Battery cell electrode plate alignment detection method and device

Abstract

This invention discloses a method and apparatus for detecting the alignment of battery cell electrodes. The method includes irradiating the electrode group of the battery cell under test with X-ray light at a set angle to obtain the X-ray projection value; comparing the X-ray projection value with a standard range of projection values; if the X-ray projection value is within the standard range of projection values, the electrode group of the battery cell under test is judged to be qualified in the initial inspection; otherwise, the electrode group of the battery cell under test is determined to be an abnormal electrode group. The standard range of projection values ​​is pre-determined based on the electrode coating value and the set angle. When using X-ray to detect electrode alignment, since the detected X-ray projection value cannot directly represent the alignment coating value, this invention calculates the standard range of projection values ​​based on the electrode coating value and the irradiation angle of the X-ray light as the detection and judgment index for electrode alignment, thereby ensuring the accuracy of the detection and reducing missed or over-detection.

Description

Technical Field

[0001] This invention relates to the field of battery cell testing technology, specifically to a method and apparatus for testing the alignment of battery cell electrodes. Background Technology

[0002] In the battery cell manufacturing process, during the electrode assembly steps—winding, stacking, and thermal bonding—it is crucial to ensure that the negative electrode completely covers the positive electrode. This guarantees that lithium ions can be fully embedded in the negative electrode during charging and discharging, eliminating any safety hazards to the battery cell. Therefore, it is necessary to inspect the coverage between the positive and negative electrodes, i.e., the electrode alignment.

[0003] Currently, the mainstream method for detecting electrode alignment in the industry is to use a CCD camera for 100% online full inspection of alignment (per layer). This method is timely and accurate, and is widely used. However, CCD inspection cannot penetrate the surface; it can only detect the surface captured by the visual CCD. Therefore, it can only be inspected layer by layer during stacking. Furthermore, during stacking / winding, various program bugs, CCD blind spots, and detection logic problems can lead to problems such as multiple or missing electrodes, or tilted electrode groups, which cannot be detected in a timely and accurate manner. After the electrode group is formed, during subsequent processing, factors such as gaps in robot interaction and sudden stops of transport trays can cause the electrodes in the electrode group to shift or rotate due to gravity and inertia, resulting in poor electrode alignment. Once the electrode group is stacked / wound, the visual CCD camera cannot detect the specific internal coating condition, leading to potential safety hazards related to leakage.

[0004] And X Ray inspection has penetrating power, allowing it to penetrate the interior of the electrode assembly and detect defects such as multiple / few electrodes, electrode misalignment, and electrode rotation issues. Therefore, some production lines directly use ray inspection. Alignment can be checked using ray spectroscopy, or an additional X-ray spectroscopy can be added after the CCD stacking process. Ray inspection is used to uniformly inspect for defects inside the electrode assembly after the electrode assembly is stacked / wound.

[0005] For example, in related technologies, patent applications CN116721055A and CN116503348A use X-ray light to image the overhang areas at the four corners of a stacked / wound battery. By analyzing the obtained overhang images, the cathode region and anode contour are extracted, and the distance between the cathode and anode poles is used to determine whether the anode overhang length is acceptable. Patent application CN112330623A uses a neural network model to obtain the vertex coordinates of each electrode in the cell's electrode assembly. By calculating the distance between the vertices of each electrode, the alignment of the electrodes is determined. Patent application CN117408937A uses a model to obtain the positions of the positive and negative poles of the electrode assembly. Based on the positions of the positive and negative poles, the coordinates of the cathode and anode poles are obtained, and traditional algorithms are used for alignment detection.

[0006] It is evident that X is currently used in the industry. The methods for ray alignment detection are not uniform. The standards are given in a rough and too lenient manner, and there is no clear theoretical basis to support them. This leads to problems such as missed detection or serious over-detection in actual production lines, which need to be improved and resolved. Summary of the Invention

[0007] The technical problem to be solved by this invention is how to improve the accuracy of electrode alignment detection and minimize the detection of missed or over-detected electrodes.

