Electrode assembly detection method and detection apparatus

Abstract

Embodiments of the present application provide an electrode assembly detection method and detection apparatus. The detection method comprises: using a scintillator to convert a radiation beam penetrating a region to be detected of an electrode assembly into visible light; using a lens to amplify the visible light, and using a detector to convert the amplified visible light into an electrical signal, so as to generate a target image, wherein the target image comprises an image of an electrode sheet of said region of the electrode assembly; and detecting the electrode sheet of the electrode assembly on the basis of the target image. The electrode assembly detection method and detection apparatus provided in the embodiments of the present application can improve the detection accuracy of an electrode sheet of an electrode assembly.

Description

Methods and apparatus for testing electrode assemblies Cross-references to related applications

[0001] This application claims priority to Chinese patent application 202510111823.X, filed on January 23, 2025, entitled "Detection Method and Detection Apparatus for Electrode Components", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery testing technology, and more specifically, to a testing method and testing device for electrode components. Background Technology

[0003] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0004] Batteries can develop various internal defects during the manufacturing process, which can affect their quality and reliability. Therefore, it is necessary to inspect batteries during production and reject any that fail to meet the standards.

[0005] During the charging and discharging process of lithium batteries, when the distance between adjacent anodes and cathodes (also known as the gap between the electrode plates) is large, lithium ions cannot be fully embedded into the anode channel, leading to lithium plating and affecting battery performance and lifespan. Therefore, it is necessary to detect the distance between adjacent anodes and cathodes in the battery's electrode assembly to ensure that the distance between the anodes and cathodes of a qualified electrode assembly is within a certain range. However, current X-ray inspection systems lack sufficient precision to meet the requirements for detecting the distance between adjacent anodes and cathodes in electrode assemblies. Summary of the Invention

[0006] This application provides a method and apparatus for detecting electrode assemblies, which can improve the detection accuracy of electrode sheets in electrode assemblies.

[0007] In a first aspect, a method for detecting an electrode assembly is provided, the method comprising: using a scintillator to convert a beam of light penetrating a region to be detected of the electrode assembly into visible light; using a lens to amplify the visible light and using a detector to convert the amplified visible light into an electrical signal to generate a target image, the target image including an image of the electrode sheet of the region to be detected of the electrode assembly; and detecting the electrode sheet of the electrode assembly based on the target image.

[0008] In this embodiment, a scintillator converts the X-ray beam penetrating the electrode assembly into visible light, a lens amplifies this visible light, and a detector converts the amplified visible light into an electrical signal to generate a target image of the electrode sheet including the area to be detected, including the electrode assembly. This increases the magnification of the electrode assembly, thereby improving the resolution of the target image, potentially achieving sub-micron level distance detection, and thus improving the detection accuracy of the electrode sheet. Simultaneously, it reduces the distance between the electrode assembly and the detector, decreasing the attenuation of the X-ray beam reaching the detector after penetrating the electrode assembly, and improving image quality.

[0009] In one possible implementation, detecting the electrodes of the electrode assembly based on the target image includes: determining the spacing between adjacent anode and cathode electrodes of the electrode assembly based on the target image, wherein the target image includes images of at least one layer of anode electrodes and at least one layer of cathode electrodes of the electrode assembly.

[0010] In this embodiment, based on detection using a scintillator, a lens is further used to amplify the visible light converted from the scintillator's rays. This increases the magnification during electrode assembly imaging, thereby improving image resolution and enhancing the detection accuracy of the spacing between adjacent anode and cathode electrodes. Simultaneously, the distance between the electrode assembly and the detector can be reduced, decreasing the attenuation of the ray beam penetrating the electrode assembly before reaching the detector, thus improving image quality.

[0011] In one possible implementation, the centerline of the beam is parallel to the target direction, which is the direction of the shortest diameter of the wound electrode assembly, which includes the wound electrode assembly.

[0012] In this embodiment, by setting the centerline direction of the X-ray beam parallel to the direction of the shortest diameter of the wound electrode assembly, the electrodes of the wound electrode assembly can be imaged along their width direction, making the size range of the anode and cathode electrodes in the target image larger along their width direction. This allows the spacing between the anode and cathode electrodes to be detected within this larger size range, thereby improving the accuracy of the detection.

[0013] In one possible implementation, a scintillator is used to convert a beam of light penetrating the area to be detected of the electrode assembly into visible light, including: using a scintillator to convert a beam of light penetrating a corner region into visible light, wherein the wound electrode assembly includes the corner region.

[0014] In this embodiment, by using a scintillator to convert the ray beam penetrating the corner region into visible light, the spacing between adjacent electrodes of the electrode assembly can be determined by the spacing between adjacent anode and cathode electrodes in the corner region. Along the shortest diameter direction of the wound electrode assembly, the ray beam passes through a smaller area in the corner region compared to the area passing through a straight region, which can reduce the emission energy of the ray beam to a certain extent and save energy consumption.

[0015] In one possible implementation, the target image includes an image of the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on a target plane, the target plane being a straight plane parallel to the straight region of the wound electrode assembly and passing through the longest diameter of the wound electrode assembly.

[0016] In this embodiment, by imaging the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on the target plane, the thickness of the X-ray beam penetrating the electrode assembly is relatively thin, and the attenuation of the X-ray beam after penetrating the electrode assembly is low, which can improve the imaging quality. On the other hand, the electrodes of the wound electrode assembly can be imaged along their width direction, so that the size range of the anode and cathode electrodes in the target image along their width direction is large. This allows for the detection of the spacing between the anode and cathode electrodes within this larger size range, thereby improving the accuracy of the detection.

[0017] In one possible implementation, determining the spacing between adjacent anode and cathode plates of the electrode assembly based on the target image includes: determining the pixel value of a pixel in the target image; and determining the spacing between adjacent anode and cathode plates of the wound electrode assembly based on the pixel value of the pixel in the target image.

[0018] In this embodiment, the spacing between adjacent anode and cathode electrodes of the electrode assembly can be determined based on the pixel values ​​of the target image, thereby improving the accuracy of electrode spacing detection.

[0019] In one possible implementation, determining the pixel value of a pixel in the target image includes: determining the pixel value of a pixel in the target image within the coordinate system Ym≤Y≤Yn, wherein along the X-axis of the coordinate system, anode and cathode electrodes are alternately arranged in the target image, and along the Y-axis of the coordinate system, the minimum value of the anode and cathode electrodes in the target image is less than or equal to Ym and the maximum value of the anode and cathode electrodes in the target image is greater than or equal to Yn.

[0020] In this embodiment of the application, by determining the pixel values ​​of the target image in the coordinate system where Ym≤Y≤Yn, the data overhead of determining the pixel values ​​of the target image can be reduced, thereby improving computational efficiency.

[0021] In one possible implementation, determining the spacing between adjacent anode and cathode plates of the wound electrode assembly based on the pixel values ​​of the target image includes: determining the sum of multiple pixel values ​​corresponding to multiple columns of pixels distributed along the X-axis of the target image within the range Ym≤Y≤Yn; determining target lines in the target image where the anode and cathode plates are parallel to the Y-axis, respectively, based on the sum of the multiple pixel values, the target lines including edges and / or centerlines; and determining the spacing between adjacent anode and cathode plates of the wound electrode assembly based on the target lines.

[0022] In this embodiment of the application, by determining the sum of multiple pixel values ​​of multiple columns of pixels arranged along the X-axis in the target image within the range of Ym≤Y≤Yn, the centerline or edge of the anode and cathode of the electrode assembly can be determined more accurately, thereby accurately determining the spacing between adjacent anode and cathode of the electrode assembly and improving the accuracy of detection.

[0023] In one possible implementation, the scintillator is made of cesium iodide inorganic crystal.

[0024] In the embodiments of this application, by using cesium iodide inorganic crystal as the material of the scintillator, the conversion efficiency of X-ray beam energy and fluorescent photons can be improved, the efficiency of X-ray beam detection can be improved, and the imaging quality can be improved.

[0025] In one possible implementation, the size of the scintillator along the centerline of the beam ranges from 100 μm to 900 μm.

