Method for testing at least two battery stacks in pairs

Abstract

The invention relates to a scanner system for testing at least two battery stacks in pairs. The scanner system comprises a feed line for feeding at least two battery stacks into an X-ray scanner for recording at least one image, said recorded image showing a recorded image region. A first manipulator for moving the first battery stack or the second battery stack is provided in front of the X-ray scanner, and a second manipulator for moving the first battery stack or the second battery stack is provided behind the X-ray scanner, wherein the first battery stack and the second battery stack can be positioned in the recorded image region of the X-ray scanner by means of the manipulators. The scanner system comprises a removal line for removing at least one of the at least two battery stacks, the feed line comprises a first rotary table, and the removal line comprises a second rotary table. The rotary tables are designed to rotate the first battery stack, alternatively or in addition to the second battery stack.

Description

[0001] Method for testing at least two battery stacks in pairs

[0002] Description:

[0003] The invention relates to a method for testing at least two battery stacks in pairs.

[0004] The invention presents an innovative application of industrial computed tomography (CT) scanning technology using an X-ray scanner, specifically a CT scanner, specifically developed for battery production. Unlike an X-ray scanner, which provides a two-dimensional image, a CT scanner uses a computer to generate a three-dimensional image from the absorption profiles of the object from multiple directions. With the growth of the automotive industry in the field of electric vehicles, the demand for high-quality, reliable batteries is increasing. However, the production of these batteries involves complex structures and materials, making fault detection and analysis a significant and time-consuming challenge.

[0005] The proposed solution leverages the power of industrial CT scanning, a transformative technology that has revolutionized the visualization of the interior of complex objects. By generating high-resolution three-dimensional (3D) images, this technology provides a beneficial level of detail about the structure and composition of electric vehicle (EV) batteries directly from the production line.

[0006] The main advantage of integrating industrial CT scanning into the battery production process is its ability to detect a wide range of defects that could potentially affect the performance and safety of EV batteries. These defects include, but are not limited to, cracks, voids, and the presence of foreign materials.

[0007] By identifying these defects at the production stage, manufacturers can ensure the highest level of quality control, significantly reducing the risk of battery failure in the field. This not only increases the reliability and safety of electric vehicles but also contributes to the overall efficiency of the production process by minimizing waste and rework.

[0008] In this context, time-efficient use of a CT scanner is crucial to enable the highest possible throughput. This contributes to reducing production costs. One object of the invention is to enable time-efficient use of the X-ray scanner, especially the CT scanner.

[0009] According to the invention, this is achieved by a method according to claim 1 and an apparatus for carrying out the method according to claim 6. Advantageous embodiments can be found, for example, in the subclaims. The content of the claims is incorporated into the description by express incorporation.

[0010] The invention relates to a method for testing at least two battery stacks in pairs, wherein the method comprises several method steps.

[0011] The first step is to provide a scanner system comprising an X-ray scanner, a feed line, and a removal line. The X-ray scanner can be designed as a CT scanner. During pairwise testing, an even number of battery stacks can be examined simultaneously, i.e., two, four, six, eight, etc. battery stacks. Furthermore, more than one X-ray scanner can be used, for example, two, three, four, five, etc. X-ray scanners. A further method step is to feed at least two battery stacks via the feed line to the scanner system, in particular the X-ray scanner, wherein the first battery stack is rotated relative to the second battery stack, or the second battery stack is rotated relative to the first battery stack. Feeding means that the battery stacks can be fed into the X-ray scanner, in particular the CT scanner, or are transported towards it.

[0012] The next step in the process is to place the first battery stack and the second battery stack into an image acquisition area of ​​the X-ray scanner. The image acquisition area of ​​an X-ray scanner, also known as the field of view (FOV), is the specific area or zone that the X-ray scanner covers during a single image acquisition. The objects to be examined—in this case, the battery stacks—are placed within this area.

[0013] The X-ray scanner then creates an image of this specific zone by sending X-rays through the object and recording the resulting images. These images can then be analyzed to obtain information about the internal structure of the scanned object. The X-ray scanner may include an X-ray tube for generating the necessary X-rays and an image detector for image acquisition. The image acquisition area may be located between the X-ray tube and the image detector. The X-ray detector may be configured to convert X-rays into image data after they have passed through an object being inspected.