[0008] The present invention solves the above-mentioned technical problems through the following technical means:

[0009] A method for detecting the alignment of battery cell electrodes is proposed, the method comprising: X-ray light is used to irradiate the electrode assembly of the battery cell under test at a set irradiation angle to obtain the X-ray projection value; The ray projection value is compared with the standard range of projection values. If the ray projection value is within the standard range of projection values, the initial inspection of the electrode group of the battery cell under test is deemed to be qualified; otherwise, the electrode group of the battery cell under test is determined to be an abnormal electrode group. The standard range of projection values ​​is determined in advance based on the cell electrode coating value and the irradiation angle.

[0010] Furthermore, the illumination angle The range of values ​​is .

[0011] Furthermore, when the battery cell is a blade battery cell, the standard range of the projection value includes the standard range of the projection value on the positive electrode tab side and the standard range of the projection value on the negative electrode tab side; The standard range for the negative ear-side projection value is [ , The standard range for the positive electrode ear-side projection value is []. , ]; in, The standard value for the negative ear-side projection. This is the standard value for the positive ear-side projection. for tolerance, for The tolerance.

[0012] Furthermore, when the battery cell is a prismatic battery cell, the standard range of the projection value includes the standard range of the projection value on the tab side and the standard range of the projection value on the non-tab side. The standard range of the pole ear side projection value is [ , The standard range for non-polar ear side projection values ​​is [ , ]; in, The standard projection value is for the pole ear side. The standard projection value is for the non-polar ear side. for tolerance, for The tolerance.

[0013] Furthermore, the formula for calculating the projection standard value is as follows:

[0014] In the formula, Core electrode coating value , These are the longitudinal and lateral coverage dimensions of the negative electrode ear side, respectively. For the angle of illumination, and These are the widths of the positive electrode and the negative electrode, respectively. and These represent the depths of the positive electrode and the negative electrode, respectively.

[0015] Furthermore, tolerance Calculation using the probability tolerance method.

[0016] Further, when the battery cell is a blade battery cell, the ray projection value includes the positive electrode tab side projection value and the negative electrode tab side projection value; the comparison of the ray projection value with the standard range of projection values, and the determination that the initial inspection of the battery cell electrode group under test is qualified when the ray projection value is within the standard range of projection values, otherwise the battery cell electrode group under test is determined to be an abnormal electrode group, includes: Determine whether the positive ear-side projection value is within the standard range of the positive ear-side projection value and the negative ear-side projection value is within the standard range of the negative ear-side projection value. If so, the initial inspection of the electrode assembly of the battery cell under test is deemed qualified. If not, then the electrode group of the cell under test is determined to be an abnormal electrode group.

[0017] Further, when the cell is a prismatic cell, the ray projection value includes the tab-side projection value and the tab-side projection value; the ray projection value includes the positive tab-side projection value and the negative tab-side projection value; the comparison of the ray projection value with the standard range of projection values, and the determination that the initial inspection of the cell electrode group under test is qualified when the ray projection value is within the standard range of projection values, otherwise the cell electrode group under test is determined to be an abnormal electrode group, includes: Determine whether the polar side projection value is within the standard range of polar side projection values ​​and the non-polar side projection value is within the standard range of non-polar side projection values. If so, the initial inspection of the electrode assembly of the battery cell under test is deemed qualified. If not, then the electrode group of the cell under test is determined to be an abnormal electrode group.

[0018] Furthermore, after determining that the electrode assembly of the cell under test has passed the initial inspection, the method further includes: To determine whether the same-pole range of the electrode group of the battery cell that has passed the initial inspection is less than or equal to the control standard value of the same-pole range, and to determine whether the same-layer range of the electrode group of the battery cell that has passed the initial inspection is less than or equal to the control standard value of the same-layer range. If so, the electrode group of the battery cell that passed the initial inspection is determined to be a qualified electrode group; If not, then the electrode group of the battery cell that passed the initial inspection is determined to be an abnormal electrode group; Among them, the same pole range is the difference between the maximum and minimum values ​​of the projection values ​​of the same pole tab side in the n-layer pole sheet of the pole group; the same layer range is the difference between the projection values ​​of the left and right sides of the same pole tab side of the same layer pole sheet.

