Abnormal battery cell screening method, storage medium and electronic equipment

Abstract

The invention discloses an abnormal battery cell screening method, a storage medium and electronic equipment. The method relates to the field of battery detection, and comprises the following steps: obtaining target capacity data of a to-be-screened battery cell, the to-be-screened battery cell being a formed battery cell, and the target capacity data being used for representing the capacity consumed by the to-be-screened battery cell in the formation process; the target capacity data is compared with a preset capacity range, a comparison result is obtained, the preset capacity range is determined based on statistical distribution of first capacity data of the sample qualified battery cells, and the first capacity data is used for representing the capacity consumed by the sample qualified battery cells in the formation process; and if the comparison result is that the target capacity data is not in the preset capacity range, taking the to-be-screened battery cell as an abnormal battery cell. According to the method and the device, the problems of cost loss and time waste caused by hysteresis due to the fact that screening of the abnormal battery cells mainly depends on internal resistance screening after the battery cells are offline in the prior art are solved.

Description

Technical Field

[0001] This application relates to the field of battery testing, and more specifically, to a method for screening abnormal battery cells, a storage medium, and an electronic device. Background Technology

[0002] Lithium-ion batteries play a crucial role in modern energy storage systems, with lithium iron phosphate batteries being particularly favored for their safety and cycle life. Battery manufacturing involves multiple processes, among which the formation process is particularly critical. This process involves the reaction of the electrolyte with electrode materials to form a stable solid electrolyte interface film, which is essential for ensuring battery performance. With the rapid development of the new energy industry, battery production has increased dramatically, leading to correspondingly higher requirements for battery quality and consistency.

[0003] Currently, cell screening methods in related technologies are usually carried out at the final stage of cell production, such as internal resistance screening. However, for cells that have potential defects during the formation process, such as poor film formation due to internal inhomogeneity or material problems, this method has obvious lag, which not only leads to cost losses and wasted time, but also affects production efficiency and the timeliness of product quality control. Summary of the Invention

[0004] The main objective of this application is to provide a method, storage medium, and electronic device for screening abnormal battery cells, in order to solve the problem that the screening of abnormal battery cells in related technologies mainly relies on the internal resistance screening after the battery cells are produced, which has the problem of cost loss and time waste due to lag.

[0005] To achieve the above objectives, according to one aspect of this application, a method for screening abnormal battery cells is provided. The method includes: acquiring target capacity data of the battery cell to be screened, wherein the battery cell to be screened is a cell that has completed formation, and the target capacity data represents the capacity consumed by the battery cell to be screened during the formation process; comparing the target capacity data with a preset capacity range to obtain a comparison result, wherein the preset capacity range is determined based on the statistical distribution of first capacity data of a sample qualified battery cell, and the first capacity data represents the capacity consumed by the sample qualified battery cell during the formation process; if the comparison result indicates that the target capacity data is not within the preset capacity range, then the battery cell to be screened is identified as an abnormal battery cell.

[0006] Further, the preset capacity range is obtained through the following steps: acquiring formation process data of qualified sample cells, and determining first capacity data based on the formation process data; performing statistical analysis on the first capacity data to determine a first screening threshold and a second screening threshold, wherein the first screening threshold is greater than the second screening threshold; and determining the preset capacity range based on the first screening threshold and the second screening threshold.

[0007] Furthermore, the formation process data includes voltage data and charging capacity data. Determining the first capacity data based on the formation process data includes: plotting the voltage data and charging capacity data to obtain a first differential curve corresponding to the qualified sample cell, wherein the first differential curve is used to characterize the correspondence between voltage change and charging capacity change; fitting the first differential curve to the target voltage range using a preset attenuation model to obtain a first fitted curve; and determining the first capacity data based on the first differential curve and the first fitted curve.

[0008] Further, determining the first capacity data based on the first differential curve and the first fitted curve includes: calculating the area between the first differential curve and the X-axis to obtain the first area; calculating the area between the first differential curve and the first fitted curve to obtain the second area; and calculating the first capacity data based on the charging capacity data, the first area, and the second area.

[0009] Furthermore, statistical analysis of the first volume data is performed to determine the first screening threshold and the second screening threshold, including: performing statistical analysis on the first volume data to determine the mean and standard deviation of the first volume data; and calculating the first screening threshold and the second screening threshold based on the mean and standard deviation.

[0010] Furthermore, before obtaining the formation process data of the qualified sample cells, the method further includes: obtaining the charging capacity data of the sample cells in a preset batch, and determining the qualified sample cells from the sample cells in the preset batch based on the charging capacity data.

[0011] Furthermore, before obtaining the target capacity data of the cell to be screened, the method also includes: obtaining the voltage data and charging capacity data of the cell to be screened during the formation process; plotting the differential curve corresponding to the cell to be screened based on the voltage data and charging capacity data; fitting the differential curve in the target voltage range using a preset attenuation model to obtain the fitted curve; and determining the target capacity data based on the differential curve and the fitted curve.

