WO2022214221A1

WO2022214221A1 - Method and device for forming a stack of flat elements for an energy storage device or a fuel cell

Info

Publication number: WO2022214221A1
Application number: PCT/EP2022/025133
Authority: WO
Inventors: Wolfgang KÖNIGER; Andreas Jakobs
Original assignee: Giesecke+Devrient Currency Technology Gmbh
Priority date: 2021-04-09
Filing date: 2022-04-06
Publication date: 2022-10-13
Also published as: DE102021001855A1

Abstract

The invention relates to a method for forming a stack of flat elements (12), for example electrodes, for an electrochemical energy storage device or a fuel cell using a stacking wheel (16) that can be rotated in a specified rotational direction (D) and has stacking compartments (18), each of which is designed to receive one of the flat elements. An individual flat element of the flat elements is transported to the stacking wheel, which is rotating in the specified rotational direction, and enters one of the stacking compartments of the stacking wheel; the flat element is further transported in the stacking compartment by rotating the stacking wheel; and the flat element is removed from the stacking compartment in a specified phase of the rotational movement. While the flat element is entering the stacking compartment and/or while the flat element is being transported in the stacking compartment, an air flow is directed towards the flat element in a specified blowing region (B) such that a force is exerted onto the respective flat element. The invention additionally relates to a device (10) for carrying out the method.

Description

Method and device for forming a stack of flat elements for an energy store or a fuel cell

The present invention relates to a method and a device for forming a stack of planar elements for an electrochemical energy store or a fuel cell. The flat elements can be, in particular, electrode or separator elements for the energy stores or fuel cells mentioned.

In recent years, interest in using electrical energy for propulsion purposes has increased dramatically. If the drive, for example an electric motor, is not stationary or is not connected to a power grid, the energy must be stored and transported. This applies in particular to motor vehicles. Two alternatives, among others, are known for the mobile provision of electrical energy: On the one hand, electrochemical energy stores, in which energy can be stored in chemical form, can be used. Examples of this are accumulators and batteries. On the other hand, energy converters are known which convert the supplied fuels directly into electrical cal energy, in particular fuel cells.

Both alternatives use electrode arrangements which comprise two electrodes, anode and cathode, and a layer arranged between the electrodes, for example a separator layer or an electrolyte layer, which form a galvanic cell. In important embodiments provided for the application, the electrodes or layers are of flat design and are used in the form of stacks. In the case of energy stores, for example, so-called prismatic cells or pouch cells are known in which the stacks are enclosed in a housing or a film. A step in the manufacture of such energy storage devices or fuel cells that is essential in large-scale production involves the formation of stacks of the electrodes or layers mentioned. For the purposes of stacking, the electrodes and layers have similar properties: they are flat elements, mostly less than 2-3 mm thick and more or less flexible. In the context of the present invention, flat elements for an electrochemical energy store or a fuel cell are understood to mean flat elements which can be handled individually and are present in stacked form in the said finished energy stores or fuel cells. Examples of such flat elements are electrodes, which themselves can have a multi-layer structure, or intermediate layers such as separator elements or separating membranes, and toes constructed from these. However, such elements can also include electrodes and separator elements connected to them. The elements can also be mono cells, which have an anode, a separator layer, a cathode and again a separator layer. Anode and cathode can also be interchanged.

In the formation of such a stack, the elements should be stacked on top of one another as precisely as possible, but the elements, in particular their edges, should not be damaged or should be damaged as little as possible.

The present invention is therefore based on the object of specifying a method for forming a stack of flat elements for an electrochemical energy store or a fuel cell, which allows rapid stack formation, but with damage to the flat elements, in particular their edges, being avoided as far as possible . Next is a device for forming a stack of flat elements th be provided for an electrochemical energy store or a fuel cell with which the method can be carried out.