[0019] Furthermore, the control standard value for the same-range range is:

[0020] In the formula, The control standard value is the same range. The difference in width between transverse electrodes. The lateral electrode positioning is extremely poor. For the longitudinal polarity range, The longitudinal electrode positioning is extremely poor. The angle of illumination.

[0021] Furthermore, the control standard values ​​for the same-layer range include the control standard values ​​for the same-layer negative electrode ear-side range and the control standard values ​​for the same-layer positive electrode ear-side range, wherein, The standard value for the range control of the negative electrode ear side in the same layer is:

[0022] The standard value for range control of the positive electrode ear side in the same layer is:

[0023] In the formula, , These are the projection values ​​of the left and right sides of the positive electrode ear on the same layer. , These are the projection values ​​of the left and right sides of the negative electrode ear on the same layer. , These represent the maximum and minimum longitudinal coverage dimensions when the negative electrode ear side is rotated to its limit. , These represent the minimum and maximum lateral coverage dimensions when the negative electrode ear side is rotated to its limit. , These represent the maximum and minimum longitudinal coverage dimensions of the positive electrode tab when it is rotated to its limit. The angle of illumination.

[0024] Furthermore, the electrode coating value of the battery cell is obtained in advance using a CCD camera.

[0025] Furthermore, the present invention also proposes a battery cell electrode alignment detection device, the device comprising: X The X-ray detection module is used to irradiate the electrode assembly of the battery cell under test with X-ray light at a set irradiation angle to obtain the X-ray projection value. The initial inspection module is used to compare the X-ray projection value with the standard range of projection values. If the X-ray projection value is within the standard range of projection values, the initial inspection of the electrode group of the battery cell under test is deemed to be qualified; otherwise, the electrode group of the battery cell under test is determined to be an abnormal electrode group. The standard range of projection values ​​is determined in advance based on the cell electrode coating value and the irradiation angle.

[0026] The advantages of this invention are: (1) When using X-ray light to detect electrode alignment, since the detected X-ray projection value cannot directly represent the electrode alignment coverage value, this invention uses theoretical analysis to calculate the standard range of projection value based on the electrode coverage value and the irradiation angle of X-ray light as the detection and judgment index of electrode alignment. When the X-ray projection value is within the standard range of projection value, the electrode group of the battery cell to be tested is judged to be qualified in the initial inspection; otherwise, the electrode group of the battery cell to be tested is determined to be an abnormal electrode group, so as to ensure the accuracy of detection and reduce the phenomenon of missed detection and over-detection.

[0027] (2) In order to ensure the detection rate of various abnormalities within the electrode group, the present invention makes a comprehensive judgment by using the standard range of projection values ​​and other additional judgment indicators such as the same electrode range and the same layer range. By using multi-dimensional and comprehensive detection judgment indicators, it ensures that various coating defects can be effectively detected by X-ray light, so as to ensure the accuracy of detection and minimize the phenomenon of missed detection and over-detection.

[0028] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation thereof. Figure 1 This is a schematic flowchart of a method for detecting the alignment of battery cell electrodes according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the electrode coating dimensions in one embodiment of the present invention; Figure 3 This is a schematic diagram of the conversion principle of projection standard value in one embodiment of the present invention, wherein (a) is a schematic diagram of the projection of a square-shell battery cell, and (b) is a schematic diagram of the conversion principle of the projection standard value of a square-shell battery cell. Figure 4 This is a schematic diagram illustrating the conversion principle of the standard value of the negative electrode ear side projection of the blade battery cell in one embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the conversion principle of the standard value of the positive electrode ear side projection of the blade battery cell in one embodiment of the present invention; Figure 6 This is a schematic diagram of the V-angle projection of the electrode sheet in one embodiment of the present invention; Figure 7 This is a schematic diagram illustrating the conversion principle of the control standard value of the same polarity range in one embodiment of the present invention; Figure 8 This is a schematic diagram showing the corresponding definition of the same pole range in one embodiment of the present invention; Figure 9 This is a schematic diagram illustrating the conversion principle of the control standard value of the same-layer range in one embodiment of the present invention; Figure 10 This is a schematic diagram of a battery cell electrode alignment detection device according to an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] like Figure 1 As shown, the first embodiment of the present invention proposes a method for detecting the alignment of battery cell electrodes, the method comprising the following steps: S10. Use X-ray light to irradiate the electrode group of the battery cell under test at a set irradiation angle to obtain the X-ray projection value; It should be noted that in this embodiment, X-ray light is used to irradiate the four corners of the electrode assembly of the battery cell under test at a certain irradiation angle, and the ray projection values ​​of the four corners, namely the left and right sides of the positive electrode tab and the left and right sides of the negative electrode tab, are obtained. This process is implemented by existing technology and will not be described in detail in this embodiment.

