Method and measuring apparatus for determining the lamination accuracy of multiple electrode sheets within a laminate.

Abstract

A method is proposed for determining the stacking accuracy of a plurality of electrode sheets (1,2,3), the electrode sheets (1,2,3) each comprising at least one anode sheet (1), one cathode sheet (2) and one separator sheet (3), the electrode sheets (1,2,3) extending in mutually parallel planes (4) and arranged stacked on top of one another to form a stack (5), the stacking accuracy representing a respective position (6,7,8) of a boundary edge (9) of at least one of the electrode sheets (1,2,3) in the stack (5), the method being performed using a measuring device (10) having at least one camera (11) and one light source (12).Furthermore, a measuring device (10) for performing the method is also proposed.

Description

Technical Field

[0001] The present invention relates to a method and a measuring device for determining the lamination accuracy of a plurality of electrode sheets in a laminate. The electrode sheets extend in a plane parallel to each other, are laminated and arranged with each other, and form one laminate. The lamination accuracy represents the position of the boundary edges of the electrode sheets with respect to each other in the laminate.

[0002] For the drive of automobiles, batteries, especially lithium-ion batteries, are increasingly being used. These batteries are usually composed of cells, where each cell has an anode sheet, a cathode sheet, and optionally a separator sheet or a composite of separator materials. These anode sheets, cathode sheets, and optionally separator sheets are hereinafter referred to as electrode sheets.

[0003] These electrode sheets are usually manufactured by punching or cutting techniques such as laser cutting.

[0004] The lamination accuracy of the individual electrode sheets in the laminate has a significant impact on the safety-related quality standards and the performance of the lithium-ion battery cell. The electrochemical performance of the battery cell decreases more rapidly as the electrode coverage or the coverage of the active material during operation is lower. Additionally, direct contact between the anode sheet and the cathode sheet triggers a short circuit or a failure of the battery cell. For this reason, it is necessary to inspect the standards in the laminate before the laminate is housed in the housing of the battery cell. The lamination accuracy, that is, the displacement of the positions of the individual electrode sheets with respect to each other, must be maintained within a narrow boundary.

[0005] An established method for determining the lamination accuracy is computer tomography (CT). Here, a three-dimensional image of the laminate is generated by a long-time measurement.

[0006] In contrast to CT, there are also inspection devices that use X-rays to create two-dimensional images of stacked materials or objects being inspected. These methods allow for faster inspections compared to computed tomography (CT). However, direct measurement of the relative positions of electrode sheets remains impossible with this method, and both techniques require high investment, operational, and maintenance costs due to their X-ray use. Furthermore, comprehensive radiation protection is necessary, limiting their suitability for use in production lines. Additionally, CT-based inspections are not suitable for inline implementation due to their long measurement times.

[0007] Furthermore, the position of the electrode sheets can already be recorded during the lamination process of each individual electrode sheet. However, this method has drawbacks such as a decrease in the cycle time of the lamination process, an increase in the amount of data, and uncertainty about the final position of the tensioned laminate.

[0008] U.S. Patent Application Publication No. 2013 / 0048340 provides known electrodes for battery cells and methods for manufacturing said electrodes. This also proposes optical capture of the edges of an active material placed on a support material. Here, different reflections of light are used to identify the location of the edges.

[0009] U.S. Patent Application Publication No. 2013 / 0320216 focuses on a method for identifying foreign particles on an electrode. This method utilizes light with wavelengths ranging from 4 μm to 10 mm.

[0010] A method for manufacturing electrodes is known from U.S. Patent No. 6,585,846.

[0011] The object of this invention is to solve, at least partially, the problems mentioned. In particular, a method for determining the lamination accuracy of multiple electrode sheets within a laminate should be proposed. Furthermore, a measuring device for determining the lamination accuracy should also be proposed.

[0012] A method having the features of claim 1 and a measuring apparatus having the features of claim 9 contribute to solving these problems. Preferred developments are the subject of the dependent claims. Features described individually in the claims are technically significant and can be combined with each other in a way that is useful, and can be supplemented by examples from the specification and / or details from the drawings, which hereby illustrate further embodiments of the present invention.

