A battery cell imaging apparatus

Abstract

A battery cell imaging apparatus comprising: an x-ray source (101) configured to provide a first x-ray beam (102) in a first direction and a second x-ray beam (103) in a second direction; a first manipulator (108) to present at least a first part of the first battery cell (106) to the first x-ray beam at a plurality of imaging angles; a second manipulator (109) configured to present at least a first part of a second battery cell (107) to the second x-ray beam at a plurality of imaging angles; a first detector (104) configured to detect the first x-ray beam having passed through the first battery cell when in use and provide an output for CT imaging of the first battery cell; and a second detector (105) configured to detect the second x-ray beam having passed through the second battery cell when in use and provide an output for CT imaging of the second battery cell.

Description

[0001] A BATTERY CELL IMAGING APPARATUS

[0002] Field

[0003] The present disclosure relates to a battery cell imaging apparatus. In particular, the invention relates to an apparatus configured to provide for computerised tomography (CT) imaging of battery cells.

[0004] Background

[0005] Defects in battery cells may lead to poor performance or thermal runaway events. It is known to use x-ray based techniques to perform non-destructive testing for the purpose of quality control. One or more battery cells from a batch of battery cells may be subjected to two-dimensional x-ray imaging to determine the presence of any defects. The use of computerised tomography (CT) imaging to provide improved three-dimensional images of a battery cell under evaluation is also known. However, the x-ray imaging or the CT imaging of battery cells is slow and the equipment is large and therefore the provision of in-line scanning as part of the manufacturing process presents a significant challenge.

[0006] Summary

[0007] According to a first aspect of the present disclosure there is provided a battery cell imaging apparatus comprising : an x-ray source configured to provide a first x-ray beam in a first direction and a second x-ray beam in a different, second direction; a first manipulator configured to receive a first battery cell and present at least a first part of the first battery cell to the first x-ray beam at a plurality of imaging angles; a second manipulator, separate from the first manipulator, and configured to receive a different, second battery cell and present at least a first part of the second battery cell to the second x-ray beam at a plurality of imaging angles; a first detector configured to detect the first x-ray beam having passed through the first battery cell when in use and provide an output for CT imaging of the first battery cell; and a second detector configured to detect the second x-ray beam having passed through the second battery cell when in use and provide an output for CT imaging of the second battery cell.

[0008] In one or more embodiments, the x-ray source is configured to emit the first x-ray beam in the first direction and emit the second x-ray beam in the different, second direction. In one or more embodiments, the x-ray source is configured to emit the first x-ray beam and emit the second x-ray beam without re-direction of a single x-ray beam to generate two or more noncontemporaneous beams; without splitting of a single x-ray beam to form a plurality of beam parts; and / or without collimation of a single x-ray beam to form a plurality of beam parts.

[0009] In one or more embodiments, the apparatus includes a placing apparatus configured to receive a series of battery cells from a first part of a production line, wherein the placing apparatus is configured to at least pick one of the series of battery cells and provide it to the first manipulator and pick a different one of the series of battery cells and provide it to the second manipulator.

[0010] In one or more embodiments, the placing apparatus or a further placing apparatus is configured to remove each of the battery cells from the first manipulator and place them on a second part of the production line and configured to remove each of the battery cells from the second manipulator and place them on the second part of the production line, wherein the second part of the production line comprises a continuation of the first part of the production line.

[0011] In one or more embodiments, the placing apparatus or the further placing apparatus is configured to selectively place a selected battery cell of the battery cells from the first manipulator and the second manipulator onto a reject line based on a determination that the CT image generated from the output provided by the first detector and the second detector is indicative of a defect in the selected battery cell.

[0012] In one or more embodiments, one or both of the first manipulator and the second manipulator are configured to: provide for rotation about a first axis of rotation to provide for said presentation of the first part of the respective first battery cell and the second battery cell at the plurality of imaging angles; and provide for one or both of translation and rotation about a different, second axis of rotation to enable the presentation of at least a different second part of the respective first battery cell and second part of the second battery cell to the respective one of the first x-ray beam and the second x-ray beam for imaging of those different, second parts.

