Battery defect detection method and device, equipment, medium and product

Abstract

The invention provides a battery defect detection method and device, electronic equipment, a storage medium and a product. The detection method comprises the steps of obtaining the width of a first pole piece and the width of a second pole piece of a battery in the direction parallel to the axis of the battery; determining a first dislocation amount of the first pole piece and the adjacent second pole piece at the first end; the first dislocation quantity is the distance between the end point of the first pole piece at the first end and the end point of the adjacent second pole piece at the first end along the direction parallel to the axis of the battery; determining a second dislocation amount of the first pole piece and the adjacent second pole piece at the second end according to the width of the first pole piece, the width of the second pole piece and the first dislocation amount; the second dislocation quantity is the distance between the end point of the first pole piece at the second end and the end point of the adjacent second pole piece at the second end along the direction parallel to the axis of the battery; and determining a detection result of the battery according to the first dislocation quantity and the second dislocation quantity.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery defect detection method and detection device, equipment, medium, and product. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] The safety and reliability of batteries are receiving more and more attention, and more stringent and comprehensive control is being implemented on defective cells that may appear during the battery manufacturing process. However, the existing detection system detects defects inside the battery through charge coupled devices (CCD) or X-rays, but this detection method has great limitations, making it difficult to fully detect defects inside the battery, and the detection efficiency is low. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems in the background technology. To this end, one purpose of the present application is to provide a battery defect detection method and detection device, equipment, medium, and product to improve the problem of low efficiency in detecting the misalignment of the cathode and anode plates.

[0005] An embodiment of the first aspect of the present application provides a battery defect detection method, wherein the battery to be tested includes a first pole piece and a second pole piece which are stacked and wound around the battery axis, and the battery to be tested includes a first end and a second end which are arranged opposite to each other along the battery axis, and the method includes: obtaining the width of the first pole piece and the width of the second pole piece of the battery to be tested in a direction parallel to the battery axis; determining a first misalignment amount between the first pole piece and the adjacent second pole piece at the first end; the first misalignment amount is the distance between the end point of the first pole piece at the first end and the end point of the adjacent second pole piece at the first end along a direction parallel to the battery axis; determining a second misalignment amount between the first pole piece and the adjacent second pole piece at the second end according to the width of the first pole piece, the width of the second pole piece and the first misalignment amount; the second misalignment amount is the distance between the end point of the first pole piece at the second end and the end point of the adjacent second pole piece at the second end along a direction parallel to the battery axis; and determining a detection result of the battery to be tested according to the first misalignment amount and the second misalignment amount.

[0006] In the technical solution of the embodiment of the present application, the second misalignment between the first pole piece and the adjacent second pole piece at the second end is determined based on the width of the first pole piece, the width of the second pole piece, and the first misalignment, so that it is not necessary to detect both ends of the electrode assembly at the same time, which can improve the efficiency of detection. And because the misalignment of the positive and negative pole pieces at the other end is calculated by an algorithm, it can alleviate the problem that X-rays are difficult to distinguish the edge positions of the pole pieces in some cases, which is conducive to improving the accuracy of the detection results.

[0007] In some embodiments, determining a first misalignment amount between a first pole piece and an adjacent second pole piece at a first end, the first misalignment amount being the distance between an endpoint of the first pole piece at the first end and an endpoint of an adjacent second pole piece at the first end along a direction parallel to the battery axis, includes: acquiring a detection image including the first end of the battery to be tested; identifying the detection image to respectively acquire a first endpoint of the nth turn of the first pole piece at the first end, and two second endpoints of two second pole pieces adjacent to the nth turn of the first pole piece at the first end; determining a first misalignment amount corresponding to the nth turn of the first pole piece according to the positions of the first endpoint and the two second endpoints in the detection image; wherein n is a positive integer greater than 0.

[0008] By detecting the first end of the battery to be tested and identifying the detection image, the first misalignment between the first pole piece and the second pole piece of each circle layer at the first end can be determined, thereby realizing the detection of the misalignment between the pole pieces of each circle layer and improving the accuracy of the detection.

[0009] In some embodiments, determining the first misalignment corresponding to the nth turn of the first pole piece according to the positions of the first endpoint and the two second endpoints in the detection image includes: determining the first sub-misalignment and the second sub-misalignment between the nth turn of the first pole piece and the two adjacent second pole pieces at the first end along the direction parallel to the battery axis according to the positions of the first endpoint and the two second endpoints in the detection image; determining the larger of the first sub-misalignment and the second sub-misalignment as the first misalignment corresponding to the nth turn of the first pole piece. By determining the larger of the first sub-misalignment and the second sub-misalignment of the nth turn of the first pole piece as the first misalignment corresponding to the nth turn of the first pole piece, the safety margin for judging the misalignment defect of the pole piece can be improved, the probability of misjudgment can be reduced to a certain extent, and the reliability of defect detection of the battery to be tested can be improved.

[0010] In some embodiments, obtaining the width of the first pole piece and the width of the second pole piece of the battery to be tested along the direction parallel to the battery axis includes: obtaining at least one first width along the direction parallel to the battery axis corresponding to at least one first preset position on the first pole piece; at least one first preset position is located on the nth circle of the first pole piece; obtaining at least one second width along the direction parallel to the battery axis corresponding to at least one second preset position on the second pole piece; at least one second preset position is located on the nth circle of the second pole piece; and wherein, determining the second misalignment of the first pole piece and the adjacent second pole piece at the second end according to the width of the first pole piece, the width of the second pole piece and the first misalignment includes: determining the second misalignment corresponding to the nth circle of the first pole piece according to at least one first width, at least one second width and the first misalignment corresponding to the nth circle of the first pole piece. By obtaining the pole piece width of the corresponding preset position on any circle of the wound pole piece, the width value obtained in this way is more accurate, and the misalignment defect detection can be more effectively performed on the pole piece of the corresponding circle layer, thereby judging whether the misalignment of any circle layer inside the battery to be tested meets the corresponding quality requirements, thereby improving the accuracy of battery defect detection.

[0011] In some embodiments, the number of at least one first preset position is multiple, and / or the number of at least one second preset position is multiple, and wherein, determining the second misalignment corresponding to the nth turn of the first pole piece according to at least one first width, at least one second width, and the first misalignment corresponding to the nth turn of the first pole piece includes: obtaining multiple second misalignment calculation values ​​according to at least one first width, at least one second width, and the first misalignment corresponding to the nth turn of the first pole piece; determining the minimum value of the multiple second misalignment calculation values ​​as the second misalignment corresponding to the nth turn of the first pole piece. By selecting the number of the first preset position and / or the second preset position to be multiple, thereby obtaining multiple second misalignment calculation values ​​by calculation and determining the second misalignment based on the multiple second misalignment calculation values, the deficiency of large single-point calculation deviation leading to error or distortion of the detection result can be avoided, and the fluctuation of the pole piece width value at different positions can be taken into account, and the minimum second misalignment calculation value is selected as the second misalignment, so that the extreme case where quality defects are most likely to occur is used as the situation for judging the misalignment defect, which can avoid misjudgment to a certain extent and improve the reliability of defect detection.

[0012] In some embodiments, at least one first preset position is equal to at least one second preset position and is arranged in one-to-one correspondence, and the line connecting any one of the at least one first preset position and the battery axis coincides with the projection of the line connecting the corresponding second preset position and the battery axis on a plane perpendicular to the battery axis. By further defining the positional relationship between the first preset position and the second preset position, the calculation of the misalignment amount can more accurately reflect the actual situation of the misalignment amount between adjacent pole pieces of the circle layer, so that the detection result can more accurately reflect the defect state inside the battery to be tested, and improve the accuracy of the detection. .

[0013] In some embodiments, determining the test result of the battery to be tested according to the first misalignment amount and the second misalignment amount includes: in response to the fact that any one of the first misalignment amount and the second misalignment amount is less than or equal to the first preset threshold, or any one of the first misalignment amount and the second misalignment amount is greater than or equal to the second preset threshold, determining the test result of the battery to be tested as unqualified; the first preset threshold is less than the second preset threshold. By setting the first preset threshold and the second preset threshold, the first misalignment amount and the second misalignment amount are limited, so that the test result of the battery to be tested can be directly judged according to the calculation result of the misalignment amount, thereby improving the detection efficiency and accuracy.

[0014] In some embodiments, the value range of the first preset threshold is greater than or equal to 0.2 mm and less than or equal to 0.5 mm. By reasonably limiting the value range of the first preset threshold, the detection accuracy requirements and quality design requirements of the misalignment of the cathode and anode plates in the battery to be tested can be taken into account, and the risk of misdetection of the battery detection leading to the outflow of defective batteries can be alleviated to a certain extent.

[0015] In some embodiments, the ratio of the second preset threshold value to the preset misalignment amount is greater than or equal to 0.95 and less than or equal to 1, and the preset misalignment amount is determined based on the width of the first pole piece and the width of the second pole piece. By limiting the ratio of the second preset threshold value to the preset misalignment amount, the degree of adaptation of the second preset threshold value to the width of the first pole piece and the width of the second pole piece is improved. Here, the second preset threshold value is based on the preset misalignment amount and can be completely independent of the value of the first preset threshold value, thereby judging from different angles whether the first misalignment amount and the second misalignment amount meet the quality requirements, further avoiding misjudgment and missed judgment, and improving the reliability of the test results of the battery to be tested.