[0013] A method is proposed for determining the stacking accuracy of multiple electrode sheets. Each of these electrode sheets comprises at least one anode sheet (or more anode sheets), one cathode sheet (or more cathode sheets), and one separator sheet (or more separator sheets). These electrode sheets extend in planes that are (substantially) parallel to each other and are stacked upon each other. These electrode sheets form a single stack. The stacking accuracy represents the position of at least the boundary edges of the anode sheet, cathode sheet, or separator sheet within the stack. The method is performed using a measuring apparatus having at least one camera and a light source. The method involves at least the following steps: a) A step of preparing a laminate and placing the laminate in a measuring device, wherein the connecting line between the light source and the camera extends substantially parallel to the plane, b) The laminate is illuminated using a light source so that the light beam penetrates or reflects from at least one region of the laminate, where the light beam is captured by a camera. c) A step of recording one (or more) mappings of at least one region of the stack using a camera, d) The step of evaluating the mapping (or more mappings) and determining the positions of the boundary edges located within the region of at least the anode sheet, cathode sheet, or separator sheet.

[0014] The above (non-final) classification of these method steps into a) to d) should be used preferentially for distinction purposes only and should not impose any order and / or dependency. Also, for example, the frequency of method steps during the implementation of this method may change. Similarly, these method steps may overlap with each other at least partially in time. Particularly preferably, method step a) is performed before steps b) to d). In particular, steps b) and c) are performed at least partially in parallel with each other in time. In particular, step d) is performed after step d). In particular, steps a) to d) are performed in the specified order.

[0015] This method is used, in particular, within the framework of a manufacturing method for battery cells. Here, electrode sheets, appropriately cut into suitable shapes, i.e., at least one anode sheet, at least one cathode sheet, and / or at least one separator sheet, are arranged in a predetermined order in a laminate and aligned with each other. In the laminate thus produced, the boundary edges of the individual (identical) electrode sheets should be positioned as flush as possible with each other.

[0016] These electrode sheets, in particular, extend in mutually parallel planes and are arranged in a stacked manner to form a single laminate. This laminate, in particular, includes at least two electrode sheets, i.e., at least one anode / cathode sheet and one separator sheet. Preferably, the laminate includes at least one anode sheet, at least one cathode sheet, and one interposed separator sheet.

[0017] The electrode sheets, in particular, each have a substantially rectangular shape. In some cases, the derivation lugs extend beyond these rectangular shapes. They are generally uncoated, that is, not coated with the active material, and are used for the electrical contact connection of each electrode sheet, i.e., the anode sheet or the cathode sheet.

[0018] Lamination accuracy, in particular, represents the position of at least the anode sheet, cathode sheet and / or separator sheet or the boundary edges of the anode sheet, cathode sheet, or separator sheet within the laminate. In particular, the electrode sheets should be positioned relative to each other at predetermined positions. Since the sizes of the anode sheet and cathode sheet, and optionally the separator sheet, may differ from each other, the lamination accuracy is determined, in particular, at the boundary edges of electrode sheets that are flush with each other along a direction extending laterally to a plane.

[0019] In particular, the lamination accuracy of the electrode sheets is determined at only one boundary edge or one location of each electrode sheet.

[0020] This method is carried out using a measuring device having at least one camera and one light source. Multiple fixed or movable light sources may be provided. Multiple fixed or movable cameras may also be provided. In particular, each light source is assigned to only one camera, but multiple light sources may be assigned to one camera.

[0021] A light source is used to emit a light beam that includes at least visible light. A camera is used to record the light beam for displaying an image. The camera includes, in particular, at least one objective lens (e.g., a telecentric system) and a sensor that converts incident light into an electrical signal.

[0022] The camera, in particular, enables the display of a two-dimensional map of the region of the stacked material illuminated by a light beam from a light source.

[0023] According to step a), a laminate is provided and positioned within the measuring device, particularly between a light source and a camera, or such that a light beam is reflected from the laminate toward the camera, where the connecting line between the light source and the camera (this connecting line either penetrates the laminate or extends away from the laminate) extends substantially parallel to a plane. The laminate can be formed separately and then positioned together within the measuring device. However, it is also possible for the laminate itself to be (partially) formed within the measuring device and therefore positioned simultaneously. The light source is positioned, in particular, toward the camera, so that a light beam is emitted from the light source toward the camera. Alternatively, the light source and the camera are oriented in the (same) region of the laminate, so that a light beam reflected from the laminate is captured by the camera. The light source and the camera are positioned relative to the laminate so that the light beam extends parallel to a plane (if it is oriented and thus emits parallel to each other from the light source and extends toward the camera along the connecting line).