[0032] S20. Compare the ray projection value with the standard range of projection values. If the ray projection value is within the standard range of projection values, the initial inspection of the electrode group of the battery cell under test is deemed qualified; otherwise, the electrode group of the battery cell under test is determined to be an abnormal electrode group. The standard range of projection values ​​is determined in advance based on the cell electrode coating value and the irradiation angle.

[0033] It should be noted that the cell electrode alignment detection method proposed in this embodiment is applicable to various types of cells, including but not limited to blade cells and prismatic cells. Taking blade cells as an example, as... Figure 2 As shown, to ensure safety, the cell electrode coating must completely cover the positive electrode with the negative electrode. The cell electrode coating value includes the lateral coating dimension of the negative electrode covering the positive electrode. b The longitudinal coverage dimension of the negative electrode completely covering the positive electrode is divided into the longitudinal coverage dimension of the negative electrode ear side. a and the longitudinal coverage size of the positive electrode ear side c A CCD camera can directly detect the coating value of the battery cell electrodes. a , b , cThe specific value. After the electrode assembly is formed, the CCD camera cannot detect the internal coating of the electrode assembly. Alignment problems can still occur even after electrode assembly. Therefore, X-ray light needs to penetrate the electrode assembly for detection. However, since X-ray light is emitted from a fixed angle to illuminate the four corners of the electrode assembly of the cell under test, it obtains the projected values ​​of the four corners (for example, for a blade cell, the projected values ​​include L1 and L2 on the positive electrode tab side and L3 and L4 on the negative electrode tab side). These projected values ​​cannot directly represent the alignment coating value and differ from the value directly detected by the CCD camera before electrode assembly. This embodiment, through theoretical analysis, utilizes the coating value through a reasonable method. a , b , c The standard range of projection values ​​used for comparison with the projection values ​​is calculated as the detection and judgment index for electrode alignment. When the ray projection value is within the standard range of projection values, the electrode group of the battery cell under test is judged to be qualified in the initial inspection. Otherwise, the electrode group of the battery cell under test is determined to be an abnormal electrode group, so as to ensure the accuracy of the detection and reduce the phenomenon of missed detection and over-detection.

[0034] Taking square-shell battery cells as an example, such as Figure 3 As shown, since the positive and negative tabs of the square-shell battery cell are on the same side, it is necessary to measure the tab-side covering dimensions. a (Positive and negative electrodes are on the same side: both are) a ) and non-polar ear side coverage size c ; and horizontal wrapping b .

[0035] As a further preferred technical solution, when the battery cell is a blade battery cell, the standard range of the projection value includes the standard range of the projection value on the positive electrode tab side and the standard range of the projection value on the negative electrode tab side. The standard range for the negative ear-side projection value is [ , The standard range for the positive electrode ear-side projection value is []. , ]; in, The standard projection value is for the negative ear side. The standard projection value is the one on the positive ear side. for tolerance, for The tolerance.

[0036] As a further preferred technical solution, when the battery cell is a prismatic battery cell, the standard range of the projection value includes the standard range of the projection value on the tab side and the standard range of the projection value on the non-tab side. The standard range of the pole ear side projection value is [ , The standard range for non-polar ear side projection values ​​is [ , ]; in, The standard projection value is for the pole ear side. The standard projection value is for the non-polar ear side. for tolerance, for The tolerance.