[0012] Furthermore, determining the target capacity data based on the differential curve and the fitted curve includes: calculating the area between the differential curve and the X-axis to obtain the first target area; calculating the area between the differential curve and the fitted curve to obtain the second target area; and calculating the target capacity data based on the charging capacity data, the first target area, and the second target area.

[0013] To achieve the above objectives, according to another aspect of this application, a screening device for abnormal battery cells is provided. The device includes: a first acquisition unit, configured to acquire target capacity data of a battery cell to be screened, wherein the battery cell to be screened is a cell that has completed formation, and the target capacity data represents the capacity consumed by the battery cell to be screened during the formation process; a first processing unit, configured to compare the target capacity data with a preset capacity range to obtain a comparison result, wherein the preset capacity range is determined based on the statistical distribution of first capacity data of a sample qualified battery cell, and the first capacity data represents the capacity consumed by the sample qualified battery cell during the formation process; and a first determination unit, configured to, if the comparison result indicates that the target capacity data is not within the preset capacity range, classify the battery cell to be screened as an abnormal battery cell.

[0014] Furthermore, the device also includes the following units for obtaining a preset capacity range through the following steps: a second acquisition unit for acquiring formation process data of qualified sample cells and determining first capacity data based on the formation process data; a second processing unit for performing statistical analysis on the first capacity data and determining a first screening threshold and a second screening threshold, wherein the first screening threshold is greater than the second screening threshold; and a second determination unit for determining the preset capacity range based on the first screening threshold and the second screening threshold.

[0015] Furthermore, the formation process data includes voltage data and charging capacity data. The second acquisition unit includes: a first processing subunit, used to plot based on the voltage data and charging capacity data to obtain a first differential curve corresponding to the qualified sample cell, wherein the first differential curve is used to characterize the correspondence between voltage change and charging capacity change; a second processing subunit, used to fit the first differential curve in the target voltage range using a preset attenuation model to obtain a first fitted curve; and a first determination subunit, used to determine the first capacity data based on the first differential curve and the first fitted curve.

[0016] Further, the first determining subunit includes: a first calculation module for calculating the area between the first differential curve and the X-axis to obtain a first area; a second calculation module for calculating the area between the first differential curve and the first fitted curve to obtain a second area; and a third calculation module for calculating based on the charging capacity data, the first area, and the second area to obtain the first capacity data.

[0017] Furthermore, the second processing unit includes: a third processing subunit for performing statistical analysis on the first capacity data to determine the mean and standard deviation of the first capacity data; and a fourth processing subunit for calculating, based on the mean and standard deviation, a first screening threshold and a second screening threshold.

[0018] Furthermore, the device also includes a third acquisition unit, used to acquire charging capacity data of a preset batch of sample cells before acquiring formation process data of qualified sample cells, and to determine qualified sample cells from the preset batch of sample cells based on the charging capacity data.

[0019] Furthermore, the device also includes: a fourth acquisition unit, used to acquire voltage data and charging capacity data of the cell to be screened during the formation process before acquiring the target capacity data of the cell to be screened; a third processing unit, used to plot the differential curve corresponding to the cell to be screened based on the voltage data and charging capacity data; a fourth processing unit, used to fit the differential curve in the target voltage range using a preset attenuation model to obtain a fitted curve; and a third determination unit, used to determine the target capacity data based on the differential curve and the fitted curve.

[0020] Furthermore, the third determining unit includes: a first calculation subunit for calculating the area between the differential curve and the X-axis to obtain a first target area; a second calculation subunit for calculating the area between the differential curve and the fitted curve to obtain a second target area; and a third calculation subunit for calculating the target capacity data based on the charging capacity data, the first target area, and the second target area.

[0021] According to another aspect of the present invention, an electronic device is also provided, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the abnormal battery cell screening method described above during runtime.

[0022] According to another aspect of the present invention, a computer-readable storage medium is also provided, the storage medium storing a program, wherein, when the program is running, the device where the storage medium is located executes the abnormal cell screening method described above.

[0023] In this embodiment, the following steps are employed: obtaining target capacity data for the cell to be screened, wherein the cell to be screened is a cell that has completed formation, and the target capacity data represents the capacity consumed by the cell to be screened during the formation process; comparing the target capacity data with a preset capacity range to obtain a comparison result, wherein the preset capacity range is determined based on the statistical distribution of the first capacity data of a sample qualified cell, and the first capacity data represents the capacity consumed by the sample qualified cell during the formation process; if the comparison result indicates that the target capacity data is not within the preset capacity range, then the cell to be screened is considered an abnormal cell. This solves the technical problem in related technologies where the screening of abnormal cells mainly relies on the internal resistance screening after the cell is produced, which results in lag, cost losses, and wasted time.