[0013] In one or more embodiments, one or both of the first part of the first battery cell and the first part of the second battery cell comprise a corner of the respective first and second battery cells.

[0014] In one or more embodiments, the first x-ray beam and the second x-ray beam are generated by the x-ray source simultaneously and the first detector and the second detector are configured to provide for concurrent detection of the respective first and second x-ray beam to provide their respective output for CT imaging.

[0015] In one or more embodiments, the battery cell imaging apparatus includes one or more processors configured to provide for a CT image generator and a controller, wherein the CT image generator is configured to generate a plurality of CT images based on the output of the first detector and the output of the second detector and wherein the controller is configured to, based on receipt of a defect detection signal indicative of a selected one of the plurality of CT images showing a battery cell having a defect, generate a reject signal to cause the battery cell represented in the selected one of the plurality of CT images to be rejected.

[0016] In one or more embodiments, the reject signal is one of: received by the battery cell imaging apparatus, and a placing apparatus is actuated to remove the battery cell determined as having a defect for rejection; provided to a tracking apparatus to electronically mark the battery cell determined as having a defect as defective for rejection elsewhere.

[0017] In one or more embodiments, the first detector is positioned on a first side of the x-ray source and the second detector is positioned on an opposed, second side of the x-ray source.

[0018] In one or more embodiments, one or both of the first detector and the second detector has a frame rate of at least 80 frames per second.

[0019] In one or more embodiments, the x-ray source has a power level of at least 350 Watts for each of the first beam and the second beam.

[0020] In one or more embodiments, the battery cell imaging apparatus comprises one or more processors provided with computer program code configured to provide for CT image generation based on the output of the first detector and the output of the second detector.

[0021] In one or more embodiments, the x-ray source is of liquid-metal anode type.

[0022] According to a second aspect of the present disclosure there is provided a method of operating the battery cell imaging apparatus of the first aspect comprising: providing a first battery cell to the first manipulator; providing a second battery cell to the second manipulator; actuating the first manipulator to present the first battery cell to the first beam from the x-ray source over a plurality of imaging angles; actuating the second manipulator to present the second battery cell to the second beam from the x-ray source over a plurality of imaging angles; detecting, by the first detector, the first x-ray beam having passed through the first battery cell and provide an output for CT imaging of the first battery cell; detecting, by the second detector, the second x-ray beam having passed through the second battery cell and provide an output for CT imaging of the second battery cell.

[0023] While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that other embodiments, beyond the particular embodiments described, are possible as well. All modifications and alternative embodiments falling within the scope of the appended claims are covered as well.

[0024] The above discussion is not intended to represent every example embodiment or every implementation within the scope of the current or future Claim sets. The figures and Detailed Description that follow also exemplify various example embodiments. Various example embodiments may be more completely understood in consideration of the following Detailed Description in connection with the accompanying Drawings.

[0025] Brief Description of the Drawings

[0026] One or more embodiments will now be described by way of example only with reference to the accompanying drawings in which:

[0027] Figure 1 shows an example embodiment of a battery cell imaging apparatus;

[0028] Figure 2 shows a first example embodiment of a battery cell imaging apparatus integrated into a battery cell production line;

[0029] Figure 3 shows a second example embodiment of a battery cell imaging apparatus integrated into a battery cell production line; and

[0030] Figure 4 shows an example flowchart illustrating a method of operating a battery cell imaging apparatus.

[0031] Detailed Description It is possible for defects to occur during the manufacturing process of battery cells. Defects that go undetected can lead to thermal runaway events and therefore the effective detection of defects is an important issue. It is known to use x-ray based technique, such as two-dimensional imaging or Computerised Tomography (CT) imaging technique, for the purpose of quality control. However, with x-ray based imaging, it has been found that it is difficult to identify misalignment issues between sheets of material that form the cells. The CT based imaging equipment is physically large and also slow to gather sufficient data for reliable determination of the presence / absence of defects because of the need for long exposure times. Accordingly, integrating it in-line with the manufacturing process is problematic and it is typically used as an offline solution. Accordingly, it is common for a sample battery cell from a batch of battery cells to be imaged using the CT equipment to determine whether there are problems with the whole batch. This can lead to defective cells going undetected or excess wastage.