[0016] In some embodiments, the defect detection method further includes: obtaining a detection image including the first end of the battery to be tested and / or the second end of the battery to be tested; identifying the detection image to obtain the position information of the first pole piece and the position information of the second pole piece; determining the gap value between the first pole piece and the adjacent second pole piece according to the position information of the first pole piece and the position information of the second pole piece, wherein the gap value is the minimum center distance between the first pole piece and the adjacent second pole piece along a direction perpendicular to the battery axis; and determining the detection result of the battery to be tested according to the gap value. The gap value between the first pole piece and the adjacent second pole piece is determined by the position information of the first pole piece and the position information of the second pole piece, and whether the battery to be tested is qualified is determined according to the detection result, so as to achieve more comprehensive defect detection of the battery to be tested.

[0017] In some embodiments, the gap value between the first pole piece and the adjacent second pole piece is determined based on the position information of the first pole piece and the position information of the second pole piece, and the gap value is the minimum center distance between the first pole piece and the adjacent second pole piece along the direction perpendicular to the battery axis, including: determining the position information of the center vertical line of the first pole piece and the position information of the center vertical line of the second pole piece based on the position information of the first pole piece and the position information of the center vertical line of the second pole piece; calculating the minimum distance between the center vertical line of the first pole piece and the center vertical line of the adjacent second pole piece along the direction perpendicular to the battery axis and using it as the gap value. Since the gap value is obtained from the center vertical line of the first pole piece and the center vertical line of the adjacent second pole piece, it can avoid that the gap value error is too large due to inaccurate local edge position identification. At the same time, the minimum distance between the center vertical line of the first pole piece and the center vertical line of the adjacent second pole piece along the direction perpendicular to the battery axis is used as the gap value, which can more reliably judge the quality of the battery to be tested and improve the reliability of the detection result of the battery to be tested.

[0018] In some embodiments, determining the test result of the battery to be tested according to the gap value includes: in response to the gap value being greater than a third preset threshold or less than a fourth preset threshold, determining the test result of the battery as unqualified, wherein the third preset threshold is greater than the fourth preset threshold. By defining the third preset threshold and the fourth preset threshold for comparison with the gap value, it is more conducive to intuitively and quantitatively evaluating whether the electrode of the battery to be tested has defects.

[0019] In some embodiments, the defect detection method further includes: in response to the test result of the battery to be tested being unqualified, the battery to be tested is rejected or re-tested. By rejecting or re-testing the battery to be tested with unqualified test results, the outflow of problematic batteries is effectively avoided, and the reliability of the outflow batteries is improved.

[0020] The second embodiment of the present application provides a battery defect detection device, including a ray source, a detector and a defect detection component, wherein the ray source is used to emit detection rays to the battery to be tested; the detector is used to receive the detection rays emitted by the ray source and penetrating the battery to be tested; the defect detection component is connected to the detector, and the defect detection component is used to execute any one of the above-mentioned defect detection methods. The battery defect detection device can execute the detection method in the above-mentioned embodiment, thereby improving the detection efficiency of the battery to be tested.

[0021] In some embodiments, the rated voltage range of the radiation source is greater than or equal to 130 kV and less than or equal to 150 kV; and / or the rated current of the radiation source is less than or equal to 500 microamperes. By limiting the rated voltage and rated current of the radiation source, it is possible to provide a radiation dose that meets the requirements while taking into account the stability and reliability of the radiation source, and at the same time, the radiation source and the detector cooperate to meet the requirements of the detection accuracy of the battery to be tested, thereby improving the efficiency and accuracy of the detection.

[0022] In some embodiments, the maximum size of the focus of the radiation source is less than or equal to 80 microns. Specifically limiting the size of the focus diameter can better match the detection accuracy of the battery detection device with the size of the battery to be tested, thereby improving the accuracy and efficiency of the detection.

[0023] The third aspect of the present application provides a battery defect detection device, which includes: an acquisition module, which is configured and used to acquire the width of the first pole piece and the width of the second pole piece in the battery to be tested along the direction parallel to the battery axis; a first determination module, which is configured to determine the first misalignment amount of the first pole piece and the adjacent second pole piece at the first end along the direction parallel to the battery axis; a second determination module, which is configured to determine the second misalignment amount of the first pole piece and the adjacent second pole piece at the second end according to the width of the first pole piece, the width of the second pole piece and the first misalignment amount; a determination module, which is configured to determine the detection result of the battery to be tested according to the first misalignment amount and the second misalignment amount. The first determination module of the defect detection device determines the first misalignment amount of the first pole piece and the second pole piece at the first end, and the second determination module determines the second misalignment amount of the first pole piece and the second pole piece at the second end, so as to solve the problem that the detection ray is difficult to distinguish the edge position of the first pole piece and the second pole piece at the second end, and improve the defect detection efficiency of the battery.

[0024] An embodiment of a fourth aspect of the present application provides a method for producing a battery, the method comprising: using any of the above-mentioned battery defect detection methods to detect a battery to be tested to determine a detection result of the battery to be tested.

[0025] An embodiment of the fifth aspect of the present application provides an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the battery defect detection method of the above-mentioned embodiment.

[0026] An embodiment of the sixth aspect of the present application provides a battery production device, including the above-mentioned battery defect detection device or electronic device.

[0027] An embodiment of the seventh aspect of the present application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the battery defect detection method or battery production method of the above-mentioned embodiment.

[0028] An embodiment of the eighth aspect of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the battery defect detection method or battery production method of the above-mentioned embodiment.

[0029] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0031] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0032] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0033] Figure 3 A cross-sectional view of a winding electrode sheet of a battery to be tested provided in some embodiments of the present application;

[0034] Figure 4 A cross-sectional view of a battery to be tested provided in some embodiments of the present application;

[0035] Figure 5 A flowchart of a battery defect detection method provided in some embodiments of the present application;

[0036] Figure 6A detection image of battery defect detection provided by some embodiments of the present application;

[0037] Figure 7 for Figure 6 A local enlarged schematic diagram of the middle A;

[0038] Figure 8 A flowchart of a battery defect detection method according to some other embodiments of the present application;

[0039] Fig. 9 A flowchart of a battery defect detection method according to some embodiments of the present application;

[0040] Fig.10 A schematic diagram of the structure of a battery defect detection device according to some embodiments of the present application;

[0041] Fig.11 A structural block diagram of a battery defect detection device provided in some other embodiments of the present application;

[0042] Fig.12 This is a flowchart of the steps of a battery defect detection method according to some embodiments of the present application.

[0043] Description of reference numerals:

[0044] 1000. Vehicles;

[0045] 100, battery, 200, controller, 300, motor;

[0046] 10. Box body, 11. First part, 12. Second part; 20. Battery cell,

[0047] 30. Battery to be tested, 31. First pole piece, 32. 32A, 32B. Second pole piece, 33. Battery axis, first end 34, second end 35;

[0048] 500. Battery defect detection method, 600, 700. Battery defect detection device;

[0049] 610, ray source, 611, detection ray, 620, detector, 630, defect detection component, 640, bearing component; 710, acquisition module; 720, first determination module; 730, second determination module; 740, judgment module. DETAILED DESCRIPTION

[0050] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0056] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0057] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0058] At present, as major automobile manufacturers and user groups pay more and more attention to the safety of electric vehicles, battery manufacturers have improved battery production efficiency while also conducting more stringent and comprehensive control over defective batteries that may be produced during the manufacturing process to reduce the risk of defective batteries entering the market. Among them, the distance between the cathode and cathode plates and the amount of misalignment of the cathode and cathode plates are important factors affecting the safety performance of batteries. Taking lithium-ion batteries as an example, during the charging and discharging process of lithium batteries, when the distance between the cathode and cathode plates is large, lithium ions cannot be fully embedded in the anode channel, resulting in the accumulation of some lithium ions and the occurrence of lithium precipitation problems, which poses a greater safety risk. It is necessary to ensure that the distance between the cathode and cathode plates is not too large. During the charging and discharging process of lithium batteries, lithium ions will repeatedly deintercalate between the cathode and cathode plates, but when lithium ions are removed from the cathode but there is not enough anode channel to embed, it is easy to cause lithium ion accumulation and lithium precipitation, causing certain product safety risks. It is necessary to ensure that the cathode plate is within the coating range of the anode as a whole, that is, the misalignment of the cathode and cathode plates is greater than 0.

[0059] In the related art, the defect detection system of the battery often detects the defects of the electrode assembly in the battery by CCD photography or irradiation. CCD photography mainly detects the defects of the electrode assembly by taking pictures and obtaining images during the electrode winding process, and cannot detect the distance between the electrode pieces after winding. The electrode assembly after winding needs to go through the processes of ear shaping, shelling, welding, liquid injection, and formation before the battery cell can be obtained. During these processes, the misalignment state of the positive and negative electrodes of the battery and the distance between the positive and negative electrodes may also change, which is not applicable to the process after winding is completed. X-ray detection needs to be aimed at one end of the battery ear and the other end opposite to the ear to detect the misalignment of the electrode piece and the distance between the positive and negative electrodes respectively. However, for some battery types, such as cylindrical batteries, which are generally designed with full-ear tabs, and the ears are located on the positive and negative sides respectively, the carbon powder on the surface of the anode sheet absorbs radiation weakly, making the change in the imaging characteristics of the anode sheet coating and the anode sheet substrate imaging unclear, and it is difficult to distinguish the coating edge. This makes it difficult for X-rays to distinguish the edge position of the anode sheet on the negative electrode side, and unable to detect the misalignment of the positive and negative electrodes on the negative electrode side, and these changes are difficult to detect after entering the shell.

