Group margin detection method and device of cylindrical battery and nonvolatile storage medium

Abstract

The invention discloses a cylindrical battery group margin detection method and device and a nonvolatile storage medium. The method comprises the steps that an image, obtained through ultrasonic signal testing, of a target battery is obtained, and the image is used for displaying the strength of an ultrasonic signal penetrating through a battery cell of the target battery; based on the image, ultrasonic signal intensities corresponding to a plurality of preset positions of a battery cell in the target battery are determined; based on the ultrasonic signal intensities corresponding to the plurality of preset positions, determining an average signal intensity corresponding to the target battery; and selecting a group margin corresponding to the average signal intensity of the target battery as a target group margin of the target battery based on a preset corresponding relationship between the group margin and the ultrasonic signal intensity. According to the invention, the technical problem that the continuous monitoring of the change of the internal structure of the battery in the normal working state cannot be realized due to the damage to the battery cell caused by the disassembly of the battery cell in the current test of the battery cell group margin is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery detection, in particular to a group margin detection method and device for cylindrical batteries and a nonvolatile storage medium. BACKGROUND

[0002] During the cycle charge-discharge test of a cylindrical battery, the volume expansion and shrinkage of the positive and negative electrode materials in the electrochemical reaction cause changes in the group margin (Gap) inside the battery cell. Currently, the test of the group margin of the battery cell is mainly based on the conversion of the expansion and shrinkage ratio of the electrode sheet after the disassembly of the battery cell to the change in the group margin of the battery cell, or directly measuring the size of the disassembled battery cell. The above group margin test scheme has a large conversion result deviation and an irreversible damage to the battery cell, and cannot realize continuous monitoring of the internal structure changes of the battery under normal working conditions.

[0003] At present, no effective solution has been proposed for the above problems. SUMMARY

[0004] The embodiments of the present application provide a group margin detection method and device for cylindrical batteries and a nonvolatile storage medium to at least solve the technical problem that the current test of the group margin of the battery cell usually involves disassembly of the battery cell, causing damage to the battery cell, and cannot realize continuous monitoring of the internal structure changes of the battery under normal working conditions.

[0005] According to an aspect of an embodiment of the present application, a group margin detection method for a cylindrical battery is provided, including: obtaining an image of a target battery obtained through ultrasonic signal testing, wherein the image is used to display the ultrasonic signal intensity of the battery cell of the target battery; determining the ultrasonic signal intensity corresponding to each of a plurality of preset positions of the battery cell in the target battery based on the image; determining the average signal intensity corresponding to the target battery based on the ultrasonic signal intensity corresponding to each of the plurality of preset positions; and selecting the group margin corresponding to the average signal intensity of the target battery as the target group margin of the target battery based on the preset corresponding relationship between the group margin and the ultrasonic signal intensity.

[0006] Optionally, before selecting the group margin corresponding to the average signal strength of the target battery as the target group margin of the target battery based on the preset correspondence between the group margin and the ultrasonic signal strength, the method comprises: obtaining a plurality of sample batteries each corresponding to a group margin; performing ultrasonic imaging tests on the plurality of sample batteries each corresponding to a group margin to obtain images each corresponding to a plurality of sample batteries; determining the ultrasonic signal strength each corresponding to a plurality of preset positions of the cell in the plurality of sample batteries based on the images each corresponding to the plurality of sample batteries; calculating the average signal strength each corresponding to the plurality of sample batteries based on the ultrasonic signal strength each corresponding to the plurality of preset positions of the cell in the plurality of sample batteries; and determining the correspondence between the group margin and the ultrasonic signal strength based on the average signal strength each corresponding to the plurality of sample batteries and the group margin.

[0007] Optionally, obtaining a plurality of sample batteries each corresponding to a group margin comprises: obtaining a sample battery; and adjusting the state of charge of the sample battery to obtain the sample battery under a plurality of group margins.

[0008] Optionally, determining the correspondence between the group margin and the ultrasonic signal strength based on the average signal strength each corresponding to the plurality of sample batteries and the group margin comprises: determining a standard curve based on the average signal strength each corresponding to the plurality of sample batteries and the group margin, wherein the standard curve is located in a coordinate system with the group margin as the x-axis and the average signal strength as the y-axis; and performing linear fitting based on the standard curve to obtain the correspondence between the group margin and the ultrasonic signal strength.

[0009] Optionally, the plurality of preset positions are 0、 1 height positions of the axial height of the cell.

[0010] Optionally, it is determined whether the target group margin exceeds a preset threshold; and in a case where the group margin exceeds the preset threshold, the target battery is determined to be an unqualified battery.

[0011] According to another aspect of the embodiment of the present application, a group margin detection device for a cylindrical battery is also provided, which comprises: an obtaining module configured to obtain an image of a target battery obtained through ultrasonic signal testing, wherein the image is used to display the ultrasonic signal strength of a cell of the target battery; a first determining module configured to determine the ultrasonic signal strength each corresponding to a plurality of preset positions of the cell in the target battery based on the image; a second determining module configured to determine the average signal strength corresponding to the target battery based on the ultrasonic signal strength each corresponding to the plurality of preset positions; and a selecting module configured to select the group margin corresponding to the average signal strength of the target battery as the target group margin of the target battery based on the preset correspondence between the group margin and the ultrasonic signal strength.