[0032] According to an example embodiment, we provide a battery cell imaging apparatus 100 comprising an x-ray source 101 configured to provide a first x- ray beam 102 in a first direction toward a first detector 104 and a second x- ray beam 103 in a different, second direction toward a second detector 105.

[0033] The apparatus 100 is configured to receive a first battery cell 106 between the x-ray source 101 and the first detector 104 such that the first battery cell 106 can be imaged. The apparatus 100 is also configured to receive a second battery cell 107 between the x-ray source 101 and the second detector 105 such that the second battery cell 107 can be imaged.

[0034] It is advantageous to provide a single x-ray source 101 that provides the first x-ray beam 102 in the first direction and the second x-ray beam 103 in a different, second direction because the arrangement is relatively compact compared to multiple x-ray sources. In one or more embodiments, the provision of such a single x-ray source 101 that can provide for simultaneous generation of two x-ray beams, and therefore imaging of two battery cells, provides an imaging apparatus 100 that is sufficiently compact for integration into a production line, as will be described in more detail below. Thus, in the present example, the first x-ray beam 102 and the second x-ray beam 103 are two distinct beams emitted in different directions from the same, single x-ray source 101 wherein the distinct beams are generated without splitting or collimating a single beam after it is emitted from the x-ray source to create two beam "parts". Thus, the x-ray source 101 is configured to emit the first x-ray beam 102 in the first direction and emit the second x-ray beam 103 in a different, second direction at the point of generation of the x-rays. This configuration has advantages over an x-ray device that includes an x-ray source that emits a single beam that is collimated or otherwise split into two parts after the point of generation or includes two x-ray sources. For example, a beam that is collimated or otherwise split to form two beam parts may generate beam parts that have lower energy per unit area than an x-ray source that inherently emits two distinct beams in different directions. Also, an x-ray device that requires two x-ray sources to generate the two beams is large and cumbersome and difficult to integrate in-line with the remainder of the steps and devices that form the battery cell manufacturing process.

[0035] In the present example, the x-ray source 101 generates the first x-ray beam 102 at a first side which projects in the first direction and generates the second x-ray beam 103 at an opposed, second side, which projects in the second direction. The provision of the beams 102, 103 at opposed sides of the x-ray source 101 allows for placement of the first detector and the second detector opposite the x-ray source on the difference sides, which is space efficient. It may then become practical to deliver a production line of battery cells to the apparatus 100 and be able to manipulate them into position for imaging at opposed sides of the x-ray source 101. Further, as the first x-ray beam 102 and the second x-ray beam 103 are generated by the x-ray source 101 simultaneously, the first detector 104 and the second detector 105 are configured to perform the process of gathering data and providing their respective output for CT imaging simultaneously, and therefore two battery cells may be imaged in parallel, significantly increasing throughput of the imaging apparatus 100.

[0036] It will be appreciated that when we reference the imaging of the battery cells we refer to battery cells in a finished state at the end of the manufacturing process as well as part-complete battery cells. For example, a battery cell typically comprises a lamination of a plurality of electrode layers and separator layers. The apparatus 100 can be configured, in one or more examples, to image the lamination prior to manufacturing being complete. Accordingly, the reference to the first battery cell 106 and the second battery cell 107 should be understood to include at least battery cells and electrode / separator structures thereof.

[0037] As an example, the battery cells 106, 107 may be imaged to identify defects caused by a misalignment between one or more electrode layers that form the battery cell.