[0026] In this embodiment, the thickness of the scintillator can be controlled between 100μm and 900μm. This can reduce the impact of low beam conversion efficiency caused by a thinner scintillator on imaging quality, and also reduce the impact of increased light scattering caused by a thinner scintillator on imaging quality, thereby maximizing the imaging quality of the target image and improving the detection accuracy of the electrode assembly.

[0027] In one possible implementation, the size of the scintillator along the centerline of the beam ranges from 400 μm to 700 μm.

[0028] In the embodiments of this application, the thickness of the scintillator can be controlled between 400μm and 700μm, and the DQE and MTF can be controlled within a relatively high range, thereby further improving the resolution of the target image and thus improving the detection accuracy.

[0029] In one possible implementation, the size of the electrode assembly is less than or equal to 35 mm along the centerline of the beam, and the size of the scintillator is between 400 μm and 500 μm.

[0030] In one possible implementation, the size of the electrode assembly is greater than or equal to 30 mm and less than or equal to 40 mm along the centerline direction of the beam, and the size of the scintillator is between 500 μm and 600 μm.

[0031] In one possible implementation, the size of the electrode assembly is greater than or equal to 35 mm along the centerline of the beam, and the size of the scintillator is between 600 μm and 700 μm.

[0032] In the embodiments of this application, the different sizes of the electrode components along the center line of the X-ray beam result in significant differences in the dose of the incident X-ray beam, and the energy of the X-ray beam after penetrating the electrode components will also vary significantly. Therefore, scintillators of different thicknesses are needed to convert the X-ray beam after penetrating the electrode components, thereby obtaining images with higher imaging quality and improving the detection accuracy of the electrode components.

[0033] In one possible implementation, the radiation source of the radiation beam satisfies one or more of the following conditions: the rated voltage of the radiation source of the radiation beam is in the range of 110kV-225kV; the rated current of the radiation source of the radiation beam is in the range of 100uA-1000uA; and the focal size of the radiation source of the radiation beam is in the range of 10um-100um.

[0034] In one possible implementation, the radiation source of the radiation beam satisfies one or more of the following conditions: the rated voltage of the radiation source of the radiation beam is in the range of 150kV-180kV; the rated current of the radiation source of the radiation beam is in the range of 100uA-500uA; and the focal size of the radiation source of the radiation beam is in the range of 20um-50um.

[0035] In the embodiments of this application, by controlling one or more of the rated voltage, rated current or focal size of the X-ray source within a reasonable range, the dose of the X-ray beam can be controlled within a reasonable range, thereby improving imaging quality while saving energy as much as possible.

[0036] In one possible implementation, the beam includes an X-ray beam.

[0037] Secondly, a detection device for an electrode assembly is provided. The detection device includes: a radiation source for emitting a radiation beam that penetrates a region to be detected of the electrode assembly; a scintillator for converting the radiation beam penetrating the region to be detected of the electrode assembly into visible light; a lens for amplifying the visible light; a detector for converting the amplified visible light into an electrical signal; and a processing unit for generating a target image based on the electrical signal and detecting the electrode plates of the electrode assembly based on the target image. The target image includes an image of the electrode plates in the region to be detected of the electrode assembly.

[0038] In one possible implementation, the processing unit is configured to determine the spacing between adjacent anode and cathode plates of the electrode assembly based on a target image, wherein the target image includes images of at least one layer of anode plates and at least one layer of cathode plates of the electrode assembly.

[0039] In one possible implementation, the centerline of the beam is parallel to the target direction, which is the direction of the shortest diameter of the wound electrode assembly, which includes the wound electrode assembly.

[0040] In one possible implementation, a scintillator is used to convert a beam of light penetrating a corner region into visible light, and a wound electrode assembly includes the corner region.

[0041] In one possible implementation, the target image includes an image of the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on a target plane, the target plane being a straight plane parallel to the straight region of the wound electrode assembly and passing through the longest diameter of the wound electrode assembly.

[0042] In one possible implementation, the processing unit is configured to: determine the pixel value of a pixel in the target image; and determine the spacing between adjacent anode and cathode plates of the wound electrode assembly based on the pixel value of the pixel in the target image.

[0043] In one possible implementation, the processing unit is used to determine the pixel values ​​of the target image within the coordinate system Ym≤Y≤Yn. Along the X-axis of the coordinate system, the anode and cathode electrodes in the target image are arranged alternately. Along the Y-axis of the coordinate system, the minimum value of the anode and cathode electrodes in the target image is less than or equal to Ym, and the maximum value of the anode and cathode electrodes in the target image is greater than or equal to Yn.

[0044] In one possible implementation, the processing unit is configured to determine the sum of multiple pixel values ​​corresponding to multiple columns of pixels distributed along the X-axis of the target image within the range Ym≤Y≤Yn; based on the sum of multiple pixel values, determine a target line in the target image parallel to the Y-axis for the anode and cathode plates, the target line including edges and / or centerlines; and based on the target line, determine the spacing between adjacent anode and cathode plates of the wound electrode assembly.

[0045] In one possible implementation, the scintillator is made of cesium iodide inorganic crystal.

[0046] In one possible implementation, the size of the scintillator along the centerline of the beam ranges from 100 μm to 900 μm.

[0047] In one possible implementation, the size of the scintillator along the centerline of the beam ranges from 400 μm to 700 μm.

[0048] In one possible implementation, the size of the electrode assembly is less than or equal to 35 mm along the centerline of the beam, and the size of the scintillator is between 400 μm and 500 μm.

[0049] In one possible implementation, the size of the electrode assembly is greater than or equal to 30 mm and less than or equal to 40 mm along the centerline direction of the beam, and the size of the scintillator is between 500 μm and 600 μm.

[0050] In one possible implementation, the size of the electrode assembly is greater than or equal to 35 mm along the centerline of the beam, and the size of the scintillator is between 600 μm and 700 μm.

[0051] In one possible implementation, the radiation source satisfies one or more of the following conditions: the rated voltage of the radiation source is between 110kV and 225kV; the rated current of the radiation source is between 100uA and 1000uA; and the focal spot size of the radiation source is between 10um and 100um.

[0052] In one possible implementation, the radiation source satisfies one or more of the following conditions: the rated voltage of the radiation source is between 150kV and 180kV; the rated current of the radiation source is between 100uA and 500uA; and the focal spot size of the radiation source is between 20um and 50um.

[0053] In one possible implementation, the beam includes an X-ray beam.

[0054] Thirdly, a detection device for an electrode assembly is provided. The detection device includes a memory and a processor. The memory is used to store instructions, and the processor is used to read the instructions and execute the detection method in the first aspect or any one of the first aspects according to the instructions.

[0055] Fourthly, an X-ray detection device is provided, the detection device including the detection apparatus in the second aspect or any possible implementation of the second aspect.

[0056] Fifthly, a computer program is provided that, when executed by a computer, causes the computer to implement the detection method as described in the first aspect and any possible implementation thereof.

[0057] In a sixth aspect, a computer-readable storage medium is provided for storing a computer program that, when executed by a computer, causes the computer to implement the detection method as described in the first aspect and any possible implementation thereof.

[0058] In a seventh aspect, a computer program product is provided, including computer program instructions that, when executed by a computer, cause the computer to implement the detection method as described in the first aspect and any possible implementation thereof. Attached Figure Description

[0059] Figure 1 is a schematic diagram of the structure of the X-ray detection system provided in the embodiment of this application.

[0060] Figure 2 is a flowchart illustrating the detection method for the electrode assembly provided in an embodiment of this application.

[0061] Figure 3 is a flowchart illustrating the detection method for the electrode assembly provided in an embodiment of this application.

[0062] Figure 4 is a simplified schematic diagram of the structure of the wound electrode assembly provided in the embodiment of this application.

[0063] Figure 5 is a schematic diagram of the target image of the electrode assembly provided in an embodiment of this application.

[0064] Figure 6 is a schematic diagram showing the relative orientation of the ray beam and the wound electrode assembly provided in an embodiment of this application.

[0065] Figure 7 is a flowchart illustrating the detection method for the electrode assembly provided in an embodiment of this application.

[0066] Figure 8 is a flowchart illustrating the detection method for the electrode assembly provided in an embodiment of this application.