[0024] According to step b), the laminate is illuminated using a light source, thereby causing a light beam to penetrate at least one region of the laminate or to be reflected from the laminate towards the camera. This light beam is captured by the camera. In other words, the laminate is illuminated, in particular, at least partially through the light. Here, only a light beam from a light source penetrating the laminate is captureable by the camera, that is, only a light beam passing through the free space present between the electrode sheets, for example, is captureable by the camera.

[0025] The light beam from the light source captures the boundary edges where the electrode sheets are arranged in overlapping positions, allowing the camera to capture and record a two-dimensional image of the boundary edges of the laminate.

[0026] According to step c), at least one mapping of the region of the laminate using a camera is recorded. In particular, only one mapping of the region of the laminate is recorded. Further recording of this region is not particularly necessary. In some cases, further mappings of other regions (formed by other aspects) may be recordable and evaluable. Usually, for capturing the boundary edges of the separator sheet, which is longer than the anode sheet and the cathode sheet, other arrangements of the light source and the camera are also possible. In this case, the light beam may extend laterally or at an angle (i.e., not necessarily parallel) with respect to the plane.

[0027] According to step d), the mapping is evaluated and the position of the boundary edges arranged within the regions of the anode sheet, the cathode sheet, and / or the separator sheet is determined. The evaluation can be carried out particularly by a system for data processing. In particular, for the laminate, only the evaluation of one mapping is carried out, and in some cases, the evaluation of further mappings generated by the recording of other regions is carried out.

[0028] In particular, the method is executed multiple times, whereby the lamination accuracy of the individual electrode sheets is determined sufficiently accurately. In particular, for this purpose, it is necessary to illuminate, capture with a camera, generate, and evaluate corresponding mappings of a plurality of different regions of the laminate. Thereby, in particular, the rotation or transfer of each electrode sheet relative to the target position can be determined.

[0029] In order to manage and determine the lamination accuracy of the entire laminate, in particular, at least three different regions, such as the edges of the laminate, etc., are recorded using a measuring device.

[0030] In particular, at specific edges of the laminate (i.e., the four shortest edges in a cuboid-shaped laminate, not considering the lead-out parts), in order to determine the spatial coordinates of the edges via triangulation, a single mapping is generated from both directions. In particular, the laminate is rotated and reoriented with respect to the camera and the light source by a holding device. Thus, each of the aforementioned edges is captured by the camera from two directions. That is, in particular, eight mappings are generated for each laminate.

[0031] In particular, the measuring device includes means that are appropriately equipped, configured, or programmed for the implementation of this method, or a system for data processing having means for executing this method. These means include, for example, a processor, a memory in which instructions executed by the processor are stored, and a data line or transmission device capable of transmitting instructions, measurement values, data, etc. between the aforementioned elements.

[0032] In particular, the laminate has a plurality of side surfaces formed by a plurality of electrode sheets. In step a), the laminate is arranged between the light source and the camera such that the connecting line extends through a first side surface and a second side surface that are arranged at a minimum angle of less than 180 degrees, particularly less than 150 degrees, preferably less than 120 degrees, with respect to each other. In particular, the minimum angle between the side surfaces is at least 70 degrees, preferably at least 80 degrees.

[0033] That is, in particular, the side surfaces are not arranged parallel to each other or opposite to each other.

[0034] The side surfaces of the laminate considered here are particularly formed by the boundary edges of electrode sheets, particularly separator sheets. This is because this separator sheet usually has a longer extension than the anode sheet and the cathode sheet in order to avoid short circuits. These side surfaces extend particularly transversely to the plane in which the electrode sheet extends along.

[0035] In particular, the first side surface and the second side surface are arranged adjacent to each other.

[0036] In particular, the region includes the edges of the laminate formed by mutually adjacent sides.

[0037] In particular, the connecting line extends with respect to the first side and the second side at a minimum second angle of less than 90 degrees, especially less than 75 degrees, and preferably less than 60 degrees. In particular, the minimum second angle between each side and the connecting line is at least 25 degrees, and preferably at least 40 degrees.

[0038] In particular, in step d), the positions of at least the boundary edges of at least one anode sheet and at least one cathode sheet are determined.

[0039] In particular, determining the boundary edge of the separator sheet is not necessary because this electrode sheet is usually longer than the anode and cathode sheets. As mentioned above, determining the boundary edge of the separator sheet can also be done using other arrangements of the light source and camera.