[0037] As a further preferred technical solution, the formula for calculating the projection standard value is:

[0038] In the formula, Cell electrode coating value , These are the longitudinal and lateral coverage dimensions of the negative electrode ear side, respectively. For the angle of illumination, and These are the widths of the V-angle of the positive electrode and the negative electrode, respectively. and These represent the depth of the V-angle of the positive electrode and the depth of the V-angle of the negative electrode, respectively.

[0039] As a further preferred technical solution, the illumination angle The range of values ​​is .

[0040] Preferably, in this embodiment, the illumination angle is... Set as At this time, the projected value is clear, the detection is accurate, and the calculation is convenient because when the illumination angle α = 45°, cosα = sinα; at this time, the calculation formula is greatly simplified, making it easy to understand and apply, and less prone to errors. Furthermore, because equipment manufacturers often use an illumination angle of 45° for ease of installation, the illumination angle is set accordingly. for The projection is clear and the detection is accurate. When the illumination angle α is not within this range, that is, when the illumination angle is too large (>60°) or too small (<30°), the illumination line is easily blocked or interfered with by the electrode tab, resulting in unclear imaging and thus misjudgment.

[0041] Specifically, such as Figure 4 As shown, taking the blade battery cell as an example, based on the longitudinal wrapping size of the negative electrode tab... Horizontal wrapping dimensions Angle with X-ray illumination of the electrode assembly of the battery cell under test The geometric relationship between them is used to obtain the standard value of the negative ear-side projection, which can be calculated using trigonometric functions:

[0042] Calculated based on the probability tolerance method The tolerance is:

[0043] like Figure 5 As shown, based on the longitudinal coverage size of the positive electrode ear side Horizontal wrapping dimensions Angle with X-ray illumination of the electrode assembly of the battery cell under test The geometric relationship between them is used to obtain the standard value of the positive electrode ear-side projection, which can be calculated using trigonometric functions:

[0044] Calculated based on the probability tolerance method The tolerance is:

[0045] In the formula, the electrode coating value of the battery cell is... , , These represent the longitudinal and transverse wrapping dimensions of the negative electrode ear side, and the longitudinal wrapping dimensions of the positive electrode ear side, respectively. , , The dimensions are respectively the horizontal wrapping size Tolerances, longitudinal wrapping dimensions of the negative electrode ear side Tolerances, longitudinal covering dimensions of the positive electrode ear side The tolerance.

[0046] As a further preferred technical solution, in practical applications, the irradiation angle can also be set to equal the V-angle of the electrode, such as... Figure 6 As shown, when the irradiation angle equals the V-angle angle of the electrode, the irradiation line illuminates along the V-angle slope, and the detected thickness suddenly increases, and the corresponding projected color changes suddenly (the point of change). At this time, the projection is clearest and the measurement point is most accurate.

[0047] As a further preferred technical solution, when the battery cell is a blade battery cell, the ray projection value includes the positive electrode tab side projection value and the negative electrode tab side projection value; Accordingly, step S20: comparing the ray projection value with the standard range of projection values, and determining that the initial inspection of the electrode group of the battery cell under test is qualified when the ray projection value is within the standard range of projection values; otherwise, determining that the electrode group of the battery cell under test is an abnormal electrode group, specifically includes the following steps: S21. Determine whether the positive ear-side projection value is within the standard range of the positive ear-side projection value and the negative ear-side projection value is within the standard range of the negative ear-side projection value. If yes, proceed to step S22; otherwise, proceed to step S23. S22. Determine that the initial inspection of the electrode assembly of the battery cell to be tested is qualified; S23. Determine that the electrode group of the cell to be tested is an abnormal electrode group.

[0048] As a further preferred technical solution, when the battery cell is a prismatic battery cell, the ray projection value includes the tab side projection value and the tab side projection value; step S20: the ray projection value includes the positive tab side projection value and the negative tab side projection value; the comparison of the ray projection value with the standard range of projection values, and the determination that the initial inspection of the battery cell electrode group under test is qualified when the ray projection value is within the standard range of projection values, otherwise the battery cell electrode group under test is determined to be an abnormal electrode group, specifically includes the following steps: S21' Determine whether the polar side projection value is within the standard range of polar side projection value and the non-polar side projection value is within the standard range of non-polar side projection value. If yes, proceed to step S22'; otherwise, proceed to step S23'. S22', Determine that the initial inspection of the electrode group of the cell to be tested is qualified; S23', Determine that the electrode group of the cell under test is an abnormal electrode group.