The object is achieved by a method having the features of claim 10 and in particular by a method for forming a stack of flat elements, for example electrodes, for an electrochemical energy store or a fuel cell, using a stacking wheel that can be rotated in a predetermined direction of rotation and has stacking compartments for receiving one of the flat elements, in which a single one of the flat elements is transported to the stacking wheel rotating in the specified direction of rotation and enters one of the stacking compartments of the stacking wheel, the flat element in the stacking compartment by rotating the stacking wheel is transported further, and is removed from the stacking compartment in a pre-given phase of the rotary movement. During the entry of the flat element into the stacking compartment and/or during transport in the stacking compartment, an air flow is directed onto the flat element in a predetermined blowing area, which the flat element passes, so that a force is exerted on the respective flat element becomes.

The object is further achieved by a device with the features of claim 1 and in particular a stacking device for forming a stack of flat elements, for example electrode elements, for an electrochemical energy store or a fuel cell, which individually enter a receiving area of the stacking device at least one stacking wheel rotatably mounted in a predetermined direction, which has stacking compartments for receiving one of the flat elements, so that at least partially sensitive, flat elements are transported in the stacking compartments when the stacking wheel rotates and a blowing device for delivering an air flow into a given blowing area, which flat elements in the stacking compartments traverse when the stacking wheel is rotated, so that a force is exerted on the respective flat elements. The air flow is preferably directed.

The method according to the invention can be carried out with the device according to the invention.

In the method and the device, a stacking wheel is used to form the stack, which is rotatably gela siege in a predetermined direction of rotation and is rotated during stacking. For this purpose, the stacking device preferably has a drive which is designed to rotate the stacking wheel in a predetermined direction of rotation. The stacking wheel has stacking compartments for receiving the flat elements, which have two walls that face each other. The stacking compartments can be formed by stacking fingers of the stacking wheel and each have a stacking compartment opening on the circumference of the stacking wheel, so that they are open on the circumference of the stacking wheel.

To form a stack, an individual flat element that enters a specific area of the stacking device, the receiving area, is introduced or conveyed into one of the stacking compartments of the stacking wheel rotating in a predetermined direction of rotation. By turning the stacking wheel, it is then transported further in the stacking compartment until it emerges from the stacking compartment in a predetermined phase of the rotary movement.

At a conveying speed that is greater than the speed of the peripheral speed of the stacking wheel and thus the web speed of the stack compartment opening, the flat element would enter the stacking compartment and itself there continue to move until it has come to rest relative to the stacker or, in other cases, is stripped. In the method according to the invention and the device according to the invention, an air flow is directed onto the flat element in the specified blowing area, which the flat element passes, during the entry of the flat element into the stacking compartment and/or during transport in the stacking compartment, so that a force is exerted on the respective flat element by the air flow when interacting with the flat element or when it hits the flat element in order to influence it in the compartment, for example to align, brake or move it in the stacking compartment.

Without the use of air according to the invention, the movement of the flat element in the stacking compartment would be determined solely by its inertia and the forces exerted by the stacking compartment walls. The flat element would enter the stacking compartment and continue to move there in a straight line, usually until an edge that is in front in the direction of movement, the front edge, comes into contact with a stacking compartment wall, usually colliding with it. Depending on the conveying speed and peripheral speed, high forces could then be exerted on the front edge of the flat element, which could damage it. Particularly in the case of elements that are somewhat stiffer in the transport direction, the front edge of the flat element would hit a wall area of the stacking compartment more or less hard and be deflected or stopped by it. By using the air or air flow, ie a fluid medium, it is possible to gently exert a force on the flat element, which preferably also acts relative to the stacking compartment. In particular, a force can be gently exerted in the stacking compartment that is at least partially un- depends on the inertia and the hardness of the stacking compartment walls. This enables gentle stacking of the flat elements.

By using the air, depending on the embodiment, different forces can be exerted on the flat element when it enters the stacking compartment or in the stacking compartment. In this context, the fact that a force acts in a specific direction is understood to mean that the total force has a component acting in this direction.