[0038] The x-ray source 101 may comprise a Metal Jet E1+ Type 160 Kv with a Power level up to 1 kW of Excillum Aktiebolag, Stockholm, Sweden. It will be appreciated that other models or manufacturers x-ray sources may have the functionality described herein, such as attain similar photon energies. In one or more examples, the x-ray source 101 may comprise an x-ray generating head which may be excited with energy such that it generates x-rays from opposed first and second faces of the x-ray generating head. In one or more examples, the x-ray source 101 may be controllable by directing the excitation energy. Thus, directing the excitation energy towards the first face may provide for generation of the first x-ray beam 102 of a greater flux than the second x- ray beam 103. Likewise, directing the excitation energy towards the second face may provide for generation of the second x-ray beam 103 having greater flux than the first x-ray beam 102. Accordingly, the x-ray source 101 may be controllable to determine the flux of the first x-ray beam 102 and the flux of the second x-ray beam 103. In one or more examples, it is preferably that the excitation energy is provided such that the first x-ray beam 102 and the second x-ray beam 103 have substantially the same energy. In one or more examples, a first shutter (not shown) may be provided to control the emission of, or block, the first x-ray beam 102 and a second shutter (not shown) may be provided to control the emission of, or block, the second x-ray beam 103 while the battery cells are moved along a line and imaged at either side of the x-ray source 101. In one or more examples, the x-ray source 101 has a photon energy range of between 10 and 160 Kev. In one or more examples, the x-ray source 101 is configured to provide a spot size between 30 to 50 micrometres. In one or more examples, the x-ray source is configured to operate with a power level between 500 and 1000 Watt. It has been found that operating an x-ray source with one or more of the above-mentioned parameters, such as the power level, allows a faster data acquisition time for the imaging of the battery cells (i.e. high photon energy leads to more available data for imaging and therefore a lower acquisition time). Hence, provision of an imaging apparatus 100 as described has been found to advantageously allow the integration of CT based imaging into a production line.

[0039] In one or more examples, the x-ray source 101 is of a microfocus tube type. In this or other examples, an anode side of the x-ray source may be of a liquid metal alloy anode type, wherein said liquid may be constantly fed and circulated throughout the x-ray source in a molten condition. It will be appreciated that, traditionally, a solid state anode is used. The use of a liquid metal alloy anode type allows higher electron energy that is not limited by the solid state conditions of a classical anode.

[0040] In one or more examples, one or both of the first detector 104 and the second detector 105 comprise a high photon counting detector with single or dual energy imaging. In one or more examples, one or both of the first detector 104 and the second detector 105 have an image acquisition rate greater than 30 fps (frames per second), greater than 100 fps, greater than 200 fps or greater than or up to 500 fps. In some examples, an image acquisition rate of up to 1000 fps may be provided. In one or more examples, one or both of the first detector 104 and the second detector 105 may have an image acquisition rate of between 30 and 500 fps at full resolution or at 2x2 binning. Alternatively, one or both of the first detector 104 and the second detector 105 may comprise a Flat Panel detector (FPD) with Caesium iodide scintillators between 100 to 600 micrometres. In one or more examples, one or both of the first detector 104 and the second detector 105 has a pixel size of 100 micrometres or less. The example of Figure 1 also shows the apparatus 100 comprising a first manipulator 108 configured to receive the first battery cell 106 and present at least a first part of the first battery cell to the first x-ray beam 102. The first part may comprise a corner of the battery cell. The first manipulator 108 is configured to present the first part to the first x-ray beam 102 at a plurality of imaging angles, such as by rotation 110 about a first axis. It will be appreciated that to form a CT image, the first detector 104 is required to detect the x-ray beam 102 having travelled through the first part of the first battery cell 106 from a plurality of different angles - the so-called imaging angles or projections. The angular range the first manipulator 108 is required to rotate or otherwise manipulate the battery cell 106 will depend on the resolution and complexity of the CT image that is being acquired but typically the imaging angles or projections cover a range from 180 to 360 degrees. Accordingly, different example embodiments may provide for a different range of imaging angles. The first detector 104 is configured to detect the first x-ray beam having passed through the first battery cell 106 as it is rotated through the imaging angles and is configured to provide an output for CT imaging of the first battery cell. The output from the first detector 104 may be provided to a processor for tomographic reconstruction to generate the CT image.