[0049] As a further preferred technical solution, after step S22: determining that the initial inspection of the electrode assembly of the battery cell to be tested is qualified, the method further includes the following steps: S24. Determine whether the same pole range of the electrode group of the battery cell to be tested that has passed the initial inspection is less than or equal to the control standard value of the same pole range, and determine whether the same layer range of the electrode group of the battery cell to be tested that has passed the initial inspection is less than or equal to the control standard value of the same layer range. If yes, proceed to step S25; otherwise, proceed to step S26. S25. Determine the electrode group of the battery cell to be tested that has passed the initial inspection as a qualified electrode group; S26. Determine the electrode group of the battery cell that passed the initial inspection as an abnormal electrode group; Among them, the same pole range is the difference between the maximum and minimum values ​​of the projection values ​​of the same pole tab side in the n-layer pole sheet of the pole group; the same layer range is the difference between the projection values ​​of the left and right sides of the same pole tab side of the same layer pole sheet.

[0050] It should be noted that during the subsequent processing steps of electrode assembly, there are gaps in the interaction of robotic arms, sudden stops of transfer trays, etc., which cause the electrode sheets in the electrode assembly to move or rotate due to gravity and inertia, resulting in poor electrode alignment. Therefore, this embodiment considers the phenomenon of electrode misalignment and movement and sets a control standard value of the same electrode range to monitor electrode movement and misalignment. It also considers the phenomenon of poor alignment caused by electrode rotation and sets a control standard value of the same layer range to monitor electrode rotation.

[0051] Specifically, such as Figures 7 to 8As shown, the same-polarity range is defined as the difference between the maximum and minimum values ​​of the positive (or negative) electrode on the tab side of n layers of electrodes within an electrode group; X-ray light is used according to the irradiation angle. Taking the irradiation of the electrode assembly of the cell under test as an example, there are Then the control standard value for the same range is:

[0052] In the formula, The control standard value is the same range. The difference in width between transverse electrodes. The lateral electrode positioning is extremely poor. For the longitudinal polarity range, The longitudinal electrode positioning is extremely poor.

[0053] Specifically, in this embodiment, the tolerance of the width of the transverse electrode is ±0.35, so the width tolerance of the transverse electrode = |upper tolerance - lower tolerance| = 0.35 - (-0.35) = 0.7; the tolerance of the length of the longitudinal electrode is ±0.35, so the length tolerance of the longitudinal electrode = 0.35 - (-0.35) = 0.7; and the electrode positioning tolerance = |upper tolerance of electrode positioning - lower tolerance of electrode positioning| = electrode positioning tolerance × 2.

[0054] Specifically, the same-layer range is defined as the difference between the projected values ​​on the left and right sides of the same electrode tab side of an n-layer electrode sheet in the same layer (the control standard value of the same-level range for positive / negative electrodes is calculated in the same direction); in an ideal situation, such as Figure 2 As shown, when the electrode assembly is formed, the electrode is relatively centered, at which point L1=L2 and L3=L4. That is: The difference in the same-layer projection values ​​on the left and right sides of the negative electrode ear side ; The difference in the same-layer projection values ​​on the left and right sides of the positive electrode ear side .

[0055] However, in the actual manufacturing process, there is a possibility of electrode rotational misalignment, such as... Figure 9 As shown, this results in L1≠L2 and L3≠L4; and as the rotation of the electrode intensifies, , As the difference continues to increase, range control is required to prevent the negative electrode from failing to cover the positive electrode due to rotation.