[0040] Determining the boundaries of at least one anode sheet and at least one cathode sheet is particularly important because the electrochemical performance of a battery cell in operation deteriorates more rapidly as the electrode coverage or active material coverage decreases.

[0041] In particular, the light source preferably generates visible light having a wavelength of at least 365 to 870 nm [nanometers].

[0042] In particular, the light beams are coherent and / or collimated (i.e., aligned parallel to each other). Alternatively, the light beams are diffused and / or coherent. Primarily, and especially in particular, light extending substantially parallel to the plane is used. This can improve the accuracy of the mapping and simplify evaluation. This accuracy can be further improved, in particular, with coherent or collimated light.

[0043] In particular, the measuring device includes a nozzle capable of supplying a gas flow to the region at least between steps b) and c). Specifically, the nozzle is positioned such that the electrode sheet is fanned out or aligned by the gas flow. This can improve the transmission of the light beam through the electrode sheet.

[0044] In particular, the gas flow may be ionized, which can trigger electrostatic charging of the electrode sheets, especially between the separator sheet and the anode or cathode sheet. This can further improve the transmission of the light beam through the electrode sheets.

[0045] In particular, artificial intelligence is used for at least step d). This artificial intelligence can be used to assist in determining the position of the boundary edges within the mapping.

[0046] In particular, the evaluation of at least one mapping is performed using a convolutional neural network (CNN). The convolutional neural network learns from the mapping of the stack captured according to step c), and then from a composite of stacks with known positions of electrode sheet boundaries, i.e., an artificially generated dataset, in order to determine the position of the (desired) electrode sheet boundary edges. If the electrode sheet is, for example, sagging, i.e., not ideally extending in a horizontal plane, the proper position of the boundary edges can be calculated using a polynomial.

[0047] Instead of using convolutional neural networks, evaluation can also be performed using other machine learning methods or automated learning techniques. The following focuses on convolutional neural networks and the processes and terminology used in them.

[0048] The use of this type of CNN for evaluating mappings, i.e., for recording images with a camera, is generally known. In this invention, it is proposed to use a CNN for quality evaluation of the (cut) boundary edges of an electrode sheet, i.e., within the context of manufacturing battery components.

[0049] Within the framework of evaluation using CNNs, in order to implement automated, inline-oriented evaluation of boundary edges, a training dataset, i.e., a synthetic dataset, may be generated first. For each mapping in this training dataset, the position of the boundary edge can be manually marked. Subsequently, this manual marking, i.e., the manually exported position of the marked boundary edge from the tool, is performed. The position of the boundary edge in the mapping, coded as a pixel matrix, is mapped to the stacked geometry or arrangement of boundary edges for the training dataset, the so-called ground truth.

[0050] In the following, a CNN is used to learn to mathematically map the boundary edges represented within a mapping to their corresponding geometric shapes. Subsequently, the trained CNN can recognize boundary edges or geometric shapes for mappings of cameras that have not been pre-trained. Based on the low variance of different mappings of substantially identical bodies—in this case, the boundary edges of stacked electrode sheets—with respect to the target geometric shape of the determined boundary edge, and the statistical significance of the large amount of data, this recognition is more accurate than similar methods, such as trend-based edge recognition.

[0051] As is well known, a CNN consists of a series of so-called convolutional layers in which multiple mapping segments are discretely convolved with a fixed number of filters. For each of these filters, this layer calculates a so-called feature map. This feature map indicates whether the pattern defined by the filter parameters was recognized at the corresponding location within each second mapping or contour. The size of these feature maps is reduced using so-called max pooling or average pooling layers to reduce computational complexity. This max pooling or average pooling layer pushes n × n windows onto the feature map, and in particular, transfers only the maximum value from one segment to the next layer.

[0052] The order and number of convolutional layers and max pooling or average pooling layers, as well as the sizes of their respective windows and filters, are so-called hyperparameters. Optimization of these hyperparameters is performed, in particular, using validation datasets that do not affect the optimization of the model parameters.

[0053] In the final step, all feature map values ​​are concatenated into a vector, resulting in a so-called flattening process, which is then used as input to a feedforward neural network. This network is also characterized by the variable number of hidden layers and the variable number of neurons within each hidden layer. These numbers form further hyperparameters.

[0054] As an alternative to flattening, transposed convolution can be used to first restore the compressed feature map to its original size, and then reduce its number again to 1 using a convolutional layer.