[0041] The example of Figure 1 also shows the apparatus 100 comprising a second manipulator 109 configured to receive the second battery cell 107 and present at least a first part of the second battery cell to the second x-ray beam 103. The first part may comprise a corner of the battery cell. The second manipulator 109 is configured to present the first part to the second x-ray beam 103 at a plurality of imaging angles (as described above), such as by rotation 111 about a first axis. The second detector 105 is configured to detect the second x-ray beam 103 having passed through the second battery cell 107 as it is rotated through the imaging angles and is configured to provide an output for CT imaging of the second battery cell. The output from the second detector 105 may also be provided to the processor or a different processor (not shown) for tomographic reconstruction to generate the CT image.

[0042] The first manipulator 108 and the second manipulator 109 may comprise a gripper to hold and support the battery cell and a movable arm or base coupled to the gripper to rotate or otherwise move the respective battery cell through the imaging angles.

[0043] In some examples, the apparatus 100 also includes one or more processors (not shown) configured to receive the output from the first detector 104 and the second detector 105. The one or more processors may be provided with computer program code to provide a CT image generator, for generating the CT images from the data acquired from the first and second detectors 104, 105. In other examples, the generation of the image from the output may be provided by a different apparatus or in the cloud.

[0044] It has been determined that the time savings provided by the advantages of efficient handling of battery cells to either side of the x-ray source 101 as well as simultaneous scanning due to the arrangement of the x-ray beams 102, 103 and detectors 104, 105 may allow for more thorough imaging of a battery cell and / or quicker imaging. Accordingly, in one or more examples, the apparatus may be configured such that a plurality of parts of each battery cell, or a plurality of parts of at least some of the battery cells, may be imaged.

[0045] Thus, in the present example, the first manipulator 108 and the second manipulator 109 are configured to provide for the rotation 110, 111 about the first axis of rotation to provide for presentation of the respective battery cell at the imaging angles. In addition, the first manipulator 108 and the second manipulator 109 may be configured to provide for a second movement action comprising one or both of translation and rotation 112, 113 about a different, second axis of rotation. The second movement action may be configured to enable the presentation of at least a different, second part of the respective first battery cell 106 and second part of the second battery cell 107 to the respective x-ray beam 102, 103 for imaging of those different, second parts. The second parts may for example, comprise a different corner of the battery cell or some other part, such as an edge or a central region of the battery cell.

[0046] The imaging apparatus 100 described herein may be for imaging prismatic battery cells and / or cylindrical battery. Figure 2 shows an example production line 200 having the battery cell imaging apparatus 100 integrated therein. As mentioned above, the real-world size of the imaging apparatus 100, given the configuration and arrangement of the x- ray source 101 and the detectors 104, 105 allows for an imaging time of approximately 1 to 4 seconds (or up to 8 seconds) and a throughput of 10 to 15 battery cells per minute. In one or more examples, the ability to provide cells for imaging to both sides of the source allows for between 18-28 battery cells per minute for a single x-ray source.

[0047] In figure 2, the first and second manipulators 108, 109 are omitted for clarity, but otherwise like reference numerals have been used for like parts. In figure 2, the battery cell imaging apparatus 100 is part of the production line 200 for the manufacture of battery cells.

[0048] Thus, in use, the apparatus 100 receives a series of battery cells 201-204 from a first part 205 of the production line which can be a gantry system or a robot. The apparatus 100 includes a placing apparatus 206 configured to receive the series of battery cells 201-204 and direct them to either side of the x-ray source 101 for imaging. The present configuration is advantageous because the single x-ray source 101 having two detectors 104, 105 at respective sides provides an arrangement that is sufficiently compact to enable the delivery of battery cells from a production line to each side by the placing apparatus 206 and the possibility to use two parallel tracks to inspect the batteries at the same time.

[0049] The placing apparatus 206 is configured to at least pick one of the series of battery cells 201-204 and place it in the first manipulator 108 (not shown in figure 2) and pick a different one of the series of battery cells and place it in the second manipulator 109 (not shown in figure 2) and so on for the battery cells arriving on the first part 205. The placing apparatus 206 may comprise one or more robotic arms having a gripper or one or more suction cups attached thereto for placing the battery cells in the manipulators. In other examples, the placing apparatus 206 may comprise one or more grippers, which may be mounted to a sliding track or a gantry system. In one or more examples, the placing apparatus 206 may comprise one or more devices to grip, translate and rotate the battery cells. However, in general, the placing apparatus 206 may be configured to receive a flow of battery cells, such as from a feeding line which can be a conveyor of the production line, and deliver them to the respective first and second manipulators 108, 109 at either side of the x-ray source 101.