[0067] Figure 9 is a schematic diagram of the coordinate system established in the target image of an embodiment of this application.

[0068] Figure 10 is a schematic diagram showing the change of the sum of multiple pixel values ​​corresponding to multiple columns of pixels in the target image provided in the embodiments of this application.

[0069] Figure 11 is a schematic block diagram of the detection device for the electrode assembly provided in an embodiment of this application.

[0070] Figure 12 is another schematic block diagram of the detection device for the electrode assembly provided in the embodiments of this application. Detailed Implementation

[0071] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0072] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0073] The term "and / or" merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. The parallelism or perpendicularity in the embodiments of this application are not strictly parallel or perpendicular, and a certain degree of error is permissible.

[0074] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0075] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0076] Batteries can develop various internal defects during the manufacturing process, which can affect their quality and reliability. Therefore, it is necessary to inspect batteries during production and reject any that fail to meet the standards.

[0077] During the charging and discharging process of lithium batteries, when the distance between adjacent anodes and cathodes (also known as the gap between adjacent anode and cathode plates) is large, lithium ions cannot be fully embedded in the anode channel, leading to lithium plating and affecting battery performance and lifespan. Therefore, it is necessary to detect the distance between adjacent anodes and cathodes in the battery's electrode assembly to ensure that the distance between adjacent anodes and cathodes in a qualified electrode assembly is within a certain range. However, current X-ray inspection systems lack sufficient accuracy, especially for electrode assemblies of 4C (battery fully charged in one-quarter of an hour) / 5C (battery fully charged in one-fifth of an hour) batteries, and cannot meet the requirements for detecting the distance between adjacent anodes and cathodes in these systems.

[0078] For example, the high-power X-ray inspection method commonly used in the lithium battery industry mainly utilizes geometric magnification, such as 8-10 times magnification, to detect the distance between the anode and cathode of the electrode assembly. However, the imaging accuracy at this magnification level cannot meet the inspection requirements. Further geometric magnification is used to improve imaging accuracy, i.e., moving the detector further away from the electrode assembly to increase the magnification. However, the increased distance between the electrode assembly and the detector leads to a significant attenuation of the X-ray dose reaching the detector after penetrating the electrode assembly, affecting image quality.

[0079] To address the aforementioned problems, this application provides a detection method and a detection apparatus for an electrode assembly. The detection method includes: using a scintillator to convert a beam of light penetrating the area to be detected of the electrode assembly into visible light; using a lens to amplify the visible light and using a detector to convert the amplified visible light into an electrical signal to generate a target image, the target image including an image of the electrode sheet of the area to be detected of the electrode assembly; and detecting the electrode sheet of the electrode assembly based on the target image.

[0080] The detection method and detection device for electrode assemblies provided in this application can improve the detection accuracy of electrode sheets in electrode assemblies.

[0081] Figure 1 is a schematic diagram of the structure of the X-ray detection system provided in an embodiment of this application.

[0082] An X-ray detection system may include an X-ray source 110, a scintillator 120, a lens 130, a detector 140, a processing unit 150, and a detection position 160.

[0083] X-ray source 110 can generate and emit X-ray beams at a specific emission angle.

[0084] When an X-ray beam penetrates the object under test 170, such as an electrode assembly, at the detection position 160, it will be absorbed and attenuated by the object under test 170. Different substances with different densities, thicknesses, and materials absorb X-ray beams differently, resulting in different attenuations of the X-ray beam after penetrating the object under test 170.

[0085] The scintillator 120 receives the X-ray beam that penetrates the object under test 170 and converts the X-ray beam into visible light.

[0086] Lens 130 can optically amplify visible light from scintillator 120.

[0087] Detector 140 can receive visible light passing through lens 130 and convert the optical signal of the visible light into an electrical signal. For example, the detector can receive X-ray beams of different intensities after penetrating the electrode assembly and generate an electrical signal proportional to the intensity of the X-ray beam. Because the X-ray beam has different penetrating power for objects of different structures and materials, the internal structure of the object can be presented by the detector in the form of an electrical signal.

[0088] In some embodiments, the detector may include a charge-coupled device (CCD) detector. CCD detectors are characterized by high sensitivity, strong stability, small size, long lifespan, and excellent photosensitivity and imaging capabilities.

[0089] The processing unit 150 can process the electrical signal to generate an image of the object under test. For example, the processing unit can convert the electrical signal into a grayscale image or a black and white image that reflects the structural information of the electrode assembly.

[0090] The processing unit 150 can also detect the object under test 170 based on the image of the object under test 170.

[0091] In some embodiments, the X-ray detection system may also include a transmission track 180.

[0092] The object under test 170 can move along the transmission track 180. That is, the object under test 170 can be moved by the movement of the transmission track 180.

[0093] For example, during the movement of the object under test 170, the X-ray source 110 generates and emits an X-ray beam at a specific emission angle. The scintillator 120 receives the X-ray beam that penetrates the object under test 170 and converts it into visible light. The lens 130 optically amplifies the visible light from the scintillator 120. The detector 140 receives the visible light passing through the lens 130 and converts the light signal into an electrical signal. The processing unit 150 can process the electrical signal to generate an image of the object under test 170, and then detect the object under test 170 based on this image. Alternatively, the object under test 170 can be moved using a transmission track 180. When the object under test 170 moves to the detection position 160, the transmission track 180 stops transmitting, and the object under test 170 at the detection position 160 is detected. After the detection is completed, the transmission track 180 continues transmitting, moving the object under test 170 away from the detection position.

[0094] In some embodiments, when testing the electrode assembly, the electrode assembly may be an electrode assembly already assembled into a battery cell. That is, the housing and the electrode assembly inside the housing can be placed together on the transport track 180, and then the electrode assembly is tested using the detection system shown in FIG1 during the movement of the electrode assembly.

[0095] Alternatively, the bare electrode assembly, which is not encased in a shell, can be placed on the transfer track 180 for testing.

[0096] In some embodiments, the X-ray source 110 may also be replaced with other types of radiation sources such as gamma-ray sources.

[0097] It should be understood that the components shown in Figure 1 are just examples. In actual applications, the components may have different names, or the components in Figure 1 may be added or deleted according to actual needs.

[0098] Figure 2 is a schematic flowchart of the detection method for the electrode assembly provided in an embodiment of this application. The detection method for the electrode assembly in Figure 2 can be applied to the X-ray detection system of Figure 1.

[0099] 210. A scintillator is used to convert the X-ray beam penetrating the area to be detected into visible light.

[0100] Electrode assemblies may include wound electrode assemblies, stacked electrode assemblies, or other types of electrode assemblies.

[0101] Electrode assemblies may include diaphragms, anode plates, and cathode plates, etc. The diaphragm can be used to reduce short circuits between the anode and cathode plates.

[0102] In the embodiments of this application, the area to be detected can be the entire area of ​​the electrode assembly, or it can be a local area of ​​the electrode assembly.

[0103] For example, a wound electrode assembly may include a flat region and corner regions located at both ends of the flat region. As an example, the detection area of ​​a wound electrode assembly may include the corner regions of the wound electrode assembly to detect the amount of misalignment of the cathode and anode electrodes along the electrode width direction. As another example, the detection area of ​​a wound electrode assembly may include the flat region of the wound electrode assembly to detect wrinkling of the electrode assembly.

[0104] A beam of light can be emitted from a radiation source onto an electrode assembly, and then a scintillator can be used to convert the beam of light that penetrates the electrode assembly into visible light.

[0105] After absorbing high-energy particles such as X-ray beams, scintillators can release photons with wavelengths at or near the visible light wavelength. For example, in the embodiments of this application, the scintillator can convert an X-ray beam into visible light.

[0106] Different materials, such as those with varying densities, thicknesses, and textures, absorb X-ray beams differently, resulting in varying degrees of attenuation of the X-ray beams penetrating the anode and cathode of the electrode assembly. In other words, the intensity of the X-ray beams after penetrating the anode and cathode of the electrode assembly differs. A scintillator can convert these differently attenuated X-ray beams into visible light carrying structural information about the electrode assembly.

[0107] 220. Visible light is magnified using a lens, and the magnified visible light is converted into an electrical signal using a detector to generate a target image.