[0060] Based on the above problems, this application proposes a battery defect detection method, which obtains the width of the first pole piece and the second pole piece in the battery to be tested, detects the first misalignment of the first pole piece and the second pole piece at one end of the battery to be tested, and calculates the second misalignment of the first pole piece and the second pole piece at the other end through an algorithm, so as to judge whether the misalignment of the pole piece inside the battery to be tested meets the quality requirements. The battery detection method does not need to detect both ends of the battery to be tested. On the one hand, it shortens the detection time, and on the other hand, it can alleviate the distortion of the detection result caused by the difficulty in distinguishing the edge position of the pole piece in the detection image at one end, thereby improving the accuracy of battery defects.

[0061] The battery defect detection method and detection device disclosed in the embodiments of the present application can effectively detect the defects of the battery (the misalignment state of the anode and cathode plates and the distance between the anode and cathode plates) after processes such as tab shaping, shelling, welding, liquid injection, and formation, and can fully meet the real-time full inspection of the production line, reduce the outflow of risky products, and improve the reliability and scope of application of the battery.

[0062] The battery defect detection method and detection device, equipment, medium, and product disclosed in the embodiments of the present application can be applicable to but not limited to cylindrical batteries, soft-pack batteries, square-shell batteries, wound batteries, etc. It can detect internal defects of bare cells, and can also detect defects of cells after processes such as tab shaping, shelling, welding, liquid injection, and formation. It can be detected offline or monitored online, meeting the real-time full inspection of battery production lines, reducing the outflow of risky products, and improving the reliability and application scope of batteries.

[0063] The battery cells disclosed in the embodiments of the present application can be used in various electrical devices, or form the power supply system of the electrical devices. The electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, the electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and the spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0064] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0065] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0066] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0067] Please refer to Figure 2 , Figure 2 An exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a box 10 and a battery cell 20, and the battery cell 20 is contained in the box 10. Among them, the box 10 is used to provide a storage space for the battery cell 20, and the box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20. The second part 12 may be a hollow structure with one end open, the first part 11 may be a plate-like structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0068] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0069] Each battery cell 20 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0070] Figure 3 is a schematic diagram of the structure of a battery cell to be tested in some embodiments of the present application, Figure 4 This is a cross-sectional view of a winding electrode sheet of a battery 30 to be tested in some embodiments of the present application. Figure 5 This is a flow chart of a battery defect detection method according to some embodiments of the present application. Figure 6 The detection image of battery defect detection in some embodiments of the present application is as follows: Figure 7 for Figure 6 A local enlarged schematic diagram of point A in the middle.

[0071] like Figure 3 and Figure 4 As shown, the battery 30 to be tested may be the battery cell 20 of the above-mentioned embodiment, such as a cylindrical battery. The battery 30 to be tested includes a first pole piece 31 and a second pole piece 32 stacked and wound around a battery axis 33. The battery 30 to be tested includes a first end 34 and a second end 35 arranged opposite to each other along the battery axis 33. The first end 34 of the battery 30 to be tested may be a positive terminal, and the second end 35 of the battery 30 to be tested may be a negative terminal. The first pole piece 31 and the second pole piece 32 are arranged in a stacked and wound shape around the battery axis 33. A diaphragm may be arranged between the first pole piece 31 and the second pole piece 32. In one example, the first pole piece 31 is a cathode piece, and the second pole piece 32 is an anode piece. The first pole piece 31, the second pole piece 32 and the diaphragm are wound in groups from the innermost circle (the first circle) to the outermost circle (the nth circle).

[0072] like Figure 5 As shown, the embodiment of the present application provides a battery defect detection method 500, and the method 500 includes:

[0073] S510: Obtaining the width of the first pole piece and the width of the second pole piece of the battery 30 to be tested along a direction parallel to the battery axis 33;

[0074] S520: determining a first misalignment amount between the first pole piece 31 and the adjacent second pole piece 32 at the first end 34; the first misalignment amount is a distance between an end point of the first pole piece at the first end and an end point of the adjacent second pole piece at the first end along a direction parallel to the battery axis;

[0075] S530: determining a second misalignment amount between the first pole piece and the adjacent second pole piece at the second end according to the width of the first pole piece, the width of the second pole piece, and the first misalignment amount; the second misalignment amount is a distance between an end point of the first pole piece at the second end and an end point of the adjacent second pole piece at the second end along a direction parallel to the battery axis;

[0076] S540: Determine the test result of the battery 30 to be tested according to the first misalignment amount and the second misalignment amount.

[0077] The width X of the first pole piece 31 refers to the width dimension of the first pole piece 31 in a direction parallel to the battery axis 33, and the width Y of the second pole piece 32 refers to the width dimension of the second pole piece 32 in a direction parallel to the battery axis 33. This width can be obtained by direct measurement, such as by X-ray detection, or by detection and acquisition during the pole piece winding process, and then the data is stored in a memory, and obtained by reading or calling the stored data. In some examples, during the process of winding the first pole piece 31 and the second pole piece 32 to form the electrode assembly of the battery 30 to be tested, one or more images containing the first pole piece 31 and / or the second pole piece 32 are obtained by taking a CCD camera, and the images are identified to obtain the width X of the first pole piece 31 and the width Y of the second pole piece 32, and then the data is saved in the memory, and can be directly called when needed later.

[0078] In step S520, the first end 34 of the battery 30 to be tested can be tested by non-destructive testing to determine the first misalignment amount. In one example, an X-ray detection is performed on the first end 34 of the battery 30 to be tested to obtain an image of the first end 34 of the battery 30 to be tested, and the image is recognized to obtain position information of the first pole piece 31 and the second pole piece 32 in the image, and the first misalignment amount M between the first pole piece 31 and the adjacent second pole piece 32 at the first end 34 is calculated based on the position information, wherein the first misalignment amount M is the distance between the endpoint of the first pole piece 31 at the first end 34 and the endpoint of the adjacent second pole piece 32 at the first end 34 along a direction parallel to the battery axis 33. It can be understood that for the first pole piece 31 located in the nth layer (n is a positive integer, and 1≤n), there are two adjacent second pole pieces 32. The first misalignment amount M in this embodiment can be the misalignment amount between the first pole piece 31 and any adjacent second pole piece 32, or it can be a value obtained after calculating and processing the two misalignment amounts between the first pole piece 31 and the two second pole pieces 32 at the first end 33. For example, the average of the two misalignment amounts can be taken as the first misalignment amount M.

[0079] It should be noted that the above steps S510-540 are serial numbers set only for the convenience of description, and should not be regarded as limiting the order of the steps of the battery defect detection method 500. In some other examples, the implementation order of some steps can be exchanged.

[0080] The second misalignment N between the first pole piece 31 and the adjacent second pole piece 32 at the second end 35 is determined according to the width X of the first pole piece 31, the width Y of the second pole piece 32, and the first misalignment M. The second misalignment N is the distance between the end point of the first pole piece 31 at the second end 35 and the end point of the adjacent second pole piece 32 at the second end 35 in a direction parallel to the battery axis 33. In an ideal state, the difference between the width X of the first pole piece 31 and the width Y of the second pole piece 32 is equal to the sum of the first misalignment M and the second misalignment N at the first end, that is, XYM=N is satisfied. When the width X of the first pole piece 31, the width Y of the second pole piece 32, and the first misalignment M are determined, the second misalignment N can be calculated by the above formula.

[0081] Determining the test result of the battery 30 to be tested according to the first misalignment amount M and the second misalignment amount N refers to judging the first misalignment amount M and the second misalignment amount N according to preset judgment conditions, respectively, and outputting the test result corresponding to the judgment result according to the judgment result. In some examples, the test result of the battery 30 to be tested is NG or OK. For example, if the first misalignment amount M and the second misalignment amount N both meet the corresponding judgment conditions, the output test result is OK. If at least one of the first misalignment amount M and the second misalignment amount N does not meet the corresponding judgment conditions, the battery 30 to be tested is judged to be unqualified. Generally, a test result of NG indicates that the product is unqualified, and a test result of OK indicates that the product is qualified.

[0082] In the defect detection method of the battery 30 to be tested in the embodiment of the present application, by determining the first misalignment M between the first pole piece 31 and the adjacent second pole piece 32 at the first end 34, the second misalignment N between the first pole piece 31 and the adjacent second pole piece 32 at the second end 35 is determined according to the width X of the first pole piece 31, the width Y of the second pole piece 32 and the first misalignment M. In this way, there is no need to detect both ends of the electrode assembly at the same time, which can improve the detection efficiency.

[0083] And because the misalignment of the anode and cathode plates at the other end is calculated by an algorithm, the problem that it is difficult for X-rays to distinguish the edge position of the plates in some cases is alleviated to a certain extent. For example, for a cylindrical battery cell with a full-ear design, since the ears are located on the positive and negative sides respectively, the carbon powder on the surface of the anode plate absorbs the rays weakly, so that the change in the anode plate coating imaging and the anode plate substrate imaging characteristics is not obvious. During detection, it is difficult for X-rays to distinguish the first pole plate 31 located at the negative end. The method proposed in this embodiment of detecting the positive end and determining the second misalignment amount N by numerical calculation can effectively avoid the above defects and is conducive to improving the accuracy of the detection results.

[0084] See also Figure 8 , Figure 8 Flowchart of a battery defect detection method according to some other embodiments of the present application.

[0085] According to some embodiments of the present application, step S520 includes:

[0086] Step S521, obtaining a detection image including the first end 34 of the battery 30 to be tested;

[0087] Step S522, identifying the detection image to respectively obtain the first endpoint of the nth circle of the first pole piece at the first end, and the two second endpoints of the two second pole pieces adjacent to the nth circle of the first pole piece at the first end;

[0088] Step S523, determining a first misalignment amount corresponding to the nth circle of the first pole piece according to the positions of the first endpoint and the two second endpoints in the detection image;

[0089] Wherein, n is a positive integer greater than 0.