[0014] A further method step is to perform at least one image acquisition with the X-ray scanner, wherein the first battery stack and the second battery stack are at least partially imaged in the image acquisition. In particular, an anode side of the first battery stack and an anode side of the second battery stack can be at least partially imaged in the image acquisition. Or, a cathode side of the first battery stack and a cathode side of the second battery stack can be at least partially imaged in the image acquisition.

[0015] The battery stack can also be referred to as a cell stack and can comprise several individual battery cells or layers that are stacked on top of each other and connected to each other. The goal may be to achieve a higher overall voltage and / or battery capacity of the battery stack. Each individual battery cell in the battery stack can comprise an anode, a cathode, an electrolyte, and a separator.

[0016] The anode is the electrode where oxidation can occur. It is usually made of a material that can absorb lithium ions, such as graphite. The anode side of a battery cell is the side facing the anode.

[0017] The cathode is the electrode where the reduction can take place. It can usually be made of a material that can release lithium ions, such as lithium cobalt oxide or lithium iron phosphate. The cathode side of a battery cell is the side facing the cathode.

[0018] Between the anode and cathode is the electrolyte, a substance that allows the flow of ions between the anode and cathode, but can also prevent the flow of electronic current. This flow of ions is necessary to close the electrical circuit when the battery is discharged.

[0019] In the battery stack, the individual cells can be arranged so that the anode side of one cell faces the cathode side of the next cell, and vice versa. This enables the efficient flow of ions and electrons through the entire battery stack when the battery stack is discharged. Each of the at least two battery stacks can have the anode side on one transverse side and a cathode side on its opposite transverse side. The battery stack can be rectangular. However, it can also have any other geometry.

[0020] The long side of a battery stack is the side that extends in the direction of the longest length of the battery stack. It runs from one end of the battery stack to the other.

[0021] The transverse side of a battery stack, on the other hand, is the side that is approximately perpendicular to the long side of a rectangular battery stack and extends in the direction of the smaller dimension of the battery stack.

[0022] A further process step is the acquisition of the resulting image data from the image acquisition.

[0023] The following analysis of the image data from the image acquisition is intended to identify possible defects or irregularities in at least two battery stacks.

[0024] In a further process step, at least one of the two battery stacks can be output to the removal line.

[0025] The individual method steps can be performed serially. In a preferred embodiment, the method steps can be performed in the order explained above. In particular, one of the at least two battery stacks can be delivered to the removal line after the image acquisition.

[0026] In a preferred embodiment, after image acquisition, only a first battery stack or a second battery stack is dispensed via the removal line. The second battery stack or the first battery stack can remain in the image acquisition area and can be moved there by a manipulator. This can serve the purpose of inspecting a side of the second battery stack or the first battery stack that has not yet been inspected, or of feeding the battery stack to the removal line.

[0027] Behind the first battery stack or the second battery stack located in the X-ray scanner, a second battery stack or a first battery stack can follow in the direction of the material flow. This second battery stack or a first battery stack has not been rotated, so that the cathode of the second battery stack points toward the cathode of the first battery stack, or the anode of the second battery stack points toward the anode of the first battery stack. In the next feed, the previously unchecked cathode or anode of the first battery stack or the second battery stack can thus be checked with the anode or cathode of the same name of a subsequent battery stack. This allows for simultaneous, at least partial, checking of two anodes and two cathodes of at least two battery stacks.

[0028] The term material flow direction refers to the direction in which materials or goods can be moved in a production or supply chain, particularly the scanner system.

[0029] In another embodiment, more than one scanner system can be used. For example, the first scanner system can inspect only the anodes of battery stacks, while a second scanner system can inspect only the cathodes of battery stacks. This can be the case if an anode inspection and a cathode inspection require different processing times and parallelization of inspection processes is desired.

[0030] The counting method for the first and second battery stacks refers to an alternating count. For four battery stacks, the sequence would be 1212. An X-ray scanner, especially a CT scanner, can be used to inspect battery stacks. In battery technology, especially for lithium-ion batteries, quality assurance is crucial. X-ray scanners can help identify internal defects or irregularities in battery stacks that could affect battery performance or safety.

[0031] These defects can include short circuits, uneven electrodes, damage, or contamination. Early detection of such problems can ensure the quality and safety of the batteries and prevent potentially dangerous situations.