[0012] According to a further aspect of the embodiments of the present application, a nonvolatile storage medium is also provided, which comprises a stored program, wherein the program, when executed, controls a device in which the nonvolatile storage medium is located to perform the group margin detection method of any one of the above.

[0013] According to a further aspect of the embodiments of the present application, a computer device is also provided, which comprises a processor configured to execute a program, wherein the program, when executed, performs the group margin detection method of any one of the above.

[0014] According to a further aspect of the embodiments of the present application, a computer program product is also provided, which comprises a computer program configured to, when executed by a processor, implement the group margin detection method of any one of the above.

[0015] In the embodiments of the present application, the group margin detection method of the cylindrical battery is adopted, an image of a target battery obtained through ultrasonic signal testing is acquired, wherein the image is used to display the ultrasonic signal strength of the battery core of the target battery; based on the image, the ultrasonic signal strength corresponding to each of a plurality of preset positions of the battery core of the target battery is determined; based on the ultrasonic signal strength corresponding to each of the plurality of preset positions, the average signal strength corresponding to the target battery is determined; based on the preset corresponding relationship between the group margin and the ultrasonic signal strength, the group margin corresponding to the average signal strength of the target battery is selected as the target group margin of the target battery, so as to achieve the purpose of detecting the group margin without damaging the battery core, thereby realizing the technical effect of improving the group margin detection efficiency, and further solving the technical problem that the current test of the group margin of the battery core usually involves disassembly of the battery core, which causes damage to the battery core, and cannot realize continuous monitoring of the internal structure change of the battery under the normal working state of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are included to provide a further understanding of the present application and constitute a part of this application, illustrate embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0017] Figure 1 Fig. 1 shows a hardware structure block diagram of a computer terminal for implementing the group margin detection method of the cylindrical battery;

[0018] Figure 2 Fig. 2 is a flowchart of the group margin detection method of the cylindrical battery according to the embodiments of the present application;

[0019] Figure 3 Fig. 3 is a schematic diagram of the ultrasonic transmission signal strength change of different group margins according to the optional embodiments of the present application;

[0020] Figure 4is a schematic diagram of the relationship between group margin and signal strength according to an alternative embodiment of the present application;

[0021] Figure 5 is a structural block diagram of a group margin detection device for a cylindrical battery according to an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiment of the present application will be described clearly and completely in the following by combining the drawings in the embodiment of the present application. Obviously, the described embodiment is only a part of the embodiment of the present application, not all. Based on the embodiment in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the scope of protection of the present application.

[0023] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0024] First, some of the nouns or terms appearing in the process of describing the embodiments of the present application are applicable to the following explanations:

[0025] Battery group margin, usually refers to a concept in cylindrical battery, which is defined as the percentage of the ratio of the cell diameter to the housing diameter. The group margin reflects the space utilization and the expansion allowance of the cell inside its housing.

[0026] According to an embodiment of the present application, a method embodiment of a cylindrical battery group margin detection method is provided. It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0027] The method embodiment provided by the first embodiment of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Figure 1A hardware structure block diagram of a computer terminal for implementing a group margin detection method of cylindrical batteries is shown. As shown in Figure 1 the computer terminal 10 can include one or more processors (processors can include, but are not limited to, processing devices such as microprocessors MCU or programmable logic devices FPGA, etc.), a memory 104 for storing data. In addition, it can also include a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which can be included as one of the ports of the BUS bus), a network interface, a power supply and / or a camera. Those skilled in the art can understand that Figure 1 the structure shown is only schematic, which does not limit the structure of the above-mentioned electronic device. For example, the computer terminal 10 can include more or fewer components than those shown in Figure 1 or have a different configuration than that shown in Figure 1 .

[0028] It should be noted that the one or more processors and / or other data processing circuits described above can be referred to herein as "data processing circuits" in general. The data processing circuit can be embodied in whole or in part as software, hardware, firmware or any other combination. In addition, the data processing circuit can be a single independent processing module, or all or part of any one of the other elements combined into the computer terminal 10. As referred to in the embodiments of the present application, the data processing circuit controls as a processor (for example, the selection of the variable resistance terminal path connected to the interface).

[0029] The memory 104 can be used to store software programs and modules of application software, such as program instructions / data storage devices corresponding to the group margin detection method of cylindrical batteries in the embodiments of the present application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, that is, implements the group margin detection method of cylindrical batteries of the above-mentioned application program. The memory 104 can include a high-speed random access memory, and can also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 can further include a memory remotely disposed with respect to the processor, which can be connected to the computer terminal 10 through a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network and a combination thereof.

[0030] The display can be, for example, a touch screen type liquid crystal display (LCD), which can enable a user to interact with the user interface of the computer terminal 10.

