Apparatus and corresponding method for producing an electrode stack from electrode stack elements

Abstract

The invention relates to an apparatus (2) for producing an electrode stack (4) from electrode stack elements (6). The device comprises: a stacking wheel (8) having at least one stacking wheel disc (10), which can be rotationally driven about an axis of rotation (D) and which has compartments (16) for receiving the electrode stack elements (6); a stripper (34) for stripping the electrode stack elements (6) from the compartments (16) during a rotation of the stacking wheel (8); a shelf (36) for the electrode stack elements (6) stripped from the stacking wheel (8); and a conveying device (18) for conveying the electrode stack elements (6) into the compartments (16). The conveying device (18) comprises a transfer device (22) for transferring the electrode stack elements (6) into the compartments (16) and a feeding device (20) for feeding the electrode stack elements (6) to the transfer device (22). The invention also relates to a method for producing an electrode stack (4) using the apparatus (2).

Description

[0001] DEVICE AND CORRESPONDING METHOD FOR PRODUCING AN ELECTRODE STACK FROM ELECTRODE STACK ELEMENTS

[0002] The invention relates to a device and a method for producing an electrode stack using a stacking wheel.

[0003] A lithium-ion battery has at least one battery cell in which an electrode stack with a number of sheet-like cathodes (cathode sheets, cathode foils) and sheet-like anodes (anode sheets, anode foils) is accommodated, wherein the cathodes and the anodes are stacked one above the other, for example, and wherein a separator is arranged between the cathodes and the anodes.

[0004] The electrode stack with stacked anodes and cathodes is manufactured, for example, using so-called single-sheet stacking. Typically, the individual anodes and cathodes are moved using a gripper system. A gripper of this gripper system picks up the respective electrode, i.e., the respective anode or cathode, transports it to a stacking location, and places it there. However, such gripper systems are comparatively slow. As a result, the manufacturing process of such an electrode stack is disadvantageously comparatively time-consuming.

[0005] Alternatively, WO 2020 / 212317 A1 discloses a device which uses a stacking wheel to produce an electrode stack of monocells.

[0006] The invention is based on the object of providing a particularly suitable device and method for producing an electrode stack. In particular, the aim is to achieve the most time-efficient production of the electrode stack and / or to reduce the risk of damage to the electrode stack elements to be stacked.

[0007] With regard to the device, the object is achieved according to the invention by the features of claim 1, and with regard to the method by the features of claim 7. Advantageous further developments and refinements are the subject of the dependent claims. The statements made in connection with the device also apply mutatis mutandis to the method, and vice versa.

[0008] The device is used to produce an electrode stack from electrode stack elements. Such an electrode stack element is, for example, an anode, a cathode, a separator, an anode laminated with a separator, or a cathode. Preferably, the electrode stack element is a composite referred to as a monocell or unit cell, which is formed by means of a (single) anode and a (single) cathode, with a separator (a separator film) arranged between the anode and the cathode. Furthermore, a further separator is arranged on the side of the cathode facing away from the anode or on the side of the anode facing away from the cathode. Preferably, the anode, the cathode, and the separators are joined to one another, in particular by lamination. The anodes and the cathodes are collectively referred to as electrodes. These are, in particular, designed in the form of films.The electrodes thus have a comparatively small extension in one spatial direction; in other words, the electrodes are flat. The electrode stack is preferably intended and configured for a lithium-ion battery cell, in particular for a lithium-ion battery cell of a traction battery for an electrically powered motor vehicle.

[0009] The device has a stacking wheel which has at least one stacking wheel element, in particular at least one stacking wheel disk, which can be driven (rotatably driven) about a rotation axis. The respective stacking wheel element comprises compartments for receiving the electrode stack elements. The compartments are also referred to here and below as pockets or receptacles. The respective stacking wheel element has so-called fingers (arms) which extend radially outwards from a central region, with a pocket being formed between each two fingers (arms). The fingers or compartments are expediently curved, in particular spiral-shaped. Thus, the compartments have an arc-shaped, in particular spiral-shaped, cross-section in a plane perpendicular to the rotation axis. In other words, the respective compartment runs in an arc or spiral shape from its circumferential compartment entrance to its rotation axis-side compartment end.Preferably, the curvature of the arcuate holder increases from the circumferential side toward the rotational axis, i.e., with decreasing radial distance from the rotational axis. As a result, the frictional force between the holders and the electrode stack elements conveyed into them increases from the circumferential side toward the rotational axis, i.e., inward, so that the electrode stack elements are decelerated increasingly strongly. Thus, the electrode stack elements are reliably decelerated to a standstill relative to the holder before the monocells are held by the stripping arm(s).