[0032] In a preferred embodiment, the X-ray scanner can be a CT scanner. A CT scanner can generate a series of two-dimensional X-ray images from various angles around the body. These images can then be combined by a computer into a three-dimensional image and displayed on a screen. This allows for a more detailed and accurate representation of a battery stack. CT scanners can be used to detect complex anomalies that might not be visible on an X-ray image that only provides two-dimensional images. This can detect cracks, voids, foreign material, or displacement of the individual stack layers.

[0033] In a further advantageous embodiment, the method comprises rotating each first battery stack or each second battery stack of the feed line such that the anode side of the first battery stack of the at least two battery stacks is arranged opposite the anode side of the second battery stack of the at least two battery stacks, or rotating each first battery stack or each second battery stack of the feed line such that the cathode side of the first battery stack of the at least two battery stacks is arranged opposite the cathode side of the second battery stack of the at least two battery stacks. The opposite position of the anode sides or the cathode sides can be assumed if the battery stacks face each other at their transverse side. The opposite arrangement can also be fulfilled if the battery stacks are offset from each other along their longitudinal and / or transverse axis.The aim of shifting the battery stacks against each other can be to arrange the battery stacks with their connection sides of the same name, anode - anode or cathode - cathode, in the image acquisition area of ​​the X-ray scanner.

[0034] In a further advantageous embodiment, the method comprises moving or positioning the first and / or second battery stack of the at least two battery stacks relative to the second battery stack of the at least two battery stacks along a longitudinal and / or transverse axis, or moving the second battery stack of the at least two battery stacks relative to the first battery stack of the at least two battery stacks along a longitudinal and / or transverse axis. This allows the position within the image acquisition area of ​​the X-ray scanner to be optimally adjusted.

[0035] The longitudinal axis of a battery stack is the axis that extends in the direction of the longest length of the battery stack. It runs from one end of the battery stack to the other, usually parallel to the direction in which the individual battery cells of the battery stack are stacked.

[0036] The transverse axis of a battery stack, on the other hand, is the axis that is perpendicular to the longitudinal axis and extends in the direction of the smaller dimension of the battery stack. It runs from one side of the battery stack to the other, perpendicular to the direction in which the individual battery cells of the battery stack are stacked.

[0037] In a typical rectangular or cylindrical battery stack, the longitudinal axis would define the length of the stack, while the transverse axis would define the width or diameter. The height of the battery stack is determined from the support surface of the battery stack to its upper edge. The respective anode sides or the respective cathode sides of the at least two battery stacks can thereby be arranged offset from one another. The at least two battery stacks can also thereby be arranged offset from one another along a longitudinal axis. This allows at least a partial area of ​​the first battery stack and at least a partial area of ​​the second battery stack to be arranged in the image recording area. This enables simultaneous image recording or examination of a partial area of ​​the first battery stack and a partial area of ​​the second battery stack.This can be done for the anode side of the battery stacks or the cathode side of the battery stacks.

[0038] In an advantageous embodiment, the method comprises correcting an offset position of the first and / or second battery stack based on a previously determined reference value, wherein the reference value is supplied via a data set and / or a barcode.

[0039] In one embodiment, the device comprises at least two stack carriers, each of the at least two stack carriers comprising at least one reference point. The reference point is required for calibrating the position of the stack carrier or the battery stack located thereon.

[0040] Calibration of the position of the battery stack or stack carrier may be necessary for several reasons.

[0041] Correct positioning of the battery stack or stack carrier can ensure that the X-ray scanner scans the battery stack as required for image analysis. Incorrect positioning could lead to inaccurate or misleading results.

[0042] Calibration can ensure that the entire battery stack, or the anode or cathode side of the battery stacks being scanned, is scanned. If the battery stack is not positioned correctly, parts of it may not be captured in the scan. When scanning multiple battery stacks, it can be important that they are all positioned the same way. This enables comparable results and facilitates the identification of anomalies or deviations.

[0043] Calibrating the position of the battery stack before image acquisition can make the scanning process more efficient, as less time is spent on adjustments or repetitions due to positioning errors. The terms "scan" and "acquisition," or combinations thereof, are synonymous.

