Battery sorting method, device, computer readable storage medium and processor

Abstract

The application discloses a battery sorting method and device, a computer readable storage medium and a processor. The method comprises the following steps: determining a first feature point and a second feature point of a charge-discharge curve of a battery to be grouped; dividing the charge-discharge curve into three parts according to a starting point, the first feature point, the second feature point and an ending point of the charge-discharge curve, wherein the curve between the starting point and the first feature point is a first polarization section, the curve between the first feature point and the second feature point is a platform section, and the curve between the second feature point and the ending point is a second polarization section; and sorting the battery to be grouped according to the platform section. The application solves the technical problem that due to the performance differences of each single battery in a battery pack, some batteries are in different charge-discharge states, resulting in poor pressure difference in the battery pack, too fast capacity attenuation and short service life.

Description

Technical Field

[0001] This invention relates to the field of batteries, and more specifically, to a battery sorting method, apparatus, computer-readable storage medium, and processor. Background Technology

[0002] Due to differences in raw materials, manufacturing processes, precision, and environmental control, lithium-ion batteries exhibit varying performance characteristics among individual cells within a lithium-ion battery pack. These differences become increasingly apparent during charge-discharge cycles, causing some cells to operate in different states of charge and discharge, leading to issues such as poor voltage differential within the battery pack, rapid capacity decay, and shorter lifespan.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This invention provides a battery sorting method, apparatus, computer-readable storage medium, and processor to at least solve the technical problems of poor voltage difference, rapid capacity decay, and short lifespan caused by the inherent performance differences among individual cells in a battery pack, which result in some cells being in different charge / discharge states.

[0005] According to one aspect of the present invention, a battery sorting method is provided, comprising: determining a first feature point and a second feature point of the charge-discharge curve of batteries to be grouped; dividing the charge-discharge curve into three parts based on the start point, the first feature point, the second feature point, and the end point of the charge-discharge curve, wherein the curve between the start point and the first feature point is a first polarization segment, the curve between the first feature point and the second feature point is a plateau segment, and the curve between the second feature point and the end point is a second polarization segment; and sorting the batteries to be grouped based on the plateau segment.

[0006] Optionally, before determining the first and second characteristic points of the charge-discharge curves of the batteries to be grouped, the method further includes: performing charge-discharge tests on the batteries to be grouped to obtain test data of the batteries to be grouped, wherein the test data includes: time nodes and the voltage corresponding to the time nodes; and generating charge-discharge curves of the batteries to be grouped based on the test data.

[0007] Optionally, performing charge-discharge tests on the batteries to be grouped to obtain test data for the batteries to be grouped includes: collecting test data of the charge-discharge tests of the batteries to be grouped at preset time intervals.

[0008] Optionally, the charge-discharge test of the batteries to be grouped includes: resting the batteries to be grouped for a preset time; discharging them at a constant current of 1C to the lower limit voltage of the battery; resting the batteries to be grouped again for the preset time; charging them at a constant current of 4C to the upper limit voltage of the battery; resting the batteries to be grouped again for the preset time; discharging them at a constant current of 4C to the lower limit voltage of the battery; and finally resting the batteries to be grouped for the preset time; the charge-discharge test ends.

[0009] Optionally, determining the first and second feature points of the charge-discharge curves of the batteries to be grouped includes: acquiring test data of the batteries to be grouped; performing polynomial fitting on the test data of the batteries to be grouped to obtain the fitting result; and performing at least two derivatives on the fitting result to obtain the first and second feature points.

[0010] Optionally, sorting the batteries to be grouped according to the platform segment includes: determining the duration of all batteries to be grouped in the platform segment within the battery pack; summing and averaging the durations of the platform segment to obtain the mean of the durations of all batteries to be grouped in the platform segment; and using the mean as a benchmark, selecting batteries to be grouped within a preset platform time range using a normal distribution.