In a preferred embodiment of the method, the stacking compartments can have opposing walls and the air flow can exert a force on the planar element in the direction of one of the walls of the stacking compartment and/or in the direction away from one of the walls of the stacking compartment. In the stacking device, the stacking compartments can each have opposite walls and the blowing device can preferably be designed in such a way that the air flow exerts a force on a respective flat element at least partially located in one of the stacking compartments in the direction of one of the walls of the stacking compartment. The fact that a force is also exerted in the direction of one of the walls means that the total force on the flat element caused by the air flow has a component which is directed towards the wall of the stacking compartment. For this purpose, the air flow can in particular be directed in such a way that it hits a surface of the flat element. For this purpose, the air flow can preferably have a component in the radial direction towards the axis of rotation or outwards in the direction of the circumference of the stacking wheel. On the one hand, this embodiment can offer the advantage that a front edge in the direction of movement of the flat element, the front edge, can be pushed away from one of the walls that it would hit, so that an impact on the stacking compartment wall is reduced or completely avoided can be. This protects the flat element. On the other hand, the embodiment can also offer the advantage of pressing the flat element with at least one section of its surface against one of the walls and thus achieving or intensifying braking by friction of the flat element on the stacking compartment wall.

The air flow can preferably also have a component along the stack compartment in the blowing area. In the method, the air flow can preferably be directed onto the planar element in such a way that it exerts a force on the planar element along one of the walls of the stacking compartment. In the stacking device, it is preferred for the stacking compartment to have opposite walls and for the blowing device to be designed in such a way that the air flow also exerts a force on the planar element along one of the walls of the stacking compartment. The fact that a force is also exerted along one of the walls means that the total force on the planar element caused by the air flow has a component that runs along one of the walls. In particular, the force can be directed at least partially parallel to the stacking compartment wall. The component of the air flow and thus also the component of the force is particularly preferably directed towards the stacking compartment opening and thus counter to a possible direction of movement of the planar element in the stacking compartment or within the stacking compartment. This design has the advantage that the flat element can be slowed down by friction in the air. This can be advantageous in particular when the flat element does not bear against any of the walls at least at times with a larger surface section.

In principle, the air flow can be generated arbitrarily. For this purpose, the stacking device will often have a pump that conveys air. the The air flow can be regulated and directed in a number of ways. Thus, in the case of the stacking device, the blowing device can preferably have at least one air outlet opening through which the air flow is discharged. The air outlet opening can be formed, for example, in an air line connected to the pump, an air duct or air pipe connected to the pump. Depending on the size of the air outlet opening, a wider air flow can preferably be generated. However, in order to achieve the aforementioned effects with little effort and to reduce the consumption of air, the air flow is preferably strongly directed in the process. In the case of the stacking device, the blowing device can preferably have at least one nozzle for discharging the air flow. Particularly preferably, several air outlet openings or nozzles arranged transversely to the direction of transport are used, so that forces on the flat element are generated in a spatially distributed manner that is as good as possible. However, it is also possible for the air outlet opening or the cross section of the nozzle to be elongated transversely to the plane of rotation of the stacking wheel, i.e. wider transversely to the plane of rotation of the stacking wheel than parallel to it, so that a wider air flow can be generated transversely to the transport direction.

In principle, the air outlet opening or nozzle can be arranged as desired, provided that the required effect can be achieved. In the method, the air stream is preferably generated next to a plane of rotation in which the stacking compartments move during rotation. In the case of the stacking device, the air outlet opening or the nozzle can preferably be arranged next to a plane of rotation in which the stacking compartments move during rotation. If the stacking wheel is disk-shaped, the air outlet opening or the nozzle can be arranged in an area next to the stacking wheel. The airflow then flows alongside the plane of the stacking wheel. This design allows a space-saving design in which the distance between the air outlet opening or nozzle and the flat element can also be kept small, which can reduce the air consumption.

In principle, the air flow can be generated permanently. In the method, however, it is preferred that the strength of the air flow is controlled as a function of a rotational speed of the stacking wheel and/or a point in time when the planar element enters the stacking compartment and/or a position of the stacking wheel. For this purpose, the stacking device also has a sensor for detecting the point in time at which the flat element enters the stacking compartment and/or a sensor for determining a position of the stacking wheel and a control device connected to the blowing device and the sensor or sensors via signal connections, which emits signals to the blowing device in order to control the strength of the air flow as a function of a rotational speed of the stacking wheel and/or a point in time when the planar element enters the stacking compartment and/or a position of the stacking wheel. In particular, the air flow can be switched on or off. However, it is also possible to modulate the strength of the air flow, for example during the period in which a flat element whose time of entry has been recorded is being transported through the blowing area.