[0031] In the design of cylindrical batteries, the volume expansion and contraction of the positive and negative materials during charging and discharging can cause the internal core of the battery to expand and contract. Due to the constraints of the battery shell, the expansion behavior of the core is closely related to the Gap Ratio of the cell. Specifically, the Gap Ratio is defined as the ratio of the cell diameter to the shell diameter. When the Gap Ratio is less than 100%, the core can freely expand and contract within the shell without being limited by the external space; when the Gap Ratio is greater than 100%, the expansion space of the core is constrained by the shell, and the expansion force is released by changing the density of the core. The density of the core plays a key role in the change of the Gap Ratio, and the greater the Gap Ratio (the stronger the shell constraint), the greater the core density may increase. Changes in density can affect the energy density, ion transport performance, and thermal management performance of the battery. In this case, the internal distribution structure and density of the core to some extent reflect the change characteristics of the Gap Ratio. Therefore, it is necessary to detect the Gap Ratio to obtain the state of the cell in the battery. However, the current detection method is based on the test of the expansion and contraction ratio of the core after disassembly of the cell, or directly measures the size of the disassembled core, which can cause damage to the cell and has low detection efficiency. To solve this technical problem, the present application provides a method for detecting the Gap Ratio of a cylindrical battery, Figure 2 The flowchart of the method for detecting the Gap Ratio of a cylindrical battery according to an embodiment of the present application is shown in Figure 2 The method comprises the following steps:

[0032] Step S202, obtaining an image of the target battery obtained by ultrasonic signal testing, wherein the image is used to display the ultrasonic signal intensity transmitted through the cell of the target battery.

[0033] In this step, the image of the target battery obtained by ultrasonic signal testing is obtained, wherein the image is used to display the ultrasonic signal intensity transmitted through the cell of the battery, i.e. the spatial distribution information of the cell transmission signal can be obtained.

[0034] The steps of ultrasonic signal testing of the target battery are as follows:

[0035] 1. Ensure that the ultrasonic testing equipment has been correctly set, including the parameters of ultrasonic frequency, transmission energy, time baseline, etc., to adapt to the testing requirements of the battery cell.

[0036] 2. Place the ultrasonic probe accurately on the test position of the target battery, usually on the outer surface of the battery, and ensure good contact between the probe and the battery surface to reduce signal attenuation and distortion.

[0037] 3. Start the ultrasonic testing equipment, which emits ultrasonic pulse signals from one probe, and the signals are received by another probe after penetrating the battery cell. Ensure that the distance and angle between the transmitting and receiving probes are fixed to control the consistency of the test.

[0038] 4. The equipment records the received ultrasonic signal intensity, which is usually represented by the amplitude or energy of the signal. During the acquisition process, a 360° scan may be required around the entire circumference of the battery to obtain comprehensive signal distribution information.

[0039] 5. Convert the acquired signal intensity data into image form. This usually involves mapping the signal intensity to different colors or gray scale values on the image to visually display the signal distribution. For example, areas with high signal intensity are displayed in bright colors on the image, while areas with low signal intensity are displayed in dark colors.

[0040] Through these steps, the internal information of the battery cell can be effectively obtained by ultrasonic signal testing and visualized as an image, providing a powerful tool for non-destructive testing and maintenance of the battery.

[0041] Step S204, based on the image, determine the ultrasonic signal intensity corresponding to each of the plurality of preset positions of the cell in the target battery.

[0042] In this step, the ultrasonic signal intensity at a plurality of preset positions in the cell can be selected to represent the ultrasonic signal intensity that can be transmitted by the cell in the target battery. For example, load the image of the target battery cell obtained by ultrasonic testing in the image processing or analysis software. This is usually a pseudo-color image or a gray scale image that shows the intensity distribution of ultrasonic signals in the cell. A plurality of preset positions on the image can be determined, which can be in proportion to the axial direction of the battery. At each preset position, define a large enough pixel area to ensure that the ultrasonic signal intensity at that position can be accurately captured. Read the pixel intensity in the defined area at each preset position. This usually involves selecting an area to obtain the average value of the pixel intensity in that area, or providing a histogram distribution from which the average value, median, etc. statistical information can be extracted. Among them, the average value of the ultrasonic signal at each preset position can be calculated by scanning around the cell to obtain the average value of the ultrasonic signal at each preset position as the ultrasonic signal intensity corresponding to each preset position.

[0043] Through the above steps, the ultrasonic signal intensity of the target battery cell at a plurality of preset positions can be accurately obtained from the ultrasonic testing image, providing key data for non-destructive testing of the internal state of the battery. These data can be further used to calculate the average signal intensity of the battery, or analyze the trend of signal intensity change with battery state, so as to evaluate the change of battery health and margin.

[0044] Step S206, based on the ultrasonic signal intensity corresponding to each of the plurality of preset positions, determine the average signal intensity corresponding to the target battery.

[0045] In this step, the average signal intensity of all preset positions is comprehensively averaged to obtain the total average signal intensity of the target battery. It can be checked whether the calculated total average signal intensity is reasonable, which can be compared with the previously collected data or the average signal intensity of other batteries. If the result is abnormal, the data collection and processing process should be rechecked. The final average signal intensity is recorded.