[0108] The target image includes an image of the electrode sheet in the area to be detected of the electrode assembly.

[0109] In this embodiment, the target image may include an image of the entire area or a portion of the electrode assembly.

[0110] Lenses can magnify visible light from a scintillator. For example, a lens can include a convex lens. Alternatively, a lens can also include a concave lens.

[0111] In this embodiment, the number of lenses can be one or more.

[0112] The detector can receive amplified visible light and convert it into an electrical signal to generate a target image of the electrode assembly, such as a grayscale image or a black and white image. For example, the detector may include a CCD detector.

[0113] 230. Based on the target image, the electrode plates of the electrode assembly are inspected.

[0114] For example, based on a target image of the electrode in the corner region of the electrode assembly, the spacing between adjacent anode and cathode electrodes of the electrode assembly can be detected. For example, the distance between adjacent anode and cathode electrodes along the winding radial direction in a wound electrode assembly can be detected. For example, the distance between adjacent anode and cathode electrodes along the stacking direction in a stacked electrode assembly can be detected.

[0115] For example, based on the target image of the electrode in the corner region of the electrode assembly, the misalignment between adjacent anode and cathode electrodes of the electrode assembly can be detected. For instance, the distance between the edges of adjacent anode and cathode electrodes along the electrode width direction in a wound electrode assembly can be detected. For instance, the center alignment of adjacent anode and cathode electrodes along the electrode thickness direction in a wound electrode assembly can be detected.

[0116] For example, wrinkling of an electrode assembly can be detected based on a target image of the electrode sheet in the flat area of ​​an electrode assembly, such as a wound electrode assembly.

[0117] In this embodiment, a scintillator converts the X-ray beam penetrating the area to be detected of the electrode assembly into visible light. A lens amplifies this visible light, and a detector converts the amplified visible light into an electrical signal to generate a target image of the electrode sheet including the area to be detected of the electrode assembly. This increases the magnification of the area to be detected by the electrode assembly, thereby improving the resolution of the target image, potentially achieving sub-micron level distance detection, thus improving the detection accuracy of the electrode assembly. Simultaneously, it reduces the distance between the electrode assembly and the detector, decreasing the attenuation of the X-ray beam reaching the detector after penetrating the electrode assembly, and improving image quality.

[0118] The detection method for the electrode assembly provided in the embodiments of this application will be further illustrated below with reference to Figures 3 to 10.

[0119] Figure 3 is a flowchart illustrating the detection method for the electrode assembly provided in an embodiment of this application.

[0120] 310, using a scintillator to convert the X-ray beam penetrating the area to be detected through the electrode assembly into visible light.

[0121] 320. Visible light is magnified using a lens, and the magnified visible light is converted into an electrical signal using a detector to generate a target image.

[0122] The contents of steps 310 and 320 can be found in the descriptions of steps 210 and 220, and will not be repeated here.

[0123] 330. Based on the target image, determine the spacing between adjacent anode and cathode electrodes of the electrode assembly.

[0124] The target image includes images of at least one anode electrode and at least one cathode electrode of the electrode assembly.

[0125] The target image may include images of all layers of anode and cathode electrodes of the electrode assembly; or it may include images of only some layers of anode and cathode electrodes.

[0126] The following description uses a wound electrode assembly as an example to illustrate the structure of an electrode assembly. As shown in Figure 4, each layer of the electrode assembly, from the outside in, includes a diaphragm, an anode electrode, a diaphragm, and a cathode electrode. The electrodes and diaphragms of the electrode assembly are wound along the winding axis and then cold-pressed to obtain the wound electrode assembly. The electrode assembly can include multiple layers of anode electrodes and multiple layers of cathode electrodes, as shown in Figure 4. The wound electrode assembly can include a straight region and corner regions located at both ends of the straight region. The corner regions are the arc-shaped regions of the electrode assembly.

[0127] Figure 5 shows an example of a target image of a wound electrode assembly. The image in Figure 5 shows the multi-layered anode and cathode electrodes in the corner area of ​​the wound electrode assembly. Due to differences in materials and sizes of the cathode, anode, and separator in the electrode assembly, there are differences in grayscale, color, position, or size of the cathode, anode, and separator in the target image. Therefore, the anode and cathode electrodes in the target image can be identified based on their grayscale, color, position, or size. As shown in Figure 5, the longer and lighter-colored row represents the anode electrodes of the electrode assembly, and the shorter and lighter-colored row represents the cathode electrodes. Thus, the spacing between adjacent anode and cathode electrodes of the electrode assembly can be determined based on the target image.

[0128] Because the material of the current collector in the cathode electrode is different from the material of the coating at both ends—for example, if the coating of the cathode electrode is lithium, it absorbs radiation more strongly than the current collector. Therefore, in the target image, the cathode electrode appears as having lighter colors at both ends and darker colors in the middle. That is, the lighter-colored parts at both ends of the cathode electrode in the target image are the coating of the cathode electrode, and the darker-colored parts in the middle are the current collector of the cathode electrode.

[0129] For the anode electrode, its coating is generally made of carbon, which absorbs less radiation than the current collector. Therefore, in the target image, it appears as a darker color at both ends and a lighter color in the middle. That is, the lighter-colored part in the middle of the anode electrode in the target image is the current collector of the anode electrode, while the darker-colored coating at both ends merges with the areas of the thin film and other materials that have a lower absorption of radiation (appearing as darker colors), making them indistinguishable.

[0130] Currently, the detection of the spacing between adjacent anode and cathode electrodes in an electrode assembly requires high imaging accuracy, generally ≤1.5µm / pixel. Therefore, the electrode assembly detection method provided in this application, based on the use of a scintillator for detection, further utilizes a lens to amplify the visible light converted from X-rays by the scintillator. This increases the magnification during electrode assembly imaging, thereby improving image resolution and enhancing the detection accuracy of the spacing between adjacent anode and cathode electrodes. Simultaneously, it reduces the distance between the electrode assembly and the detector, thereby decreasing the attenuation of the X-ray beam penetrating the electrode assembly before reaching the detector, thus improving image quality.

[0131] In some embodiments, the centerline of the ray beam is parallel to the target direction, which is the direction of the shortest diameter of the wound electrode assembly, which includes a wound electrode assembly.

[0132] The centerline of a ray beam can be understood as the ray beam in the central part of the beam.

[0133] For example, the centerline of the beam can be directed toward the corner region along a direction parallel to the shortest diameter of the wound electrode assembly.

[0134] As shown in Figure 6, the centerline of the X-ray beam is parallel to the shortest diameter of the wound electrode assembly. Alternatively, it can be understood that the perpendicular line from the center of the X-ray source to the scintillator is parallel to the shortest diameter of the wound electrode assembly.

[0135] The shortest diameter of the wound electrode assembly is perpendicular to the plane of the straight area of ​​the wound electrode assembly (as shown in Figure 6, the plane containing the upper or lower surface of the electrode sheet), and the longest diameter of the wound electrode assembly is parallel to the plane of the straight area of ​​the wound electrode assembly.

[0136] In this embodiment, by setting the centerline direction of the X-ray beam parallel to the direction of the shortest diameter of the wound electrode assembly, the electrodes of the wound electrode assembly can be imaged along their width direction, making the size range of the anode and cathode electrodes in the target image larger along their width direction. This allows the spacing between the anode and cathode electrodes to be detected within this larger size range, thereby improving the accuracy of the detection.

[0137] For example, a scintillator can be used to convert a beam of light penetrating a corner region into visible light, and the electrode assembly includes a wound electrode assembly that includes the corner region.

[0138] That is, in this embodiment, the corner area of ​​the wound electrode assembly can be imaged, and the target image includes images of the anode and cathode electrodes in the corner area.

[0139] Typically, a wound electrode assembly may include two flat regions and two corner regions.

[0140] During the inspection, you can inspect only one corner area, or you can inspect both corner areas.

[0141] Along the shortest diameter of the wound electrode assembly, the size of the beam passing through the corner region is smaller than that passing through the normal region. The smaller the thickness of the object through which the beam passes, the lower the emission energy of the beam can be.