[0056] In this embodiment, X-ray light is used according to the irradiation angle. Taking the irradiation of the electrode assembly of the battery cell under test as an example: When the negative electrode ear side is rotated to the limit of coverage

[0057] Right now: ≤

[0058] When the positive electrode ear side is rotated to the limit of coverage

[0059] Right now: ≤

[0060] In the formula, , These are the projection values ​​of the left and right sides of the positive electrode ear on the same layer. , These are the projection values ​​of the left and right sides of the negative electrode ear on the same layer. , These represent the maximum and minimum longitudinal coverage dimensions when the negative electrode ear side is rotated to its limit. , These represent the minimum and maximum lateral coverage dimensions when the negative electrode ear side is rotated to its limit. , These represent the maximum and minimum longitudinal coverage dimensions of the positive electrode tab when it is rotated to its limit. The angle at which X-ray light is irradiated.

[0061] This embodiment comprehensively judges the standard range of projection values ​​and other additional judgment indicators such as the same-polarity range and the same-layer range. By utilizing multi-dimensional and comprehensive detection judgment indicators, it ensures that various coating defects can be effectively detected by X-ray light, thereby ensuring the accuracy of detection and minimizing the phenomena of missed detection and over-detection.

[0062] In addition, such as Figure 10 As shown, the second embodiment of the present invention also proposes a cell electrode alignment detection device, the device comprising: X The ray detection module 10 is used to irradiate the electrode group of the battery cell under test with X-ray light at a set irradiation angle to obtain the ray projection value. The initial inspection module 20 is used to compare the X-ray projection value with the standard range of projection values. If the X-ray projection value is within the standard range of projection values, the initial inspection of the electrode group of the battery cell under test is deemed to be qualified; otherwise, the electrode group of the battery cell under test is determined to be an abnormal electrode group. The standard range of projection values ​​is determined in advance based on the cell electrode coating value and the irradiation angle.

[0063] As a further preferred technical solution, the preliminary inspection module 20 specifically includes: The first judgment unit is used to determine whether the positive ear-side projection value is within the standard range of the positive ear-side projection value and the negative ear-side projection value is within the standard range of the negative ear-side projection value. The first determining unit is used to determine that the initial inspection of the electrode group of the battery cell under test is qualified when the output result of the first determining unit is yes; and to determine that the electrode group of the battery cell under test is an abnormal electrode group when the output result of the first determining unit is no.

[0064] As a further preferred technical solution, the device also includes a re-inspection module, specifically comprising: The second judgment unit is used to judge whether the same pole range of the electrode group of the battery cell that has passed the initial inspection is less than or equal to the control standard value of the same pole range, and to judge whether the same layer range of the electrode group of the battery cell that has passed the initial inspection is less than or equal to the control standard value of the same layer range. The second determining unit is used to determine the electrode group of the battery cell that passed the initial inspection as a qualified electrode group when the output result of the second determining unit is yes; and to determine the electrode group of the battery cell that passed the initial inspection as an abnormal electrode group when the output result of the second determining unit is no.

[0065] It should be noted that other embodiments or specific implementation methods of the battery cell electrode alignment detection device of the present invention can refer to the above-described method embodiments, and will not be repeated here.

[0066] It should be noted that the computer-readable medium disclosed in this embodiment may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, and portable compact disk read-only memory (CD-ROM). ROM, optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0067] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device. The aforementioned computer-readable medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform a zero-sample image anomaly detection method according to the above embodiments.

[0068] Computer program code for performing the operations of this disclosure can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server.

[0069] In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0070] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0071] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" or "several" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0073] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for detecting the alignment of battery cell electrodes, characterized in that, include: X-ray light is used to irradiate the electrode assembly of the battery cell under test at a set irradiation angle to obtain the X-ray projection value; The ray projection value is compared with the standard range of projection values. If the ray projection value is within the standard range of projection values, the initial inspection of the electrode group of the battery cell under test is deemed to be qualified; otherwise, the electrode group of the battery cell under test is determined to be an abnormal electrode group. The standard range of the projection value is based on the electrode coating value of the battery cell and the illumination angle. Determined by the conversion.

2. The method for detecting the alignment of battery cell electrodes as described in claim 1, characterized in that, The irradiation angle The range of values ​​is .