[0010] The stacking wheel preferably comprises more than one such stacking wheel element, in particular two, three, four, or five stacking wheel elements. These are arranged spaced apart from one another in an axial direction, i.e., in a direction along the axis of rotation. The stacking wheel elements are expediently jointly rotatably driven by an axis defining the axis of rotation. The stacking wheel elements are preferably aligned with one another in the axial direction. In other words, the stacking wheel elements are of identical design and overlap in the axial direction.

[0011] The device further comprises a stripper for stripping the electrode stack elements out of the compartments during rotation of the stacking wheel. Thus, the electrode stack elements accommodated in the compartments are held against further entrainment by the stacking wheel during rotation of the stacking wheel and are stripped out of the compartment. The stripper thus forms a type of stop for the electrode stack elements. The electrode stack elements are stacked one on top of the other in a tray, i.e., placed one on top of the other to form the electrode stack. The stop surface of the stripper for the electrode stack elements is arranged in the axial direction in front of and / or behind the stacking wheel element, and / or - if more than one stacking wheel element is used - between the stacking wheel elements.Preferably (and / or during the method for producing the electrode stack), the distance of the stop surface, in particular its edge facing away from the storage area, from the rotational axis is adjusted such that it is smaller than the smallest distance of the electrode stack element from the rotational axis while it is being carried along in the compartment. Consequently, the electrode stack element is prevented from striking the stripper and from damaging it. For example, a radial distance of the stripper, in particular its stop surface, from the rotational axis is smaller than the end of the compartments on the rotational axis side.

[0012] The device further comprises a conveyor device for conveying the electrode stack elements into the compartments of the stacking wheel. Firstly, the conveyor device comprises a transfer device which serves to transfer the electrode stack elements into the compartments. Secondly, the conveyor device comprises a feed device which is separate, i.e. structurally distinct, from the transfer device and which serves to feed the electrode stack elements to the transfer device. The feed device is expediently a conveyor belt, for example a vacuum conveyor belt. Particularly advantageously, the device enables a comparatively precise and defined positioning of the electrode stack elements in the electrode stack. Furthermore, the electrode stack elements are transferred into the stacking compartment by means of the stacking wheel without the use of a gripper or gripping device.Advantageously, the alternating stacking of the electrode stack elements is comparatively fast, thus saving time, especially compared to the aforementioned production of the electrode stack using a gripping device. This advantageously increases the process rate for producing the electrode stack—in other words, throughput.

[0013] According to an advantageous embodiment of the device, the transfer time, i.e., the time at which the leading edge of the respective electrode stack element in the transfer direction enters the stacking wheel, in particular at which the leading edge of the respective electrode stack element first touches the stacking wheel, can be changed using the transfer device, in particular solely using the transfer device, in particular adaptable to the position of the compartment provided for receiving the respective electrode stack element. Thus, adapting (synchronizing) the transfer time and / or the transfer speed, the rotational speed, and / or the (rotational, angular) position of the stacking wheel is comparatively easy.Particularly if the stacking wheel rotates at a constant rotational speed, such adjustment based solely on the transfer device is comparatively efficient, since the stacking wheel, with its comparatively high inertia, does not need to be accelerated. The stacking wheel and / or a drive unit for rotating the stacking wheel expediently comprises a position sensor, by means of which the (angular, rotational) position of the stacking wheel or its stacking wheel element(s) and, from this, the position of the respective compartment can be determined. The device expediently further comprises a sensor, for example a camera, for detecting the position of the respective electrode stack element in the feed device, so that the feed time (transfer time) can be determined based on this position.

[0014] Furthermore, in comparison to conveying the electrode stack elements only by means of a conveyor belt, the transfer time of the respective electrode stack element can be changed due to the separate design of the transfer device from the feed device, without also changing the conveying speed of the feed device (at least temporarily).