[0024] In this solution, by statistically analyzing the film-forming capacity consumption of existing qualified battery cells during the formation process, the upper and lower limits of the film-forming capacity consumption (i.e., the preset capacity range) are calculated, providing a data basis for screening abnormal battery cells. Using the upper and lower limits to screen battery cells in the production process, when the screened battery cell does not meet the upper and lower limits, it means that the battery cell has other side reactions, insufficient charging capacity, or insufficient film formation, thus screening the battery cell. This achieves effective identification and screening of internal defects in battery cells, and abnormalities can be detected and eliminated in the early stage of battery cell production, avoiding the huge cost and time loss caused by later screening, and significantly improving the production quality and efficiency of battery cells. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 A hardware block diagram of a computer terminal for implementing a method for screening abnormal battery cells is shown.

[0027] Figure 2 This is a flowchart of a method for screening abnormal battery cells according to an embodiment of this application;

[0028] Figure 3 This is a schematic diagram of the film formation curve provided according to the embodiments of this application;

[0029] Figure 4 This is a schematic diagram of the screening process for abnormal battery cells provided according to the embodiments of this application;

[0030] Figure 5 This is a schematic diagram of a screening device for abnormal battery cells provided according to an embodiment of this application;

[0031] Figure 6 This is a structural block diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application 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 this application 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 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.

[0034] It should be noted that the information collected in this application (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for display, data used for analysis, etc.) are information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of this data all comply with relevant laws, regulations, and standards, necessary confidentiality measures have been taken, and they do not violate public order and good morals. Corresponding access points are provided for users to choose to authorize or refuse. For example, interfaces are set up between this system and relevant users or organizations, providing users with corresponding access points to choose to agree to or refuse automated decision-making results; if the user chooses to refuse, the process proceeds to the expert decision-making stage.

[0035] Example 1

[0036] According to an embodiment of this application, a method embodiment for screening abnormal battery cells is also 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.

[0037] The method embodiment provided in Embodiment 1 of this application can be executed on a mobile terminal, computer terminal, or similar computing device. Figure 1 A hardware block diagram of a computer terminal (or mobile device) for implementing a method for screening abnormal battery cells is shown. Figure 1As shown, the computer terminal 10 (or mobile device) may include one or more processors 102 (shown as 102a, 102b, ..., 102n in the figure) 102 (processor 102 may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 104 for storing data, and a transmission device 106 for communication functions. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus), a network interface, a power supply, and / or a camera. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0038] It should be noted that the aforementioned one or more processors 102 and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be embodied, in whole or in part, in software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or may be integrated, in whole or in part, into any other element within the computer terminal 10 (or mobile device). As involved in the embodiments of this application, the data processing circuits serve as a processor control mechanism (e.g., selection of a variable resistor termination path connected to an interface).

[0039] The memory 104 can be used to store software programs and modules for application software, such as the program instructions / data storage device corresponding to the abnormal battery cell screening method in this embodiment. The processor 102 executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby implementing the aforementioned abnormal battery cell screening method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the computer terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0040] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the communication provider of the computer terminal 10. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0041] The display may be a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 10 (or mobile device).

[0042] Under the aforementioned operating environment, this application provides the following: Figure 2 The method for screening abnormal battery cells is shown. Figure 2 This is a flowchart of a method for screening abnormal battery cells according to Embodiment 1 of this application. The method for screening abnormal battery cells includes:

[0043] Step S201: Obtain the target capacity data of the cell to be screened, wherein the cell to be screened is a cell that has completed formation, and the target capacity data is used to represent the capacity consumed by the cell to be screened during the formation process.

[0044] Step S202: Compare the target capacity data with the preset capacity range to obtain the comparison result. The preset capacity range is determined based on the statistical distribution of the first capacity data of the qualified sample cells. The first capacity data is used to represent the capacity consumed by the qualified sample cells during the formation process.

[0045] Step S203: If the comparison result shows that the target capacity data is not within the preset capacity range, then the cell to be screened is regarded as an abnormal cell.

[0046] Optionally, during the screening of abnormal cells, the screening system first obtains the film-forming capacity consumption data (i.e., target capacity data) of the cells to be screened after formation. Then, it uses the upper and lower limits of the film-forming capacity consumption (i.e., preset capacity range) obtained by statistical analysis and calculation of the film-forming capacity consumption of existing qualified cells during the formation process for screening. That is, the target capacity data is compared with the preset capacity range. When the screened cell does not meet the upper and lower limits, that is, the target capacity data is not within the preset capacity range, it is considered that the cell has other side reactions, or insufficient charging capacity, or insufficient film formation. Then, the cell is screened as an abnormal cell.