[0046] Through the above steps, the overall average signal intensity of the target battery can be accurately calculated from the ultrasonic signal intensity data of multiple preset positions, providing a solid foundation for subsequent deeper battery analysis.

[0047] Step S208, based on the preset relationship between group margin and ultrasonic signal intensity, select the group margin corresponding to the average signal intensity of the target battery as the target group margin of the target battery.

[0048] In this step, based on the preset relationship between group margin and ultrasonic signal intensity, the group margin corresponding to the average signal intensity of the target battery is selected as the target group margin of the target battery, wherein the relationship between the group margin and the ultrasonic signal intensity can be obtained based on the pre-experiment.

[0049] Through these steps, the average ultrasonic signal intensity of the target battery can be converted to its current group margin value, thereby realizing non-invasive detection of the internal state of the battery, which is of great significance for battery manufacturing quality control, performance evaluation and life prediction.

[0050] Through the above steps, the purpose of group margin detection without damaging the battery cell is achieved, thereby realizing the technical effect of improving the efficiency of group margin detection, and further solving the technical problem that the current test of the group margin of the battery cell usually involves disassembly of the battery cell, causing damage to the battery cell, and cannot realize continuous monitoring of the internal structure changes of the battery under normal working state.

[0051] As an optional embodiment, before selecting the group margin corresponding to the average signal strength of the target battery as the target group margin of the target battery based on the correspondence between the preset group margin and the ultrasonic signal strength, the method comprises: obtaining a plurality of sample batteries corresponding to the respective group margins; performing ultrasonic imaging tests on the plurality of sample batteries corresponding to the respective group margins to obtain images corresponding to the respective sample batteries; determining ultrasonic signal strengths corresponding to the plurality of preset positions of the cells in the plurality of sample batteries based on the images corresponding to the respective sample batteries; calculating average signal strengths corresponding to the respective sample batteries based on the ultrasonic signal strengths corresponding to the plurality of preset positions of the cells in the plurality of sample batteries; and determining the correspondence between the group margin and the ultrasonic signal strength based on the average signal strengths corresponding to the respective sample batteries and the group margins.

[0052] Optionally, a group of batteries with different group margins can be selected as samples. The other parameters (such as materials, sizes, states of charge, etc.) of the sample batteries are ensured to be as consistent as possible to reduce non-group margin factors affecting the test results. The exact group margin of each sample battery is recorded and given a unique identification for subsequent data tracking. Ultrasonic imaging tests are performed on each sample battery to obtain the ultrasonic signal strength distribution image inside the cell. During the test, the test conditions are kept consistent to ensure the comparability of the data. A sample battery can also be selected to control the sample battery to be in different group margin states for ultrasonic signal testing to obtain multiple ultrasonic signal strength distribution images. Figure 3 is a schematic diagram of ultrasonic transmission signal strength changes at different group margins according to an optional embodiment of the present application, as shown in Figure 3 The ultrasonic signal strength distribution images at multiple group margins are shown. The preset position points are defined on the ultrasonic images of each sample battery, and these points are usually set based on the axial height proportion of the battery. The ultrasonic signal strength of each preset position point is read. The reading method is ensured to be consistent to obtain reliable comparison data. The ultrasonic signal strength value of each preset position of each sample battery is recorded, and the data is arranged for the next calculation. The preset position data of each sample battery is averaged to calculate the average signal strength of each sample battery. The average signal strength data of all sample batteries is summarized to form a complete data set. The average signal strength of each sample battery is paired with its corresponding group margin value to form a two-dimensional data set. The data point distribution in the scatter plot can be observed to analyze whether there is an obvious trend or pattern. For example, does the signal strength change regularly with the increase of the group margin. Based on the observed trend, a suitable mathematical model (such as linear regression, polynomial regression, etc.) is selected to fit the data to determine the mathematical relationship between the group margin and the ultrasonic signal strength.

[0053] Through the above steps, the corresponding relationship between the group margin and the ultrasonic signal strength can be determined, providing a scientific and quantitative method for non-destructive testing and state evaluation of the battery.

[0054] As an optional embodiment, obtaining a plurality of sample batteries corresponding to respective group margins comprises: obtaining a sample battery; and adjusting the state of charge of the sample battery to obtain the sample battery under a plurality of group margins.

[0055] Optionally, the state of charge of the sample battery can be adjusted by controlling the charging and discharging process to reach the different SoC states (state of charge) corresponding to the preset group margins. The relationship between the group margin and the SoC can be determined by experiment or theoretical model in advance, for example, charging to 100% SoC may correspond to the minimum volume state of the internal materials of the battery, thereby obtaining the maximum group margin; and discharging to 50% SoC may correspond to the medium state of the group margin. During the adjustment of the state of charge, the voltage, current and temperature of the battery and other parameters are continuously monitored by using the battery management or test system to ensure that the battery is within a safe operating range and accurately reaches the expected SoC state. After reaching each preset SoC state, the sample battery is placed in an ultrasonic test device to prepare for the collection of ultrasonic signals. The position and test conditions of the battery in the test environment are ensured to be consistent to reduce the interference of external factors.