[0142] In this embodiment, by using a scintillator to convert the ray beam penetrating the corner region into visible light, the spacing between adjacent electrodes of the electrode assembly can be determined by the spacing between adjacent anode and cathode electrodes in the corner region. Along the shortest diameter direction of the wound electrode assembly, the ray beam passes through a smaller area in the corner region compared to the area passing through a straight region, which can reduce the emission energy of the ray beam to a certain extent and save energy consumption.

[0143] In some embodiments, the target image includes an image of the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on a target plane, the target plane being a straight plane parallel to the straight region of the wound electrode assembly and passing through the longest diameter of the wound electrode assembly.

[0144] In Figure 4, section A-A' represents the cross-section of the multi-layered anode and cathode plates in the corner region on the target plane. By detecting the corner region, the cross-section of at least one layer of anode and at least one layer of cathode plates in the corner region on the target plane can be imaged to obtain the target image shown in Figure 5.

[0145] For example, by setting the centerline of the ray beam parallel to the direction of the shortest diameter of the wound electrode assembly, and then imaging its corner area, the target image shown in Figure 5 can be obtained.

[0146] In this embodiment, by imaging the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on the target plane, the thickness of the X-ray beam penetrating the electrode assembly is relatively thin, and the attenuation of the X-ray beam after penetrating the electrode assembly is low, which can improve the imaging quality. On the other hand, the electrodes of the wound electrode assembly can be imaged along their width direction, so that the size range of the anode and cathode electrodes in the target image along their width direction is large. This allows for the detection of the spacing between the anode and cathode electrodes within this larger size range, thereby improving the accuracy of the detection.

[0147] Figure 7 is a flowchart illustrating the detection method for the electrode assembly provided in an embodiment of this application.

[0148] 710, using a scintillator to convert the ray beam that penetrates the corner area into visible light.

[0149] In this embodiment, the electrode assembly includes a wound electrode assembly, which includes a corner region.

[0150] In other words, the area to be detected in a wound electrode assembly can include the corner area of ​​the wound electrode assembly.

[0151] 720. Visible light is magnified using a lens, and the magnified visible light is converted into an electrical signal using a detector to generate a target image of the corner area.

[0152] The target image includes images of at least one layer of anode and at least one layer of cathode in the corner area.

[0153] In some embodiments, the centerline of the beam is parallel to the target direction, which is the direction of the shortest diameter of the wound electrode assembly.

[0154] In some embodiments, the target image includes an image of the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on a target plane, the target plane being a straight plane parallel to the straight region of the wound electrode assembly and passing through the longest diameter of the wound electrode assembly.

[0155] The contents of steps 710 and 720 can be found in steps 210, 220 and the relevant descriptions above, and will not be repeated here.

[0156] 730, determines the pixel value of the pixel in the target image.

[0157] Pixel values ​​can reflect the brightness information of each pixel in the target image.

[0158] In some embodiments, the target image may include a grayscale or black-and-white image of the multilayer anode and multilayer cathode of the electrode assembly. For example, the black-and-white image shown in Figure 5.

[0159] As an example, the pixel values ​​of a grayscale image can also be called grayscale values. The range of grayscale values ​​in a recovered image is generally 0-255, with white being 255 and black being 0. The pixel values ​​of a black and white image generally include 0 and 255, with white being 255 and black being 0.

[0160] As an example, before determining the pixel values ​​of the target image, the processing unit can convert the visible light signal into an initial digital signal such as a grayscale image, and then perform denoising processing on the grayscale image such as mean filtering, Gaussian filtering, variance filtering, etc., to obtain a denoised black and white image.

[0161] 740. Based on the pixel values ​​of the target image, determine the spacing between adjacent anode and cathode electrodes of the electrode assembly.

[0162] As an example, the pixel value of each point in the target image can be determined. Then, the pixel values ​​of each column of pixels can be summed or averaged to obtain an image showing the change of the sum or average pixel value of each column of pixels with respect to X. Based on this image, the edges (or centerlines) of the anode and cathode plates of the electrode assembly can be determined. Thus, the spacing between adjacent anode and cathode plates of the electrode assembly can be determined based on the edges (centerlines) of adjacent anode and cathode plates.

[0163] In this embodiment of the application, the spacing between adjacent anode and cathode electrodes of the electrode assembly can be determined based on the pixel values ​​of the target image, which can improve the accuracy of electrode spacing detection.

[0164] In some embodiments, the anode and cathode electrodes in the target image can be determined according to an electrode resolution model, wherein the electrode resolution model is obtained by inputting multiple training images into a machine learning model for training, and the training images include labeled anode and cathode electrodes.

[0165] As an example, machine learning models can include deep learning models, neural network models, and so on.

[0166] For example, a large number of training images labeled with anode and cathode electrodes can be input into a neural network model for training to obtain a trained electrode resolution model. This electrode resolution model can determine the anode and cathode electrodes in the target image based on the input target image.

[0167] In the embodiments of this application, the anode and cathode electrodes in the target image can be accurately and quickly determined based on the trained electrode resolution model.

[0168] Figure 8 is a flowchart illustrating the detection method for the electrode assembly provided in an embodiment of this application.

[0169] 810, using a scintillator to convert the X-ray beam penetrating the area to be detected through the electrode assembly into visible light.

[0170] 820 uses a lens to amplify visible light and a detector to convert the amplified visible light into an electrical signal to generate a target image.

[0171] In some embodiments, the centerline of the beam is parallel to the target direction, which is the direction of the shortest diameter of the wound electrode assembly.

[0172] In some embodiments, a scintillator can be used to convert a beam of light penetrating a corner region into visible light, and the electrode assembly includes a wound electrode assembly that includes a corner region.

[0173] In some embodiments, the target image includes an image of the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on a target plane, the target plane being a straight plane parallel to the straight region of the wound electrode assembly and passing through the longest diameter of the wound electrode assembly.

[0174] The contents of steps 810 and 820 can be found in steps 210, 220 and the relevant descriptions above, and will not be repeated here.

[0175] 830, determine the pixel values ​​of the target image within the coordinate system range of Ym≤Y≤Yn.

[0176] Along the X-axis of the coordinate system, the anode and cathode plates in the target image are arranged alternately. Along the Y-axis of the coordinate system, the minimum value of the anode and cathode plates in the target image is less than or equal to Ym, and the maximum value of the anode and cathode plates in the target image is greater than or equal to Yn.

[0177] As an example, as shown in Figure 9, a coordinate system is established with the horizontal axis of the target image as the X-axis and the vertical axis of the target image as the Y-axis.

[0178] In the target image, the anode and cathode electrodes of the electrode assembly are arranged alternately along the X-axis.

[0179] Along the Y-axis, one end of each anode electrode of the electrode assembly is located at Ym or at a coordinate less than Ym, and the other end is located at Yn or at a coordinate greater than Yn; and one end of each cathode electrode of the electrode assembly is located at Ym or at a coordinate less than Ym, and the other end is located at Yn or at a coordinate greater than Yn.

[0180] As an example, within the range [Ym,Yn] along the Y-axis, the number of pixels at a unit coordinate on the X-axis is Ym-Yn+1.

[0181] For example, the coordinates of each column of pixels along the X-axis are X1, X2, ..., Xn. Within the range [Ym, Yn], the pixel value corresponding to X = X1 is H... m X1 H m+1X1 ..., H n X1 The pixel values ​​corresponding to X = X2 are H respectively. m X2 H m+1X2 ..., H n X2 The pixel values ​​corresponding to X = Xn are H respectively. m Xn Hm+1Xn ..., H nXn .

[0182] In this embodiment of the application, by determining the pixel values ​​of the target image within the range of Ym≤Y≤Yn in the coordinate system, the spacing between adjacent anode and cathode plates of the electrode assembly can be determined using the pixel values ​​of the pixels within the range of Ym≤Y≤Yn, which can reduce data overhead and improve computational efficiency.

[0183] 840, determine the sum of multiple pixel values ​​corresponding to multiple columns of pixels distributed along the X-axis of the target image within the range of Ym≤Y≤Yn.

[0184] The multi-column pixel data may include pixels from all columns of the target image, or it may include pixels from only some columns of the target image.