[0015] According to a suitable embodiment, the transfer device comprises at least two upper transport elements, which are designed, for example, as belts or rollers, and which are spaced from one another in a direction transverse to the transfer direction, i.e. in the axial direction. When the transport elements are designed as belts, the rollers are expediently connected to a motor via a common first shaft to drive the upper belts. Furthermore, the transfer device comprises at least two lower transport elements, which are designed, for example, as belts or rollers, and which are spaced from one another in a direction transverse to the transfer direction, i.e. in the axial direction. When the transport elements are designed as belts, the rollers are expediently connected to one another via a common second shaft to drive the lower belts.In particular, the first and second shafts are coupled to each other by means of a pair of gears.

[0016] For example, the upper transport elements and the lower transport elements are arranged offset from one another in the axial direction, in other words, the upper and lower transport elements are arranged one behind the other in a meshing manner in the axial direction. However, for the clamping conveyance of the electrode stack elements, the upper transport elements and the lower transport elements are preferably arranged one above the other in a direction perpendicular to the conveying direction, i.e. to the direction in which the electrode stack elements are conveyed in the transfer device, and / or perpendicular to the axial direction. In this case, one of the upper transport elements is located opposite one of the lower transport elements. In other words, a pair is preferably formed from one of the upper and one of the lower transport elements, between which the respective electrode stack element is clamped.In other words, they are not offset from each other in the axial direction. This prevents the electrode stack elements from bending due to the belts.

[0017] For example, the width of the transport elements, i.e., their axial extension, ranges between 1 mm and 250 mm. For example, the upper transport elements each have a width that differs from the width of the lower transport elements. Depending on the design of the electrode stack elements and a suitable clamping force, the width of the transport elements and / or their spacing from one another are selected accordingly. If the electrode stack elements are designed as monocells, the wider transport elements are located on the separator side of the monocell, thus reducing the risk of contamination of its electrodes.

[0018] Preferably, each of the transport elements has a width, i.e., an axial extension, which is less than a quarter, preferably less than a tenth, of the axial extension of the stacking wheel element, or—if multiple stacking wheel elements are used—which is less than a quarter, preferably less than a tenth, of the distance between the first and last stacking wheel elements in the axial direction. In this way, the electrode stack elements to be conveyed are only touched by the belts over a comparatively small area. Consequently, the risk of damage to or contamination of the respective electrode stack element by the transfer device is at least reduced.

[0019] According to a preferred embodiment, the upper transport elements are spring-loaded against the lower transport elements. In other words, a spring force, i.e. a restoring force, acts on the upper transport elements in the direction towards the lower transport elements, i.e. downwards. Additionally or alternatively, the lower transport elements are spring-loaded against the upper transport elements. In other words, a spring force, i.e. a restoring force, acts on the lower transport elements in the direction towards the upper transport elements, i.e. upwards. In this way, when the respective electrode stack element is fed into the transfer device, the upper and lower transport elements are adjusted against the spring force. This results in better clamping of the respective electrode stack element.

[0020] For example, the upper transport elements project beyond the lower transport elements in a direction opposite to the conveying direction. When designed as belts, the upper belts are longer than the lower belts in the conveying direction. The region of the upper belts that projects beyond the lower belts expediently covers the feed device designed as a conveyor belt, in particular the end region of the conveyor belt on the transfer device side, for feeding the respective electrode stack element. This end region and the upper belts are expediently arranged one above the other, so that the electrode stack elements in this region are fed from the conveyor belt into the transfer device in a clamped manner. This advantageously results in a comparatively reliable and error-free feed of the respective electrode stack element into the transfer device.

[0021] In particular, when the transport elements are designed as belts, for example, the one of the two axes of rotation of the upper transport elements that is closer to the stacking wheel is offset in the conveying direction from the one of the two axes of rotation of the lower transport elements that is closer to the stacking wheel. In this way, the respective electrode stack element is guided for a longer time by the transport element that is offset closer to the stacking wheel. According to an advantageous embodiment of the device, the transfer device is spaced from the axis of rotation in the radial direction, i.e. in a direction perpendicular to the axis of rotation, by a distance that is greater than the radius, in particular greater than the diameter, of the stacking wheel element. The transfer device is therefore arranged completely outside the area concealed by the stacking wheel in the axial direction. In other words, the transfer device is spaced apart from the stacking wheel in the radial direction.At the same time, the electrode stack elements are also conveyed into the stacking wheel from outside the area covered by the stacking wheel in the axial direction. As the electrode stack element slides along the inside of the compartment during transfer, its direction of movement changes. When the transfer device is arranged at a distance from the stacking wheel, a space is formed between them into which the rear end of the electrode stack element with respect to the conveying direction can move during the change of direction, so that bending of the electrode stack element due to the change in its direction of movement is advantageously avoided and the risk of damage is thus reduced. The transport elements are preferably arranged opposite the stacking wheel elements in a direction perpendicular to the axial direction; in other words, the transport elements are not offset from the stacking wheel elements in the axial direction.In this way, only the area of ​​the electrode stack elements rests on the stacking wheel or its stacking wheel elements where the transport elements act on the respective electrode stack element. The area of ​​force transmission to the respective electrode stack element is thus reduced.