[0044] The offset position can be determined via an optical system, in particular based on the reference point in front of or within the feed line. In a further advantageous embodiment, the optical system can comprise a camera system for determining the offset position. The camera system can be designed using a marking on one of the battery stacks. Alternatively or additionally, the marking can be arranged on at least two stack carriers for each of which holds a battery stack. The camera can be designed to determine a relative position between the stack carrier and the respective battery stack positioned thereon. This determination of the offset position is important for identifying errors when analyzing the image data.

[0045] In an advantageous embodiment, the method comprises positioning the first battery stack and / or the second battery stack such that at least a partial area of ​​the anode side or at least a partial area of ​​the cathode side of the first battery stack and the at least a partial area of ​​the anode side or at least a partial area of ​​the cathode side of the second battery stack are arranged in the image recording area of ​​the X-ray scanner, wherein in each case at least a partial area of ​​the anode side of the first battery stack is arranged relative to at least the partial area of ​​the anode side of the second battery stack or at least the partial area of ​​the cathode side of the first battery stack is arranged relative to at least the partial area of ​​the cathode side of the second battery stack in the image recording area.This advantageous arrangement allows the anode side or the cathode side of at least two battery stacks to be examined simultaneously, thus achieving significant time savings in the production process or in the inspection of the battery stacks.

[0046] The invention also relates to a device for testing at least two battery stacks in pairs, which is suitable for carrying out the method. The device comprises an X-ray scanner for taking at least one image; a feed line for feeding at least two battery stacks; a first manipulator for moving a first battery stack or a second battery stack of the at least two battery stacks; a second manipulator for moving a first battery stack or a second battery stack of the at least two battery stacks; and a removal line for removing at least one of the two battery stacks.

[0047] In an advantageous embodiment, the feed line can comprise a first turntable. The removal line can additionally comprise a second turntable. The turntables are designed to rotate the first battery stack, or alternatively or additionally the second battery stack. This allows the anode side of the first battery stack to be aligned with the anode side of the second battery stack, or the cathode side of the first battery stack to be aligned with the cathode side of the second battery stack.

[0048] In a further embodiment, the device comprises at least two stack carriers, each of the at least two stack carriers comprising a data carrier. The stack carriers can each be configured to accommodate a battery stack.

[0049] In one embodiment, the device comprises a data transmission unit configured to send image data from the image acquisition to a data server and / or via machine-to-machine (M2M) communication. The M2M communication can be configured to interact with the scanner system and send control commands to the manipulators, alternatively or additionally to the turntables. Alternatively or additionally, the M2M communication can be further configured to receive status information from the manipulators, alternatively or additionally from the turntables, alternatively or additionally from the X-ray scanner. In particular, the M2M communication can be configured as an interface connected to a machine controller for controlling the scanner system.

[0050] M2M enables devices, especially the scanner system, to collect, send and receive information in real time to trigger actions or processes.

[0051] In a further embodiment, the device comprises an evaluation unit which is designed to detect a defect in one of the battery stacks and to sort out the respective defective battery stack.

[0052] The device described above is designed to carry out the method described above.

[0053] The invention is not limited to the described embodiments. Within the scope of the invention, all described and / or illustrated features may be combined as desired, unless otherwise stated. The figures show:

[0054] - Figure 1 shows a scanner system for battery stack control; and

[0055] - Figure 2 shows a section of a scanner system for battery stack control; and

[0056] - Figure 3 shows a procedure for battery stack control.

[0057] Figure 1 shows a scanner system 100 for testing at least two battery stacks 101, 102 in pairs. The scanner system 100 comprises a feed line 110 for feeding at least two battery stacks 101, 102 into an X-ray scanner 130 for performing at least one image acquisition. The image acquisition shows an image acquisition area 131. The X-ray scanner 130 comprises an X-ray tube 133 for generating the necessary X-ray radiation and an image detector 132 for image acquisition. The image acquisition area 131 is arranged between the X-ray tube 133 and the image detector 132. The feed line 110 and the removal line 120 move the battery stacks 101, 102 in a material flow direction 400. A first manipulator 140 for moving the first battery stack 101 or the second battery stack 102 is arranged upstream of the X-ray scanner 130. A second manipulator 150 for moving the first battery stack 101 or the second battery stack 102 is arranged downstream of the X-ray scanner 130.The manipulators 140, 150 can position the first battery stack 101 and the second battery stack 102 in the image acquisition area 131 of the X-ray scanner 130. The scanner system 100 includes a removal line 120 for moving at least one of the two battery stacks 101, 102. The feed line 110 includes a first turntable 160, and the removal line 120 includes a second turntable 170. The turntables 160, 170 are designed to rotate the first battery stack 101, or alternatively or additionally, the second battery stack 102. The battery stacks 101, 102 are each arranged on stack carriers 105 for transport and position calibration.