[0090] In step S521, a detection image including the first end 34 of the battery 30 to be tested can be obtained by an X-ray detection device. For example, the X-ray detection device includes a ray source and a detector that are relatively arranged. The ray source detects the battery 30 to be tested located on the detection station, and the detector obtains the detection ray that penetrates the battery 30 to be tested to form a detection image including the first end 34 of the battery 30 to be tested. The detection image can be a grayscale image.

[0091] In step S522, a preset image recognition algorithm may be used to recognize the detection image to determine the position information of the pole piece in the first end 34 of the battery 30 to be tested. In some examples, the X-ray detection device may further include a processor, which pre-processes the detection image acquired by the detector, and recognizes and grasps the image in combination with the trained algorithm grasping point model, and grasps the vertices of all the first pole pieces 31 and the vertices of the second pole pieces in the image, and calculates the misalignment of adjacent first pole pieces 31 and second pole pieces 32.

[0092] It can be understood that the electrode assembly in the battery 30 to be tested is formed by stacking and winding the first electrode sheet 31 and the second electrode sheet 32 ​​into multiple layers. Figure 6 and Figure 7 As shown, the vertex of the first electrode piece 31 located at the nth circle of the electrode assembly of the battery to be tested is the first endpoint P1, and the two second electrode pieces 32 adjacent to the first electrode piece are the second electrode piece 32A located at the nth circle and the second electrode piece 32B located at the n+1th circle, and the corresponding vertices are the second endpoints P2 and P3, respectively.

[0093] In step S523, the first misalignment amount corresponding to the nth circle of the first pole piece 31 may be determined according to the positions of the first endpoint P1 and the two second endpoints P2 and P3 in the detection image. Figure 7 As shown, the distance between the first end point P1 of the first pole piece 31 and the second end point P2 of the second pole piece 32A along the direction of the battery axis 33 is the first sub-misalignment amount M n1 The distance between the first end point P1 of the first pole piece 31 and the second end point P3 of the second pole piece 32B along the direction of the battery axis 33 is the second sub-misalignment amount M n2 , according to the first sub-dislocation M n1 and the second sub-dislocation M n2 The first misalignment amount corresponding to the n-th circle of the first pole piece 31 is determined. For example, one of them or a value obtained by performing data processing on both of them is taken as the first misalignment amount.

[0094] By detecting the first end 34 of the battery 30 to be tested and identifying the detection image, the first misalignment amount between the first pole piece 31 and the second pole piece 32 of each circle layer at the first end 34 can be determined, thereby realizing the detection of the misalignment amount between the pole pieces of each circle layer and improving the accuracy of the detection.

[0095] According to some embodiments of the present application, S523 includes:

[0096] According to the positions of the first endpoint P1 and the two second endpoints P2 and P3 in the detection image, determine the first sub-misalignment amount Mn1 and the second sub-misalignment amount Mn2 of the nth circle of the first pole piece 31 between the first end 34 and the two adjacent second pole pieces 32 along the direction parallel to the battery axis 33;

[0097] The larger one between the first sub-misalignment amount Mn1 and the second sub-misalignment amount Mn2 is determined as the first misalignment amount corresponding to the n-th circle of the first pole piece 31 .

[0098] like Figure 7 As shown, the distance between the first end point P1 of the first pole piece 31 and the second end point P2 of the second pole piece 32A along the direction of the battery axis 33 is the first sub-misalignment amount M n1 The distance between the first end point P1 of the first pole piece 31 and the second end point P3 of the second pole piece 32B along the direction of the battery axis 33 is the second sub-misalignment amount M n2 , the first sub-dislocation M n1 and the second sub-dislocation M n2 The larger one of the two is determined as the first misalignment corresponding to the nth circle of the first pole piece 31. According to the relationship between the first misalignment and the second misalignment, when the first misalignment is large, it means that the second misalignment at the second end is small, and the misalignment between adjacent pole pieces may be in a more dangerous situation.

[0099] In order to better understand the determination of the larger one of the first sub-misalignment amount Mn1 and the second sub-misalignment amount Mn2 as the first misalignment amount n corresponding to the nth circle of the first pole piece, a specific example is given below for explanation.

[0100] like Figure 7 As shown, the pixel size of the detector is 100um, the magnification is 10 times, the single pixel accuracy is 100um / 10=10um, the misalignment between the first end point P1 of the first pole piece 31 and the second end point P2 of the second pole piece 32A is 70 pixel points, then the first sub-misalignment M between the first pole piece 31 and the second pole piece 32A is n1 =70×10um=700um, the offset between the first pole piece 31 and the second pole piece 32B is 10 pixels, then the second sub-offset M n2 =58×10um=580um, at this time the first misalignment M n=max{M 11 , M 12}=700um.

[0101] By setting the nth circle first sub-displacement amount M of the first pole piece 31 n1 and the second sub-dislocation M n2 The larger one is determined as the first misalignment amount M corresponding to the nth circle of the first pole piece 31, which can improve the safety margin of judging the pole piece misalignment defect, reduce the probability of misjudgment to a certain extent, and improve the reliability of defect detection of the battery 30 to be tested.

[0102] According to some embodiments of the present application, step S510 includes:

[0103] Obtain at least one first preset position A on the first pole piece 31 n Corresponding to at least one first width in a direction parallel to the battery axis 33; at least one first preset position A n The nth circle located at the first pole piece 31;

[0104] Obtain the second pole piece 32 and at least one second preset position B n Correspondingly, at least one second width Y along a direction parallel to the battery axis 33; at least one second preset position B n The nth circle located at the second pole piece 32;

[0105] And wherein step S530 includes:

[0106] The second misalignment amount corresponding to the nth turn of the first pole piece is determined according to at least one first width X, at least one second width Y, and the first misalignment amount corresponding to the nth turn of the first pole piece.

[0107] The electrode assembly in the battery 30 to be tested is a winding body with n layers formed by winding a first electrode sheet 31 and a second electrode sheet 32. Considering the limited accuracy of the electrode sheet processing process and the electrode sheet winding process, the width values ​​corresponding to different positions will inevitably fluctuate, that is, they will fluctuate around the design width.

[0108] First preset position A n It can be located at any position on the nth circle of the first pole piece 31, and the first width X is the first pole piece 31 at the first preset position A. n The width of the position along the direction parallel to the battery axis 33, the second preset position B n It can be located at any position on the nth circle of the second pole piece 32, and the second width Y is the width of the second pole piece 32 at the second preset position B. n The width along the direction parallel to the battery axis 33 is obtained at the position.

[0109] like Figure 3 and Figure 4 As shown, in some examples, the first preset position A n It can be located at the top of the nth circle of the first pole piece 31 at the first end 34. The second preset position A n It is the top of the nth circle of the second pole piece 32 located at the first end 34. It can be understood that any position on the nth circle of the first pole piece 31 along the width direction of the first pole piece can be set as the first preset position A. n When the first preset position A is set at the end face (top) position, the number of turns of the first pole piece 31 is conveniently matched with the width of the first pole piece 31, which is convenient for retrieving the width of the first pole piece 31 from other devices. Similarly, any position along the direction of the width of the second pole piece on the nth turn of the second pole piece 32 can be set as the second preset position B. When the second preset position B is set at the end face (top) position, the number of turns of the second pole piece 32 is conveniently matched with the width of the second pole piece 32, which is convenient for retrieving the width of the second pole piece 32 from other devices.

[0110] In some embodiments, the first preset position A n The number can be one or more, the second preset position B n The number can be one or more, so that with the first preset position A n The corresponding value of the first width X is also one or more, which is also related to the second preset position B n The corresponding value of the second width Y is also one or more. n and the second preset position B n The number of can be the same or different. Figure 4 As shown, the first preset position A n and the second preset position B n The number of them is 4, and the first preset position A n and the second preset position B n One-to-one correspondence setting, so that the first preset position A can be called n The corresponding four first widths X and the second preset position B n The corresponding four second widths Y are obtained, and the second misalignment amount N is calculated based on the four first widths X and the four second widths Y.

[0111] By obtaining the pole piece width corresponding to a preset position on any circle of the wound pole piece, the width value obtained in this way is more accurate, and the misalignment defect detection can be more effectively performed on the pole piece of the corresponding circle layer, so as to determine whether the misalignment amount of any circle layer inside the battery to be tested meets the corresponding quality requirements, thereby improving the accuracy of battery defect detection.

[0112] According to some embodiments of the present application, at least one first preset position A n The number is multiple, and / or at least one second preset position B n The number is multiple. Step S530 includes:

[0113] A plurality of second misalignment calculation values ​​are obtained by calculating at least one first width X, at least one second width Y, and a first misalignment M corresponding to the nth circle of the first pole piece 31.

[0114] The minimum value among the plurality of second misalignment amount calculation values ​​is determined as the second misalignment amount N corresponding to the n-th circle of the first pole piece 31 .

[0115] It can be understood that the first preset position A n The number of the first width X is directly related to the number of the second preset position B. n The number of is directly related to the number of values ​​of the second width Y. Any first width X and first width Y can be calculated to obtain a corresponding second misalignment calculation value, and finally the second misalignment N corresponding to the nth circle of the first pole piece 31 is determined according to multiple second misalignment calculation values.