[0022] Alternatively, the transfer device is spaced radially from the rotational axis, i.e., in a direction perpendicular to the rotational axis, by a distance that is smaller than the radius of the stacking wheel element. In this case, the transport elements extend between the stacking wheel elements. In other words, the transport elements are then arranged axially, at least in some areas, between the stacking wheel elements. In particular, the transport elements and the stacking wheel elements are arranged meshing with respect to the axial direction. This advantageously reduces the installation space for the device.

[0023] According to an advantageous embodiment, the distance of the scraper, in particular its stop surface, from the rotational axis is adjustable. Alternatively, or preferably additionally, the inclination of the scraper, in particular its stop surface, is adjustable.

[0024] Preferably, the stop surface of the stripper is always perpendicular to the storage surface of the tray. In this way, the position of the stripper relative to the compartments can be adjusted and / or readjusted. In particular, the stripper is or will be arranged such that the electrode stack elements strike the stripper essentially perpendicularly, so that pinching and thus damage to the electrode stack elements during stripping is avoided or at least reduced.

[0025] A further aspect of the invention relates to a method for producing an electrode stack from electrode stack elements. For this purpose, a device in one of the variants described above is used; thus, such a device is provided according to the method.

[0026] According to the method, the electrode stack elements are fed to the transfer device by the feed device and transferred to the stacking wheel by the transfer device, i.e., conveyed into the compartments of the stacking wheel element(s). Conveniently, only one of the electrode stack elements is transferred into each compartment.

[0027] The electrode stack elements stored in the compartments are then conveyed to a storage area by the rotation of the stacking wheel. The electrode stack elements are guided to the storage area by the stacking wheel.

[0028] The electrode stack elements are then held in the storage area by the stripper. Due to the rotation of the stacking wheel, the electrode stack elements are guided out of the respective receptacle and into the storage area. In other words, the electrode stack elements are held (supported) against the rotation of the stacking wheel by the stripper, so that the respective compartment is adjusted relative to the respective electrode stack element due to the rotation of the stacking wheel and transferred accordingly from the respective compartment to the storage area. The electrode stack elements are stacked on top of each other in the storage area, forming the electrode stack.

[0029] Preferably, the stacking wheel rotates at a constant speed.

[0030] According to an advantageous embodiment of the method—as already described in connection with the device—in order to adapt the transfer time to a position of the stacking wheel, in particular, only the conveying speed of the electrode stack elements in the transfer device is changed. The stacking wheel is preferably driven at a constant rotational speed. Thus, based on the transfer device, in particular solely based on the transfer direction, the transfer time of the respective electrode stack element is adapted to a (rotational, angular) position of the stacking wheel, in particular to the position of the respective compartment for receiving this electrode stack element.If necessary, the transfer time is changed for this purpose; in particular, the transfer time is delayed or brought forward in time compared to a transfer process in which the respective electrode stack element is conveyed at a constant speed in the transfer device (transfer apparatus). For this purpose, the respective electrode stack element is temporarily decelerated or accelerated in the transfer device. The temporary acceleration or deceleration is expediently carried out in such a way that the respective electrode stack element has a predetermined transfer speed upon exiting the transfer device. In particular, the running speed of the upper and lower belts is changed accordingly to adjust the transfer time.

[0031] According to a preferred embodiment, electrode stack elements are used which have a rectangular base area with different edge lengths, i.e. which do not have a square base area. If the electrode stack element has at least one electrode, an electrical contact, also referred to as a tab or contact lug, of the respective electrode expediently protrudes laterally beyond the base area. These contacts expediently protrude beyond the base area on one or both short edges of the respective electrode stack element. The length of the longer edge is preferably between 1.5 times and 10 times, in particular between 2 times and 5 times, the length of the short edge.

