DE102022211988A1 - Device and method for producing an electrode stack - Google Patents

Abstract

The invention relates to a device (2) for producing an electrode stack (4) from electrode stack elements (6). This comprises a stacking wheel (8) with at least one stacking wheel disk (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) when the stacking wheel (8) rotates, a storage area (36) for the electrode stack elements (6) stripped out of the stacking wheel (8), and a conveyor device (18) for conveying the electrode stack elements (6) into the compartments (16). 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). The invention further relates to a method for producing an electrode stack (4) using the device (2).

Description

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

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 on top of each other, for example, and wherein a separator is arranged between the cathodes and the anodes.

The electrode stack with anodes and cathodes stacked on top of each other is produced, for example, using what is known as single-sheet stacking. Typically, the individual anodes and cathodes are moved using a gripper system (gripping 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 while holding it, and places the electrode there. However, such gripper systems are comparatively slow. As a result, the manufacturing process of such an electrode stack is disadvantageously comparatively time-consuming.

Alternatively, the WO 2020/212317 A1 A device is known which uses a stacking wheel to produce an electrode stack from monocells.

The invention is based on the object of specifying a particularly suitable device and a method for producing an electrode stack. In particular, the electrode stack should be manufactured as quickly as possible and/or the risk of damage to the electrode stack elements to be stacked should be reduced.

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 subclaims. The statements in connection with the device also apply mutatis mutandis to the method and vice versa.

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 or cathode laminated with a separator. Preferably, an electrode stack element is a composite known as a monocell or a 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 together, in particular by means of lamination. The anodes and the cathodes are also collectively referred to as electrodes. These are in particular designed like films. The electrodes therefore have a comparatively small extension in one spatial direction, in other words the electrodes are flat. The electrode stack is preferably provided 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.

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 in rotation about an axis of rotation. 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 area, with a pocket being formed between two fingers (arms). The fingers or the compartments are expediently curved, in particular spiral-shaped. The compartments therefore have an arcuate, in particular spiral-shaped, cross-section in a plane perpendicular to the axis of rotation. In other words, the respective compartment runs in an arcuate or spiral shape from its peripheral compartment entrance to its rotation axis-side compartment end. A curvature of the arcuate receptacle preferably increases from the peripheral side towards the axis of rotation, i.e. as the radial distance from the axis of rotation decreases. As a result, the frictional force between the holders and the electrode stack elements conveyed into them increases from the peripheral side towards the axis of rotation, i.e. inwards, so that the electrode stack elements are increasingly braked. The electrode stack elements are thus reliably braked to a standstill relative to the holder before the mono cells are held by the stripping arm or by the stripping arms.

Preferably, the stacking wheel comprises more than one such stacking wheel element, in particular two, three, four or five stacking wheel elements. These are arranged in an axial direction, i.e. in a direction long of the axis of rotation, spaced apart from one another. The stacking wheel elements can expediently be driven together in rotation using 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 the same design and overlap with respect to the axial direction.

The device further comprises a stripper for stripping the electrode stack elements out of the compartments when the stacking wheel rotates. When the stacking wheel rotates, the electrode stack elements accommodated in the compartments are held against further entrainment by 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 on top of one another in a tray, i.e. placed on top of one another 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 in the course of the method for producing the electrode stack) the distance of the stop surface, in particular its edge facing away from the tray, from the axis of rotation is set such that it is smaller than the smallest distance of the electrode stack element from the axis of rotation while it is being carried along in the compartment. As a result, the electrode stack element is prevented from striking the stripper and damaging it is avoided. For example, the radial distance of the stripper, in particular its stop surface, to the axis of rotation is smaller than the end of the compartments on the axis of rotation side.

The device also has a conveyor device for conveying the electrode stack elements into the compartments of the stacking wheel. On the one hand, the conveyor device comprises a transfer device, which serves to transfer the electrode stack elements into the compartments. On the other hand, the conveyor device comprises a feed device, which is separate from the transfer device, i.e. structurally separate, 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 comparatively precise and defined positioning of the electrode stack elements in the electrode stack. Furthermore, the electrode stack elements are transferred to 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 carried out comparatively quickly, i.e. time-saving, particularly in comparison to the production of the electrode stack by means of a gripping device mentioned at the beginning. This advantageously increases the process rate of the production of the electrode stack, in other words, throughput is increased.