[0185] For example, multiple columns of pixels distributed along the X-axis correspond to coordinates X1, X2, ..., Xn. Within the range [Ym, Yn], the sum of the pixel values ​​corresponding to X = X1 is H. m X1 +H m+1 X1 +……+H n X1 The sum of the pixel values ​​corresponding to X = X2 is H. m X2 +H m+1 X2 +……+H n X2 The sum of the pixel values ​​corresponding to X = Xn is H. m Xn +H m+1Xn +……+H nXn .

[0186] 850. Based on the sum of multiple pixel values, determine the target lines in the target image where the anode and cathode plates are parallel to the Y-axis.

[0187] The target line includes the edge and / or centerline.

[0188] 860. Based on the target line, determine the spacing between adjacent anode and cathode plates of the wound electrode assembly.

[0189] In the target image, each electrode can include a centerline parallel to the Y-axis and two edges. Each electrode has two edges along the X-axis, for example, one edge corresponds to the coordinate X = Xa, the other edge corresponds to the coordinate X = Xb, and the centerline can correspond to the coordinate (Xb-Xa) / 2.

[0190] As an example, the pixel values ​​of each column of pixels distributed along the X-axis shown in Figure 9 within the range of [Ym,Yn] can be summed to obtain the total pixel values ​​of each column within the range of [Ym,Yn].

[0191] As an example, the pixel values ​​of a column of pixels arranged along the X-axis in Figure 9 within the range [Ym,Yn] can be summed to obtain the image shown in Figure 10. The X-axis in Figure 10 can be represented by distance or pixels; the Y-axis in Figure 10 represents the sum of pixel values ​​of a column of pixels within the range [Ym,Yn] in Figure 9. In Figure 10, along the X-axis, the sum of pixel values ​​first increases to a first maximum value, then decreases to 0 and remains at a first distance; then it increases to a second maximum value, then rapidly decreases to 0 and remains at a second distance; then it rapidly increases to a third maximum value, and then gradually decreases to 0, repeating this cyclical pattern.

[0192] The target image shows that the anode and cathode plates differ in size, outline, and brightness. The anode plate is narrower and brighter, while the cathode plate is wider and darker. The current collector in the middle of the cathode plate is darker, while the film layers on both sides are brighter.

[0193] As an example, the first maximum value in Figure 10 can be taken as the centerline of the anode, the second maximum value as the centerline of the film layer on one side of the cathode, and the third maximum value as the centerline of the film layer on the other side of the cathode. The extension of the midpoint of the second distance along the Y-axis can be taken as the centerline of the cathode.

[0194] If the centerline of the anode plate is X = X1 and the centerline of the cathode plate is X = X2, X2 - X1 can be used as the distance D between the centerlines of the adjacent anode and cathode plates. Then, using D - (T_anode + T_cathode) / 2, the interval between the adjacent anode and cathode plates can be obtained.

[0195] Of course, the edges of the anode and cathode plates can also be determined according to Figure 10, and the interval between adjacent anode and cathode plates can be determined according to the X coordinates corresponding to the edges. For example, in Figure 10, the X coordinates corresponding to the first time the sum of pixel values ​​starts to increase and the first time it starts to decrease to 0 can be used as the coordinates of the two side edges of the anode plate, and the X coordinates corresponding to the second time the sum of pixel values ​​starts to increase and the third time it starts to decrease to 0 can be used as the coordinates of the two side edges of the cathode plate.

[0196] Alternatively, the average value of the pixel values ​​of multiple columns of pixels distributed along the X-axis in the target image within the range of [Ym,Yn] can be calculated, and then the target lines of the anode and cathode electrodes can be determined based on the average value.

[0197] In this embodiment, by determining the sum of multiple pixel values ​​corresponding to multiple columns of pixels arranged along the X-axis of the target image within the range of Ym≤Y≤Yn, the centerline or edge of the anode and cathode of the electrode assembly can be determined more accurately. This allows for accurate determination of the spacing between adjacent anode and cathode of the electrode assembly, thereby improving the accuracy of detection.

[0198] In some embodiments, the scintillator is made of one or more of the following materials: organic crystal, plastic, organic liquid, inorganic crystal, glass, or gas.

[0199] In the embodiments of this application, the material of the scintillator may include one or more of organic crystals, plastics, organic liquids, inorganic crystals, glass, or gases, thereby flexibly selecting the scintillator for the detection of electrode components.

[0200] In some embodiments, the scintillator is made of cesium iodide inorganic crystal.

[0201] In the embodiments of this application, by using cesium iodide inorganic crystal as the material of the scintillator, the conversion efficiency of X-ray beam energy and fluorescent photons can be improved, the efficiency of X-ray beam detection can be improved, and the imaging quality can be improved.

[0202] For example, the size of the scintillator along the centerline of the beam ranges from 100 μm to 900 μm.

[0203] The dimension of the scintillator along the centerline of the beam can also be understood as the thickness of the scintillator.

[0204] Detective quantum efficiency (DQE) can be interpreted as the utilization rate of effective quantum mechanics in an imaging system. A higher DQE value (maximum value of 1, i.e., 100% utilization) indicates higher effective quantum utilization, resulting in a higher signal-to-noise ratio (SNR) and better image quality. DQE can be calculated using the following formula: DQE = (Output image SNR / Input image SNR) 2

[0205] As a scintillator, cesium iodide, when its thickness is increased, can improve the conversion efficiency of the X-ray beam, that is, improve the DQE (distribution quality). Under the same dose, a thicker cesium iodide scintillator produces more photon signals, improving the signal-to-noise ratio of the output image, thereby improving imaging quality and helping to enhance image resolution.

[0206] The modulation transfer function (MTF) is the spatial frequency transfer function for contrast in an imaging system, typically used to represent the system's ability to resolve image details. MTF can be calculated using the following formula: MTF = Output image contrast / Input image contrast.

[0207] As the thickness of the cesium iodide scintillator increases, the degree of light scattering increases, causing a decrease in MTF, which in turn reduces the spatial resolution of the imaging system, resulting in more blurred edge features of the object being measured.

[0208] There is a contradictory relationship between DQE and MTF. As the thickness of cesium iodide increases, DQE improves, resulting in a higher image signal-to-noise ratio, which helps improve the detection of low-contrast features. However, this also causes a decrease in MTF, leading to a reduction in the spatial resolution of the imaging system and making the edge features of the measured object more blurred. Therefore, it is necessary to control the thickness of the scintillator within a certain range to improve the image resolution.

[0209] In this embodiment, the thickness of the scintillator can be controlled between 100μm and 900μm. This can reduce the impact of low beam conversion efficiency caused by a thinner scintillator on imaging quality, and also reduce the impact of increased light scattering caused by a thinner scintillator on imaging quality, thereby maximizing the imaging quality of the target image and improving the detection accuracy of the electrode assembly.

[0210] For example, the thickness of the scintillator ranges from 400 μm to 700 μm.

[0211] Calculations show that a cesium iodide scintillator with a thickness of 400 μm has a DQE ranging from 0.5 to 0.7 and an MTF of approximately 72.0%. A cesium iodide scintillator with a thickness of 600 μm has a DQE ranging from 0.55 to 0.7 and an MTF of approximately 67.0%. A cesium iodide scintillator with a thickness of 700 μm has a DQE ranging from 0.6 to 0.8 and an MTF of approximately 58.2%.

[0212] In the embodiments of this application, the thickness of the scintillator can be controlled between 400μm and 700μm, and the DQE and MTF can be controlled within a relatively high range, thereby further improving the resolution of the target image and thus improving the detection accuracy.

[0213] For example, along the centerline direction of the ray beam, the size of the electrode assembly is less than or equal to 35 mm, and the size of the scintillator ranges from 400 μm to 500 μm.

[0214] For example, when the size of the electrode assembly is greater than or equal to 30 mm and less than or equal to 40 mm along the centerline direction of the beam, the size of the scintillator ranges from 500 μm to 600 μm.

[0215] For example, along the centerline direction of the ray beam, the size of the electrode assembly is greater than or equal to 35 mm, and the size of the scintillator is between 600 μm and 700 μm.