[0011] According to another aspect of the present invention, a battery sorting device is also provided, comprising: a determining module, configured to determine a first feature point and a second feature point of the charge-discharge curve of a battery to be grouped; a processing module, configured to divide the charge-discharge curve into three parts based on the start point, the first feature point, the second feature point, and the end point of the charge-discharge curve, wherein the curve between the start point and the first feature point is a first polarization segment, the curve between the first feature point and the second feature point is a plateau segment, and the curve between the second feature point and the end point is a second polarization segment; and a sorting module, configured to sort the batteries to be grouped based on the plateau segment.

[0012] Optionally, the device further includes: a testing module, configured to perform a charge-discharge test on the battery to be grouped before determining the first and second characteristic points of the charge-discharge curve of the battery to be grouped, to obtain test data of the battery to be grouped, wherein the test data includes: time nodes and the voltage corresponding to the time nodes; and a generation module, configured to generate the charge-discharge curve of the battery to be grouped based on the test data.

[0013] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform the battery sorting method described in any one of the above.

[0014] According to another aspect of the present invention, a processor is also provided, the processor being configured to run a program, wherein the program, when running, executes the battery sorting method described in any of the above embodiments.

[0015] In this embodiment of the invention, a first characteristic point and a second characteristic point of the charge-discharge curve of the batteries to be grouped are determined. Based on the start point, the first characteristic point, the second characteristic point, and the end point of the charge-discharge curve, the charge-discharge curve is divided into three parts. The curve between the start point and the first characteristic point is the first polarization segment, the curve between the first characteristic point and the second characteristic point is the plateau segment, and the curve between the second characteristic point and the end point is the second polarization segment. The batteries to be grouped are sorted according to the plateau segment of the charge-discharge curve of the batteries to be grouped. By sorting the batteries to be grouped through the plateau segment of the charge-discharge curve, the battery pack composed of the sorted batteries can fully utilize the performance of each individual battery. This solves the technical problem that due to the various differences in the performance of each individual battery in the battery pack, some batteries are in different charge-discharge states, resulting in poor voltage difference, rapid capacity decay, and short lifespan within the battery pack. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0017] Figure 1 This is a flowchart of a battery sorting method according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the battery charging curve and fitting according to an optional embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the first derivative according to an optional embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the second derivative according to an optional embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of a battery sorting device according to an embodiment of the present invention. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] Example 1

[0025] According to an embodiment of the present invention, an embodiment of a battery sorting method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0026] Figure 1 This is a flowchart of a battery sorting method according to an embodiment of the present invention, such as... Figure 1 As shown, the battery sorting method includes the following steps:

[0027] Step S102: Determine the first and second characteristic points of the charge-discharge curves of the batteries to be grouped.

[0028] The batteries to be grouped include, but are not limited to, lithium-ion batteries. Optionally, the batteries to be grouped are lithium-ion batteries, which can be any single cell in a lithium-ion battery pack. It should be noted that the first and second feature points mentioned above can be used to divide the charge-discharge curves into segments that represent different battery performance characteristics.

[0029] Step S104: Based on the start point, first characteristic point, second characteristic point and end point of the charge and discharge curve, the charge and discharge curve is divided into three parts. The curve between the start point and the first characteristic point is the first polarization segment, the curve between the first characteristic point and the second characteristic point is the plateau segment, and the curve between the second characteristic point and the end point is the second polarization segment.

[0030] The aforementioned start point, first characteristic point, second characteristic point, and end point are points on the charge-discharge curve, corresponding to time nodes and voltages, respectively. Using the start point, first characteristic point, second characteristic point, and end point of the charge-discharge curve, it can be divided into three parts. The curve between the first and second characteristic points is a plateau segment, which has a significant impact on battery capacity and can reflect the battery's performance characteristics.

[0031] Step S106: Sort the batteries to be grouped according to the platform segment.

[0032] In practical implementation, for each battery to be grouped in the battery pack, those with similar or nearly identical plateau segments in their charge-discharge curves can be sorted out. Specifically, the plateau segments of the charge-discharge curves for each battery to be grouped should have similar durations. Furthermore, the sorted batteries can be assembled into a battery pack, ensuring that the performance of each individual battery in the pack is similar, effectively avoiding performance differences between individual batteries.