[0116] In some examples, the first preset position A n The number and second preset position B n The number of is 2, at the 2 first preset positions A n Determine the two first widths (X n1 , X n2 ), 2 second widths (Y n1 , Y n2 ), according to the 2 first widths (X n1 , X n2 ), 2 second widths (Y n1 , Y n2 ) and the first misalignment amount M corresponding to the nth circle of the first pole piece 31 n Calculate and get 2 second misalignment calculation values ​​Nn1 = X n1 -Y n1 -Mn1, Nn2 = X n2 -Y n2 -Mn, and the smaller one of Nn2 and Nn1 is determined as the second misalignment amount Nn corresponding to the nth circle of the first pole piece, that is, Nn=min{Nn2, Nn1}.

[0117] By selecting the first preset position A n and / or at least one second preset position B nThe number of is multiple, so that multiple second misalignment calculation values ​​are obtained by calculation and the second misalignment is determined based on the multiple second misalignment calculation values. This can avoid the problem of large single-point calculation deviation leading to erroneous or distorted detection results, and can also take into account the fluctuation of the pole piece width value at different positions. The smallest second misalignment calculation value is selected as the second misalignment. In this way, the extreme situation where quality defects are most likely to occur is used as the situation for judging the misalignment defect. This can avoid misjudgment to a certain extent and improve the reliability of defect detection.

[0118] like Figure 4 As shown, according to some embodiments of the present application, at least one first preset position A n and at least one second preset position B n The number is equal and arranged one by one, at least one first preset position A n The line connecting any one of the above and the battery axis 33 is connected to the corresponding second preset position B n The projection of the line connecting the battery axis 33 onto the plane perpendicular to the battery axis 33 coincides.

[0119] At least one first preset position A n and at least one second preset position B n The numbers are equal and arranged one by one, and coincide with the projection of the line connecting the battery axis 33 on the plane perpendicular to the battery axis 33, so that the corresponding first width X and second width Y are also the width values ​​of adjacent positions. Using such a set of data to calculate the misalignment amount can more accurately reflect the misalignment of the battery pole piece at this position.

[0120] In some examples, the battery 30 to be tested is a cylindrical battery. At the first preset position A at the nth turn, n and the second preset position B n In the same radial direction (see Figure 4 The first width X and the second width Y respectively corresponding to the two are also the width values ​​corresponding to the positions where the adjacent pole pieces are in contact with each other.

[0121] By further defining the first preset position A n and the second preset position B n The positional relationship can make it possible to more accurately reflect the actual situation of the misalignment between adjacent pole pieces in the circle layer when calculating the misalignment amount, so that the detection result can more accurately reflect the defect state inside the battery to be tested, thereby improving the accuracy of detection.

[0122] According to some embodiments of the present application, step S540 further includes:

[0123] In response to either the first misalignment amount or the second misalignment amount being less than or equal to a first preset threshold, or either the first misalignment amount or the second misalignment amount being greater than or equal to a second preset threshold, the battery inspection result is determined to be unqualified; the first preset threshold is less than the second preset threshold.

[0124] Taking the charging and discharging process of lithium-ion batteries as an example, when the first misalignment and the second misalignment are large, it indicates that the distance between the cathode and cathode plates is large, and the lithium ions cannot be fully embedded in the anode channel, resulting in the accumulation of some lithium ions and the occurrence of lithium precipitation, which poses a greater safety risk. The upper limit values ​​of the first misalignment and the second misalignment are limited by the second preset threshold value to ensure that the distance between the cathode and cathode plates is not too large. During the charging and discharging process of lithium batteries, lithium ions will repeatedly deintercalate between the cathode and cathode plates. When the first misalignment and the second misalignment are small, it indicates that when lithium ions are deintercalated from the cathode but not embedded in enough anode channels, it is easy to cause lithium ion accumulation and lithium precipitation, which may cause certain product safety hazards. It is necessary to ensure that the cathode plate is within the coating range of the anode as a whole, and the lower limit values ​​of the first misalignment and the second misalignment are limited by the first preset threshold value.

[0125] It should be understood that the first preset threshold value and the second preset threshold value can be set and adjusted according to the specifications and parameters of the battery 30 to be tested.

[0126] It should be noted that, in the present embodiment, the first misalignment amount M of any circle of the first end 34 and the second misalignment amount N of the second end 35 of the battery 30 to be tested are required to be within an appropriate range, so that the misalignment amount of the anode and cathode plates of the battery 30 to be tested can be considered to meet the quality requirements, otherwise it will be deemed unqualified.

[0127] By setting the first preset threshold and the second preset threshold, the first misalignment amount and the second misalignment amount are limited, so that the detection result of the battery 30 to be tested can be directly determined according to the calculation result of the misalignment amount, thereby improving the detection efficiency and accuracy.

[0128] According to some embodiments of the present application, the value range of the first preset threshold is greater than or equal to 0.2 mm and less than or equal to 0.5 mm.

[0129] In the embodiment of the present application, if the first preset threshold is too large or too small, it will affect the reliability and safety of the battery 30 to be tested. Therefore, it is necessary to limit the value of the first preset threshold. For example, the first preset threshold can be 0.2mm, 0.3mm or 0.5mm.

[0130] By reasonably limiting the value range of the first preset threshold, the detection accuracy requirements and quality design requirements of the misalignment of the anode and cathode plates in the battery 30 to be tested can be taken into account, and the risk of false detection of battery detection leading to the outflow of defective batteries can be alleviated to a certain extent.

[0131] According to some embodiments of the present application, the ratio of the second preset threshold to the preset misalignment amount is greater than or equal to 0.95 and less than or equal to 1, and the preset misalignment amount is determined according to the width of the first pole piece and the width of the second pole piece.

[0132] The preset misalignment is a designed misalignment determined according to the width of the first pole piece and the width of the second pole piece. In some examples, the preset misalignment can be the difference between the width of the first pole piece and the width of the second pole piece, that is, the preset misalignment is the sum of the first misalignment and the second misalignment. The width of the first pole piece and the width of the second pole piece can be the designed widths of the two, that is, the theoretical width values, or can be the values ​​corresponding to the detected or called data or the values ​​obtained by further processing, such as taking multiple sets of data and calculating the average value.

[0133] The second preset threshold is a judgment threshold for limiting the upper limit of the first misalignment amount and the second misalignment amount. When either one exceeds the second preset threshold, it actually means that the misalignment amount at the other end is also very small, which may also cause safety hazards. The ratio of the second preset threshold to the preset misalignment amount can be 0.95, 0.98 or 1.

[0134] Here, the second preset threshold is taken based on the preset misalignment amount, which can be completely independent of the value of the first preset threshold, and then judge whether the first misalignment amount and the second misalignment amount meet the quality requirements from different angles, further avoiding misjudgment and missed judgment, and improving the reliability of the detection results of the battery 30 to be tested.

[0135] Fig. 9 Flowchart of a battery defect detection method according to some other embodiments of the present application. Fig. 9 As shown, according to some embodiments of the present application, the battery defect detection method 500 further includes:

[0136] Step S550: acquiring a detection image including the first end of the battery 30 to be tested and / or the second end of the battery 30 to be tested;

[0137] Step S560: Identify the detection image to obtain the position information of the first pole piece and the position information of the second pole piece;

[0138] Step S570: determining a gap value Gap between the first pole piece and the adjacent second pole piece according to the position information of the first pole piece and the position information of the second pole piece, wherein the gap value Gap is the minimum center distance between the first pole piece 31 and the adjacent second pole piece 32 along a direction perpendicular to the battery axis 33;

[0139] Step S580: determining the test result of the battery to be tested according to the gap value.

[0140] In this embodiment, the detection image of the first end and / or the second end may be obtained by an image acquisition device, and the image acquisition device may be a ray detection device, and the image is obtained by the ray penetrating the first end and / or the second end of the battery 30 to be tested, and the ray may be an X-ray. The detection image may be a plurality of images respectively including the first end and the second end of the battery 30 to be tested, or an image simultaneously including the first end and the second end, so that the structural information inside the battery 30 to be tested can be obtained by identifying the detection image. In some examples, an X-ray detection device may be used to detect the first end and the second end of the battery 30 to be tested respectively, for example, the detection ray is emitted by the ray source of the X-ray detection device, the detection ray penetrates the battery 30 to be tested, and the detector receives the detection ray to form a detection image including the first end 34 of the battery 30 to be tested, and / or the second end 35 of the battery. The detection device first detects the first end 34 of the battery 30 to be tested to form a detection image of the first end 34 of the battery 30 to be tested, and then detects the second end 35 of the battery 30 to be tested to form a detection image of the second end 35 of the battery 30 to be tested. There is no order relationship between obtaining the detection image of the first end 34 of the battery 30 to be tested and obtaining the detection image of the second end 35 of the battery. For example, the detection device first detects the second end 35 of the battery 30 to be tested to form a detection image of the second end 35 of the battery 30 to be tested, and then detects the first end 34 of the battery 30 to be tested to form a detection image of the first end 34 of the battery 30 to be tested.

[0141] In step S560, the detection image includes a plurality of first pole pieces 31 and second pole pieces 32 arranged at intervals, and after identifying the detection image, position information of the plurality of first pole pieces 31 and position information of the second pole pieces 32 are obtained. It should be understood that the position information of the first pole piece 31 and the position information of the second pole piece 32 include but are not limited to the contours and vertex positions of the first pole piece 31 and the second pole piece 32, and the spacing between adjacent first pole pieces 31 and the second pole piece 32.

[0142] The gap value Gap between the first pole piece 31 and the adjacent second pole piece 32 is determined based on the position information of the first pole piece 31 and the position information of the second pole piece 32. The gap value Gap is the minimum center distance between the first pole piece 31 and the adjacent second pole piece 32 along the direction perpendicular to the battery axis 33. For example, Figure 7 As shown, the gap value Gap between the first pole piece 31 and the adjacent second pole piece 32B.