[0055] In the output layer, the network attempts to approximate the edge geometry of the manually generated stacked ground truth by assigning either 0 or 1 ("1") to each pixel.

[0056] At the start of training, the filter parameters and the feedforward neural network parameters (together forming the CNN) can be initialized randomly, which initially leads to inaccurate geometric predictions. During training, all model parameters are fitted using a method known as gradient descent so that the number of misclassified pixels is minimized over all training examples.

[0057] After training is complete, the CNN can be used, for example, within the framework of step d) to recognize the location of at least one boundary edge within an unknown stack or a newly created mapping.

[0058] In particular, in a further step, at least one process parameter used in the manufacture of each laminate is determined and modified based on the evaluation of the lamination accuracy in step d), thereby improving the lamination accuracy of subsequent laminates.

[0059] In other words, especially if, for example, an exceedance of the limit value is confirmed and / or verified within the framework of subsequent measurements, it is possible to determine the mispositioned electrode sheet and its deviation from the target position. Accordingly, the manufacturing process can be traced from the knowledge of the electrode sheet, and in some cases, configurable process parameters can be changed.

[0060] A measuring device for carrying out the described method has also been proposed, which includes at least a camera and a light source. In particular, a laminate consisting of mutually stacked electrode sheets extending in mutually parallel planes can be positioned with respect to the camera and the light source such that the connecting line between the light source and the camera extends substantially parallel to the plane. Specifically, the light source is aligned toward the camera, and the laminate is positioned between the light source and the camera, so that the light beam penetrates at least one region of the laminate. Alternatively, the light source and the camera are aligned in the (same) region of the laminate, where the light beam is reflected by the region and captured by the camera.

[0061] In particular, the measuring device includes at least two cameras and two light sources, where the laminate has multiple sides formed by a plurality of electrode sheets. The cameras and light sources are arranged such that a first connecting line between the first camera and the first light source extends through a first side and a second side of the laminate arranged at a minimum first angle of less than 180 degrees relative to each other, and a second connecting line between the second camera and the second light source extends through a third side and a fourth side of the laminate arranged at a minimum first angle of less than 180 degrees relative to each other, particularly less than 150 degrees, preferably less than 120 degrees. In particular, the minimum first angle between the sides is at least 70 degrees, preferably at least 80 degrees.

[0062] In particular, the measuring device may include three or even four cameras and a number of comparable or adapted light sources. This can further accelerate the determination of the lamination accuracy of all electrode sheets because it allows for the simultaneous generation and evaluation of mappings of different or identical regions (and possibly recorded from other directions as well).

[0063] In particular, a system for data processing is proposed, which has means appropriately equipped, configured or programmed for carrying out the Method, or means for carrying out the Method.

[0064] This means includes, for example, a processor, a memory storing instructions executed by the processor, and a data line or transmission device capable of transmitting instructions, measurements, data, etc., between the aforementioned elements.

[0065] Furthermore, a computer program is proposed which, when the program is executed by a computer, includes instructions that cause the computer to perform the described method or the steps of the described method.

[0066] Furthermore, a computer-readable storage medium is proposed, which, when executed by a computer, includes instructions that cause the computer to perform the described method or steps of the described method.

[0067] In particular, embodiments of this method can be adapted to systems and / or computer implementations for data processing (i.e., computer programs and computer-readable storage media), and vice versa.

[0068] In particular, the use of the indefinite article ("one") in patent claims and the specification reproducing them should not be understood as a numerical notation. Therefore, it should be understood that the terms or components introduced accordingly exist at least once, but may also exist multiple times.

[0069] It should be noted, preemptively, that the numerals used herein ("first," "second," etc.) are used primarily to distinguish between multiple similar objects, sizes, or processes, and not necessarily to predetermine any interdependence and / or order of these objects, sizes, or processes. Where such interdependence and / or order is required, this will be explicitly shown herein or will become apparent to those skilled in the art when studying the specifically described embodiments. While a description of one of these components may appear multiple times (e.g., "at least one"), it is not necessarily required that such description apply equally to all or some of these components.