[0033] Through the above steps, the first and second characteristic points of the charge-discharge curves of the batteries to be grouped can be determined. Based on the start point, first characteristic point, second characteristic point, and end point of the charge-discharge curve, the curve is divided into three parts: the curve between the start point and the first characteristic point is the first polarization segment, the curve between the first characteristic point and the second characteristic point is the plateau segment, and the curve between the second characteristic point and the end point is the second polarization segment. The batteries to be grouped are sorted according to the plateau segment of the charge-discharge curve. This achieves the technical effect that the battery pack composed of the sorted batteries can fully utilize the performance of each individual battery. This solves the technical problem that due to the various differences in the performance of individual batteries in the battery pack, some batteries are in different charge-discharge states, resulting in poor voltage difference, rapid capacity decay, and short lifespan within the battery pack.

[0034] Optionally, before determining the first and second characteristic points of the charge-discharge curves of the batteries to be grouped, the above method further includes: performing charge-discharge tests on the batteries to be grouped to obtain test data of the batteries to be grouped, wherein the test data includes: time nodes and the voltage corresponding to the time nodes; and generating charge-discharge curves of the batteries to be grouped based on the test data.

[0035] As an optional embodiment, during the charge-discharge test of the batteries to be grouped, test data of the batteries to be grouped is collected in real time, and then charge-discharge curves of the batteries to be grouped can be generated based on the collected test data. The charge-discharge curves of the batteries to be grouped can more intuitively and accurately describe the performance of the batteries during the charge-discharge test.

[0036] Optionally, the battery to be grouped is subjected to charge and discharge tests to obtain test data of the battery to be grouped, including: collecting test data of charge and discharge tests of the battery to be grouped at preset time intervals.

[0037] As an optional embodiment, the aforementioned preset time interval can be set according to application requirements. For example, the preset time interval can be 0.1s, 0.5s, etc. Specifically, test data for the charge-discharge test of the batteries to be grouped can be collected at a preset time interval of 0.1s or 0.5s, and no limitation is made in the specific implementation process.

[0038] Optionally, the charge-discharge test of the batteries to be grouped includes: resting the batteries to be grouped for a preset time; discharging them at a constant current of 1C to the lower limit voltage of the battery; resting the batteries to be grouped again for a preset time; charging them at a constant current of 4C to the upper limit voltage of the battery; resting the batteries to be grouped again for a preset time; discharging them at a constant current of 4C to the lower limit voltage of the battery; and finally resting the batteries to be grouped for a preset time; the charge-discharge test ends.

[0039] Optionally, the preset time may include, but is not limited to, 30 minutes.

[0040] The above method can cover the entire charge and discharge testing process of the batteries to be grouped, ensuring the accuracy and completeness of the test data.

[0041] Optionally, determining the first and second characteristic points of the charge-discharge curves of the batteries to be grouped includes: acquiring test data of the batteries to be grouped; performing polynomial fitting on the test data of the batteries to be grouped to obtain the fitting result; and taking the derivative of the fitting result at least twice to obtain the first and second characteristic points.

[0042] As an optional embodiment, the battery pack to be tested includes at least multiple cells to be grouped. Polynomial fitting is performed on the test data of each cell in the battery pack to obtain the corresponding fitting result. In specific implementation, the fitting result is differentiated twice. For example, the first derivative is performed, followed by a second derivative based on the first derivative. These two derivatives determine the first and second characteristic points of the charge-discharge curves of the cells to be grouped.

[0043] Optionally, sorting the batteries to be grouped based on the platform segment includes: determining the duration of all batteries to be grouped in the platform segment within the battery pack; summing and averaging the durations of the platform segments to obtain the mean of the durations of all batteries to be grouped in the platform segment; and using the mean as a benchmark, selecting batteries to be grouped within a preset platform time range using a normal distribution.