[0143] The detection result of the battery 30 to be tested is determined according to the gap value Gap. For example, if a plurality of gap values ​​Gap obtained from the detection image all meet the requirements of preset values, the detection result of the battery 30 to be tested is determined to be qualified.

[0144] It should be noted that the above steps S550-S580 are only serial numbers set for the convenience of description, and should not be regarded as limiting the order of the steps of the battery defect detection method 500. In particular, steps S550-S580 and steps S510-S540 can be completely independent steps, or can be part of a complete detection process. In some other examples, the order of implementation of some steps can be exchanged or even combined, for example, step S510 can be the same execution step as step S550, or step S510 can be a part of step S550.

[0145] The gap value Gap between the first pole piece 31 and the adjacent second pole piece 32 is determined by the position information of the first pole piece 31 and the second pole piece 32, and whether the battery 30 to be tested is qualified is determined according to the test result, thereby achieving more comprehensive defect detection of the battery 30 to be tested.

[0146] According to some embodiments of the present application, step S570 includes:

[0147] Determine the position information of the center vertical line of the first pole piece 31 and the position information of the center vertical line of the second pole piece 32 according to the position information of the first pole piece 31 and the position information of the second pole piece 32;

[0148] The minimum distance between the center vertical line of the first pole piece 31 and the center vertical line of the adjacent second pole piece 32 along the direction perpendicular to the battery axis 33 is calculated and used as the gap value Gap.

[0149] like Figure 7 As shown, in the detection image, the first pole piece 31 and the second pole piece 32 occupy certain pixel positions along the direction perpendicular to the battery axis 33. By identifying the pixel positions of the first pole piece 31 and the second pole piece 32, the contours of the first pole piece 31 and the second pole piece 32 are determined. The first pole piece 31 and the adjacent second pole piece 32 are roughly in the shape of vertical strips. In order to facilitate the determination of the gap value between the first pole piece 31 and the adjacent second pole piece 32, when performing image recognition, the pixel position of the central vertical line of the first pole piece 31 can be determined according to the contour of the first pole piece 31, and the pixel position of the central vertical line of the second pole piece 32 can be determined according to the contour of the second pole piece 32. According to the pixel positions of the two central vertical lines and the pixel distance along the direction perpendicular to the battery axis 33, the actual gap value is calculated according to the resolution of the detector. In this embodiment, the direction perpendicular to the battery axis 33 is actually the direction perpendicular to the approximate extension direction of the battery pole piece, or in other words, along the thickness direction of the battery pole piece.

[0150] Considering that the positions and thicknesses of the first pole piece 31 and the second pole piece 32 may be different, the central vertical line of the first pole piece 31 and the central vertical line of the second pole piece 32 may not be straight lines, and the two may not be parallel, and the pixel distance between the two central vertical lines is actually variable, that is, the pixel distance values ​​corresponding to different positions may be different. In this embodiment, the minimum value of the distance between the two central vertical lines is taken as the gap value Gap.

[0151] Since the gap value Gap is obtained from the center vertical line of the first pole piece 31 and the center vertical line of the adjacent second pole piece 32, it is possible to avoid excessive gap value errors caused by inaccurate local edge position identification. At the same time, the minimum distance between the center vertical line of the first pole piece 31 and the center vertical line of the adjacent second pole piece 32 in a direction perpendicular to the battery axis 33 is used as the gap value Gap, which can more reliably judge the quality of the battery 30 to be tested and improve the reliability of the detection results of the battery 30 to be tested.

[0152] According to some embodiments of the present application, step S580 includes: in response to the gap value being greater than a third preset threshold or less than a fourth preset threshold, determining the test result of the battery 30 to be unqualified. The third preset threshold is greater than the fourth preset threshold.

[0153] The gap value Gap is determined based on the center vertical line of the first pole piece 31 and the center vertical line of the adjacent second pole piece 32, and the minimum distance between the center vertical line of the first pole piece 31 and the center vertical line of the adjacent second pole piece 32 in the direction perpendicular to the battery axis 33 is used as the gap value Gap. The gap value Gap is compared with the third preset threshold and the fourth preset threshold to determine whether the gap value is within a reasonable range. When the gap value Gap is greater than the third preset threshold or less than the fourth preset threshold, it is considered that the pole piece gap exceeds the normal range, and the test result of the battery 30 to be tested is determined to be unqualified.

[0154] It should be noted that the third preset threshold and the fourth preset threshold can be selected or adjusted according to the size and specification of the battery 30 to be tested, such as the size and specification of the first electrode piece 31 and the second electrode piece 32 .

[0155] By limiting the third preset threshold and the fourth preset threshold for comparison with the gap value Gap, it is more conducive to intuitively and quantitatively evaluating whether the pole piece of the battery 30 to be tested has defects.

[0156] According to some embodiments of the present application, the battery defect detection method 500 further includes:

[0157] Step S590: In response to the test result of the battery to be tested being unqualified, the battery to be tested is discarded or retested.

[0158] The test result of the battery 30 to be tested can be made based on the fact that the first misalignment amount and the second misalignment amount do not meet the preset judgment condition, or can be made based on the fact that the gap value does not meet the preset judgment condition, or can be made based on the judgment results of both at the same time. Removing the battery to be tested means removing the battery determined to be unqualified from the normal transmission path on the production line, which can be moved or transmitted to a specified location. Additional detection devices or detection processes can also be set up to re-test the unqualified batteries to verify the accuracy of the test results.

[0159] By rejecting or re-inspecting the batteries 30 with unqualified test results, the outflow of problematic batteries is effectively avoided, and the reliability of the outflow batteries is improved.

[0160] Fig.10 Schematic diagram of the structure of a battery defect detection device 600 according to some embodiments of the present application. Fig.10 As shown, an embodiment of the present application provides a battery defect detection device 600, which includes a ray source 610, a detector 620 and a defect detection component 630, wherein the ray source 100 is used to emit a detection ray 621 to the battery 30 to be tested, the detector 620 is used to receive the detection ray 621 emitted by the ray source 610 and penetrating the battery 30 to be tested, the defect detection component 630 is connected to the detector 620, and the defect detection component 630 is used to execute the battery defect detection method 500 in any of the above embodiments.

[0161] like Fig.10 As shown, the battery 100 to be tested is placed on the upper surface of the carrying assembly 640 , and is moved into and out of the detection area between the radiation source 610 and the detector 620 by a driving mechanism (not shown in the figure).

[0162] The ray source 610 is a device for emitting detection rays, mainly including a ray tube and a corresponding power supply. The detection rays 611 can be X-rays or other rays. The ray tube can emit corresponding detection rays, such as an X-ray tube or a gamma-ray tube. The ray source 610 can be open (open tube) or closed (closed tube). In one example, the ray source 610 is an X-ray source, and the detection rays 611 emitted by it are X-rays. The detector 620 is a two-dimensional flat-panel detector, such as an indirect flat-panel detector.

[0163] The defect detection component 630 may be a processor or a computer device that executes a preset program. The defect detection component 630 is connected to the detector 620 by signal, recognizes the detection image collected by the detector 620, and determines and outputs the detection result of the battery to be tested 30. The support component 640 may be any support structure that can fix the battery to be tested in a supporting or clamping manner, such as a tray, a clamp, etc.

[0164] The defect detection component 630 of the battery defect detection device 600 can execute the detection method in the above embodiment, thereby improving the detection efficiency of the battery to be tested.

[0165] According to some embodiments of the present application, the rated voltage V of the ray source 610 satisfies: 130 kilovolts (kV) ≤ V ≤ 150 kilovolts (kV), and / or the rated current I of the ray source 610 satisfies: I ≤ 500 microamperes (uA).

[0166] The maximum photon energy of the ray emitted by the ray source 610 is equal to the energy obtained by the incident electron in the accelerating electric field of the ray tube - the electron charge multiplied by the accelerating electric field. The accelerating electric field is the magnitude of the tube voltage, that is, the magnitude of the rated voltage V of the ray source 610. The higher the rated voltage V, the higher the energy of the ray generated, the shorter the wavelength, and the stronger the ability to penetrate matter.

[0167] The larger the rated current I of the ray source 610, the more high-speed electrons bombard the target per unit time, and the more rays emitted by the ray source 610, which is equivalent to an increase in the dose of rays in a certain area, and an increase in the brightness of the corresponding image. However, if the rated voltage or rated current of the ray source 610 is too large, the focal size of the ray source 610 will be too large, thereby reducing the spatial resolution of the flat panel detector 430, which is not conducive to subsequent image recognition and defect judgment.

[0168] By way of example, the rated voltage of the radiation source 100 is 140 kV.

[0169] For example, the rated current of the radiation source 100 is 300 microamperes (uA) ≤ I ≤ 500 microamperes (uA), for example, 400 microamperes.

[0170] By limiting the rated voltage V and rated current I of the radiation source 610, it is possible to provide a detection radiation dose that meets the requirements while taking into account the stability and reliability of the radiation source 610. At the same time, the radiation source 610 and the detector 620 can cooperate with each other to meet the requirements for detection accuracy of the battery 30 to be tested, thereby improving the efficiency and accuracy of detection.

[0171] According to some embodiments of the present application, the maximum size d (not shown in the figure) of the focus of the ray source 610 satisfies: 0<d≤80um.