[0070] The present invention and its technical background will be described in more detail below with reference to the accompanying drawings. It should be noted that the present invention is not to be limited by the embodiments described. In particular, unless otherwise explicitly indicated, some aspects of those described in the drawings may be extracted and combined with other components and findings from this specification. It should be noted that these drawings, and especially the size ratios shown, are approximate. [Brief explanation of the drawing]

[0071] [Figure 1] This is a perspective view showing the laminate within the holding device. [Figure 2] Figure 1 is a side view showing the laminated structure. [Figure 3] This diagram shows a mapping of a stacked structure and a measuring device on which the stacked structure is placed, and the mapping can be generated using the measuring device. [Figure 4] This is a plan view showing a further measuring device placed on top of the laminate. [Figure 5] This is a plan view showing the laminated structure and other measuring devices placed on it.

[0072] Figure 1 shows a perspective view of the laminate 5 inside the holding device 23. Figure 2 shows a side view of the laminate 5 shown in Figure 1. Figures 1 and 2 will be explained together below.

[0073] The electrode sheets 1, 2, and 3 include an anode sheet 1, a cathode sheet 2, and a separator sheet 3. The electrode sheets 1, 2, and 3 extend within mutually parallel planes 4 and are stacked on top of each other. The electrode sheets 1, 2, and 3 form a single laminate. The stacking accuracy represents the respective positions 6, 7, and 8 of the boundary edges 9 of the anode sheet 1, cathode sheet 2, or separator sheet 3 within the laminate 5. The electrode sheets 1, 2, and 3 extend within mutually parallel planes 4 and are stacked on top of each other to form the laminate 5.

[0074] Each of the electrode sheets 1, 2, and 3 has a substantially rectangular shape. The laminate 5 has multiple sides 16, 17, 18, and 19 formed by the multiple electrode sheets 1, 2, and 3. These sides 16, 17, 18, and 19 of the laminate 5 are formed by the boundary edges 9 of the electrode sheets 1, 2, and 3, in this case the separator sheet 3. This is because the separator sheet 3 typically extends longer than the anode sheet 1 and cathode sheet 2 to avoid short circuits. The sides 16, 17, 18, and 19 extend laterally with respect to the plane 4 along which the electrode sheets 1, 2, and 3 extend.

[0075] The lead-out portions (lead-out lugs) 24 extend beyond the rectangular shape of the electrode sheets 1, 2, and 3. These lead-out portions 24 are generally uncoated, that is, not coated with the active material, and are used for electrical contact connections between the respective electrode sheets 1 and 2, i.e., the anode sheet 1 or the cathode sheet 2.

[0076] Figure 2 provides a detailed view of how the boundary edges 9 of electrode sheets 1, 2, and 3 are positioned in the target configuration. The electrode sheets 1, 2, and 3 are arranged alternately along the stacking direction (extending laterally to the plane 4). The second position 7 of cathode sheet 2 is located furthest inward, i.e., at the greatest distance from the first side surface 16. The first position 6 of anode sheet 1 is located between the second position 7 and the third position 8 of separator sheet 3. The first side surface 16 of the laminate 5 is formed by the boundary edge 9 of separator sheet 3.

[0077] The holding device 23 here includes two plates, with the laminate 5 positioned between them. Through these holding devices 23, the electrode sheets 1, 2, and 3 are fixed or secured in their positions 6, 7, and 8, thereby allowing the laminate 5 to be placed inside the measuring device 10.

[0078] Figure 3 shows a mapping of the laminate 5 (left) and a measuring device 10 (right) on which the laminate 5 is placed. The mapping 15 can be generated using this measuring device 10. Embodiments of Figures 1 and 2 are referenced.

[0079] The measuring device 10 includes a camera 11 and a light source 12. In step a), the laminate 5 is positioned between the light source 12 and the camera 11 such that a connecting line 27 (here extending parallel to the collimated light beam 13) is positioned at a minimum first angle 20 of 90 degrees relative to each other and extends through mutually adjacent first side surfaces 16 and second side surfaces 17.

[0080] According to step b), the laminate 5 is illuminated using the light source 12, thereby causing the light beam 13 to penetrate a region 14 of the laminate 5 and be captured by the camera 11. This region 14 includes the edge 25 of the laminate 5 formed by adjacent sides 16, 17.

[0081] The connecting line 27 extends at a minimum second angle 26 of approximately 45 degrees relative to the first side 16 and the second side 17.

[0082] In other words, the laminate 5 is illuminated at least partially. Here, only the light beam 13 from the light source 12 that penetrates the laminate 5 can be captured by the camera 11, that is, only the light beam passing through the free space between the electrode sheets 1, 2, and 3 can be captured by the camera.