3. The method for detecting the alignment of battery cell electrodes as described in claim 1, characterized in that, When the battery cell is a blade battery cell, the standard range of the projection value includes the standard range of the projection value on the positive electrode tab side and the standard range of the projection value on the negative electrode tab side. The standard range for the negative ear-side projection value is [ , The standard range for the positive electrode ear-side projection value is []. , ]; in, The standard projection value is for the negative ear side. The standard projection value is the one on the positive ear side. for tolerance, for The tolerance.

4. The method for detecting the alignment of battery cell electrodes as described in claim 1, characterized in that, When the battery cell is a prismatic cell, the standard range of the projection value includes the standard range of the projection value on the tab side and the standard range of the projection value on the non-tab side. The standard range of the pole ear side projection value is [ , The standard range for non-polar ear side projection values ​​is [ , ]; in, The standard projection value is the one on the pole ear side. The standard projection value is for the non-polar ear side. for tolerance, for The tolerance.

5. The method for detecting the alignment of battery cell electrodes as described in claim 3 or 4, characterized in that, The formula for calculating the projection standard value is: In the formula, Core electrode coating value , These are the longitudinal and lateral coverage dimensions of the negative electrode ear side, respectively. For the angle of illumination, and These are the widths of the positive electrode and the negative electrode, respectively. and These represent the depths of the positive electrode and the negative electrode, respectively.

6. The method for detecting the alignment of battery cell electrodes as described in claim 1, characterized in that, After determining that the electrode assembly of the cell under test has passed the initial inspection, the method further includes: To determine whether the same-pole range of the electrode group of the battery cell that has passed the initial inspection is less than or equal to the control standard value of the same-pole range, and to determine whether the same-layer range of the electrode group of the battery cell that has passed the initial inspection is less than or equal to the control standard value of the same-layer range. If so, the electrode group of the battery cell that passed the initial inspection is determined to be a qualified electrode group; If not, then the electrode group of the battery cell that passed the initial inspection is determined to be an abnormal electrode group; Among them, the same pole range is the difference between the maximum and minimum values ​​of the projection values ​​of the same pole tab side in the n-layer pole sheet of the pole group; the same layer range is the difference between the projection values ​​of the left and right sides of the same pole tab side of the same layer pole sheet.

7. The method for detecting the alignment of battery cell electrodes as described in claim 6, characterized in that, The control standard value for the same-range difference is: In the formula, The control standard value is the same range. The difference in the width of the transverse electrode is due to the wide difference. The lateral electrode positioning is extremely poor. For the longitudinal polarity range, The longitudinal electrode positioning is extremely poor. The angle of illumination.

8. The method for detecting the alignment of battery cell electrodes as described in claim 6, characterized in that, The control standard values ​​for the same-layer range include the control standard values ​​for the same-layer negative electrode ear-side range and the control standard values ​​for the same-layer positive electrode ear-side range, wherein, The standard value for the range control of the negative electrode ear side in the same layer is: The standard value for range control of the positive electrode ear side in the same layer is: In the formula, , These are the projection values ​​of the left and right sides of the positive electrode ear on the same layer. , These are the projection values ​​of the left and right sides of the negative electrode ear on the same layer. , These represent the maximum and minimum longitudinal coverage dimensions when the negative electrode ear side is rotated to its limit. , These represent the minimum and maximum lateral coverage dimensions when the negative electrode ear side is rotated to its limit. , These represent the maximum and minimum longitudinal coverage dimensions of the positive electrode tab when it is rotated to its limit. The angle of illumination.

9. The method for detecting the alignment of battery cell electrodes as described in any one of claims 1 to 8, characterized in that, The electrode coating value of the battery cell is obtained in advance using a CCD camera.

10. A device for detecting the alignment of battery cell electrodes, characterized in that, include: X The X-ray detection module is used to irradiate the electrode assembly of the battery cell under test with X-ray light at a set irradiation angle to obtain the X-ray projection value. The initial inspection module is used to compare the X-ray projection value with the standard range of projection values. If the X-ray projection value is within the standard range of projection values, the initial inspection of the electrode group of the battery cell under test is deemed to be qualified; otherwise, the electrode group of the battery cell under test is determined to be an abnormal electrode group. The standard range of projection values ​​is determined in advance based on the cell electrode coating value and the irradiation angle.

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