[0172] Taking the ray source 100 that emits X-rays as an example, X-rays are generated by high-speed electrons interacting with matter. In an X-ray tube, electrons emitted from the cathode are accelerated by the electric field between the cathode and the anode, and then bombard the X-ray tube target. The electrons emitted by the cathode will be focused to a point on the target, which is called the focus of the X-rays. In some examples, the focus of the ray source 610 can be circular or elliptical. The focus size of the ray source 610 refers to the size of the focus along a direction parallel to the plane where the focus is located. Under the same conditions, the smaller the focus, the higher the resolution and the better the imaging quality. Common methods for measuring the focus size of the ray source 610 are divided into direct method and indirect method. The direct method refers to the direct observation of the focus shape and size, such as the pinhole method; the indirect method is to calculate the focus size by observing the point spread function or line spread function caused by the focus size, including the edge method, the slit method and the ball target method.

[0173] The focal diameter size is directly related to the image resolution of the battery detection device. Specifically limiting the focal diameter size can better match the detection accuracy of the battery detection device with the size of the battery to be tested, thereby improving the detection accuracy and detection efficiency.

[0174] Fig.11 This is a structural block diagram of a battery defect detection device in some other embodiments of the present application, such as Fig.11 As shown, an embodiment of the present application provides a battery defect detection device 700, which includes an acquisition module 710, a first determination module 720, a second determination module 730 and a judgment module 740, wherein the acquisition module 710 is configured and used to obtain the width of the first pole piece 31 and the width of the second pole piece 32 in the battery 30 to be tested along a direction parallel to the battery axis 33, the first determination module 720 is configured to determine the first misalignment amount of the first pole piece 31 and the adjacent second pole piece 32 at the first end 34 along the direction parallel to the battery axis 33, the second determination module 730 is configured to determine the second misalignment amount of the first pole piece 31 and the adjacent second pole piece 32 at the second end 35 according to the width of the first pole piece 31, the width of the second pole piece 32 and the first misalignment amount, and the judgment module 740 is configured to determine the battery detection result according to the first misalignment amount and the second misalignment amount.

[0175] The battery 30 to be tested needs to go through multiple processes during the production process, and the corresponding equipment often collects and obtains parameter information of the battery 30 to be tested, and obtains the width of the first electrode piece 31 and the width of the second electrode piece 32 in the battery 30 to be tested along the direction parallel to the battery axis 33 through the acquisition module 710.

[0176] The acquisition module 710 may be a measuring device that can directly measure the width of the first pole piece 31 and the width of the second pole piece 32 , or may be obtained by reading corresponding data pre-stored in a memory.

[0177] The first determination module 720 may include a detection unit and a calculation unit. The detection unit is used to detect the detection image of the first pole piece 31 and the adjacent second pole piece 32 at the first end 34. The calculation unit can identify and calculate the size of the first misalignment according to the detection image.

[0178] The second determination module 730 may calculate the corresponding second misalignment amount according to the width of the first pole piece 31 , the width of the second pole piece 32 , and the first misalignment amount.

[0179] The determination module 740 can pre-set corresponding determination conditions, and determine whether the battery 30 to be tested meets the corresponding determination conditions according to the calculation results of the first determination module 720 and the second determination module 730, and output the corresponding test results. The output test results include NG and OK, where NG means that the battery 30 to be tested is unqualified, and OK means that the battery 30 to be tested is qualified.

[0180] By detecting the first misalignment amount of the first end 34 of the battery to be tested 30 and calculating the second misalignment amount of the second end 35 based on the first misalignment amount, the detection time can be shortened and the detection effect of the battery to be tested 30 can be improved.

[0181] Some embodiments of the present application provide a battery production method, which includes: using any of the above-mentioned battery defect detection methods to detect a battery to be tested to determine a detection result of the battery to be tested.

[0182] Some embodiments of the present application provide an electronic device, comprising at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the battery defect detection method in the above-mentioned embodiment.

[0183] Some embodiments of the present application provide a battery production device, including the above-mentioned electronic device.

[0184] Some embodiments of the present application provide a computer-readable storage medium storing a computer program, which implements the battery defect detection method in the above embodiment when executed by a processor.

[0185] Some embodiments of the present application provide a computer program product, including a computer program, which, when executed by a processor, implements the battery defect detection method in the above-mentioned embodiment.

[0186] Fig.12This is a flowchart of the steps of the battery defect detection method of some embodiments of the present application. In order to better understand the battery defect detection method of the embodiment of the present application, the specific process of the battery defect detection method is described below. Figure 3-Figure 12 As shown, the specific detection steps are as follows:

[0187] S10, cylindrical batteries enter the inspection station;

[0188] The battery 30 to be tested is a cylindrical battery, the first end 33 is the positive terminal of the battery 30 to be tested, the second end is the negative terminal of the battery 30 to be tested, the first pole piece 31 is the cathode piece, and the second pole piece 32 is the anode piece. The detection station is located between the ray source 610 and the detector 620. The ray source 610 is a micro-focus X-ray source, and the detector 620 is an amorphous silicon flat panel detector. The cylindrical battery on the logistics line is clamped by the front-end manipulator and placed on the detection line pull belt and moved into the detection station.

[0189] S11. Align the micro-focus X-ray to the positive terminal of the cylindrical battery.

[0190] The ray source 610 is adjusted so that the optical path of the detection ray 611 is directly facing the first end of the cylindrical battery.

[0191] S12, turn on the X-ray, and the detector receives the image.

[0192] The ray source 610 emits X-rays, which penetrate the first end 34 of the battery 30 to be tested and are received by the detector 620. The detector 620 receives the light signal and converts it into an electrical signal internally and transmits it to the processor, outputs a grayscale image and saves it as a detection image.

[0193] S13, automatic identification algorithm model.

[0194] Specifically, it includes: image sample data set, image preprocessing and image data annotation, neural network model training, and automatic recognition algorithm model. Among them, the image sample data set can collect multiple sample images, and through sample image preprocessing and data annotation, and combined with the neural network model to train the algorithm, the automatic recognition algorithm can recognize the detection image formed by the battery 30 to be tested after detection, and automatically annotate the contour, vertex and other position information of any pole piece in the detection image.

[0195] S14. Image processing and algorithm recognition.

[0196] The automatic recognition algorithm obtained by training in S13 is called to pre-process the saved detection image. At the same time, the trained algorithm point grabbing model is used to identify and grab points on the detection image, and the vertex positions of all the first pole pieces 31 and the second pole pieces 32 in the detection image are grabbed. At the same time, the line contours of all the first pole pieces 31 and the second pole pieces 32 are fitted to obtain the position information of all the first pole pieces 31 and the second pole pieces 32.

[0197] S15, calculating the misalignment amount (first misalignment amount M) and spacing of the positive and negative pole pieces of all the layers at the positive end.

[0198] According to the position information of all the first pole pieces 31 and the second pole pieces 32 obtained by image processing and recognition, the misalignment amount (first misalignment amount M) of the positive and negative pole pieces of all the layers of the first end 34 and the distance between the positive and negative pole pieces (gap value Gap) are calculated, where the gap value Gap is the minimum center distance between the center vertical lines of adjacent pole pieces in the detection image.

[0199] S16. Call MSE data (width of the cathode and anode plates of the battery to be tested).

[0200] The MSE data includes a first width X of the first pole piece 31 and a second width Y of the second pole piece 32 in the battery to be tested 30. The first width X and the second width Y may be test results obtained and saved by CCD during the pole piece winding process.

[0201] S17. Theoretically calculate the misalignment amount (second misalignment amount N) of all positive and negative electrode sheets at the negative terminal.

[0202] The second misalignment N can be calculated according to the first width X, the second width Y and the first misalignment M. The calculation can be performed from the innermost circle of the battery 30 to the outside. For details, refer to the following table:

[0203]

[0204]

[0205] Among them, 1 st Characterized as the innermost circle, 2 nd ……n th Represents the second circle, the third circle, and finally the outermost circle, starting from the innermost circle. X 11 , X 12 It represents the width of the first pole piece obtained at two first preset positions on the same circle. Similarly, it is similar to understand X (n-1)1 , X (n-1)2 is the width of the first pole piece corresponding to the two first preset positions on the (n-1)th circle, and so on. 11 , Y 12 is the width of the second pole piece corresponding to the two second preset positions on the same circle. Similarly, Y (n-1)1 , Y (n-1)2 Etc. M1, M1…M n The first displacement of different layers is represented by N1, N1…N n It characterizes the second misalignment of different layers respectively.

[0206] It should be noted that, since two sets of first preset positions and second preset positions are selected in each circle, two second misalignment calculation values ​​are calculated according to the two sets of corresponding first widths X and second widths Y, and the smaller value is taken as the second misalignment. For example, the two second misalignment calculation values ​​N calculated in the (n-1)th circle are (n-1)1 , N (n-1)2 , the corresponding second misalignment is N (n-1) =min{N (n-1)1 , N (n-1)2}.

[0207] S18. Photograph the negative terminal of the cylindrical battery and process and identify it.

[0208] Move the ray source 610 and the detection device 620 to face the negative end (second end) of the cylindrical battery, emit X-rays and obtain a detection image of the end. Similarly, the automatic recognition algorithm trained in S13 can be called to recognize the detection image and determine the position information of the pole piece in the detection image.

[0209] S19. Calculate the distance between the cathode and anode plates of all layers at the negative terminal.

[0210] According to the recognition result, the gap value Gap between adjacent pole pieces in all circles of the negative terminal is calculated. The gap value Gap is the minimum center distance of the center vertical lines of adjacent pole pieces in the detection image.

[0211] S20, determining whether the battery is a risky product;

[0212] The detection result is compared with the preset judgment threshold to determine whether the preset conditions are met, and the corresponding detection result is output according to the judgment result.