[0216] For example, D in Figure 6 represents the size of the electrode assembly along the centerline of the beam. Of course, if the placement angle of the electrode assembly changes, D in Figure 6 will generally also change.

[0217] In the embodiments of this application, the different sizes of the electrode components along the center line of the X-ray beam result in significant differences in the dose of the incident X-ray beam, and the energy of the X-ray beam after penetrating the electrode components will also vary significantly. Therefore, scintillators of different thicknesses are needed to convert the X-ray beam after penetrating the electrode components, thereby obtaining images with higher imaging quality and improving the detection accuracy of the electrode components.

[0218] In some embodiments, the radiation source of the radiation beam satisfies one or more of the following conditions:

[0219] The rated voltage of the X-ray source for the X-ray beam is between 110kV and 225kV.

[0220] The rated current of the X-ray source for the X-ray beam is between 100uA and 1000uA.

[0221] The focal size of the X-ray source ranges from 10µm to 100µm.

[0222] In some embodiments, the radiation source of the radiation beam satisfies one or more of the following conditions:

[0223] The rated voltage of the X-ray source for the X-ray beam is between 150kV and 180kV.

[0224] The rated current of the X-ray source for the X-ray beam ranges from 100uA to 500uA.

[0225] The focal size of the X-ray source ranges from 20µm to 50µm.

[0226] In the embodiments of this application, by controlling one or more of the rated voltage, rated current or focal size of the X-ray source within a reasonable range, the dose of the X-ray beam can be controlled within a reasonable range, thereby improving imaging quality while saving energy as much as possible.

[0227] In some embodiments, the detector may include a detector with an elongated detection surface, such as an elongated CCD detector.

[0228] For example, the size and shape of the detector can be increased by splicing chips.

[0229] This can reduce the impact of the small field of view of existing detectors on the detection of electrode components.

[0230] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0231] The detection method for electrode components according to embodiments of this application has been described in detail above. The detection device for battery system according to embodiments of this application will be described in detail below with reference to FIG11 and FIG12. The technical features described in the method embodiments are applicable to the following device embodiments.

[0232] Figure 11 is a schematic block diagram of a detection device for an electrode assembly provided in an embodiment of this application. As shown in Figure 11, the detection device 4000 includes an X-ray source 4010, a scintillator 4020, a lens 4030, a detector 4040, and a processing unit 4050.

[0233] The X-ray source 4010 is used to emit a X-ray beam that penetrates the area to be detected of the electrode assembly; the scintillator 4020 is used to convert the X-ray beam penetrating the area to be detected of the electrode assembly into visible light; the lens 4030 is used to amplify the visible light; the detector 4040 is used to convert the amplified visible light into an electrical signal; and the processing unit 4050 is used to generate a target image based on the electrical signal and to detect the electrode plates of the electrode assembly based on the target image, wherein the target image includes an image of the electrode plates in the area to be detected of the electrode assembly.

[0234] In some embodiments, the processing unit 4050 is configured to determine the spacing between adjacent anode and cathode plates of the electrode assembly based on a target image, wherein the target image includes an image of at least one layer of anode plates and at least one layer of cathode plates of the electrode assembly.

[0235] In some embodiments, the centerline of the ray beam is parallel to the target direction, which is the direction of the shortest diameter of the wound electrode assembly, which includes a wound electrode assembly.

[0236] In some embodiments, the scintillator 4020 is used to convert a beam of light penetrating a corner region into visible light, and the wound electrode assembly includes the corner region.

[0237] In some embodiments, the target image includes an image of the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on a target plane, the target plane being a straight plane parallel to the straight region of the wound electrode assembly and passing through the longest diameter of the wound electrode assembly.

[0238] In some embodiments, the processing unit 4050 is configured to: determine the pixel value of a pixel in a target image; and determine the spacing between adjacent anode and cathode plates of the wound electrode assembly based on the pixel value of the pixel in the target image.

[0239] In some embodiments, the processing unit 4050 is used to determine the pixel values ​​of the target image within the range Ym≤Y≤Yn in the coordinate system. Along the X-axis direction of the coordinate system, the anode and cathode plates in the target image are arranged alternately. Along the Y-axis direction of the coordinate system, the minimum value of the anode and cathode plates in the target image is less than or equal to Ym and the maximum value of the anode and cathode plates in the target image is greater than or equal to Yn.

[0240] In some embodiments, the processing unit 4050 is configured to determine the sum of multiple pixel values ​​corresponding to multiple columns of pixels distributed along the X-axis of the target image within the range of Ym≤Y≤Yn; based on the sum of multiple pixel values, determine target lines in the target image where the anode and cathode plates are parallel to the Y-axis, the target lines including edges and / or centerlines; and based on the target lines, determine the spacing between adjacent anode and cathode plates of the wound electrode assembly.

[0241] In some embodiments, the scintillator 4020 is made of cesium iodide inorganic crystal.

[0242] In some embodiments, the size of the scintillator 4020 along the centerline direction of the beam ranges from 100 μm to 900 μm.

[0243] In some embodiments, the size of the scintillator 4020 along the centerline direction of the beam ranges from 400 μm to 700 μm.

[0244] In some embodiments, the size of the electrode assembly is less than or equal to 35 mm along the centerline direction of the beam, and the size of the scintillator 4020 is between 400 μm and 500 μm.

[0245] In some embodiments, along the centerline direction of the beam, the size of the electrode assembly is greater than or equal to 30 mm and less than or equal to 40 mm, and the size of the scintillator 4020 is in the range of 500 μm to 600 μm.

[0246] In some embodiments, the size of the electrode assembly is greater than or equal to 35 mm along the centerline direction of the beam, and the size of the scintillator 4020 is between 600 μm and 700 μm.

[0247] In some embodiments, the radiation source 4010 satisfies one or more of the following conditions: the rated voltage of the radiation source of the radiation beam is in the range of 110kV-225kV; the rated current of the radiation source of the radiation beam is in the range of 100uA-1000uA; and the focal spot size of the radiation source of the radiation beam is in the range of 10um-100um.

[0248] In some embodiments, the radiation source 4010 satisfies one or more of the following conditions: the rated voltage of the radiation source of the radiation beam is in the range of 150kV-180kV; the rated current of the radiation source of the radiation beam is in the range of 100uA-500uA; and the focal spot size of the radiation source of the radiation beam is in the range of 20um-50um.

[0249] In some embodiments, the beam includes an X-ray beam.

[0250] It should be understood that the above and other operations and / or functions of the various modules in the detection device 4000 of the battery system are to implement the corresponding processes in the various methods of Figures 2 to 10, and for the sake of brevity, they will not be described in detail here.

[0251] Figure 12 shows a schematic block diagram of an electrode assembly detection device 5000 according to an embodiment of this application. As shown in Figure 12, the detection device 5000 includes a processor 5010 and a memory 5020, wherein the memory 5020 is used to store instructions, and the processor 5010 is used to read the instructions and execute the methods of the various embodiments of this application described above based on the instructions.

[0252] The memory 5020 can be a separate device independent of the processor 5010, or it can be integrated into the processor 5010.

[0253] Optionally, as shown in Figure 12, the detection device 5000 for the electrode assembly may further include a transceiver 5030, and the processor 5010 can control the transceiver 5030 to communicate with other devices. Specifically, it can send information or data to other devices, or receive information or data sent by other devices.

[0254] It should be understood that the processor in the embodiments of this application may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor described above can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0255] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0256] Optionally, embodiments of this application also provide an X-ray detection device, which includes the detection apparatus provided in embodiments of this application.

[0257] This application also provides a computer-readable storage medium for storing computer programs.

[0258] Optionally, the computer-readable storage medium can be applied to the detection device of the electrode assembly in the embodiments of this application, and when the computer program is run on the computer, it causes the computer to execute the corresponding processes implemented by the detection device of the electrode assembly in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0259] This application also provides a computer program product, including computer program instructions.

[0260] Optionally, the computer program product can be applied to the detection device of the electrode assembly in the embodiments of this application, and the computer program instructions, when run on a computer, cause the computer to execute the corresponding processes implemented by the detection device of the electrode assembly in the various methods of the embodiments of this application. For the sake of brevity, they will not be described in detail here.