[0056] Through the above steps, the ultrasonic signal strength data under different group margins can be obtained by adjusting the state of charge of the sample battery, providing experimental basis for further analysis and establishment of the application of ultrasonic testing in the detection of the group margin of the battery.

[0057] As an optional embodiment, determining the corresponding relationship between the group margin and the ultrasonic signal strength based on the average signal strength and the group margin corresponding to each of a plurality of sample batteries comprises: determining a standard curve based on the average signal strength and the group margin corresponding to each of the plurality of sample batteries, wherein the standard curve is located in a coordinate system with the group margin as the x-axis and the average signal strength as the y-axis; and performing linear fitting based on the standard curve to obtain the corresponding relationship between the group margin and the ultrasonic signal strength.

[0058] Optionally, the standard curve is determined based on the average signal strength and the group margin corresponding to each of the plurality of sample batteries, and linear fitting is performed to obtain the corresponding relationship between the group margin and the ultrasonic signal strength, and the specific steps are as follows:

[0059] 1. The group margin (X-axis) and average signal strength (Y-axis) data of all sample batteries are arranged in tabular form to ensure the accuracy and integrity of the data.

[0060] 2. Using charting software, plot a scatter plot with the group margin data on the x-axis and the average signal strength data on the y-axis. This helps to visually observe the relationship between the two.

[0061] 3. On a scatter plot, connecting the scatter points forms a trend line, which is the standard curve. If the data points exhibit a linear distribution, the standard curve will be a straight line. If the trend between the data points is non-linear, more advanced curve fitting methods are needed.

[0062] 4. For data exhibiting a linear trend, use the least squares method or a relevant linear fitting algorithm (such as functions from the NumPy or SciPy libraries in Python) for linear fitting. The goal of the fitting is to find a straight line that minimizes the sum of the squared vertical distances (residuals) from all data points to that line.

[0063] 5. After linear fitting is completed, an equation can be obtained, specifically... Figure 4 This is a schematic diagram illustrating the relationship between group margin and signal strength according to an optional embodiment of the present invention, such as... Figure 4 As shown, there is an approximately linear positive correlation between the change in cell transmission signal and group margin. Therefore, after obtaining the standard curve, the group margin corresponding to the cell under different states can be obtained by ultrasonic testing. By linearly fitting the relationship between ultrasonic signal intensity and group margin, the relationship between ultrasonic signal intensity (Y) and group margin (X) can be obtained as follows: Y = 0.115x - 0.0815.

[0064] 6. Determine the goodness of fit and calculate the coefficient of determination R. 2 Among them, the closer the coefficient of determination is to 1, the better the fitted curve can explain the variation in the data, and the stronger the predictive ability of the model. Specifically, the coefficient of determination is... Figure 4 For example, the coefficient of determination R 2 =0.9974.

[0065] 7. Analyze the slope and intercept of the standard curve to understand the relationship between group margin and ultrasound signal intensity. If the slope is positive, it means that the average signal intensity increases with the increase of group margin; conversely, it means that the signal intensity decreases with the increase of group margin.

[0066] 8. Compare the fitted curve with the original data points to ensure that the curve reasonably reflects the trend of the data. If the fitted curve deviates too much from the data points, it may be necessary to re-examine the dataset or the fitting parameters.

[0067] 9. Based on the standard curve and the fitting equation, the ultrasonic signal intensity data of any battery can be substituted into the equation to calculate its corresponding group margin, thereby realizing non-destructive testing and evaluation of the battery status.

[0068] Through the above steps, a model showing the correspondence between group margin and ultrasonic signal intensity can be obtained, and this relationship can be visualized in the form of a standard curve, providing a powerful tool for subsequent battery testing and condition monitoring.

[0069] As an optional embodiment, multiple preset positions are 0, 0, and 0.5 times the axial height of the battery cell. 1. Height position.

[0070] Optionally, the area for sampling the ultrasonic signal of the battery cell is the axial height of the cylindrical battery cell at 0, Five height positions can be used to calculate the average value of the ultrasonic signal under each height condition by scanning 0-360° around the entire circle; finally, the average value of the ultrasonic signals at the five heights is taken as the battery transmission signal intensity value.

[0071] As an optional embodiment, it is determined whether the target group margin exceeds a preset threshold; if the group margin exceeds the preset threshold, the target battery is determined to be a defective battery.

[0072] Optionally, a preset threshold for group margin can be determined based on battery design specifications, safety standards, and performance requirements. The target group margin value is then compared with the preset threshold. If the target group margin is lower than the preset threshold, the battery may be in a normal state; if the target battery's group margin exceeds the preset threshold, this indicates that the battery has excessively expanded or contracted during charge-discharge cycles, causing changes in its internal structure, which may affect the battery's performance and safety. In this case, the target battery can be determined to be a substandard battery.

[0073] Substandard batteries need to be labeled and isolated to prevent them from entering the market or being used in the environment, thus preventing potential safety accidents. For substandard batteries, the reasons for their non-compliance should be further analyzed, such as material problems, manufacturing defects, or misuse, and measures should be taken to improve the design or production process to enhance the consistency and reliability of the batteries.