In principle, only one stacking wheel needs to be used in the method and the stacking device. However, it is preferred in the method that a further stacking wheel that can be rotated in the specified direction is used, that has stacking compartments for receiving one of the flat elements, that the stacking wheel and the further stacking wheel are rotated synchronously, and that the blowing area is completely or partially between the stacking wheels. The stacking device can also have a further stacking wheel that can be rotated in the specified direction, the stacking compartments for receiving one of the flat elements in each case, and in which the blowing device is designed such that the blowing area lies entirely or partially between the stacking wheels. In this case, stacking wheel and further stacking wheel can be of the same design and can be rotated synchronously about the same axis of rotation, preferably driven. This design has the advantage that the forces on the flat element in both stacking compartments that are produced by the air flow are more similar, which reduces disruptions and reduces or even prevents uneven stress on the flat elements when stacking.

In the process, a flat element located in one of the stacking compartments is removed from the stacking compartment in a predetermined phase of the rotary movement. This can be done in different ways. In a preferred embodiment, the stacking device can also have a stripper for stripping the flat element out of the stacking compartment. The stripper can preferably not rotate with the rotary speed of the stacking wheel. In particular, he can rest. It stops the movement of the planar element that hits it, causing it to be stripped out of the stacking compartment that continues to rotate.

In particular, the stripper can stop the movement of a flat element located in one of the stacking compartments, so that the element can be stripped out of the compartment by the continued movement of the stacking wheel. The specified phase of the rotary movement is then determined by the position and design of the scraper.

In order to form a stack, the stacking device can also include a shelf, on which flat elements that have come out of the stacking compartments can be stacked. This can preferably be arranged in such a way that removed from the stacking compartments, in particular by means of a scraper made of striped planar elements on the tray or already be sensitive planar elements on the tray.

In the case of the method and the device, in some embodiments the stacking wheel can be rotated solely by the momentum of the planar elements entering. However, it is preferred in the device that a drive device is provided by means of which the stacking wheel can be rotated. In the method, it is then preferred that the stacking wheel is rotated by means of a drive device. The use of the drive device has the advantage, among other things, that the speed and phase position of the rotational movement can be more easily matched to the transport movement of the elements before they enter the receiving area.

The stacking device does not need to have a transport device for transporting individual flat elements. However, the device preferably also comprises a transport device for transporting individual planar elements to the stacking wheel, with the transport device and the at least one stacking wheel being arranged relative to one another such that a planar element brought in by the transport device is transported into one of the stacking compartments that is on moved past the transport device. The drive of the stacking wheel and the transport device are preferably controlled in a coordinated manner.

In the following, the invention is explained further by way of example with reference to the drawings. Show it:

1 shows a schematic view of a first exemplary embodiment of a stacking device for flat elements in the form of monocells, 2 shows a schematic representation of a monocell

3 shows a schematic view of stacking wheels of the stacking device in FIG. 1 in the transport direction of the flat elements or in a

Direction parallel to a plane of rotation of stacking wheels of the stacking device,

4 shows a schematic view of a section of a stacking wheel in FIG. 1,

5 shows a schematic view of a second exemplary embodiment of a stacking device for flat elements in the form of monocells,

6 shows a schematic view of stacking wheels of the stacking device in FIG. 5 in the direction of transport of the flat elements or in a direction parallel to a plane of rotation of stacking wheels of the stacking device,

7 shows a schematic view of part of a third embodiment of a stacking device for planar elements in the form of monocells, and FIG. 8 shows a schematic view of a fourth embodiment of a stacking device for planar elements in the form of monocells.