[0261] This application also provides a computer program.

[0262] Optionally, the computer program can be applied to the detection device of the electrode assembly in the embodiments of this application. When the computer program is run on the computer, the computer executes the corresponding processes implemented by the detection device of the electrode assembly in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0263] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0264] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0265] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection involved in the embodiments of this application may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0266] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0267] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0268] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0269] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for detecting an electrode assembly, characterized in that, The detection method includes: A scintillator is used to convert the X-ray beam that penetrates the area to be detected through the electrode assembly into visible light; The visible light is magnified using a lens, and the magnified visible light is converted into an electrical signal using a detector to generate a target image, the target image including an image of the electrode sheet of the area to be detected of the electrode assembly; The electrodes of the electrode assembly are detected based on the target image.

2. The detection method according to claim 1, characterized in that, The step of detecting the electrode plates of the electrode assembly based on the target image includes: Based on the target image, the spacing between adjacent anode and cathode plates of the electrode assembly is determined, wherein the target image includes images of at least one layer of anode plates and at least one layer of cathode plates of the electrode assembly.

3. The detection method according to claim 1 or 2, characterized in that, The centerline of the ray beam is parallel to the target direction, which is the direction of the shortest diameter of the wound electrode assembly, and the electrode assembly includes the wound electrode assembly.

4. The detection method according to claim 3, characterized in that, The method of converting the X-ray beam penetrating the detection area of ​​the electrode assembly into visible light using a scintillator includes: The scintillator converts the ray beam penetrating the corner region into visible light, and the wound electrode assembly includes the corner region.

5. The detection method according to claim 4, characterized in that, The target image includes an image of the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on a target plane, wherein the target plane is a straight plane parallel to the straight region of the wound electrode assembly and passes through the longest diameter of the wound electrode assembly.

6. The detection method according to claim 4 or 5, characterized in that, Determining the spacing between adjacent anode and cathode electrodes of the electrode assembly based on the target image includes: Determine the pixel values ​​of the pixels in the target image; The spacing between adjacent anode and cathode electrodes of the wound electrode assembly is determined based on the pixel values ​​of the target image.

7. The detection method according to claim 6, characterized in that, Determining the pixel values ​​of the pixels in the target image includes: Determine the pixel values ​​of the target image within the coordinate system Ym≤Y≤Yn. Along the X-axis of the coordinate system, the anode and cathode electrodes in the target image are arranged alternately. Along the Y-axis of the coordinate system, the minimum value of the anode and cathode electrodes in the target image is less than or equal to Ym, and the maximum value of the anode and cathode electrodes in the target image is greater than or equal to Yn.

8. The detection method according to claim 7, characterized in that, Determining the spacing between adjacent anode and cathode electrodes of the wound electrode assembly based on the pixel values ​​of the target image includes: Determine the sum of multiple pixel values ​​corresponding to multiple columns of pixels distributed along the X-axis of the target image in the range Ym≤Y≤Yn; Based on the sum of the multiple pixel values, target lines are determined in the target image in which the anode and cathode plates are parallel to the Y-axis, respectively, and the target lines include edges and / or centerlines. Based on the target line, the spacing between adjacent anode and cathode electrodes of the wound electrode assembly is determined.

9. The detection method according to any one of claims 1 to 8, characterized in that, The beam of light includes an X-ray beam.

10. A detection device for an electrode assembly, characterized in that, The detection device includes: A radiation source, used to emit a beam of radiation that penetrates the area to be detected in the electrode assembly; A scintillator is used to convert a beam of light that penetrates the area to be detected in the electrode assembly into visible light; A lens for amplifying the visible light; A detector is used to convert the amplified visible light into an electrical signal; A processing unit is configured to generate a target image based on the electrical signal, and to detect the electrode plates of the electrode assembly based on the target image, wherein the target image includes an image of the electrode plates in the area to be detected of the electrode assembly.

11. The detection device according to claim 10, characterized in that, The processing unit is configured to determine the spacing between adjacent anode and cathode plates of the electrode assembly based on the target image, wherein the target image includes images of at least one layer of anode plates and at least one layer of cathode plates of the electrode assembly.

12. The detection device according to claim 10 or 11, characterized in that, The centerline of the ray beam is parallel to the target direction, which is the direction of the shortest diameter of the wound electrode assembly, and the electrode assembly includes the wound electrode assembly.

13. The detection device according to claim 12, characterized in that, The scintillator is used to convert the ray beam penetrating the corner region into visible light, and the wound electrode assembly includes the corner region.

14. The detection device according to claim 13, characterized in that, The target image includes an image of the cross-section of at least one layer of anode and at least one layer of cathode in the corner region on a target plane, wherein the target plane is a straight plane parallel to the straight region of the wound electrode assembly and passes through the longest diameter of the wound electrode assembly.

15. The detection device according to claim 13 or 14, characterized in that, The processing unit is configured to determine the pixel values ​​of the pixels in the target image; and The spacing between adjacent anode and cathode electrodes of the wound electrode assembly is determined based on the pixel values ​​of the target image.

16. The detection device according to claim 15, characterized in that, The processing unit is used to determine the pixel values ​​of the target image within the coordinate system range of Ym≤Y≤Yn. Along the X-axis of the coordinate system, the anode and cathode plates in the target image are arranged alternately. Along the Y-axis of the coordinate system, the minimum value of the anode and cathode plates in the target image is less than or equal to Ym, and the maximum value of the anode and cathode plates in the target image is greater than or equal to Yn.

17. The detection device according to claim 16, characterized in that, The processing unit is used to determine the sum of multiple pixel values ​​corresponding to multiple columns of pixels distributed along the X-axis of the target image in the range of Ym≤Y≤Yn; Based on the sum of the multiple pixel values, target lines are determined in the target image in which the anode and cathode plates are parallel to the Y-axis, respectively, and the target lines include edges and / or centerlines. as well as Based on the target line, the spacing between adjacent anode and cathode electrodes of the wound electrode assembly is determined.

18. The detection device according to any one of claims 10 to 17, characterized in that, The scintillator is made of cesium iodide inorganic crystal.

19. The detection apparatus according to any one of claims 10 to 18, characterized in that, The thickness of the scintillator ranges from 100 μm to 900 μm.

20. The detection apparatus according to any one of claims 10 to 19, characterized in that, The thickness of the scintillator ranges from 400 μm to 700 μm.

21. The detection device according to any one of claims 10 to 20, characterized in that, When the size of the electrode assembly is less than or equal to 35 mm along the centerline of the ray beam, the size of the scintillator is between 400 μm and 500 μm.

22. The detection device according to any one of claims 10 to 21, characterized in that, When the size of the electrode assembly is greater than or equal to 30 mm and less than or equal to 40 mm along the centerline of the ray beam, the size of the scintillator is between 500 μm and 600 μm.

23. The detection apparatus according to any one of claims 10 to 22, characterized in that, When the size of the electrode assembly is greater than or equal to 35 mm along the centerline of the ray beam, the size of the scintillator is between 600 μm and 700 μm.

24. The detection device according to any one of claims 10 to 23, characterized in that, The radiation source satisfies one or more of the following conditions: The rated voltage of the radiation source is between 110kV and 225kV. The rated current of the radiation source is between 100uA and 1000uA. The focal size of the radiation source is in the range of 10um-100um.

25. The detection device according to any one of claims 10 to 24, characterized in that, The radiation source of the radiation beam satisfies one or more of the following conditions: The rated voltage of the radiation source is between 150kV and 180kV. The rated current of the radiation source is between 100uA and 500uA. The focal size of the radiation source is in the range of 20um-50um.

26. The detection apparatus according to any one of claims 10 to 25, characterized in that, The beam of light includes an X-ray beam.

27. A detection device for an electrode assembly, characterized in that, The device includes a memory and a processor, the memory being used to store instructions, and the processor being used to read the instructions and execute the detection method as described in any one of claims 1 to 9 according to the instructions.

28. An X-ray inspection device, characterized in that, The X-ray detection equipment includes the detection device according to any one of claims 10 to 27.

29. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program, which, when executed by a computer, causes the computer to implement the detection method as described in any one of claims 1 to 9.

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