According to an advantageous embodiment of the device, the transfer time, i.e. the time at which the front edge of the respective electrode stack element in the transfer direction enters the stacking wheel, in particular at which the front edge of the respective electrode stack element first touches the stacking wheel, can be changed using the transfer device, in particular only using the transfer device, in particular it can be adapted to the position of the compartment provided for receiving the respective electrode stack element. This makes it comparatively easy to adapt (synchronize) the transfer time and/or the transfer speed, the rotational speed and/or the (rotational, angular) position of the stacking wheel. In particular, if the stacking wheel rotates at a constant rotational speed, such an adaptation using only the transfer device is comparatively efficient, since the stacking wheel with a comparatively high inertia does not have 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 or elements and from this the position of the respective compartment can be determined. The device expediently also 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.

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).

According to a suitable embodiment, the transfer device comprises at least two upper transport elements, which are designed, for example, as belts or as rollers, and which are spaced apart from one another in a direction transverse to the transfer direction, i.e. in the axial direction. In the design of the transport elements As belts, the rollers are expediently connected to a motor for driving the upper belts using a common first shaft. Furthermore, the transfer device comprises at least two lower transport elements, which are designed, for example, as belts or as rollers, and which are spaced apart 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 for driving the lower belts using a common second shaft. In particular, the first and second shafts are coupled to one another using a pair of gears.

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 an intermeshing manner in the axial direction. However, for clamping conveying 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. 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 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 conveyed in a clamping manner. In still other words, these are not arranged offset from one another in the axial direction. In this way, bending of the electrode stack elements by the belt bands is avoided.

For example, the width of the transport elements, i.e. their extension in the axial direction, is between 1 mm and 250 mm. For example, the upper transport elements each have a width that is different to the width of the lower transport elements. Depending on the design of the electrode stack elements and a clamping force suitable for them, the width of the transport elements and/or their distance from one another is selected accordingly. If the electrode stack elements are designed as monocells, the wider transport elements are provided on the separator side of the monocell, so that the risk of contamination of its electrodes is reduced.

Preferably, each of the transport elements has a width, i.e. an extension in the axial direction, which is less than a quarter, preferably less than a tenth, of the extension of the stacking wheel element in the axial direction, or - if several stacking wheel elements are used - which is less than a quarter, preferably less than a tenth, of the extension 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 belt bands on a comparatively small area. Consequently, the risk of damage or contamination of the respective electrode stack element by the transfer device is at least reduced.

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 of the lower transport elements, i.e. downwards. In addition or alternatively to this, 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 of the upper transport elements, i.e. upwards. In this way, when the respective electrode stack element is fed into the transfer device, the upper or lower transport elements are adjusted against the spring force. This results in better clamping of the respective electrode stack element.

For example, the upper transport elements protrude over 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 terms of the conveying direction. The area of the upper belts that protrudes over the lower belts expediently covers the feed device designed as a conveyor belt, in particular the end area of the conveyor belt on the transfer device side, for feeding the respective electrode stack element. This end area and the upper belts are expediently arranged one above the other so that the electrode stack elements in this area are fed from the conveyor belt into the transfer device in a clamped manner. This advantageously enables a comparatively safe and error-free feed of the respective electrode stack element into the transfer device.

In particular, when the transport elements are designed as belts, the one of the two axes of rotation of the upper transport elements that is closer to the stacking wheel is arranged 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 elect The harvesting stacking elements are guided for a longer period using the transport element which is positioned closer to the stacking wheel.

According to an advantageous embodiment of the device, the transfer device is at a distance from the axis of rotation in the radial direction, i.e. in a direction perpendicular to the axis of rotation, which 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 covered 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. As a result, 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 the 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 in which the rear end of the electrode stack element in terms of the conveying direction can move when the direction changes, 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 reduced. Preferably, the transport elements are 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 that area of the electrode stacking elements lies on the stacking wheel or its stacking wheel elements where the transport elements act on the respective electrode stacking element. The area of force introduction onto the respective electrode stacking element is thus reduced.