[0047] In summary, by statistically analyzing the film-forming capacity consumption of existing qualified battery cells during the formation process, the upper and lower limits of film-forming capacity consumption (i.e., the preset capacity range) are calculated, providing a data basis for screening abnormal battery cells. Using these upper and lower limits to screen battery cells during the production process, when a screened battery cell does not meet the upper or lower limits, it indicates that the battery cell has other side reactions, insufficient charging capacity, or incomplete film formation. This allows for effective identification and screening of internal defects in battery cells, enabling the detection and elimination of abnormalities in the early stages of battery cell production. This avoids the huge costs and time losses caused by later screening, significantly improving the production quality and efficiency of battery cells.

[0048] Optionally, in the abnormal cell screening method provided in this application embodiment, the preset capacity range is obtained through the following steps: obtaining the formation process data of the qualified sample cells, and determining the first capacity data based on the formation process data; performing statistical analysis on the first capacity data to determine the first screening threshold and the second screening threshold, wherein the first screening threshold is greater than the second screening threshold; and determining the preset capacity range based on the first screening threshold and the second screening threshold.

[0049] In an optional embodiment, in determining the upper and lower limits of film-forming capacity consumption, firstly, the formation process data of qualified sample cells is acquired. Based on the formation process data, the film-forming capacity consumption data (i.e., the first capacity data) of the qualified sample cells is determined. Then, statistical analysis is performed on this data to determine the upper limit (i.e., the first screening threshold) and the lower limit (i.e., the second screening threshold) of the film-forming capacity consumption. These upper and lower limits are then used as preset capacity ranges. For example, for qualified sample cells that have already been screened, their formation process data (such as voltage data and charging capacity data during cell formation) are traced back in reverse. Based on the voltage data and charging capacity data, their film-forming capacity consumption data is determined. Through statistical analysis of the film-forming capacity consumption data, the upper and lower limits of the film-forming capacity consumption are determined.

[0050] By statistically analyzing the film-forming capacity consumption data of qualified battery cells, the upper and lower limits of film-forming capacity consumption during the cell formation process were determined, providing a quantitative standard for screening abnormal cells. This enables accurate identification of cells with abnormal reactions during the film-forming process, avoiding subsequent screening costs and time losses caused by internal defects in the cells.

[0051] Optionally, in the abnormal cell screening method provided in this application embodiment, the formation process data includes voltage data and charging capacity data. Determining the first capacity data based on the formation process data includes: plotting the voltage data and charging capacity data to obtain a first differential curve corresponding to the sample qualified cell, wherein the first differential curve is used to characterize the correspondence between voltage change and charging capacity change; fitting the first differential curve to the target voltage range using a preset attenuation model to obtain a first fitted curve; and determining the first capacity data based on the first differential curve and the first fitted curve.

[0052] In an optional embodiment, during the process of determining the film-forming capacity consumption data of a qualified sample cell based on formation process data, differential curves are first plotted using voltage data and charging capacity data to obtain the first differential curve dQ / dV-V corresponding to the qualified sample cell. Here, dQ / dV-V represents the ΔQ corresponding to an increase of ΔV at a certain voltage. When a peak exists at a certain voltage, it indicates that a reaction has occurred and capacity has been consumed at that voltage. Based on cell consistency, the film formation process should overlap. Since the film-forming capacity consumption is similar, when there are internal defects in the cell that affect film formation, the curves will exhibit different characteristics. Therefore, the presence of internal defects in the cell can be determined by analyzing dQ / dV-V.

[0053] After extensive cell verification, without considering film formation, the charging process of the battery conforms to the double exponential decay model. Its characteristic range highly overlaps with the film formation range of the battery. Therefore, after obtaining the first differential curve dQ / dV-V corresponding to the qualified sample cell, the double exponential decay model (i.e., the preset decay model) is used to fit the first differential curve dQ / dV-V in the target voltage range to obtain the first fitting curve. The target voltage range can be 0-1500mV and 2700-3000mV. This range is considered to be the range where the electrolyte and electrode materials do not react. The first fitting curve is used to characterize the voltage change under the theoretically no consumption condition. Therefore, the film consumption capacity data of the qualified sample cell can be determined based on the first differential curve and the first fitting curve dQ / dV-V.

[0054] Differential curve analysis allows for a clear observation of the characteristics of the film-forming reaction, enabling precise identification of abnormal consumption during the film-forming process and providing a basis for screening abnormal cells.

[0055] Optionally, in the abnormal cell screening method provided in this application embodiment, determining the first capacity data based on the first differential curve and the first fitted curve includes: calculating the area between the first differential curve and the X-axis to obtain a first area; calculating the area between the first differential curve and the first fitted curve to obtain a second area; and calculating based on the charging capacity data, the first area, and the second area to obtain the first capacity data.