A stacking device 10 for forming a stack of planar elements

12 for an electro-chemical energy store, in the example for mono cells a battery, in Figures 1 and 3 comprises a transport device 14 for transporting individual flat elements 12, two stacking wheels 16 and 16', each rotatably mounted about an axis of rotation, with stacking compartments 18 and 18', as well as a drive 22, in the example an electric motor for rotating of the stacking wheels 16, 16' in a predetermined direction of rotation D. The stacking device 10 also comprises a stripper 24 at a predetermined position between the stacking wheels 16 and 16' for stripping flat elements 12 out of the stacking wheels 16 and 16' and in the vicinity of the Ausstrei fers 24 a tray 26, on which the stacking wheel 16 or 16 'striped or exiting planar elements 12 are stored or stacked Kings NEN. The identically designed stacking wheels 16 and 16' are arranged parallel to one another in such a way that they can be rotated about the same geometric axis of rotation. Next they are driven synchronously.

The stacking device 10 also has a blowing device 28 for delivering an air flow into a predetermined blowing area B, which flat elements 12 in the stacking compartments 18 pass through when the stacking wheel 16 or 16' rotates, so that a force is then exerted on the respective flat elements . The blowing device 28 comprises a pump 30 and two nozzles 31 and 31', which are connected to the pump 30 via an air line 33, so that air delivered by the pump can be discharged through the nozzles 31 and 31'.

Monocells are understood to be flat elements 12 with a rectangular base area (cf. FIG. 2) which, arranged one above the other, have an anode AN, a separator layer SSI, a cathode KA and again a separator layer SS2. The transport device 14, which is only partially shown, is used to transport individual flat elements 12 into a receiving area A of the stacking device 10. The flat elements 12 are conveyed in the transverse transport, in which the longer side of the flat elements is aligned transversely to the transport direction T, the shorter parallel to the transport direction T. The transport device 14 and the stacking wheel 16 or 16' are arranged relative to one another in such a way that a flat element 12 brought up by the transport device 14 is transported into one of the stacking compartments 18 or 18' when this passes through the receiving area A moves. The transport device 14 has a drive, not shown, partially driven by the drive on rollers 34, and driven over the rollers 34 guided conveyor belt 36, between which the flat elements 12 in the receiving area A are promoted.

The stacking wheels 16 and 16' have the same design and are arranged in parallel. Therefore, only the stacking wheel 16 is described in more detail; the statements then apply to the stacking wheel 16' accordingly.

The stacking wheel 16 has stacking fingers 38, of which two neigh disclosed stacking fingers form a stacking compartment 18 which is open at the periphery of the stacking wheel 16 and has a stacking compartment opening 40 there. The stacking compartments therefore have stacking compartment walls 42 and 420 ⁾ lying opposite one another, which are formed by corresponding surfaces of the stacking fingers 38 . The stacking compartment 18 extends from the stacking compartment opening 40 towards the interior of the stacking wheel 16 and ends with a stacking compartment floor. The width of the stacking compartment 18 is determined by the shape and the spacing of the stacking fingers 38 and is selected so that flat elements 12 can enter the stacking compartment 18 and be transported therein if they come from the receiving area A in a suitable direction. By turning the stacking wheel 16 and thus of the stacking compartment 18, the stacking compartment opening 40 can be moved or pivoted through the receiving area A, so that a planar element 12 conveyed into the receiving area A can enter the stacking compartment 18.

The stacking wheels are rotatably mounted and coupled by means of a shaft 32 so that the drive 22 can rotate them synchronously in the specified direction of rotation D.

The stacking device 10 also has the stripper 24 which is arranged above the shelf 20 and meshes with the stacking wheels, by means of which an element 12 can be stripped out of the stacking compartment 18 . When the stacking wheel 16 rotates, a flat element 12 in the stacking compartment 18 will at some point hit the stripper 24, which stops the movement of the element 12. Since the stacking compartment 18 is pivoted on by the rotation of the stacking wheel 16, the planar element 12 finally occurs entirely out of the stacking compartment 18 and is placed on the tray 26, if already present on planar elements already stacked on the tray 26. As in this exemplary embodiment, the stripper 24 is preferably only slightly narrower than the distance between the stacking wheels 16 and 16', so that the force occurring when the front edge of a flat element strikes the stripper 24 is distributed over the widest possible section of the front edge. so that it is less heavily loaded.