[0058] Figure 2 shows a section of a scanner system 100 for testing at least two battery stacks 101, 102 in pairs. A first battery stack 101 is arranged opposite a second battery stack 102 such that an outer edge of a first battery stack 101 is aligned with an outer edge of a second battery stack 102. The battery stacks 101, 102 are positioned such that at least a partial area of ​​the anode side 103 of the first battery stack 101 and at least a partial area of ​​the anode side 103 of the second battery stack 102 are arranged in the image recording area 131 of the X-ray scanner 130. The X-ray scanner 130 comprises an X-ray tube 133 for generating the necessary X-ray radiation and an image detector 132 for image recording. The image recording area 131 is arranged between the X-ray tube 133 and the image detector 132.By rotating the first battery stack 101 or the second battery stack 102, the battery stacks 101, 102 can be arranged such that the battery stacks 101, 102 are arranged with their anode sides 103 facing each other. The anode side 103 and the cathode side 104 are arranged opposite each other on the end faces of the respective battery stacks 101, 102.

[0059] The first battery stack 101 and / or the second battery stack 102 can be moved relative to the second battery stack 102 or relative to the first battery stack 101 along a longitudinal and / or transverse axis 200, 300. This can be done by a first manipulator 140, which is arranged below the first battery stack, or by the second manipulator 150, which is arranged below the second battery stack 102.

[0060] The longitudinal axis 200 of the battery stacks 101, 102 is the axis that extends in the direction of the greatest length of the battery stacks 101, 102. It therefore runs from one end of the battery stacks 101, 102 to the other.

[0061] The illustrated transverse axis 300 of the battery stacks 101, 102 is the axis perpendicular to the longitudinal axis 200 and extends in the direction of the smaller dimension of the battery stack 101, 102. It therefore runs from one side of the battery stack to the other.

[0062] Behind the first battery stack 101, in the direction of a material flow direction 400, follows a second battery stack 102. This second battery stack 102 has not been rotated, so that the cathode of the second battery stack 102 points toward the cathode of the first battery stack 101. Thus, the cathode of the at least two battery stacks 101, 102 can be checked in the next feed.

[0063] Figure 3 shows a method sequence for testing at least two battery stacks 101, 102 in pairs. The method sequence comprises the following method steps: As a first method step S1, the provision of a scanner system 100 with at least one X-ray scanner 130, wherein the X-ray scanner 130 has a feed line 110 and a removal line 120; as a second method step S2, the feeding of at least two battery stacks 101, 102 via the feed line 110 to the scanner system 100, wherein the first battery stack 101 is rotated relative to the second battery stack 102 or the second battery stack 102 is rotated relative to the first battery stack 101; as a third method step S3, the introduction of the first battery stack 101 and the second battery stack 102 into an image recording area 131 of the X-ray scanner;as a fourth method step S4, at least one image is taken with the X-ray scanner, wherein the first battery stack 101 and the second battery stack 102 are at least partially imaged on the image; as a fifth method step S5, the resulting image data of the image is acquired; as a sixth method step S6, the image data of the image is analyzed to identify possible defects or irregularities in the at least two battery stacks 101, 102; and as a seventh method step S7, the output of at least one of the two battery stacks 101, 102 to the removal line 120.