[0032] Particularly preferably, the electrode stack elements are transferred into the compartments with their longer edge, i.e. with one of the two sides that forms the longer side, first. In other words, the two longer edges extend transversely to the transfer direction and the two shorter edges parallel to the transfer direction. In this way, the force acting on the electrode stack element when it hits the stripper and / or the compartment end closest to the rotation axis is distributed over a comparatively large area of ​​the electrode stack element, thus reducing the risk of damage. Secondly, compared to transfer with the short edge first, the speed of the stacking wheel is particularly advantageously reduced for a given stacking rate. This also enables the electrode stack elements to be braked particularly gently in the compartments.

[0033] According to a preferred embodiment, at any given time, a maximum of one electrode stack element, i.e., one or none, is conveyed by the transfer device. In other words, the electrode stack elements are fed to the transfer device at such a time interval that a maximum of one electrode stack element is always present in the transfer device and / or is being conveyed by the upper belts for transfer. In this way, the transfer time of one electrode stack element can be adjusted without affecting the transfer time of the subsequently fed electrode stack element.

[0034] Preferably, in a space-saving manner, the length of the transfer device, in particular its upper belt bands, with respect to the transfer direction is smaller than the radius of the stacking wheel element(s) and / or smaller than twice the edge length of the short edge of the electrode stack elements.

[0035] In the following, exemplary embodiments of the invention are explained in more detail with reference to a drawing. In the drawings:

[0036] Fig. 1 shows a schematic side view of a device for producing an electrode stack from electrode stack elements, wherein the device comprises a stacking wheel with stacking wheel elements designed as stacking wheel discs and a conveyor device with a transfer device by means of which the electrode stack elements can be transferred into compartments of the stacking wheel discs,

[0037] Fig. 2 schematically and partially the device in perspective view,

[0038] Fig. 3a, b schematically in perspective exploded view and in side view an electrode stack element designed as a monocell with a rectangular base area, and

[0039] Fig. 4 shows a flow chart of a process sequence for producing an electrode stack using the device.

[0040] Corresponding parts and sizes are always provided with the same reference symbols in all figures.

[0041] Fig. 1 shows a schematic side view of a device 2 for producing an electrode stack 4 from electrode stack elements 6, and Fig. 2 shows it in perspective. The device 2 comprises a stacking wheel 8, which in turn has at least one stacking wheel element 10, five stacking wheel elements 10 according to the exemplary embodiment shown here. According to the exemplary embodiment shown here, the stacking wheel elements 10 are designed as stacking wheel disks 10. These are rotationally driven by a common drive shaft 12. The direction of rotation of the stacking wheel 8 is designated by the reference symbol "U" in Fig. 1. The drive shaft 12 thus defines the axis of rotation D of the stacking wheel disks 10. Each of the stacking wheel disks 10 comprises a plurality of fingers 14 which extend outwards from a central region in a curved manner, in particular in a spiral manner.Thus, a compartment 16 is formed between each two of the fingers 14, which serves to accommodate one of the electrode stack elements 6. The compartments 16 are arranged one behind the other with respect to the direction of rotation U.

[0042] The stacking wheel discs 10 are constructed uniformly to one another and are arranged in alignment in the direction referred to as axial direction A along the axis of rotation D. Thus, the compartments 16 of the stacking wheel discs 10 are arranged one behind the other in the axial direction A, i.e., in alignment with one another.

[0043] The device 2 further comprises a conveyor device 18, by means of which the electrode stack elements are conveyed, namely transferred, into the stacking wheel 8, namely into the compartments 16 of the stacking wheel disks. For this purpose, the conveyor device 18 is designed in two parts. The conveyor device 18 comprises a feed device 20 designed as a conveyor belt, by means of which the electrode stack elements 6 are fed to a transfer device 22. The feed device 20 is not shown in detail in Fig. 2 for the sake of better clarity. The transfer device 22 serves to convey, namely transfer, the electrode stack elements 6 into the compartments 16 of the stacking wheel 10. The transfer direction 22, i.e. the direction in which the electrode stack elements are conveyed when leaving the transfer device 6, is provided with the reference symbol "F" in Fig. 1.