[0083] The light beam 13 of the light source 12 captures the overlapping boundary edges 9 of the electrode sheets 1, 2, and 3, thereby enabling the camera 11 to capture and record a two-dimensional image 15 of the boundary edges 9 of the laminate 5.

[0084] According to step c), a mapping 15 of at least one region 14 of the stack 5 is recorded using the camera 11. A mapping 15 of region 14 of the stack 5 is recorded. Further recording of region 14 or other regions 14 may be necessary to determine the stacking accuracy and can be generated by changing the position of the stack 5 or by changing the position of the camera 11 or the light source 12. This makes further mappings 15 of at least one other region 14 (formed by other sides 18, 19; see Figure 4) recordable and evaluable.

[0085] According to step d), the mapping 15 is evaluated and the positions 6, 7, and 8 of the boundary edges 9 located within the region 14 of at least the anode sheet 1 and cathode sheet 2 are determined. The evaluation is performed by the data processing system 28.

[0086] Figure 4 shows a plan view of a further measuring device 10 in which the laminate 5 is placed. Embodiments corresponding to Figures 1 to 3 are referenced.

[0087] Each of the electrode sheets 1, 2, and 3 has a substantially rectangular shape. The laminate 5 has multiple sides 16, 17, 18, and 19 formed by the multiple electrode sheets 1, 2, and 3. These sides 16, 17, 18, and 19 of the laminate 5 are formed by the boundary edges 9 of the electrode sheets 1, 2, and 3, in this case the separator sheet 3. The sides 16, 17, 18, and 19 extend laterally with respect to the plane 4 along which the electrode sheets 1, 2, and 3 extend. The lead-out portion (lead-out lug) 24 extends beyond this rectangular shape of the electrode sheets 1, 2, and 3. The laminate 5 is placed inside the holding device 23.

[0088] The measuring device 10 includes a first camera 11 and a first light source 12, and a second camera 21 and a second light source 22. In step a), the laminate 5 is positioned between the first light source 12 and the first camera 11, and simultaneously between the second light source 22 and the second camera 21, such that each connecting line 27 extends through the first side 16 and the second side 17, or through the third side 18 and the fourth side 19.

[0089] The first side 16 and the second side 17 are adjacent to each other and are positioned at a minimum first angle 20 of 90 degrees to each other. According to step b), the laminate 5 is illuminated using the first light source 12, thereby causing a light beam 13 to penetrate a region 14 of the laminate 5 and be captured by the first camera 11. This region 14 includes the edge 25 of the laminate 5 formed by the adjacent side 16,17. The connecting line 27 extends at a second angle 26 of approximately 30 degrees to the first side 16 and at a minimum second angle 26 of approximately 60 degrees to the second side 17.

[0090] The third side 18 and the fourth side 19 are adjacent to each other and are positioned at a minimum first angle 20 of 90 degrees to each other. According to step b), the laminate 5 is illuminated using a second light source 22, thereby causing a light beam 13 to penetrate a further region 14 of the laminate 5 and be captured by the second camera 21. This region 14 includes the edge 25 of the laminate 5 formed by the adjacent side 18,19. The connecting line 27 extends at a minimum second angle 26 of about 30 degrees to the third side 18 and at a minimum second angle 26 of about 60 degrees to the fourth side 19.

[0091] According to step c), the mappings 15 of two regions 14 of the stacked material 5 are recorded using the respective cameras 11 and 21. Only the two mappings 15 of the two regions 14 of the stacked material 5 are recorded. Further recordings of these regions 14 can be generated sequentially or simultaneously for the purpose of determining the stacking accuracy.

[0092] According to step d), the mapping 15 is evaluated and the positions 6, 7, and 8 of the boundary edges 9 located within the respective regions 14 of the anode sheet 1 and cathode sheet 2 are determined. The evaluation is performed by the data processing system 28.

[0093] Figure 5 shows a plan view of the laminate 5 and the other measuring device 10 in which it is placed. Embodiments with respect to Figures 1 to 4, in particular Figures 3 and 4, are referenced.