[0050] Once the battery cells have been imaged, a further placing apparatus 207 is configured to remove each of the battery cells from the first and second manipulator 106, 107 or otherwise receive removed battery cells and place them on a second part 208 of the production line. It will be appreciated that, effectively, the second part of the production line 208 comprises a continuation of the first part of the production line 205.

[0051] If the imaging of a battery cell in either of the first and second manipulators 106, 107 reveals the battery cell has a defect, the further placing apparatus 207 is configured to selectively place the defective cell onto a reject line 209. Accordingly, the further placing apparatus 207 is configured to receive a signal to determine whether to place the battery cell on the production line 208 or the reject line 209. In other examples, the reject line 209 is not provided and the imaging apparatus 100 may be configured to provide a signal indicative that a defective battery cell has been identified by the imaging to a tracking system (not shown), such that the defective battery cell is electronically marked (such as based on a computer readable identifier (e.g. a QR. code) present on the cell). The defective cell can then be identified and dealt with later in the manufacturing processes rather than by the placing apparatus 207. The tracking system may be configured to associate the CT images taken by the imaging apparatus 100 with the computer readable identifier for defective cells, or alternatively, for at least some or all of the cells irrespective of a defect being detected. Providing this enhanced tracking of cells and their "as manufactured" internal structure is advantageous for quality control and enables assessment of the in-use performance, if later inspection of the cell was ever required.

[0052] The reject signal may be generated by a controller 210. As mentioned previously, a CT image generator (not shown) may be configured to generate a plurality of CT images based on the output of the first detector 104 and the output of the second detector 105. The controller 210 is configured to, based on receipt of a defect detection signal indicative of a selected one of the plurality of CT images showing a battery cell having a defect, such as one or more misaligned electrode layers or separator layers above a threshold misalignment, generate the reject signal to cause the battery cell represented in the selected one of the plurality of CT images to be placed on the reject line 209 by the further placing apparatus 207 or electronically marked.

[0053] The controller 210 may be configured to judge the result of the CT images, and record a judgment of cells, such as OK / "Not good" (defective). The judgement may be provided to a manufacturing execution system, which may be provided on a server or in the cloud. Such judgments may be associated with a QR. code (or other marking to link the electronic mark to the cell) of the particular battery cell once it is been dispatched to the reject line 209 or passed to production line 208 for separation downstream.

[0054] In one or more examples, the defect detection signal is provided by a human operator viewing said plurality of CT images. In other examples, the defect detection signal is generated based on an automatic, computer-implemented, comparison between said selected one of the plurality of CT images and a predetermined reference image. In one or more examples, the defect detection signal is generated by a machine learning model trained to identify a defect, such as a battery cell having one or more misaligned electrode layers or separator layers above a threshold misalignment. It will be appreciated that such Al / machine learning models will be trained on training data showing different defects for future recognition of defects.

[0055] Figure 3 shows a second example production line 300 having the battery cell imaging apparatus 100 integrated therein. Like parts have been given the same reference numerals.

[0056] In this example, the first x-ray beam 102 and first detector is used to image a first part of the battery cell. A placing apparatus 307 is configured to transfer the battery cell to the other side of the x-ray source 101 such that the second x-ray beam 103 and the second detector 105 is used to image a second, different, part of the battery cell.

[0057] Accordingly, the placing apparatus 307 may be configured to transfer the battery cell from a first side (the side of the first detector) to the second side (the side of the second detector) of the apparatus 100 if no defect is detected based on the image captured by the first detector 104. Alternatively, if a defect is detected, then the placing apparatus 307 is configured to place the battery cell on a reject line 209 or alternatively electronically mark, as described above. When transferred to the second side of the apparatus, the battery cell is received in the second manipulator such that the second, different, part of the battery cell is imaged. As before, it is then either placed on the second part of the production line 208 or a further reject line 309.