[0044] The transfer device 22 comprises at least two, according to the embodiment shown here, five upper transport elements, which according to the embodiment shown here are designed as belts 24, which can be driven by means of a common first drive shaft 26. The upper belts 24 are arranged spaced from one another in the axial direction A, i.e. transversely to the transfer direction F, in particular equidistantly. The transfer device 22 further comprises at least two, here five, lower transport elements, which according to the embodiment shown here are also designed as belts 28. Five pairs are formed, each consisting of an upper and a lower belt 24, 28. Thus, the lower belts 28 are arranged spaced from one another in the axial direction A, i.e. transversely to the transfer direction F, in particular equidistantly. The lower belts 28 are arranged by means of a

[0045] The upper belt bands 24 and the lower belt bands 28 are arranged one above the other in a direction perpendicular to the transfer direction F and perpendicular to the axial direction A, so that the electrode stack elements 6 can be driven in a clamping manner by means of a common second drive shaft 30, wherein the first drive shaft 26 and the second drive shaft 30 are expediently coupled to one another in a manner not shown in more detail, for example by means of a pair of gears. As shown in more detail in connection with Fig. 4, the transfer time U of the respective electrode stack element 6 can be changed, in particular adjusted, using the transfer device 22. The transfer time U is understood to be the time at which the respective electrode stack element 6 completely leaves the transfer device 22.

[0046] Optionally, the transfer device 22 comprises a guide element 32, in particular a guide plate for the electrode stack elements 6. The guide element 32 has recesses 33 for the lower belt bands. The guide element advantageously prevents bending of the electrode stack elements 6 during transfer and also guides the electrode stack elements 6.

[0047] The transfer device 22 is arranged at a distance from the rotational axis D in the radial direction, i.e., in a direction perpendicular to the rotational axis D, such that their distance is greater than the radius of the stacking wheel discs 10. In other words, the transfer device, in particular its belt bands 24, 28 and / or its guide element 32, is arranged completely outside the area encompassed by the stacking wheel discs 10. In other words, the stacking wheel discs 10 do not overlap the transfer device 22 in the axial direction A.

[0048] As can be seen in particular in Fig. 1, the upper belt bands 24 project beyond the lower belt bands 28 in a direction opposite to the transfer direction F (conveying direction F). This area projecting beyond the lower belt bands 28 is formed in a direction perpendicular to the transfer direction and perpendicular to the axial direction A above the end section of the feed device 20 designed as a conveyor belt. In the transfer direction F, the guide element 32 and the second belt bands 28 are arranged next to the feed device. In this way, the electrode stack elements 6 can be safely transferred from the feed device 20 to the transfer device 22 (transfer apparatus 22), i.e., fed thereto. According to a variant not shown in detail, the drive shaft 26 is arranged above the drive shaft 30. The two drive shafts 26, 30 are therefore arranged one above the other in a direction perpendicular to the conveying direction F.

[0049] Optionally, in particular in the variant not shown in detail, the upper belt bands 24 are spring-loaded against the lower belt bands 28. The transfer device 22 is therefore designed such that when the upper belt bands 24 are adjusted away from the lower belt bands 28, a restoring force acts on the upper belt bands in a direction towards the lower belt bands 28. Additionally or alternatively to this, the lower belt bands 28 are spring-loaded against the upper belt bands 24. The transfer device 22 is therefore designed such that when the lower belt bands 28 are adjusted away from the upper belt bands 24, a restoring force acts on the lower belt bands 28 in a direction towards the upper belt bands 24.

[0050] The device 2 further comprises a stripper 34, which serves to strip the electrode stack elements 6 received and conveyed in the compartments from the compartments onto a storage area 36. The shape of the stripper 34 is adapted to the shape of the compartments 16 such that the electrode stack elements 6 are arranged as perpendicular as possible to the stop surface 38 during abutment and stripping. In particular, the stop surface 38 is flat. To position the stripper 34, in particular its stop surface 38 with respect to the position and / or shape of the compartments 16, the distance dA of the stripper 34 from the rotational axis D and / or an inclination of the stripper 34, in particular its stop surface 38, is adjustable.

[0051] The distance dA of the stripper 34 to the rotation axis D is smaller than the distance dp of the rotation axis-side compartment end 40 to the rotation axis D.

[0052] Figure 4 shows a flowchart representing a method for producing an electrode stack 4 from electrode stack elements 6. The electrode stack elements 6 are rectangular and have different edge lengths. The longer edges are designated KL and the shorter edges KK.