[0044] As an optional embodiment, the average duration of the plateau segment for all batteries to be grouped within the battery pack can be summed to obtain the mean duration of the plateau segment for all batteries to be grouped. Then, the mean can be combined with a normal distribution to select batteries within a preset plateau time range. In this way, batteries with similar or nearly identical plateau segment durations within the battery pack can be accurately selected.

[0045] The following is a detailed description of an optional embodiment of the present invention.

[0046] As an optional embodiment, the batteries to be grouped after capacity grading can be subjected to charge and discharge tests. Data is collected using a computer in the test cabinet, with a time interval of 0.1s. The detailed steps are as follows: 1. Let stand for 30 minutes; 2. Discharge at a constant current of 1C to the lower limit voltage of the battery; 3. Let stand for 30 minutes; 4. Charge at a constant current of 4C to the upper limit voltage of the battery; 5. Let stand for 30 minutes; 6. Discharge at a constant current of 4C to the lower limit voltage of the battery; 7. Let stand for 30 minutes.

[0047] Furthermore, the data collected by the computer was exported, and data software was used to perform polynomial fitting on the time-voltage data of the charge-discharge curve to obtain... , Figure 2 This is a schematic diagram of a battery charging curve and fitting according to an optional embodiment of the present invention, such as... Figure 2 As shown, the higher the degree of the polynomial, the better the curve fitting effect. Among them, for Perform the first and second derivatives respectively. Figure 3 This is a schematic diagram of the first derivative according to an optional embodiment of the present invention. Figure 4 This is a schematic diagram of the second derivative according to an optional embodiment of the present invention, such as... Figure 3 , Figure 4 As shown, we obtain and , There will be 7 points (Note: Cannot find) The point can be found using the Zero Point Theorem. Points where the function values ​​have opposite signs, i.e. , and then combine Observe the point of fastest change in the image to obtain That is, a function The characteristic points are defined as follows: the start of the charge / discharge curve, characteristic point 1, characteristic point 2, and the end of the curve are named as nodes respectively. The nodes divide the curve into three parts, each named Polarization Segment 1, Plateau Segment, and Polarization Segment 2, respectively. The capacity of lithium-ion batteries is mainly utilized during the plateau period, so we only need to select batteries with similar plateau durations to complete the battery packing. The plateau duration t = (bc), and each battery will have a plateau time. By fitting and solving all the batteries in the group using a similar method, we can obtain... Sum the duration of all platforms and take the average. , Using the mean as a benchmark, the discharge curve is obtained using a similar method. Based on your needs, you can use the normal distribution to select batteries with suitable plateau times, for example, by selecting a plateau time range. The battery.

[0048] Example 2

[0049] According to another aspect of the present invention, a battery sorting device is also provided. Figure 5 This is a schematic diagram of a battery sorting device according to an embodiment of the present invention, such as... Figure 5 As shown, the battery sorting device includes: a determining module 52, a processing module 54, and a sorting module 56. The battery sorting device will now be described in detail.

[0050] The determining module 52 is used to determine the first and second characteristic points of the charge-discharge curves of the batteries to be grouped; the processing module 54 is connected to the determining module 52 and is used to divide the charge-discharge curves into three parts based on the start point, the first characteristic point, the second characteristic point, and the end point of the charge-discharge curves, wherein the curve between the start point and the first characteristic point is the first polarization segment, the curve between the first characteristic point and the second characteristic point is the plateau segment, and the curve between the second characteristic point and the end point is the second polarization segment; the sorting module 56 is connected to the processing module 54 and is used to sort the batteries to be grouped based on the plateau segment.

[0051] In the above embodiments of the present invention, the battery sorting device can sort the batteries to be grouped by the plateau segment of the charge-discharge curve of the batteries to be grouped, thereby realizing the technical effect that the battery pack composed of the sorted batteries can give full play to the performance of each individual battery. This solves the technical problem that due to the various differences in the performance of each individual battery in the battery pack, some batteries are in different charge-discharge states, resulting in poor voltage difference, rapid capacity decay and short life in the battery pack.

[0052] It should be noted that the above modules can be implemented by software or hardware. For example, for the latter, it can be implemented in the following ways: the above modules can be located in the same processor; or the above modules can be located in different processors in any combination.