[0058] The production line 300 may be particularly suited to imaging cylindrical battery cells, such as 4680, 4690, 4695 and 46120 cells, although any other sized cylindrical cell may be imaged. For example, the production line 130 may be suited to cylindrical cells having a diameter ranging from 32 to 48 mm and a length ranging from 70 to 130 mm as the apparatus allows for timely and sufficiently detailed scanning of such sizes, which was previously impractical in an in-line manner. Thus, in one or more examples, a first end of the cylindrical battery cell is imaged by beam 102 and detector 104. The placing apparatus 307 may be configured to rotate the cylindrical battery cell and place it in the second manipulator (not shown) such that the opposed, second end is imaged by the beam 103 and the detector 105. In some examples, the detectors 104, 105 are limited in the size of their active area for detecting x-ray photons. Accordingly, the size of the object to be imaged is also limited. Providing a single x-ray source 101 in combination with the rotation provided by the placing apparatus 307 to enable timely scanning of the cylindrical battery cell is advantageous, particularly when considering the higher speeds that a cylindrical battery cell production line typically operates. Also, enabling the rotation of "long" cylindrical cells so that both ends can be imaged using one x-ray source 101 is efficient. Example figure 4 shows a flow chart illustrating a method of operating the battery cell imaging apparatus 100. The method comprises: providing 401 a first battery cell to the first manipulator; providing 402 a second battery cell to the second manipulator; actuating 403 the first manipulator to present the first battery cell to the first beam from the x-ray source over a plurality of imaging angles; actuating 404 the second manipulator to present the second battery cell to the second beam from the x-ray source over a plurality of imaging angles; detecting 405, by the first detector, the first x-ray beam having passed through the first battery cell and provide an output for CT imaging of the first battery cell; detecting 406, by the second detector, the second x-ray beam having passed through the second battery cell and provide an output for CT imaging of the second battery cell.

[0059] The instructions and / or flowchart steps in the above figures can be executed in any order, unless a specific order is explicitly stated. Also, those skilled in the art will recognize that while one example set of instructions / method has been discussed, the material in this specification can be combined in a variety of ways to yield other examples as well, and are to be understood within a context provided by this detailed description.

[0060] In some example embodiments the set of instructions / method steps described above are implemented as functional and software instructions embodied as a set of executable instructions which are effected on a computer or machine which is programmed with and controlled by said executable instructions, such one or more of the CT image reconstruction, defect detection or production line control processes. Such instructions are loaded for execution on a processor (such as one or more CPUs or GPUs). The term processor includes microprocessors, microcontrollers, processor modules or subsystems (including one or more microprocessors or microcontrollers), or other control or computing devices. A processor can refer to a single component or to plural components. In other examples, the set of instructions / methods illustrated herein and data and instructions associated therewith are stored in respective storage devices, which are implemented as one or more non-transient machine or computer- readable or computer-usable storage media or mediums.

[0061] In one example, one or more instructions or steps discussed herein are automated. The terms automated or automatically (and like variations thereof) mean controlled operation of an apparatus, system, and / or process using computers and / or mechanical / electrical devices without the necessity of human intervention, observation, effort and / or decision.

Claims

CLAIMS1. A battery cell imaging apparatus comprising: an x-ray source configured to provide a first x-ray beam in a first direction and a second x-ray beam in a different, second direction; a first manipulator configured to receive a first battery cell and present at least a first part of the first battery cell to the first x-ray beam at a plurality of imaging angles; a second manipulator, separate from the first manipulator, and configured to receive a different, second battery cell and present at least a first part of the second battery cell to the second x-ray beam at a plurality of imaging angles; a first detector configured to detect the first x-ray beam having passed through the first battery cell when in use and provide an output for CT imaging of the first battery cell; and a second detector configured to detect the second x-ray beam having passed through the second battery cell when in use and provide an output for CT imaging of the second battery cell.

2. The battery cell imaging apparatus of claim 1, wherein the x-ray source is configured to emit the first x-ray beam in the first direction and emit the second x-ray beam in the different, second direction.