[0213] In response to the fact that any one of the first misalignment amount M and the second misalignment amount N is less than or equal to the first preset threshold, or any one of the first misalignment amount and the second misalignment amount is greater than or equal to the second preset threshold, the inspection result of the battery is determined to be unqualified; wherein the first preset threshold is less than the second preset threshold; the first preset threshold can be 0.3 mm, and the second preset threshold can be 0.95 times the preset misalignment amount, and the preset misalignment amount is the design difference between the first pole piece 31 and the second pole piece 32.

[0214] In response to the gap value Gap being greater than the third preset threshold or less than the fourth preset threshold, the detection result of the battery 30 to be tested is determined to be unqualified.

[0215] S21. Product OK.

[0216] If the test results meet the corresponding preset conditions for product qualification, the output is OK, and the battery flows directly into the next process.

[0217] S22, product NG.

[0218] If the test result does not meet the corresponding preset conditions for qualified products, the output is NG, and the battery is rejected or re-tested.

[0219] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery defect detection method, characterized in that: The battery to be tested includes a first pole piece and a second pole piece stacked and wound around the battery axis, and the battery to be tested includes a first end and a second end oppositely arranged along the battery axis. The method includes: Obtaining a width of a first pole piece and a width of a second pole piece of the battery to be tested along a direction parallel to an axis of the battery; Determine a first misalignment amount between the first pole piece and the adjacent second pole piece at the first end; the first misalignment amount is a distance between an endpoint of the first pole piece at the first end and an endpoint of the adjacent second pole piece at the first end along a direction parallel to the battery axis; Determine a second misalignment between the first pole piece and the adjacent second pole piece at the second end according to the width of the first pole piece, the width of the second pole piece, and the first misalignment; the second misalignment is the distance between the endpoint of the first pole piece at the second end and the endpoint of the adjacent second pole piece at the second end along a direction parallel to the battery axis; A detection result of the battery to be tested is determined according to the first misalignment amount and the second misalignment amount.

2. The battery defect detection method according to claim 1, characterized in that: The determining of a first misalignment amount between the first pole piece and the adjacent second pole piece at the first end, wherein the first misalignment amount is a distance between an endpoint of the first pole piece at the first end and an endpoint of the adjacent second pole piece at the first end along a direction parallel to the battery axis, includes: Acquire a detection image including the first end of the battery to be tested; Identify the detection image to respectively obtain a first endpoint of the nth circle of the first pole piece at the first end, and two second endpoints of two second pole pieces adjacent to the nth circle of the first pole piece at the first end; determining a first misalignment amount corresponding to an nth circle of the first pole piece according to positions of the first endpoint and the two second endpoints in the detection image; Wherein, n is a positive integer greater than 0.

3. The battery defect detection method according to claim 2, characterized in that: Determining a first misalignment amount corresponding to the nth circle of the first pole piece according to the positions of the first endpoint and the two second endpoints in the detection image comprises: Determine, according to the positions of the first endpoint and the two second endpoints in the detection image, a first sub-misalignment amount and a second sub-misalignment amount between the nth circle of the first pole piece and two adjacent second pole pieces at the first end along a direction parallel to the battery axis; The larger one of the first sub-misalignment amount and the second sub-misalignment amount is determined as the first misalignment amount corresponding to the nth turn of the first pole piece.

4. The battery defect detection method according to claim 2 or 3, characterized in that: The step of obtaining the width of the first pole piece and the width of the second pole piece of the battery to be tested along a direction parallel to the battery axis includes: Acquire at least one first width along a direction parallel to the battery axis corresponding to at least one first preset position on the first pole piece; the at least one first preset position is located at the nth circle of the first pole piece; Acquire at least one second width along a direction parallel to the battery axis corresponding to at least one second preset position on the second pole piece; the at least one second preset position is located at the nth circle of the second pole piece; And among them, The determining, according to the width of the first pole piece, the width of the second pole piece, and the first misalignment amount, of the second misalignment amount of the first pole piece and the adjacent second pole piece at the second end comprises: A second misalignment amount corresponding to the nth turn of the first pole piece is determined according to the at least one first width, the at least one second width, and the first misalignment amount corresponding to the nth turn of the first pole piece.

5. The battery defect detection method according to claim 4, characterized in that: The number of the at least one first preset position is plural, and / or the number of the at least one second preset position is plural, and wherein Determining the second misalignment amount corresponding to the nth circle of the first pole piece according to the at least one first width, the at least one second width, and the first misalignment amount corresponding to the nth circle of the first pole piece comprises: A plurality of second misalignment calculation values ​​are obtained by calculating the at least one first width, the at least one second width, and the first misalignment corresponding to the nth circle of the first pole piece; The minimum value among the plurality of second misalignment calculation values ​​is determined as the second misalignment corresponding to the nth turn of the first pole piece.

6. The battery defect detection method according to claim 4 or 5, characterized in that: The at least one first preset position is equal in number to the at least one second preset position and is arranged in one-to-one correspondence, and a line connecting any one of the at least one first preset position and the battery axis coincides with a projection of a line connecting the corresponding second preset position and the battery axis on a plane perpendicular to the battery axis.

7. The battery defect detection method according to any one of claims 1 to 6, characterized in that: The step of determining the test result of the battery to be tested according to the first misalignment amount and the second misalignment amount includes: In response to the fact that any one of the first misalignment amount and the second misalignment amount is less than or equal to the first preset threshold, or any one of the first misalignment amount and the second misalignment amount is greater than or equal to the second preset threshold, determining the test result of the battery to be tested as unqualified; The first preset threshold is smaller than the second preset threshold.

8. The battery defect detection method according to claim 7, characterized in that: The value range of the first preset threshold is greater than or equal to 0.2 mm and less than or equal to 0.5 mm.

9. The battery defect detection method according to claim 7 or 8, characterized in that: The ratio of the second preset threshold to the preset misalignment amount is greater than or equal to 0.95 and less than or equal to 1, and the preset misalignment amount is determined according to the width of the first pole piece and the width of the second pole piece.

10. The battery defect detection method according to any one of claims 1 to 9, characterized in that: The defect detection method further comprises: Acquire a detection image including the first end of the battery and / or the second end of the battery; Identify the detection image to obtain position information of the first pole piece and position information of the second pole piece; Determine a gap value between the first pole piece and the adjacent second pole piece according to the position information of the first pole piece and the position information of the second pole piece, wherein the gap value is the minimum center distance between the first pole piece and the adjacent second pole piece along a direction perpendicular to the battery axis; The detection result of the battery to be tested is determined according to the gap value.

11. The battery defect detection method according to claim 10, characterized in that: The step of determining a gap value between the first pole piece and the adjacent second pole piece according to the position information of the first pole piece and the position information of the second pole piece, wherein the gap value is a minimum center distance between the first pole piece and the adjacent second pole piece along a direction perpendicular to the battery axis, comprises: Determine the position information of the center vertical line of the first pole piece and the position information of the center vertical line of the second pole piece according to the position information of the first pole piece and the position information of the second pole piece; The minimum distance between the center vertical line of the first pole piece and the center vertical line of the adjacent second pole piece along the direction perpendicular to the battery axis is calculated and used as the gap value.

12. The battery defect detection method according to claim 10 or 11, characterized in that: Determining the detection result of the battery to be tested according to the gap value includes: In response to the gap value being greater than a third preset threshold or less than a fourth preset threshold, the detection result of the battery to be tested is determined to be unqualified, wherein the third preset threshold is greater than the fourth preset threshold.

13. The battery defect detection method according to any one of claims 1 to 12, characterized in that: The defect detection method further comprises: In response to the test result of the battery to be tested being unqualified, the battery to be tested is discarded or retested.

14. A battery defect detection device, characterized in that: include: A ray source, used for emitting detection rays to the battery to be tested; A detector, used for receiving the detection ray emitted by the ray source and penetrating the battery to be tested; A defect detection component is connected to the detector, and the defect detection component is used to execute the defect detection method as described in any one of claims 1-12.

15. The battery defect detection device according to claim 14, characterized in that: The rated voltage range of the radiation source is greater than or equal to 130 kV and less than or equal to 150 kV; and / or The rated current of the ray source is less than or equal to 500 microamperes.

16. The battery defect detection device according to claim 14 or 15, characterized in that: The maximum size of the focus of the ray source is less than or equal to 80 microns.

17. A battery defect detection device, characterized in that: The battery to be tested includes a first pole piece and a second pole piece stacked and wound around the battery axis, the battery to be tested includes a first end and a second end arranged opposite to each other along the battery axis, and the device includes: An acquisition module is configured and used to acquire the width of the first pole piece and the width of the second pole piece in the battery to be tested along a direction parallel to the battery axis; A first determination module is configured to determine a first misalignment amount between the first pole piece and the adjacent second pole piece at the first end along a direction parallel to the battery axis; A second determination module is configured to determine a second misalignment amount between the first pole piece and the adjacent second pole piece at the second end according to the width of the first pole piece, the width of the second pole piece and the first misalignment amount; A determination module is configured to determine a detection result of the battery to be tested according to the first misalignment amount and the second misalignment amount.

18. A method for producing a battery, characterized in that: The production method comprises: The battery defect detection method according to any one of claims 1 to 13 is used to detect the battery to be tested to determine the detection result of the battery to be tested.

19. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively coupled to the at least one processor; The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the battery defect detection method according to any one of claims 1 to 13.

20. A battery production device, characterized in that: The device comprises the battery defect detection device as claimed in any one of claims 14 to 17 or the electronic device as claimed in claim 19.

21. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the battery defect detection method according to any one of claims 1 to 13 is implemented.

22. A computer program product, characterized in that It comprises a computer program, which, when executed by a processor, implements the battery defect detection method according to any one of claims 1 to 13.

Images