[0056] In an alternative embodiment, Figure 3 This is a schematic diagram of the film formation curve provided in the embodiments of this application, such as... Figure 3 As shown, this includes the original differential curve (such as the first differential curve), the fitted curve, and the area from 1500 to 3000 mV. In determining the film-forming capacity consumption data of the qualified sample cell based on the first differential curve and the first fitted curve, the area between the first differential curve and the X-axis is calculated to obtain the first area S0, and the area between the first differential curve and the first fitted curve is calculated to obtain the second area S1. Based on the charging capacity data Q0 corresponding to the first differential curve, the first area S0, and the second area S1, the film-forming capacity consumption data Q1 of the qualified sample cell can be obtained, as shown in the following formula:

[0057] Q1 = (S1) Q0) / S0

[0058] By calculating the area difference between the differential curve and the X-axis, and the fitted curve, the capacity consumed during the cell formation process is quantified. This allows for accurate evaluation of the cell film quality, screening out cells with insufficient film formation or side reactions, and improving the production quality and efficiency of cells.

[0059] Optionally, in the abnormal cell screening method provided in this application embodiment, statistical analysis of the first capacity data to determine the first screening threshold and the second screening threshold includes: statistical analysis of the first capacity data to determine the average value and standard deviation of the first capacity data; and calculation based on the average value and standard deviation to obtain the first screening threshold and the second screening threshold.

[0060] In an optional embodiment, by performing statistical analysis on Q1 of existing qualified cells, the average value μ and standard deviation σ of Q1 are determined. Based on the average value μ and standard deviation σ, the minimum and maximum film-forming capacity consumption of the cell are calculated, as follows:

[0061] Lower limit LSL = μ - 3σ, upper limit UCL = μ + 3σ

[0062] Statistical analysis of film-forming capacity consumption data of qualified battery cells in the samples enabled the accurate determination of the screening threshold.

[0063] Optionally, in the abnormal cell screening method provided in the embodiments of this application, before obtaining the formation process data of the qualified sample cells, the method further includes: obtaining the charging capacity data of the sample cells in a preset batch, and determining the qualified sample cells from the sample cells in the preset batch based on the charging capacity data.

[0064] In an optional embodiment, the charging capacity data of sample cells in a preset batch are first obtained, and qualified sample cells are determined from the sample cells in the preset batch based on the charging capacity data. For example, any batch of cells is processed to the production line, and then cells with qualified capacity and similar capacity differences are selected as qualified sample cells for statistical analysis.

[0065] By comparing the charging capacity data of the battery cells, cells with similar and qualified capacities were selected as samples, ensuring the accuracy of the statistical analysis.

[0066] Optionally, in the abnormal cell screening method provided in this application embodiment, before obtaining the target capacity data of the cell to be screened, the method further includes: obtaining the voltage data and charging capacity data of the cell to be screened during the formation process; plotting the differential curve corresponding to the cell to be screened based on the voltage data and charging capacity data; fitting the differential curve in the target voltage range using a preset attenuation model to obtain a fitted curve; and determining the target capacity data based on the differential curve and the fitted curve.

[0067] Optionally, in the abnormal cell screening method provided in this application embodiment, determining the target capacity data based on the differential curve and the fitted curve includes: calculating the area between the differential curve and the X-axis to obtain a first target area; calculating the area between the differential curve and the fitted curve to obtain a second target area; and calculating the target capacity data based on the charging capacity data, the first target area, and the second target area.

[0068] In an optional embodiment, the film-forming capacity consumption data of the cell to be screened is obtained as follows: First, the voltage data and charging capacity data of the cell to be screened during the formation process are obtained. Then, a differential curve dQ / dV-V is plotted based on the voltage data and charging capacity data as the original differential curve. Then, a double exponential decay model is used to fit the differential curve in the voltage range of 0-1500mV and the voltage range of 2700-3000mV to obtain the fitted curve. Then, the film-forming capacity consumption data of the cell to be screened can be calculated based on the differential curve and the fitted curve. The specific calculation method can refer to the film-forming capacity consumption data of the qualified sample cells, which will not be elaborated here.

[0069] Through the above process, the film-forming capacity consumption data of the cells to be screened was accurately determined, providing a data basis for the subsequent screening of abnormal cells.

[0070] In an alternative embodiment, Figure 4 This is a schematic diagram of the screening process for abnormal battery cells provided in the embodiments of this application, as shown below. Figure 4As shown, the process mainly includes testing qualified batteries, tracing formation data, plotting differential curves, calculating integral area, setting upper and lower limits, and screening battery formation. Specific implementation details can be found in the aforementioned embodiments and will not be repeated here.

[0071] It should be noted that the abnormal cell screening method provided in this application embodiment includes, but is not limited to, application to lithium iron phosphate batteries, and can also be applied to the formation of other types of batteries.

[0072] The abnormal cell screening method provided in this application provides a data basis for screening abnormal cells by statistically analyzing the film-forming capacity consumption of existing qualified cells during the formation process and calculating the upper and lower limits of the film-forming capacity consumption (i.e., the preset capacity range). The upper and lower limits are used to screen cells in the production process. When the screened cell does not meet the upper and lower limits, it means that the cell has other side reactions, insufficient charging capacity, or insufficient film formation. This allows for effective identification and screening of internal defects in the cell. Abnormalities can be detected and eliminated in the early stage of cell production, avoiding the huge cost and time loss caused by later screening, and significantly improving the production quality and efficiency of the cell.