Alternatively, the transfer device has a distance from the axis of rotation in the radial direction, i.e. in a direction perpendicular to the axis of rotation, which is smaller than the radius of the stacking wheel element. In this case, the transport elements protrude between the stacking wheel elements. In other words, the transport elements are then arranged in the axial direction at least partially between the stacking wheel elements. In particular, the transport elements and the stacking wheel elements are arranged in a meshing manner with respect to the axial direction. In this way, the installation space for the device is advantageously smaller.

According to an advantageous embodiment, the distance of the stripper, in particular its stop surface, from the axis of rotation is adjustable. Alternatively or preferably additionally, an inclination of the stripper, in particular its stop surface, is adjustable.

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

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 shown above is used, i.e. such a device is provided according to the method.

According to the method, the electrode stack elements are fed to the transfer device using the feed device and transferred to the stacking wheel using the transfer device, i.e. conveyed into the compartments of the stacking wheel element or elements. Expediently, only one of the electrode stack elements is transferred to each compartment.

The electrode stack elements stored in the compartments are then transported to a storage area by means of the rotation of the stacking wheel. The electrode stack elements are therefore guided towards the storage area by means of the stacking wheel.

The electrode stack elements are then held in the storage area using the stripper. Due to the rotation of the stacking wheel, the electrode stack elements are guided out of the respective holder and into the storage area. In other words, the electrode stack elements are held (supported) against the rotation of the stacking wheel using 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 is transferred from the respective compartment into the storage area accordingly. The electrode stack elements are stacked on top of one another in the storage area to form the electrode stack.

Preferably, the stacking wheel rotates at a constant speed.

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 speed of the electrode stack elements in the transfer device. The stacking wheel is preferably driven at a constant rotational speed. The transfer device, in particular solely based on the transfer direction, is used to adjust the transfer time of the respective electrode stack element 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 braked or accelerated in the transfer device. The temporary acceleration or braking is expediently carried out in such a way that the respective electrode stack element has a predetermined transfer speed when it exits the transfer device. In particular, the running speed of the upper and lower belt bands is changed accordingly to adjust the transfer time.

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 of the respective electrode, also referred to as a tab or contact lug, 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.

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 on the rotation axis side is distributed over a comparatively large area of the electrode stack element, so that the risk of damage is reduced. On the other hand, compared to transferring 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 in the compartments to be braked particularly gently.

According to a preferred embodiment, at any time a maximum of one electrode stack element, i.e. one or none, is conveyed by means of 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 for transfer and/or is conveyed by means of the upper belts. In this way, the transfer time of an electrode stack element can be adjusted without influencing the transfer time of the electrode stack element fed in after it.

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 or the stacking wheel elements and/or smaller than twice the edge length of the short edge of the electrode stack elements.

• 1 schematisch in einer Seitenansicht eine Vorrichtung zur Herstellung eines Elektrodenstapels aus Elektrodenstapelelementen, wobei die Vorrichtung ein Stapelrad mit als Stapelradscheiben ausgebildeten Stapelradelementen sowie eine Fördereinrichtung mit einer Übergabeeinrichtung aufweist, anhand welcher die Elektrodenstapelelemente in Fächer der Stapelradscheiben übergeben werden können,
• 2 schematisch und ausschnittsweise die Vorrichtung in perspektivischer Ansicht,
• 3a,b schematisch in perspektivischer Explosionsdarstellung bzw. in Seitenansicht ein als Monozelle ausgebildetes Elektrodenstapelelement mit einer rechteckigen Grundfläche, und
• 4 anhand eines Flussdiagramms einen Verfahrensablauf zur Herstellung eines Elektrodenstapels anhand der Vorrichtung.