In this exemplary embodiment, the blowing device 28 is designed such that the air flow exerts a force on a respective flat element 12 at least partially located in one of the stacking compartments 18 in the direction of one of the walls 42, 420 ⁾ of the stacking compartment. On the other hand, the blowing device 28 is designed so that the flat through the air flow member 12, a force is also exerted along one of the walls 42, 420 ⁾ of the stacking compartment 18.

This property of the blowing device is achieved in the present example by the design and arrangement of the identically designed nozzles 31 and 31' of the blowing device 28. Since the nozzles 31 and 31' are of the same design, only the nozzle 31 is partially referred to in the following, the corresponding statements apply accordingly to the other nozzle.

In this example, the nozzles 31 and 31' are arranged with their opening approximately on the circumference of the stacking wheel 16 or 16', viewed in the radial direction of the stacking wheels. Furthermore, they are each arranged next to a plane of rotation in which the stacking compartments of the stacking wheels 16 and 16' move when rotating. More specifically, as shown in FIG. 3, they are arranged between the stacking wheels 16 and 16' as viewed in a direction perpendicular to the plane of rotation of the stacking wheels 16, 16'.

As can be seen from FIG. 1 and FIG. 3, the nozzle openings are wider transversely to the plane of rotation of the stacking compartments 18 than parallel to the plane of rotation of the stacking compartments 18, ie elongated in a direction transverse to the plane of rotation. As a result, forces are distributed more evenly over the width of a flat element 12 .

In the direction of movement, on the other hand, the flow of air is more localized.

The nozzles 31 and 31' are further inclined in such a way that the air flow discharged from them is directed in a plane parallel to the plane of rotation of the stacking wheels 16, 16' into the blowing area B, which in this example extends between the stacking wheels 16, 16' and the paths of the stacking compartments 18 in rotational positions of the stacking wheels 16, 16' crosses, in which elements 12 are completely in have entered the respective stacking compartment 18, but are still in the vicinity of the stacking compartment opening 40.

The inclination is further chosen so that the airflow impinges on a surface of the element 12 in the stack compartment 18 in the blowing area B, having a component towards the stack compartment wall 42 and a component along the stack compartment wall 42 . The rotation of the Sta pelrades 16, the size and direction of the components in the course fe of turning through the blowing area B can change something.

A force is exerted on the element in the stacking compartment in the blowing area B by the air flow. As illustrated in FIG. 4, the air flow can be broken down into two flow components, each of which causes different force components when interacting with the flat element.

The component So of the air flow in the direction of the stacking compartment wall 42 causes a force or force component on the flat element in the direction of the stacking compartment wall 42. This force can have two effects: on the one hand, the flat element can be pressed with its surface against the stacking compartment wall 42 , As a result of which the friction of the flat element with a section from its surface on the stacking compartment wall is increased and braking can be achieved. On the other hand, the flat element can be pushed away from the opposite stacking compartment wall with its front edge in the direction of movement, the front edge, so that the front edge does not hit the stacking compartment wall 42Ü ⁾ or only less hard and is thus protected. The component S _p of the air flow along the stacking compartment wall 42 or parallel to the stacking compartment wall 42 rubs on the surface of the flat element and leads to a braking force or force component that slows down the movement of the flat element into the stacking compartment 18 .

Overall, the effects mentioned lead to better deceleration of the flat element within the stacking compartment and protection of the front edge of the flat element.

The stacking device 10 also has the stripper 24 which is arranged above the tray 20 and meshes with the stacking wheels, by means of which a flat element 12 can be stripped out of the stacking compartment 18 . When the stacking wheel 16 rotates, a flat element 12 in the stack 18 hits the stripper 24 at some point, which stops the movement of the element 12 flächi gene. Since the stacking compartment 18 is pivoted further by the rotation of the stacking wheel 16, the planar element 12 finally occurs completely out of the stacking compartment 18 and is placed on the tray 26, if planar elements already stacked on the tray 26 are already present. As in this exemplary embodiment, the stripper 24 is preferably only slightly narrower than the distance between the stacking wheels 16 and 16', so that the force occurring when the front edge of a flat element 12 hits the stripper 24 is distributed over the widest possible section of the front edge so that it is less heavily loaded.