[0053] According to this exemplary embodiment, so-called monocells are used as electrode stack elements 6. These are shown in more detail in Figures 3a and 3b. Each of the monocells is a composite comprising an anode 42, a cathode 44, a first separator 46 arranged between the anode 42 and the cathode 44, and a second separator 48 arranged on the side of the anode 42 facing away from the cathode 44 or the first separator 46. In other words, the anode 42, the cathode 44, and the two separators 46, 48 are arranged one above the other in a monocell vertical direction Z. According to an alternative not shown in detail, the second separator 48 is arranged on the side of the cathode 44 facing away from the anode 42 or the first separator 46.

[0054] The monocells have a rectangular base in a plane perpendicular to the monocell vertical direction Z (stacking direction Z). Furthermore, the anode 42 and the cathode 44 each comprise an electrical contact 50, referred to as a tab, which protrudes beyond the base. The separators 46, 48 protrude beyond the anode 42 and the cathode 44, with the exception of the tabs 50. In other words, the separators 46, 48 protrude beyond the electrodes 42, 44. As the monocell slides along the inner wall of the respective compartment 16, the separator(s) 46, 48 touch this inner wall, thus preventing damage to the electrodes 42, 44.

[0055] Preferably, the monocells are provided and configured for a lithium-ion battery cell for a traction battery of an electrically powered motor vehicle.

[0056] The electrode stack 4 is manufactured according to the method using the device 2 according to Figures 1 and 2.

[0057] In a first step I, the electrode stack elements 6 are fed to the transfer device 22 by means of the feed device 20. The electrode stack elements are preferably fed to the transfer device 22 in such a way that at any given time, a maximum of one of the electrode stack elements is conveyed by the transfer device 22, i.e., that only one (or no) electrode stack element 6 is in contact with the upper and / or lower belt bands 24, 28.

[0058] In a second step II, a target transfer time tA.soii is determined for the respective electrode stack element 6. For this purpose, the current position of the compartment 16 into which this electrode stack element 6 is to be transferred, the (preferably constant) rotational speed of the stacking wheel discs 10 of the stacking wheel 8, as well as the position of the respective electrode stack element 6 on the feed device 20 designed as a conveyor belt, as well as the (preferably constant) conveying speed of the feed device 20 are determined. For this purpose, the device 2 comprises, in a manner not shown in detail, a (rotational, angular) position sensor for the stacking wheel and a detection device, for example comprising a camera, for determining the position of the respective electrode stack element 6 on the feed device 20.

[0059] Furthermore, an expected transfer time tA,e is determined for conveying the respective electrode stack element 6 at a constant conveying speed in the transfer device 22, i.e. for a constant running speed of the upper and lower belts 24, 28.

[0060] In step III, the transfer time U is adjusted to the target transfer time tA.soii and thus to the position of the stacking wheel 8, provided the expected transfer time tA,e deviates from the target transfer time tA.soii. For this purpose, the running speed of the upper and lower belts 24, 28 is temporarily increased, resulting in an earlier transfer time tA, or temporarily reduced, resulting in a delayed transfer time tA. In summary, only the running speed of the belts is adjusted. The rotational speed of the stacking wheel 8 preferably remains constant.

[0061] In step IV, the electrode stack elements 6 are transferred to the stacking wheel 8 according to the respective target transfer times tA.soii using the transfer device 22. In particular, the respective electrode stack element is introduced into compartments 16 of all stacking wheel disks 10 that are aligned with one another in the axial direction. Furthermore, the electrode stack elements are expediently transferred to the stacking wheel 8 in such a way that only one of the electrode stack elements 6 is transferred into the respective compartment 16 and the next electrode stack element 6 is transferred into the next compartment opposite to the direction of rotation U.

[0062] The electrode stack elements 6 are transferred into the respective compartment 16 with their longer edge KL first.

[0063] In step V, the electrode stack elements 6 transferred to the stacking wheel 8 are entrained by the rotation of the stacking wheel 8 and conveyed into the area of ​​the depository 36. There, the electrode stack elements 6 are held against further entrainment by the stripper 34 and are stripped out of the respective compartment 16 due to the rotation of the stacking wheel 8. The stripped electrode stack elements 6 are transferred to the depository 36 so that they are deposited on top of one another. The upper side in the transfer device 22 is arranged on top in the electrode stack 4 due to the deflection by the stacking wheel 8 and vice versa. In summary, the electrode stack elements 6 are stacked on top of one another by the stacking wheel 8 to form the electrode stack 4.

[0064] The invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can be derived from them by those skilled in the art within the scope of the claims without departing from the subject matter of the invention. In particular, all individual features described in connection with the exemplary embodiments and / or in the claims can also be combined with one another in other ways without departing from the subject matter of the invention.