In the following, embodiments of the invention are explained in more detail with reference to a drawing. In the drawing:

• 1 schematically shows a side view of a device for producing an electrode stack from electrode stack elements, the device having a stacking wheel with stacking wheel elements designed as stacking wheel disks 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 disks,
• 2 schematic and partial perspective view of the device,
• 3a ,b schematically in perspective exploded view or in side view an electrode stack element designed as a monocell with a rectangular base area, and
• 4 A flow chart shows a process sequence for producing an electrode stack using the device.

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

In the 1 is a schematic view of a device 2 for producing an electrode stack 4 from Electrode stack elements 6 in side view and in the 2 shown in perspective. The device 2 comprises a stacking wheel 8, which in turn has at least one stacking wheel element 10, according to the embodiment shown here five stacking wheel elements 10. The stacking wheel elements 10 are designed as stacking wheel disks 10 according to the embodiment shown here. These can be driven in rotation by means of a common drive shaft 12. The direction of rotation of the stacking wheel 8 is in the 1 provided with the reference symbol "U". 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.

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

The device 2 further comprises a conveyor device 18, by means of which the electrode stack elements are conveyed 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 in the 2 not shown in more detail for the sake of clarity. The transfer device 22 serves to convey, namely to 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 leave the transfer device 6, is shown in the 1 marked with the reference symbol “F”.

The transfer device 22 comprises at least two, in 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 in the axial direction A, i.e. transversely to the transfer direction F, in particular equidistantly, spaced from one another. The transfer device 22 further comprises at least two, in this case five, lower transport elements, which according to the embodiment shown here are also designed as belts 28. In this case, five pairs are formed, each consisting of an upper and a lower belt 24, 28. Thus, the lower belts 28 are arranged in the axial direction A, i.e. transversely to the transfer direction F, in particular equidistantly, spaced from one another. The lower belts 28 are arranged in the axial direction A, i.e. transversely to the transfer direction F, in particular equidistantly, spaced from one another.

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 using 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 detail, for example using a pair of gears. As in connection with the 4 As shown in more detail, the transfer time t _A of the respective electrode stack element 6 can be changed, in particular set, using the transfer device 22. The transfer time t _A is understood to be the time at which the respective electrode stack element 6 completely leaves the transfer device 22.

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.

The transfer device 22 is arranged in the radial direction, i.e. in a direction perpendicular to the axis of rotation D, at a distance from the axis of rotation D such that their distance is greater than the radius of the stacking wheel disks 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 disks 10. In other words, the stacking wheel disks 10 do not cover the transfer device 22 in the axial direction A.

As particularly in the 1 As can be seen, the upper belt bands 24 protrude beyond the lower belt bands 28 in a direction opposite to the transfer direction F (conveying direction F). This area protruding beyond the lower belt bands 28 is in a direction perpendicular to the transfer direction and perpendicular to the axial direction A above the end section of the conveyor belt Feed device 20 is formed. 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 to it.

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.

Optionally, and 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 toward the lower belt bands 28. Additionally or alternatively, 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 toward the upper belt bands 24.

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 shelf 36. The shape of the stripper 34 is adapted to the shape of the compartments 16 in such a way that the electrode stack elements 6 are arranged as perpendicular as possible to the stop surface 38 when striking 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 d _A of the stripper 34 to the axis of rotation D and/or an inclination of the stripper 34, in particular its stop surface 38, can be adjusted.

The distance d _A of the stripper 34 from the rotation axis D is smaller than the distance d _F of the rotation axis-side compartment end 40 from the rotation axis D.

In the 4 A flow chart is shown which represents 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 K _L and the shorter edges are designated K _K.

According to this embodiment, so-called monocells are used as electrode stack elements 6. These are shown in the 3a and 3b shown in more detail. Each of the monocells is a composite of an anode 42, a cathode 44, a first separator 46, which is arranged between the anode 42 and the cathode 44, and a second separator 48, which is arranged on the side of the anode 42 which faces 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 further detail, the second separator 48 is arranged on the side of the cathode 44 which faces away from the anode 42 or the first separator 46.

The monocells have a rectangular base area 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 area. 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. When the monocell slides along the inner wall of the respective compartment 16, the separator(s) 46, 48 touch this inner wall, so that damage to the electrodes 42, 44 is avoided.