With the stacking device 10 described, the following method for forming a stack of flat elements, in the example monocells, can be carried out. The stacking wheels are rotated in the specified direction of rotation D. By means of the transport device 14 isolated flat elements 12 are transported into the receiving area A and enter there into one of the stacking compartments 18, the stacking compartment opening 40 of which is in the receiving area A at the moment. The transport speed, the distance between the flat elements 12 and the rotational speed of the stacking wheels are matched to one another accordingly.

The element 12, which is at least partially in the stacking compartment 18, is then transported further with the stacking compartment 18 by rotating the stacking wheels 16 and 16'. In the process, the flat element 12 also moves into the stacking compartment 18 .

When the element 12 enters the stacking compartment 18 or during transport in the stacking compartment 18, the flat element passes the specified blowing area B. There, an air flow is directed onto the flat element 12 by means of the nozzles 31 or 31', see above that a force is exerted on the respective flat element 12 .

On the one hand, the air flow is directed in such a way that it then exerts a force on the flat element 12 in the direction of the stacking compartment wall 42 of the stacking compartment 18 and in the direction away from the stacking compartment wall 420 ^of the stacking compartment. As a result, the flat element 12 is braked on the one hand by friction on the stacking compartment wall 42 . On the other hand, the front edge of the element 12 is pushed away from the stacking compartment wall 420 ⁾ .

Furthermore, the air flow is directed in such a way that at the same time the air flow also exerts a force on the flat element 12 along or parallel to the stacking compartment wall 42 of the stacking compartment 18 . This brakes the surface Chige element 12 in its movement in the stacking compartment relative to the Sta pelfach 18 from.

During further rotation, the flat element is then stripped out of the stacking compartment by the flattener 22 in a phase given by the flattener 22 and is thus removed and placed on the tray 22 or on a flat element already placed on the tray 22 .

A second exemplary embodiment of a stacking device, which is illustrated roughly schematically in FIG. 5 and FIG. 6, differs from the first exemplary embodiment in that the blowing device 28 is replaced by a blowing device 48 . This, in turn, differs from the blowing device 28 only in the arrangement and orientation of the nozzles 31 and 31', which are identified below by the reference symbols 49 and 49'. The other components are unchanged compared to the first exemplary embodiment, so that the statements relating to these apply accordingly and the same reference symbols are used for the same components.

The nozzles 49 and 49' are designed and aligned in the same way as in the first exemplary embodiment, so that only the nozzle 49 will be described in more detail below. The statements then apply accordingly to the nozzle 49'. The nozzle 49 is arranged next to the stacking wheel 16, more precisely between the stacking wheels 16 and 16'. Seen in a plane of rotation of the stacking wheel 16, the nozzle 49 is now directed from the inside of the stacking wheel outwards towards the circumference. More specifically, the nozzle 49 is oriented such that the airflow in the blowing area B is directed towards the outer stacking compartment wall 420 ⁾ . The force exerted by the air flow when it hits a flat element in the stack compartment 18 then has the greatest component in the direction ^of the stack compartment wall 420 and presses this against the corresponding stack compartment wall, which increases braking.

With the stacking device of the second exemplary embodiment, a method can be carried out as in the context of the first exemplary embodiment, in which, however, the air flow is directed differently according to the stacking device.

A third exemplary embodiment differs from the second exemplary embodiment, among other things, in that the nozzles are oriented somewhat differently.

Figure 7 shows a schematic view of a portion of the stacking apparatus with stack wheels 54 and 54', respectively, and nozzles 58 and 58' modified somewhat from stack wheels 16 and 16'. As in the second embodiment, the stacking wheels and nozzles are of the same design. For other parts of the device, the comments on the previous exemplary embodiments apply accordingly.

