pre-processed cell to obtain several battery combination roll codes. The statistics module is used to calculate the roll code of each battery combination to obtain the sample number of battery cells; The secondary screening module is used to classify the battery cell sample to obtain a first battery cell group or a second battery cell group, and to perform voltage drop calculation on each of the pre-processed battery cells in the first battery cell group to obtain good battery cells. The pre-processed cells in the second cell group are further classified to obtain a first electrode roll group and a second electrode roll group. Voltage drop calculation is performed on each pre-processed cell in the first electrode roll group and the second electrode roll group to obtain the good quality cells.

6. The cell consistency dynamic screening system according to claim 5, characterized in that, The initial screening module is also used to place each of the charged cells in a constant temperature and humidity space and let them stand still, test the voltage of each charged cell to obtain several first voltage values, and compare each of the first voltage values ​​with a first preset voltage value to obtain several initial screened cells. Each of the pre-screened cells is placed in the constant temperature and humidity space and left to stand. The voltage of the pre-screened cells is tested to obtain a second voltage value. The second voltage value is compared with a second preset voltage value to obtain a number of pre-treated cells.

7. The cell consistency dynamic screening system according to claim 6, characterized in that, The secondary screening module is also used to calculate the number of all the pre-processed cells in the first cell group. If the number is less than a preset number threshold, the first cell group is merged with the first pole roll group and the second pole roll group respectively to obtain the first cell merge group and the second cell merge group. Obtain the first voltage value and the second voltage value corresponding to all the pre-processed cells in the first cell merging group; calculate the first voltage value and the second voltage value to obtain a plurality of first voltage difference values; sort the first voltage difference values ​​to obtain the first voltage difference median; calculate the first voltage difference value and the first voltage difference median to obtain a plurality of first dynamic reference voltage drop values. Obtain the first voltage value and the second voltage value corresponding to all the pre-processed cells in the second cell merging group, and calculate the first voltage value and the second voltage value to obtain several second voltage difference values; Sort the second differential pressure values ​​to obtain the median of the second differential pressure; Each of the second differential pressure values ​​is calculated with the median of the second differential pressure to obtain several second dynamic reference pressure drop values; The first dynamic reference voltage drop value and the second dynamic reference voltage drop value corresponding to each pre-processed cell in the first cell group are compared to obtain the extreme value of the dynamic reference voltage drop corresponding to each pre-processed cell; The extreme values ​​of each dynamic reference voltage drop are compared with the preset voltage drop values ​​to obtain the good quality battery cells.

8. The cell consistency dynamic screening system according to claim 6, characterized in that, The secondary screening module is further configured to obtain the first voltage value and the second voltage value corresponding to all the pre-processed cells in the first electrode roll group, calculate the first voltage value and the second voltage value of each pre-processed cell to obtain several third voltage difference values, sort the third voltage difference values ​​to obtain the median of the third voltage difference, calculate several third dynamic reference voltage drop values ​​by comparing each third voltage difference value with the median of the third voltage difference, and compare each third dynamic reference voltage drop value with a preset voltage drop value to obtain the good cell. Obtain the first voltage value and the second voltage value corresponding to all the pre-processed cells in the second electrode roll group. Calculate the first voltage value and the second voltage value of each pre-processed cell to obtain several fourth voltage difference values. Sort the fourth voltage difference values ​​to obtain the fourth voltage difference median. Calculate the fourth voltage difference value with the fourth voltage difference median to obtain several fourth dynamic reference voltage drop values. Compare each fourth dynamic reference voltage drop value with a preset voltage drop value to obtain the good cell.

9. An electronic device, characterized in that, include: processor; as well as A memory having executable code stored thereon, which, when executed by the processor, causes the processor to perform the method as described in any one of claims 1-4.

10. A computer-readable storage medium having executable code stored thereon, which, when executed by a processor of an electronic device, causes the processor to perform the method as described in any one of claims 1-4.

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