3. The battery cell imaging apparatus of claim 1 or claim 2, wherein the apparatus includes a placing apparatus configured to receive a series of battery cells from a first part of a production line, wherein the placing apparatus is configured to at least pick one of the series of battery cells and provide it to the first manipulator and pick a different one of the series of battery cells and provide it to the second manipulator.

4. The battery cell imaging apparatus of claim 3, wherein the placing apparatus or a further placing apparatus is configured to remove each of the battery cells from the first manipulator and place them on a second part of the production line and configured to remove each of the battery cells from the second manipulator and place them on the second part of the production line,wherein the second part of the production line comprises a continuation of the first part of the production line.

5. The battery cell imaging apparatus of claim 4, wherein the placing apparatus or the further placing apparatus is configured to selectively place a selected battery cell of the battery cells from the first manipulator and the second manipulator onto a reject line based on a determination that the CT image generated from the output provided by the first detector and the second detector is indicative of a defect in the selected battery cell.

6. The battery cell imaging apparatus of any preceding claim, wherein one or both of the first manipulator and the second manipulator are configured to: provide for rotation about a first axis of rotation to provide for said presentation of the first part of the respective first battery cell and the second battery cell at the plurality of imaging angles; and provide for one or both of translation and rotation about a different, second axis of rotation to enable the presentation of at least a different second part of the respective first battery cell and second part of the second battery cell to the respective one of the first x-ray beam and the second x-ray beam for imaging of those different, second parts.

7. The battery cell imaging apparatus of any preceding claim, wherein one or both of the first part of the first battery cell and the first part of the second battery cell comprise a corner of the respective first and second battery cells.

8. The battery cell imaging apparatus of any preceding claim, wherein the first x-ray beam and the second x-ray beam are generated by the x-ray source simultaneously and the first detector and the second detector are configured to provide for concurrent detection of the respective first and second x-ray beam to provide their respective output for CT imaging.

9. The battery cell imaging apparatus of any preceding claim, including one or more processors configured to provide for a CT image generator and a controller, wherein the CT image generator is configured to generate a plurality of CT images based on the output of the first detector and the output of thesecond detector and wherein the controller is configured to, based on receipt of a defect detection signal indicative of a selected one of the plurality of CT images showing a battery cell having a defect, generate a reject signal to cause the battery cell represented in the selected one of the plurality of CT images to be rejected.

10. The battery cell imaging apparatus of claim 9, wherein the reject signal is one of: received by the battery cell imaging apparatus, and a placing apparatus is actuated to remove the battery cell determined as having a defect for rejection; provided to a tracking apparatus to electronically mark the battery cell determined as having a defect as defective for rejection elsewhere.

11. The battery cell imaging apparatus of any preceding claim, wherein the first detector is positioned on a first side of the x-ray source and the second detector is positioned on an opposed, second side of the x-ray source.

12. The battery cell imaging apparatus of any preceding claim, wherein one or both of the first detector and the second detector has a frame rate of at least 80 frames per second.

13. The battery cell imaging apparatus of any preceding claim, wherein x- ray source has a power level of at least 350 Watts for each of the first beam and the second beam.

14. The battery cell imaging apparatus of any preceding claim, comprising one or more processors provided with computer program code configured to provide for CT image generation based on the output of the first detector and the output of the second detector.

15. The battery cell imaging apparatus of any preceding claim, wherein the x-ray source is of liquid-metal anode type.

16. A method of operating the battery cell imaging apparatus of any preceding claim comprising: providing a first battery cell to the first manipulator; providing a second battery cell to the second manipulator; actuating the first manipulator to present the first battery cell to the first beam from the x-ray source over a plurality of imaging angles; actuating the second manipulator to present the second battery cell to the second beam from the x-ray source over a plurality of imaging angles; detecting, by the first detector, the first x-ray beam having passed through the first battery cell and provide an output for CT imaging of the first battery cell; detecting, by the second detector, the second x-ray beam having passed through the second battery cell and provide an output for CT imaging of the second battery cell.

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