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

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

In a first step I, the electrode stack elements 6 are fed to the transfer device 22 using 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 using the transfer device 22, i.e. that only a single (or no) electrode stack element 6 is in contact with the upper and/or lower belt bands 24, 28.

In a second step II, a target transfer time t _A,target is determined for the respective electrode stack element 6. For this purpose, the current position tion of the compartment 16 into which this electrode stack element 6 is to be transferred, the (preferably constant) rotational speed of the stacking wheel disks 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. 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 comprising, for example, a camera for determining the position of the respective electrode stack element 6 on the feed device 20.

Furthermore, an expected transfer time t _A,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 belt bands 24, 28.

In step III, the transfer time t _A is adjusted to the target transfer time t _A,target and thus to the position of the stacking wheel 8, provided that the expected transfer time t _A,e deviates from the target transfer time t _A, target. To do this, the running speed of the upper and lower belts 24, 28 is temporarily increased, which results in an earlier transfer time t _A , or temporarily reduced, which results in a delayed transfer time t _A. In summary, only the running speed of the belts is adjusted. The rotational speed of the stacking wheel 8 preferably remains constant.

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

The electrode stack elements 6 are transferred into the respective compartment 16 with their longer edge K _L first.

In step V, the electrode stack elements 6 transferred to the stacking wheel 8 are carried along by the rotation of the stacking wheel 8 and conveyed into the area of the storage area 36. There, the electrode stack elements 6 are held against further movement by the stripper 34 and are stripped out of the respective compartment 16 by the rotation of the stacking wheel 8. The stripped electrode stack elements 6 are transferred to the storage area 36 so that they are placed on top of one another. The upper side in the transfer device 22 in the electrode stack 4 is arranged at the top due to the deflection by the stacking wheel 8 and vice versa.

In summary, the electrode stack elements 6 are stacked on top of each other using the stacking wheel 8 to form the electrode stack 4.

The invention is not limited to the embodiments described above. Rather, other variants of the invention can be derived from this by a person 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 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.

List of reference symbols

2

contraption

4

Electrode stack

6

Electrode stack element

8th

Stacking wheel

10

Stacking wheel disc

12

Drive shaft of the stacking wheel

14

finger

16

Academic subject

18

Conveyor system

20

Feeding device

22

Transfer device

24

upper transport element/belt

26

Drive shaft of the upper belts / first drive shaft

28

lower transport element/belt

30

Drive shaft of the lower belts / second drive shaft

32

Guide element

33

Recess

34

Stripper

36

Filing

38

Stop surface

40

Subject end

42

anode

44

cathode

46, 48

separator

50

Tab, electrical contact

A

Axial direction

D

Rotation axis

there

Distance of the stripper to the rotation axis

dF

Distance of the compartment end to the axis of rotation

F

Conveying direction of the transfer device

KK

short edge

CL

long edge

tA

Handover time

tA,e

expected handover time

tA,target

Target handover time

U

Direction of rotation

Z

Monocell direction

I

Supply of electrode stack elements

II

Determining the target handover time

III

Adjusting the handover time according to the target handover time

IV

Transferring the electrode stack elements into the stacking wheel

V

Stacking the electrode stack elements using the stacking wheel

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• WO 2020212317 A1 [0004]

Claims (10)

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) when the stacking wheel (8) rotates, - 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 which 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 clampingly conveying 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 the Claims 1 until 4 , characterized in that a transfer time (t _A ) of the respective electrode stack element (6) can be changed by means of the transfer device (22). Device according to one of the Claims 1 until 5 , characterized in that the distance (d _A ) of the stripper (34) to 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 the Claims 1 until 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). Procedure according to Claim 7 , characterized in that in order to adapt the transfer time (t _A ) 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. Procedure according to Claim 7 or 8th , characterized in that - such electrode stack elements (6) are used which have a rectangular base area with different edge lengths, and/or - that the electrode stack elements (6) are transferred into the compartments (16) with their longer edge (K _L ) first Method according to one of the Claims 7 until 9 , characterized in that at any one time a maximum of one single electrode stack element (6) is conveyed by means of the transfer device (22).

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