[0053] It should be noted that the determining module 52, processing module 54, and sorting module 56 mentioned above correspond to steps S102 to S106 in Embodiment 1. The examples and application scenarios implemented by the above modules and their corresponding steps are the same, but they are not limited to the content disclosed in Embodiment 1. It should be noted that the above modules, as part of the device, can be executed in a computer system such as a set of computer-executable instructions.

[0054] Optionally, the above apparatus further includes: a testing module, used to perform charge-discharge tests on the batteries to be grouped before determining the first and second characteristic points of the charge-discharge curves of the batteries to be grouped, to obtain test data of the batteries to be grouped, wherein the test data includes: time nodes and the voltage corresponding to the time nodes; and a generation module, used to generate charge-discharge curves of the batteries to be grouped based on the test data.

[0055] Optionally, the above-mentioned test module includes: a data acquisition unit, used to acquire test data of the charge and discharge tests of the batteries to be grouped at preset time intervals.

[0056] Optionally, the charge-discharge test of the batteries to be grouped includes: resting the batteries to be grouped for a preset time; discharging them at a constant current of 1C to the lower limit voltage of the battery; resting the batteries to be grouped again for a preset time; charging them at a constant current of 4C to the upper limit voltage of the battery; resting the batteries to be grouped again for a preset time; discharging them at a constant current of 4C to the lower limit voltage of the battery; and finally resting the batteries to be grouped for a preset time; the charge-discharge test ends.

[0057] Optionally, the determination module includes: an acquisition unit for acquiring test data of the batteries to be grouped; a fitting unit for performing polynomial fitting on the test data of the batteries to be grouped to obtain a fitting result; and a differentiation unit for performing at least two differentiations on the fitting result to obtain a first feature point and a second feature point.

[0058] Optionally, the sorting module includes: a determining unit for determining the duration of all batteries to be grouped in the battery pack during the platform segment; a first processing unit for summing and averaging the durations of the platform segment to obtain the mean of the durations of all batteries to be grouped during the platform segment; and a second processing unit for selecting batteries to be grouped within a preset platform time range based on the mean and using a normal distribution.

[0059] Example 3

[0060] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the above-described battery sorting methods.

[0061] Optionally, in this embodiment, the computer-readable storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals, and the computer-readable storage medium includes a stored program.

[0062] Optionally, during program execution, the device containing the computer-readable storage medium is controlled to perform the following functions: determine the first and second characteristic points of the charge-discharge curves of the batteries to be grouped; divide the charge-discharge curves into three parts based on the start point, the first characteristic point, the second characteristic point, and the end point of the charge-discharge curves, wherein the curve between the start point and the first characteristic point is the first polarization segment, the curve between the first characteristic point and the second characteristic point is the plateau segment, and the curve between the second characteristic point and the end point is the second polarization segment; and sort the batteries to be grouped based on the plateau segment.

[0063] Example 4

[0064] According to another aspect of the present invention, a processor is also provided for running a program, wherein the program executes any of the battery sorting methods described above.

[0065] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs the following steps: determining a first characteristic point and a second characteristic point of the charge-discharge curve of the batteries to be grouped; dividing the charge-discharge curve into three parts based on the start point, the first characteristic point, the second characteristic point, and the end point of the charge-discharge curve, wherein the curve between the start point and the first characteristic point is a first polarization segment, the curve between the first characteristic point and the second characteristic point is a plateau segment, and the curve between the second characteristic point and the end point is a second polarization segment; and sorting the batteries to be grouped based on the plateau segment.

[0066] This invention also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having the following method steps: determining a first characteristic point and a second characteristic point of the charge-discharge curve of the batteries to be grouped; dividing the charge-discharge curve into three parts based on the start point, the first characteristic point, the second characteristic point, and the end point of the charge-discharge curve, wherein the curve between the start point and the first characteristic point is a first polarization segment, the curve between the first characteristic point and the second characteristic point is a plateau segment, and the curve between the second characteristic point and the end point is a second polarization segment; and sorting the batteries to be grouped based on the plateau segment.