[0073] 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, and 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.

[0074] Example 2

[0075] This application also provides a screening device for abnormal battery cells. It should be noted that the abnormal battery cell screening device of this application can be used to execute the screening method for abnormal battery cells provided in this application. The abnormal battery cell screening device provided in this application will be described below.

[0076] According to an embodiment of this application, an apparatus for screening abnormal battery cells to implement the above-described method for screening abnormal battery cells is also provided, such as... Figure 5 As shown, the device includes: a first acquisition unit 501, a first processing unit 502, and a first determination unit 503.

[0077] The first acquisition unit 501 is used to acquire the target capacity data of the battery cell to be screened, wherein the battery cell to be screened is a battery cell that has completed formation, and the target capacity data is used to represent the capacity consumed by the battery cell to be screened during the formation process.

[0078] The first processing unit 502 is used to compare the target capacity data and the preset capacity range to obtain a comparison result. The preset capacity range is determined based on the statistical distribution of the first capacity data of the sample qualified battery cells. The first capacity data is used to represent the capacity consumed by the sample qualified battery cells during the formation process.

[0079] The first determining unit 503 is used to identify the cell to be screened as an abnormal cell if the comparison result shows that the target capacity data is not within the preset capacity range.

[0080] The abnormal cell screening device provided in this application embodiment acquires target capacity data of the cell to be screened through a first acquisition unit 501, wherein the cell to be screened is a cell that has completed formation, and the target capacity data is used to represent the capacity consumed by the cell to be screened during the formation process; a first processing unit 502 compares the target capacity data with a preset capacity range to obtain a comparison result, wherein the preset capacity range is determined based on the statistical distribution of the first capacity data of the sample qualified cell, and the first capacity data is used to represent the capacity consumed by the sample qualified cell during the formation process; if the comparison result is that the target capacity data is not within the preset capacity range, the first determining unit 503 identifies the cell to be screened as an abnormal cell. By statistically analyzing the film-forming capacity consumption of existing qualified battery cells during the formation process, the upper and lower limits of film-forming capacity consumption (i.e., the preset capacity range) are calculated, providing a data basis for screening abnormal battery cells. Using the upper and lower limits to screen battery cells in the production process, when the screened battery cell does not meet the upper and lower limits, it means that the battery cell has other side reactions, insufficient charging capacity, or insufficient film formation, thus screening the battery cell. This achieves effective identification and screening of internal defects in battery cells, and abnormalities can be detected and eliminated in the early stage of battery cell production, avoiding the huge cost and time loss caused by later screening, and significantly improving the production quality and efficiency of battery cells.

[0081] Optionally, in the abnormal cell screening device provided in this application embodiment, the device further includes the following units for obtaining a preset capacity range through the following steps: a second acquisition unit for acquiring formation process data of qualified sample cells and determining first capacity data based on the formation process data; a second processing unit for performing statistical analysis on the first capacity data and determining a first screening threshold and a second screening threshold, wherein the first screening threshold is greater than the second screening threshold; and a second determination unit for determining the preset capacity range based on the first screening threshold and the second screening threshold.

[0082] Optionally, in the abnormal cell screening device provided in this application embodiment, the formation process data includes voltage data and charging capacity data. The second acquisition unit includes: a first processing subunit, used to plot based on the voltage data and charging capacity data to obtain a first differential curve corresponding to the sample qualified cell, wherein the first differential curve is used to characterize the correspondence between voltage change and charging capacity change; a second processing subunit, used to fit the first differential curve in the target voltage range using a preset attenuation model to obtain a first fitted curve; and a first determination subunit, used to determine the first capacity data based on the first differential curve and the first fitted curve.

[0083] Optionally, in the abnormal cell screening device provided in the embodiments of this application, the first determining subunit includes: a first calculation module, used to calculate the area between the first differential curve and the X-axis to obtain a first area; a second calculation module, used to calculate the area between the first differential curve and the first fitted curve to obtain a second area; and a third calculation module, used to calculate based on the charging capacity data, the first area, and the second area to obtain the first capacity data.

[0084] Optionally, in the abnormal cell screening device provided in the embodiments of this application, the second processing unit includes: a third processing subunit, used to perform statistical analysis on the first capacity data to determine the average value and standard deviation of the first capacity data; and a fourth processing subunit, used to calculate based on the average value and standard deviation to obtain a first screening threshold and a second screening threshold.

[0085] Optionally, in the abnormal cell screening device provided in the embodiments of this application, the device further includes: a third acquisition unit, used to acquire the charging capacity data of a preset batch of sample cells before acquiring the formation process data of the qualified sample cells, and to determine the qualified sample cells from the sample cells in the preset batch based on the charging capacity data.