[0074] The above steps enable accurate determination of battery quality based on non-destructive testing results of group margin, which is crucial for quality control during battery manufacturing and safety assessment of battery products. When the target group margin exceeds a preset threshold, the determination of unqualified batteries helps to promptly identify and address potential battery problems, prevent unqualified products from entering the market, and ensure user safety and product quality.

[0075] It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the action sequence described, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0076] Through the description of the above embodiments, those skilled in the art can clearly understand that the group margin detection method of the cylindrical battery according to the above embodiments can be realized by means of software and the necessary general hardware platform, of course, it can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a plurality of instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the method described in each embodiment of the present application.

[0077] According to the embodiments of the present application, a group margin detection device for cylindrical batteries is also provided, Figure 5 is a structural block diagram of the group margin detection device for cylindrical batteries provided by the embodiments of the present application, as Figure 5 shown, the group margin detection device for cylindrical batteries includes an acquisition module 502, a first determination module 504, a second determination module 506, and a selection module 508, which will be described below.

[0078] The acquisition module 502 is configured to acquire an image of a target battery obtained through ultrasonic signal testing, wherein the image is used to display the ultrasonic signal strength penetrating through the battery cell of the target battery.

[0079] The first determination module 504 is connected with the acquisition module 502 and is configured to determine the ultrasonic signal strength corresponding to each of a plurality of preset positions of the battery cell in the target battery based on the image.

[0080] The second determination module 506 is connected with the first determination module 504 and is configured to determine the average signal strength corresponding to the target battery based on the ultrasonic signal strength corresponding to each of the plurality of preset positions.

[0081] The selection module 508 is connected with the second determination module 506 and is configured to select the group margin corresponding to the average signal strength of the target battery as the target group margin of the target battery based on the preset corresponding relationship between the group margin and the ultrasonic signal strength.

[0082] It should be noted that the above acquisition module 502, the first determination module 504, the second determination module 506 and the selection module 508 correspond to steps S202 to S208 in the embodiment, and the multiple modules have the same instances and application scenarios as the corresponding steps, but are not limited to the above disclosed content. It should be noted that the above modules as part of the device can run in the computer terminal 10 provided in the embodiment.

[0083] The embodiment of the present application can provide a computer device. Optionally, in the embodiment, the computer device can be located in at least one network device of multiple network devices of a computer network. The computer device comprises a memory and a processor.

[0084] The memory can be used to store software programs and modules, such as program instructions / modules corresponding to the cylindrical battery group margin detection method and device in the embodiment of the present application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, implements the above cylindrical battery group margin detection method. The memory can include a high-speed random access memory, and can also include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some examples, the memory can further include a memory remotely arranged with respect to the processor, which can be connected to the computer terminal through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0085] The processor can call the information and application programs stored in the memory through the transmission device to perform the following steps: acquiring an image of a target battery obtained through ultrasonic signal testing, wherein the image is used to display the ultrasonic signal intensity penetrating through the battery cell of the target battery; determining the ultrasonic signal intensity corresponding to each of a plurality of preset positions of the battery cell in the target battery based on the image; determining the average signal intensity corresponding to the target battery based on the ultrasonic signal intensity corresponding to each of the plurality of preset positions; and selecting the group margin corresponding to the average signal intensity of the target battery as the target group margin of the target battery based on the preset corresponding relationship between the group margin and the ultrasonic signal intensity.

[0086] Optionally, the processor can further execute program codes of the following steps: before selecting the group margin corresponding to the average signal strength of the target battery as the target group margin of the target battery based on the preset correspondence between the group margin and the ultrasonic signal strength, comprising: obtaining sample batteries corresponding to the plurality of group margins respectively; performing ultrasonic imaging test on the sample batteries corresponding to the plurality of group margins respectively to obtain images corresponding to the plurality of sample batteries respectively; determining ultrasonic signal strengths corresponding to the plurality of preset positions of the battery cell in the plurality of sample batteries respectively based on the images corresponding to the plurality of sample batteries respectively; calculating average signal strengths corresponding to the plurality of sample batteries respectively based on the ultrasonic signal strengths corresponding to the plurality of preset positions of the battery cell in the plurality of sample batteries respectively; and determining the correspondence between the group margin and the ultrasonic signal strength based on the average signal strengths corresponding to the plurality of sample batteries respectively and the group margins.

[0087] Optionally, the processor can further execute program codes of the following steps: obtaining sample batteries corresponding to the plurality of group margins respectively, comprising: obtaining a sample battery; and adjusting the state of charge of the sample battery to obtain the sample battery under the plurality of group margins.

[0088] Optionally, the processor can further execute program codes of the following steps: determining the correspondence between the group margin and the ultrasonic signal strength based on the average signal strengths corresponding to the plurality of sample batteries respectively and the group margins, comprising: determining a standard curve based on the average signal strengths corresponding to the plurality of sample batteries respectively and the group margins, wherein the standard curve is located in a coordinate system with the group margin as the x-axis and the average signal strength as the y-axis; and performing linear fitting based on the standard curve to obtain the correspondence between the group margin and the ultrasonic signal strength.