[0067] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0068] In the above embodiments of the present invention, 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.

[0069] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0070] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0071] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0072] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0073] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A battery sorting method, characterized in that, include: Determine the first and second characteristic points of the charge-discharge curves of the batteries to be grouped; The first and second characteristic points of the charge-discharge curves of the batteries to be grouped include: Obtain test data for the batteries to be grouped; The test data of the batteries to be grouped are subjected to polynomial fitting to obtain the fitting results; The fitting result is differentiated at least twice to obtain the first feature point and the second feature point; Based on the start point, the first feature point, the second feature point, and the end point of the charge-discharge curve, the charge-discharge curve is divided into three parts, wherein the curve between the start point and the first feature point is the first polarization segment, the curve between the first feature point and the second feature point is the plateau segment, and the curve between the second feature point and the end point is the second polarization segment. The sorting of the batteries to be grouped according to the platform segment includes: Determine the duration of all cells to be grouped within the battery pack in the platform segment; The average duration of the platform segment is obtained by summing the durations of the segments and taking the average duration of all batteries to be grouped in the platform segment. Based on the mean value, batteries within a preset platform time range are selected using a normal distribution.

2. The method according to claim 1, characterized in that, Before determining the first and second characteristic points of the charge-discharge curves of the batteries to be grouped, the method further includes: A charge-discharge test is performed on the batteries to be grouped to obtain test data of the batteries to be grouped, wherein the test data includes: time points and the voltage corresponding to the time points; Based on the test data, charge and discharge curves of the batteries to be grouped are generated.

3. The method according to claim 2, characterized in that, The battery to be grouped was subjected to charge-discharge tests, and the test data obtained included: Test data for the charge and discharge tests of the batteries to be grouped are collected at preset time intervals.

4. The method according to claim 3, characterized in that, The charge / discharge tests of the batteries to be grouped include: The batteries to be grouped are left idle for a preset time. Discharge the battery at a constant current of 1C until the lower limit voltage of the battery; The batteries to be grouped are then set aside for the preset time again. Charge the battery at a constant current of 4C to its upper limit voltage. The batteries to be grouped were once again set aside for the preset time. Discharge the battery at a constant current of 4C until the lower limit voltage of the battery. Finally, the batteries to be grouped are set aside for the preset time. The charge / discharge test is complete.

5. A battery sorting device, characterized in that, include: A determining module is used to determine the first and second feature points of the charge-discharge curves of the batteries to be grouped. Determining the first and second feature points of the charge-discharge curves of the batteries to be grouped includes: acquiring test data of the batteries to be grouped; performing polynomial fitting on the test data of the batteries to be grouped to obtain a fitting result; and performing at least two derivatives on the fitting result to obtain the first and second feature points. A processing module is used to divide the charge-discharge curves into three parts based on the start point, the first feature point, the second feature point, and the end point of the charge-discharge curves. The curve between the start point and the first feature point is the first polarization segment, the curve between the first feature point and the second feature point is the plateau segment, and the curve between the second feature point and the end point is the second polarization segment. The sorting module is used to sort the batteries to be grouped according to the platform segment and determine the duration of all batteries to be grouped in the platform segment within the battery pack. The average duration of the platform segment is obtained by summing the durations of the segments and taking the average duration of all batteries to be grouped in the platform segment. Based on the mean value, batteries within a preset platform time range are selected using a normal distribution.

6. The apparatus according to claim 5, characterized in that, The device further includes: The testing module is used to perform charge-discharge tests on the batteries to be grouped before determining the first and second characteristic points of the charge-discharge curves, and to obtain test data of the batteries to be grouped, wherein the test data includes: time nodes and the voltage corresponding to the time nodes; The generation module is used to generate the charge-discharge curves of the batteries to be grouped based on the test data.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the battery sorting method according to any one of claims 1 to 4.

8. A processor, characterized in that, The processor is used to run a program, wherein the program executes the battery sorting method according to any one of claims 1 to 4.

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