[0065] List of reference symbols

[0066] device

[0067] Electrode stack

[0068] Electrode stack element

[0069] Stacking wheel

[0070] Stacking wheel disc

[0071] Drive shaft of the stacking wheel

[0072] finger

[0073] Academic subject

[0074] conveyor system

[0075] Feed device

[0076] Transfer device upper transport element / belt

[0077] Drive shaft of the upper belts / first drive shaft of the lower transport element / belt

[0078] Drive shaft of the lower belts / second drive shaft

[0079] Guide element

[0080] recess

[0081] Stripper

[0082] filing

[0083] Stop surface

[0084] subject end

[0085] anode

[0086] Cathode, 48 separator 50 tab, electrical contact

[0087] A axial direction

[0088] D axis of rotation

[0089] ÖA Distance of the stripper to the rotation axis dp Distance of the compartment end to the rotation axis

[0090] F Conveying direction of the transfer device

[0091] KK short edge

[0092] KL long edge tA handover time tA.e expected handover time tA.soii target handover time

[0093] U Direction of rotation

[0094] Z Monocell vertical direction

[0095] I Supply of the electrode stack elements

[0096] II Determining the target handover time

[0097] III Adjusting the handover time according to the target handover time

[0098] IV Transfer of the electrode stack elements into the stacking wheel

[0099] V Stacking the electrode stack elements using the stacking wheel

Claims

Patent claims Device (2) for producing an electrode stack (4) from electrode stack elements (6), comprising a stacking wheel (8) with at least one stacking wheel element (10) which can be driven in rotation about an axis of rotation (D) and which has compartments (16) for receiving the electrode stack elements (6), a stripper (34) for stripping the electrode stack elements (6) out of the compartments (16) during rotation of the stacking wheel (8), a storage area (36) for the electrode stack elements (6) stripped out of the stacking wheel disk (8), and a conveyor device (18) for conveying the electrode stack elements (6) into the compartments (16), wherein the conveyor device (18) has a transfer device (22) for transferring the electrode stack elements (6) into the compartments (16) and a feed device (20) for feeding the electrode stack elements (6) to the transfer device (22).Device (2) according to claim 1, characterized in that the transfer device (22) has a distance from the axis of rotation (D) in the radial direction that is greater than the radius of the stacking wheel disc (10). Device (2) according to claim 1 or 2, characterized in that the transfer device (22) has at least two upper transport elements (24), in particular belt bands, spaced apart from one another transversely to the transfer direction (F), that the transfer device (22) has at least two lower transport elements (28), in particular belt bands, spaced apart from one another transversely to the transfer direction (F), and / or. - wherein the upper transport elements (24) and the lower transport elements (28) are arranged one above the other for clamping the electrode stack elements (6) in a direction perpendicular to the conveying direction (F). Device (2) according to claim 3, characterized in that the upper transport elements (24) are spring-loaded against the lower transport elements (28), and / or that the lower transport elements (28) are spring-loaded against the upper transport elements (24). Device (2) according to one of claims 1 to 4, characterized in that a transfer time (U) of the respective electrode stack element (6) can be changed using the transfer device (22). Device according to one of claims 1 to 5, characterized in that the distance (dA) of the stripper (34) from the axis of rotation (D) and / or an inclination of its stop surface (38) for the electrode stack elements (6) is adjustable.Method for producing an electrode stack (4) from electrode stack elements (6), in which a device (2) according to one of claims 1 to 6 is provided, in which the electrode stack elements (6) are transferred to the stacking wheel (8) by means of the transfer device (22), and in which the electrode stack elements (6) are stacked on top of one another by means of the stacking wheel (8). Method according to claim 7, characterized in that in order to adapt the transfer time (tA) to a position of the stacking wheel (8), in particular only, the conveying speed of the electrode stack elements (6) in the transfer device (6) is changed, and / or wherein the stacking wheel (8) is driven at a constant rotational speed. Method according to claim 7 or 8, characterized in that such electrode stack elements (6) are used which have a rectangular Have a base area with different edge lengths, and / or that the electrode stack elements (6) are transferred into the compartments (16) with their longer edge (KL) first. Method according to one of claims 7 to 9, characterized in that at any time a maximum of one single electrode stack element (6) is conveyed by means of the transfer device (22).

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