[0089] Optionally, the plurality of preset positions are 0、 1 height positions of the axial height of the battery cell.

[0090] Optionally, the processor can further execute program codes of the following steps: determining whether the target group margin exceeds a preset threshold; and determining the target battery as an unqualified battery in the case that the group margin exceeds the preset threshold.

[0091] The embodiment of the present application provides a group margin detection method for a cylindrical battery, and the method comprises the following steps: obtaining an image of a target battery subjected to ultrasonic signal testing, wherein the image is used for displaying ultrasonic signal intensity of a battery cell of the target battery; determining ultrasonic signal intensity corresponding to each of a plurality of preset positions of the battery cell in the target battery based on the image; determining average signal intensity corresponding to the target battery based on the ultrasonic signal intensity corresponding to each of the plurality of preset positions; and selecting a group margin corresponding to the average signal intensity of the target battery as a target group margin of the target battery based on a preset corresponding relationship between the group margin and the ultrasonic signal intensity, so that the group margin detection is realized without damaging the battery cell, and the technical effect of improving the group margin detection efficiency is achieved, and the technical problem that the current group margin testing of the battery cell usually involves disassembly of the battery cell and causes damage to the battery cell and cannot realize continuous monitoring of internal structure changes of the battery cell in a normal working state is solved.

[0092] Those skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the hardware related to the terminal device through a program, and the program can be stored in a nonvolatile storage medium, and the storage medium can include a flash disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0093] The embodiment of the present application further provides a nonvolatile storage medium. Optionally, in the embodiment, the nonvolatile storage medium can be used to save program codes executed by the group margin detection method for the cylindrical battery provided by the above embodiment.

[0094] Optionally, in the embodiment, the nonvolatile storage medium can be located in any one of computer terminals in a computer terminal group in a computer network, or in any one of mobile terminals in a mobile terminal group.

[0095] Optionally, in the embodiment, the nonvolatile storage medium is configured to store program codes for executing the following steps: obtaining an image of a target battery subjected to ultrasonic signal testing, wherein the image is used for displaying ultrasonic signal intensity of a battery cell of the target battery; determining ultrasonic signal intensity corresponding to each of a plurality of preset positions of the battery cell in the target battery based on the image; determining average signal intensity corresponding to the target battery based on the ultrasonic signal intensity corresponding to each of the plurality of preset positions; and selecting a group margin corresponding to the average signal intensity of the target battery as a target group margin of the target battery based on a preset corresponding relationship between the group margin and the ultrasonic signal intensity.

[0096] Optionally, in the embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: before selecting, based on a preset correspondence between the group margin and the ultrasonic signal strength, a group margin corresponding to the average signal strength of the target battery as the target group margin of the target battery, the steps include: obtaining sample batteries corresponding to the plurality of group margins respectively; performing ultrasonic imaging tests on the sample batteries corresponding to the plurality of group margins respectively to obtain images corresponding to the plurality of sample batteries respectively; determining, based on the images corresponding to the plurality of sample batteries respectively, ultrasonic signal strengths corresponding to the plurality of preset positions of the battery cell in the plurality of sample batteries respectively; calculating, based on the ultrasonic signal strengths corresponding to the plurality of preset positions of the battery cell in the plurality of sample batteries respectively, average signal strengths corresponding to the plurality of sample batteries respectively; and determining, based on the average signal strengths corresponding to the plurality of sample batteries respectively and the group margins, the correspondence between the group margin and the ultrasonic signal strength.

[0097] Optionally, in the embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: obtaining sample batteries corresponding to the plurality of group margins respectively includes: obtaining a sample battery; and adjusting the state of charge of the sample battery to obtain the sample battery under the plurality of group margins.

[0098] Optionally, in the embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: determining, based on the average signal strengths corresponding to the plurality of sample batteries respectively and the group margins, the correspondence between the group margin and the ultrasonic signal strength includes: determining, based on the average signal strengths corresponding to the plurality of sample batteries respectively and the group margins, a standard curve, wherein the standard curve is located in a coordinate system with the group margin as the x-axis and the average signal strength as the y-axis; and performing linear fitting based on the standard curve to obtain the correspondence between the group margin and the ultrasonic signal strength.

[0099] Optionally, in the embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: the plurality of preset positions are 0、 1 height positions of the axial height of the battery cell.

[0100] Optionally, in the embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: determining whether the target group margin exceeds a preset threshold; and in the case where the group margin exceeds the preset threshold, determining that the target battery is an unqualified battery.

[0101] The embodiment of the present application further provides a computer program product comprising a computer program, which, when executed by a processor, can realize the following: obtaining an image of a target battery obtained through ultrasonic signal testing, wherein the image is used to display ultrasonic signal intensity penetrating through a cell of the target battery; determining ultrasonic signal intensity corresponding to each of a plurality of preset positions of the cell in the target battery based on the image; determining average signal intensity corresponding to the target battery based on the ultrasonic signal intensity corresponding to each of the plurality of preset positions; and selecting a group margin corresponding to the average signal intensity of the target battery as a target group margin of the target battery based on a preset corresponding relationship between group margins and ultrasonic signal intensities.