[0094] The measuring device 10 includes two nozzles 29, which allow a gas flow 30 to be supplied to each region 14 at least during steps b) and c). The nozzles 29 are positioned such that the electrode sheets 1, 2, and 3 are fanned out or aligned by the gas flow 30 (see details in the lower right of Figure 5). This can improve the transmission of the light beam 13 through the electrode sheets 1, 2, and 3. [Explanation of Symbols]

[0095] 1. Anode sheet (electrode sheet) 2. Cathode sheet (electrode sheet) 3. Separator sheet (electrode sheet) 4 planes 5. Laminate 6. First position 7. Second position 8. Third position 9. Boundary edge 10 Measuring device 11 (First) Camera 12 (First) light source 13 Light beam 14 areas 15 Mappings 16. First Aspect 17. Second Aspect 18. The Third Aspect 19. The Fourth Aspect 20 First angle 21 Second Camera 22 Second light source 23 Holding device 24 Derivation part 25 Edge 26 Second Angle 27 Connection Line 28 Systems 29 nozzles 30 Gas flow

Claims

1. A method for determining the stacking accuracy of multiple electrode sheets (1, 2, 3), The electrode sheets (1, 2, 3) each include at least one anode sheet (1), one cathode sheet (2), and one separator sheet (3), the electrode sheets (1, 2, 3) extend in mutually parallel planes (4) and are arranged in a stacked manner to form a single stack (5), the stacking accuracy represents the respective positions (6, 7, 8) of the boundary edges (9) of at least the anode sheet (1), the cathode sheet (2), or the separator sheet (3) within the stack (5), the method is carried out using a measuring device (10) having at least one camera (11) and one light source (12), and the steps are at least as follows: a) Providing the laminate (5) and placing the laminate (5) in the measuring device (10), wherein the connecting line (27) between the light source (12) and the camera (11) extends substantially parallel to the plane (4), b) The laminate (5) is illuminated using the light source (12), thereby the light beam (13) penetrates at least one region (14) of the laminate (5) or is reflected from said region (14), and the light beam (13) is captured by the camera (11), c) A step of recording at least one mapping (15) of the region (14) of the laminate (5) using the camera (11), d) A step of evaluating the mapping (15) and determining the positions (6, 7, 8) of the boundary edge portions (9) located within the region (14) of at least the anode sheet (1), the cathode sheet (2), or the separator sheet (3), Includes, The light source (12) generates visible light, Between at least step b) and step c), a gas flow is supplied to the region (14), or The light beam (13) is coherent and / or collimated. method.

2. The method according to claim 1, wherein the laminate (5) has a plurality of sides (16, 17, 18, 19) formed by the plurality of electrode sheets (1, 2, 3), and in step a), the laminate (5) is positioned between the light source (12) and the camera (11) such that the connecting line (27) extends through a first side (16) and a second side (17) which are arranged at the smallest first angle (20) of less than 180 degrees relative to each other.

3. The method according to claim 2, wherein the first side surface (16) and the second side surface (17) are arranged adjacent to each other.

4. The method according to claim 3, wherein the region (14) includes the edge (25) of the laminate (5) formed by mutually adjacent sides (16, 17).

5. The method according to claim 1, wherein in step d), the positions (6, 7, 8) of at least the boundary edge (9) between the anode sheet (1) and the cathode sheet (2) are determined.

6. The method according to claim 1, wherein the light beam (13) is at least coherent or collimated and extends substantially parallel to the plane (4).

7. The method according to claim 1, wherein artificial intelligence is used for at least step d).

8. A measuring device (10) for carrying out the method according to any one of claims 1 to 7, comprising at least a camera (11) and a light source (12), wherein a laminate (5) consisting of mutually stacked electrode sheets (1, 2, 3) extending in mutually parallel planes (4) can be arranged with respect to the camera (11) and the light source (12) such that a connecting line (27) between the light source (12) and the camera (11) extends substantially parallel to the plane (4).

9. Measuring device (10) according to claim 8, comprising at least two cameras (11, 21) and two light sources (12, 22), wherein the laminate (5) has a plurality of sides (16, 17, 18, 19) formed by a plurality of electrode sheets (1, 2, 3), and the cameras (11, 21) and the light sources (12, 22) are arranged such that a first connecting line (27) between a first camera (11) and a first light source (12) extends through a first side (16) and a second side (17) of the laminate (5) which are arranged at a minimum first angle (20) of less than 180 degrees relative to each other, and a second connecting line (27) between a second camera (21) and a second light source (22) extends through a third side (18) and a fourth side (19) of the laminate (5) which are arranged at a minimum angle (20) of less than 180 degrees relative to each other.

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