[0064] List of reference symbols

[0065] Scanner system 100

[0066] First Battery Stack 101

[0067] Second battery stack 102

[0068] Anode side 103

[0069] Cathode side 104

[0070] Stack carrier 105

[0071] Feed line 110

[0072] Withdrawal line 120

[0073] X-ray scanners, especially CT scanners 130

[0074] Image capture area 131

[0075] Image detector 132

[0076] X-ray tube 133

[0077] First Manipulator 140

[0078] Second Manipulator 150

[0079] First turntable 160

[0080] Second turntable 170

[0081] Process steps S1-S7

[0082] Longitudinal axis 200

[0083] Transverse axis 300

[0084] Material flow direction 400

Claims

Claims: 1 . Method for testing at least two battery stacks in pairs, comprising the following method steps: - Providing a scanner system (100) comprising an X-ray scanner (130), a feed line (110) and a removal line (120); - feeding at least two battery stacks (101, 102) via the feed line (110) to the scanner system (100), wherein the first battery stack (101) is rotated relative to the second battery stack (102) or the second battery stack (102) is rotated relative to the first battery stack (101); - introducing the first battery stack (101) and the second battery stack (102) into an image recording area (131) of the X-ray scanner (130); - performing at least one image recording with the X-ray scanner (130), wherein the first battery stack (101) and the second battery stack (102) are at least partially imaged on the image recording; - Capturing the resulting image data from the image acquisition; - analyzing the image data of the image acquisition to identify possible defects or irregularities in the at least two battery stacks (101, 102); - Dispensing at least one of the two battery stacks (101, 102) to the removal line (120).

2. Method according to claim 1, characterized by the following method step: - Rotating each first battery stack (101) or each second battery stack (102) of the feed line (110) so that an anode side (103) of the first battery stack (101) of the at least two battery stacks (101, 102) is aligned with an anode side (103) of the second battery stack (102) of the at least two battery stacks (101, 102) is arranged opposite one another or rotating each first battery stack (101) or each second battery stack (102) of the feed line (110) so that a cathode side (104) of the first battery stack (101) of the at least two battery stacks (101, 102) is arranged opposite one cathode side (104) of the second battery stack (102) of the at least two battery stacks (101, 102).

3. Method according to at least one of the preceding claims, characterized by the following method step: - moving the first battery stack (101) and / or second battery stack (102) of the at least two battery stacks (101, 102) relative to the second battery stack (102) of the at least two battery stacks (101, 102) along a longitudinal and / or transverse axis (200, 300) or moving the second battery stack (102) of the at least two battery stacks (101, 102) relative to the first battery stack (101) of the at least two battery stacks (101, 102) along a longitudinal and / or transverse axis (200, 300).

4. Method according to at least one of the preceding claims, characterized by the following method step: - Correcting an offset position of the first and / or second battery stack (101, 102) based on a previously determined reference value, wherein the reference value is supplied via a data set and / or a barcode.

5. Method according to at least one of the preceding claims, characterized by the following method step: - Positioning the first battery stack (101) and / or the second battery stack (102) such that at least a partial area of the anode side (103) or at least a partial area of the cathode side (104) of the first battery stack (101) and the at least a partial area of the anode side (103) or at least a partial area of the cathode side (104) of the second battery stack (102) is arranged in the image recording area (131) of the X-ray scanner (130), wherein in each case at least a partial area of the anode side (103) of the first battery stack (101) is arranged relative to the partial area of the anode side (103) of the second battery stack (102) or the partial area of the cathode side (104) of the first battery stack (101) is arranged relative to the partial area of the cathode side (104) of the second battery stack (102) in the image recording area (131).

6. Device for testing at least two battery stacks in pairs for carrying out the method according to at least one of the preceding claims, comprising: - an X-ray scanner (130) for performing at least one image recording of an image recording area (131); - a feed line (110) for feeding at least two battery stacks (101, 102); - a first manipulator (140) for moving a first battery stack (101) or a second battery stack (102) of the at least two battery stacks (101, 102); - a second manipulator (150) for moving a first battery stack (101) or a second battery stack (102) of the at least two battery stacks (101, 102); - a removal line (120) for removing at least one of the two battery stacks (101, 102).

7. The device of claim 6, further comprising: - at least two stack carriers (105) for transporting one of the battery stacks (101, 102), each of the at least two stack carriers (105) comprising at least one reference point.

8. Device according to at least one of the preceding claims 6 or 7, further comprising: - at least two stack carriers (105), wherein each of the at least two stack carriers (105) comprises a data carrier.

9. Device according to at least one of the preceding claims 6 to 8, further comprising: - a data transmission unit which is designed to send image data from the image recording to a data server and / or via machine-to-machine communication.

10. Device according to at least one of the preceding claims 6 to 9, further comprising: - an evaluation unit which is designed to detect a defect in one of the battery stacks (101, 102) and to sort out the respective defective battery stack (101, 102).

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