[0102] The above-mentioned serial numbers of the embodiments of the present application are only for description, and do not represent the advantages or disadvantages of the embodiments.

[0103] In the above-mentioned embodiments of the present application, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0104] In several embodiments provided in the present application, it should be understood that the disclosed technical contents can be realized by other manners. Among them, the above-mentioned device embodiments are only schematic, for example, the division of the units can be a logical function division, and in actual implementation, there can be another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or modules shown or discussed can be indirect coupling or communication connection through some interfaces, units or modules, which can be electrical or other forms.

[0105] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed to a plurality of units. According to actual needs, part or all of the units can be selected to realize the purpose of the embodiment.

[0106] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be realized in the form of hardware or in the form of software functional unit.

[0107] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a nonvolatile storage medium. Based on such understanding, the technical solutions of the present application, essentially or in part, or all or part of the technical solutions, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, and various media that can store program codes.

[0108] The above description is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A method for detecting a group margin of a cylindrical battery, characterized by, The method comprises: obtaining an image of a target battery obtained through ultrasonic signal testing, wherein the image is used to display ultrasonic signal intensity of a battery cell of the target battery; determining, based on the image, ultrasonic signal intensity corresponding to each of a plurality of preset positions of the battery cell of the target battery; determining, based on the ultrasonic signal intensity corresponding to each of the plurality of preset positions, average signal intensity corresponding to the target battery; selecting, based on a preset correspondence between group margin and ultrasonic signal intensity, a group margin corresponding to the average signal intensity of the target battery as a target group margin of the target battery.

2. The method of claim 1, wherein, Before the step of selecting, based on the preset correspondence between group margin and ultrasonic signal intensity, the group margin corresponding to the average signal intensity of the target battery as the target group margin of the target battery, the method comprises: obtaining a plurality of sample batteries each corresponding to a group margin; performing ultrasonic imaging testing on the plurality of sample batteries each corresponding to a group margin to obtain an image corresponding to each of the plurality of sample batteries; determining, based on the image corresponding to each of the plurality of sample batteries, ultrasonic signal intensity corresponding to each of a plurality of preset positions of a battery cell of the sample battery; calculating, based on the ultrasonic signal intensity corresponding to each of the plurality of preset positions of the battery cell of the sample battery, average signal intensity corresponding to each of the plurality of sample batteries; determining, based on the average signal intensity and the group margin corresponding to each of the plurality of sample batteries, the correspondence between the group margin and the ultrasonic signal intensity.

3. The method of claim 2, wherein, The step of obtaining a plurality of sample batteries each corresponding to a group margin comprises: obtaining a sample battery; adjusting a state of charge of the sample battery to obtain the sample battery under the plurality of group margins.

4. The method of claim 2, wherein, The step of determining, based on the average signal intensity and the group margin corresponding to each of the plurality of sample batteries, the correspondence between the group margin and the ultrasonic signal intensity comprises: determining, based on the average signal intensity and the group margin corresponding to each of the plurality of sample batteries, a standard curve, wherein the standard curve is located in a coordinate system with the group margin as the x-axis and the average signal intensity as the y-axis; performing linear fitting based on the standard curve to obtain the correspondence between the group margin and the ultrasonic signal intensity.

5. The method of claim 1, wherein, The plurality of preset positions are 0, height positions of the 1.

6. The method according to any one of claims 1 to 5, characterized in that, The method further comprises: determining whether the target group margin exceeds a preset threshold; in a case where the group margin exceeds the preset threshold, determining that the target battery is an unqualified battery.

7. A group margin detection device for cylindrical batteries, characterized in that, The method comprises: an obtaining module configured to obtain an image of a target battery obtained through ultrasonic signal testing, wherein the image is used to display ultrasonic signal intensity of a battery cell of the target battery; a first determining module configured to determine, based on the image, ultrasonic signal intensity corresponding to each of a plurality of preset positions of the battery cell of the target battery; a second determining module configured to determine, based on the ultrasonic signal intensity corresponding to each of the plurality of preset positions, average signal intensity corresponding to the target battery; a selecting module configured to select, based on a preset correspondence between group margin and ultrasonic signal intensity, a group margin corresponding to the average signal intensity of the target battery as a target group margin of the target battery.

8. A non-volatile storage medium, comprising: The nonvolatile storage medium includes a stored program, wherein the program, when executed, controls a device in which the nonvolatile storage medium is located to perform the group margin detection method of the cylindrical battery according to any one of claims 1 to 6.

9. A computer device, comprising: Comprise: a memory and a processor, the memory stores a computer program; the processor is configured to execute the computer program stored in the memory, and the computer program, when executed, causes the processor to perform the group margin detection method of the cylindrical battery according to any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that, The computer program, when executed by the processor, implements the group margin detection method of the cylindrical battery according to any one of claims 1 to 6.

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