[0086] Optionally, in the abnormal cell screening device provided in this application embodiment, the device further includes: a fourth acquisition unit, used to acquire voltage data and charging capacity data of the cell to be screened during the formation process before acquiring the target capacity data of the cell to be screened; a third processing unit, used to plot the differential curve corresponding to the cell to be screened based on the voltage data and charging capacity data; a fourth processing unit, used to fit the differential curve in the target voltage range using a preset attenuation model to obtain a fitted curve; and a third determination unit, used to determine the target capacity data based on the differential curve and the fitted curve.

[0087] Optionally, in the abnormal cell screening device provided in the embodiments of this application, the third determining unit includes: a first calculation subunit, used to calculate the area between the differential curve and the X-axis to obtain a first target area; a second calculation subunit, used to calculate the area between the differential curve and the fitted curve to obtain a second target area; and a third calculation subunit, used to calculate based on the charging capacity data, the first target area, and the second target area to obtain target capacity data.

[0088] It should be noted that the first acquisition unit 501, the first processing unit 502, and the first determination unit 503 mentioned above correspond to steps S201 to S203 in Embodiment 1. The three units and the corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in Embodiment 1. It should be noted that the above modules or units can be hardware or software components stored in memory (e.g., memory 104) and processed by one or more processors (e.g., processors 102a, 102b, ..., 102n). The above units can also be part of a device and run in the computer terminal 10 provided in Embodiment 1.

[0089] Example 3

[0090] Embodiments of this application may provide an electronic device. Figure 6 This is a structural block diagram of an electronic device according to an embodiment of this application. Figure 6 As shown, the electronic device may include: one or more ( Figure 6 (Only one is shown) Processor 602, memory 604, memory controller, and peripheral interface, wherein the peripheral interface is connected to the radio frequency module, audio module and display.

[0091] The memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the methods and apparatus in the embodiments of this application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby implementing the above-described methods. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0092] The processor can access information and applications stored in the memory via a transmission device to perform the following steps: acquiring target capacity data of the cell to be screened, wherein the cell to be screened is a cell that has completed formation, and the target capacity data is used to represent the capacity consumed by the cell to be screened during the formation process; comparing the target capacity data with a preset capacity range to obtain a comparison result, wherein the preset capacity range is determined based on the statistical distribution of the first capacity data of the sample qualified cell, and the first capacity data is used to represent the capacity consumed by the sample qualified cell during the formation process; if the comparison result is that the target capacity data is not within the preset capacity range, then the cell to be screened is identified as an abnormal cell.

[0093] The processor can call the information and application stored in the memory through the transmission device to perform the following steps: obtain the formation process data of the qualified sample cells, and determine the first capacity data based on the formation process data; perform statistical analysis on the first capacity data to determine the first screening threshold and the second screening threshold, wherein the first screening threshold is greater than the second screening threshold; and determine the preset capacity range based on the first screening threshold and the second screening threshold.

[0094] The processor can call the information and application program stored in the memory through the transmission device to perform the following steps: plotting based on voltage data and charging capacity data to obtain the first differential curve corresponding to the qualified sample cell, wherein the first differential curve is used to characterize the correspondence between voltage change and charging capacity change; fitting the first differential curve in the target voltage range using a preset attenuation model to obtain the first fitted curve; and determining the first capacity data based on the first differential curve and the first fitted curve.

[0095] The processor can call the information and application program stored in the memory through the transmission device to perform the following steps: calculate the area between the first differential curve and the X-axis to obtain the first area; calculate the area between the first differential curve and the first fitted curve to obtain the second area; and calculate the first capacity data based on the charging capacity data, the first area, and the second area.

[0096] The processor can access the information and application programs stored in the memory via the transmission device to perform the following steps: perform statistical analysis on the first capacity data to determine the average value and standard deviation of the first capacity data; and calculate the first screening threshold and the second screening threshold based on the average value and standard deviation.

[0097] The processor can call the information and application stored in the memory through the transmission device to perform the following steps: before obtaining the formation process data of the qualified sample cells, obtain the charging capacity data of the sample cells in a preset batch, and determine the qualified sample cells from the sample cells in the preset batch based on the charging capacity data.

[0098] The processor can call the information and application stored in the memory through the transmission device to perform the following steps: before obtaining the target capacity data of the cell to be screened, obtain the voltage data and charging capacity data of the cell to be screened during the formation process; draw a differential curve corresponding to the cell to be screened based on the voltage data and charging capacity data; fit the differential curve in the target voltage range using a preset attenuation model to obtain the fitted curve; determine the target capacity data based on the differential curve and the fitted curve.

[0099] The processor can access the information and application programs stored in the memory via the transmission device to perform the following steps: calculate the area between the differential curve and the X-axis to obtain a first target area; calculate the area between the differential curve and the fitted curve to obtain a second target area; and calculate the target capacity data based on the charging capacity data, the first target area, and the second target area.

[0100] Those skilled in the art will understand that Figure 6 The structure shown is for illustrative purposes only. Electronic devices can also be smartphones, tablets, handheld computers, mobile internet devices (MIDs), PADs, and other terminal devices. Figure 6 This does not limit the structure of the aforementioned electronic device. For example, electronic devices may also include components that are more... Figure 6 The more or fewer components shown (such as network interfaces, display devices, etc.), or having the same Figure 6 The different configurations shown.

[0101] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a computer-readable storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0102] Example 4

[0103] Embodiments of this application also provide a computer-readable storage medium. Optionally, in this embodiment, the storage medium can be used to store the program code executed by the abnormal battery cell screening method provided in Embodiment 1.

[0104] Optionally, in this embodiment, the 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.

[0105] This application also provides a computer program product, which, when executed on a data processing device, is suitable for performing the steps of a method for screening abnormal battery cells.

[0106] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0107] In the above embodiments of this application, 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.

[0108] 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 is only a logical functional division, and in actual implementation, there may be other division methods. For example, 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.

[0109] 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 network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0110] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0111] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0112] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method of screening for abnormal battery cells, the method comprising: The method comprises the following steps: obtaining target capacity data of a to-be-screened battery cell, wherein the to-be-screened battery cell is a completed formation battery cell, and the target capacity data is used to represent the capacity consumed by the to-be-screened battery cell in a formation process; comparing the target capacity data with a preset capacity range to obtain a comparison result, wherein the preset capacity range is determined based on a statistical distribution of first capacity data of a sample qualified battery cell, and the first capacity data is used to represent the capacity consumed by the sample qualified battery cell in the formation process; if the comparison result is that the target capacity data is not within the preset capacity range, regarding the to-be-screened battery cell as an abnormal battery cell.

2. The method of claim 1, wherein, The preset capacity range is obtained by the following steps: obtaining formation process data of the sample qualified battery cell, and determining the first capacity data according to the formation process data; statistically analyzing the first capacity data to determine a first screening threshold and a second screening threshold, wherein the first screening threshold is greater than the second screening threshold; determining the preset capacity range according to the first screening threshold and the second screening threshold.

3. The method of claim 2, wherein, The formation process data comprises voltage data and charging capacity data, and the first capacity data is determined according to the formation process data by the following steps: drawing according to the voltage data and the charging capacity data to obtain a first differential curve corresponding to the sample qualified battery cell, wherein the first differential curve is used to represent the corresponding relationship between voltage change and charging capacity change; fitting the first differential curve in a target voltage interval by using a preset attenuation model to obtain a first fitted curve; determining the first capacity data according to the first differential curve and the first fitted curve.

4. The method of claim 3, wherein, The first capacity data is determined according to the first differential curve and the first fitted curve by the following steps: calculating the area between the first differential curve and the X-axis to obtain a first area; calculating the area between the first differential curve and the first fitted curve to obtain a second area; calculating according to the charging capacity data, the first area and the second area to obtain the first capacity data.

5. The method of claim 2, wherein, The first capacity data is statistically analyzed to determine a first screening threshold and a second screening threshold by the following steps: statistically analyzing the first capacity data to determine the average value and the standard deviation of the first capacity data; calculating according to the average value and the standard deviation to obtain the first screening threshold and the second screening threshold.

6. The method of claim 2, wherein, Before obtaining the formation process data of the sample qualified battery cell, the method further comprises: obtaining charging capacity data of sample battery cells in a preset batch, and determining the sample qualified battery cell from the sample battery cells in the preset batch according to the charging capacity data.

7. The method according to any one of claims 1 to 6, characterized in that, Before obtaining the target capacity data of the to-be-screened battery cell, the method further comprises: obtaining voltage data and charging capacity data of the to-be-screened battery cell in a formation process; drawing according to the voltage data and the charging capacity data to obtain a differential curve corresponding to the to-be-screened battery cell; fitting the differential curve in a target voltage interval by using a preset attenuation model to obtain a fitted curve; The target capacity data is determined according to the differential curve and the fitting curve.

8. The method of claim 7, wherein, The target capacity data is determined according to the differential curve and the fitting curve, comprising: calculating the area between the differential curve and the X axis to obtain a first target area; calculating the area between the differential curve and the fitting curve to obtain a second target area; calculating the target capacity data according to the charging capacity data, the first target area and the second target area.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium comprises a stored executable program, wherein the executable program controls the device where the computer readable storage medium is located to execute the abnormal battery cell screening method in any one of claims 1 to 8 when the executable program is running.

10. An electronic device, comprising: comprising: a memory storing an executable program; a processor for running the program, wherein the program executes the abnormal battery cell screening method in any one of claims 1 to 8 when the program is running.

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