The stacking wheels 54 and 54' differ from the stacking wheels 16 and 16' only in the number and shape of the stacking compartments 18, but otherwise have the same function.

Nozzles 58 and 58' are located between stacking wheels 54 and 54' like nozzles 16 and 16', but are oriented differently. The blowing area B, into which the air flow is directed, now corresponds to a later phase of the rotational movement of the stacking wheels 54, 54', with a flat element 12 in a NEM stacking compartment 18 but is also pushed in the direction of the periphery of the stacking compartment nearer the wall.

A fourth exemplary embodiment in FIG. 8 differs from the first exemplary embodiment in that the strength of the air flow is controlled as a function of the rotational speed of the stacking wheel and the point in time at which the planar element 12 enters the stacking compartment 18 . The stacking device 10^ differs from the stacking device 28 of the first exemplary embodiment only in that it also has a sensor 60 for detecting the time at which a planar element enters the stacking compartment and a control device 62 connected to the blowing device 28 and the sensor 60 via signal connections , which emits signals to the blowing device 28 in order to control the strength of the air flow as a function of a rotational speed of the stacking wheel and a point in time when the planar element 12 enters the stacking compartment 18 . All other components of the stacking device are unchanged, so that the same reference numbers are used for them and the explanations for the first exemplary embodiment also apply here, unless something else is explicitly described.

The sensor 60 includes a light barrier, by means of which the point in time at which the front edge of a flat element 12 enters the receiving area, more precisely a stacking compartment 18, can be detected.

The sensor 60 is connected to the control device 62 via a signal connection, so that it can detect the point in time at which the flat element enters the stacking compartment. The control device 62 is also connected via a signal connection to the blowing device 28, more precisely the pump 30 connected, and can control them by signals to adjust the strength of the air flow emitted.

The control device 62 is designed in such a way that, to control the blowing device 28, it uses the recorded point in time at which the planar element enters the stacking compartment and the rotational speed of the stacking wheels 16, 16'. In the present exemplary embodiment, the rotational speed is fixed; in other exemplary embodiments, the stacking device can include a device for detecting the rotational speed and, if necessary, also the rotational position of the stacking wheel, which transmits the detected rotational speed to the control device 62 via a signal connection.

For example, the controller 62 may be configured to turn the air flow on when it detects that the sheet 12 is entering the blowing area B, or off when it detects that the sheet is leaving the blowing area B.

In variants of the fourth exemplary embodiment, however, it is also possible to switch on the air flow only at a point in time from which the air flow acts on a sufficiently large section of the surface of the flat element 12 and not only on the front edge.

In other variants, the strength of the air flow can additionally be modulated during the period in which a flat element whose time of entry has been recorded is transported through the blowing area B in order to control forces on the flat element more variably. Further exemplary embodiments differ from the exemplary embodiments described above in that the stacking wheels 16 and 16' are formed by sections of a wide stacking wheel. The wide stacking wheel then meshes with the otherwise unchanged stripper.

Other exemplary embodiments differ from the exemplary embodiments described in that the stacking devices are designed for stacking electrodes.

Claims

P a tent claims

1. _Stacking device for forming a stack of flat elements, for example electrode elements, for an electrochemical energy storage device or a fuel cell, which individually enter a receiving area of the stacking device, comprising at least one stacking wheel that is rotatably mounted in a predetermined direction, the Stacking compartments for receiving one of the flat elements, so that flat elements located at least partially in the stacking compartments are transported when the stacking wheel rotates, and a blower device for delivering an air flow into a predetermined blowing area, the flat elements in the stacking compartments traverse during rotation of the stacking wheel, so that a force is exerted on the respective flat elements.

2. Stacking device according to claim 1, in which the stacking compartment has opposite walls, and the blowing device is designed such that the air flow exerts a force in the direction of one of the walls of the stacking compartment on a respective flat element at least partially located in one of the stacking compartments .

3. Stacking device according to claim 1 or claim 2, in which the stacking compartment has opposing walls, and the blowing device is designed such that a force is also exerted along one of the walls of the stacking compartment by the air flow on the planar element.

4. _Stack device according to one of the preceding claims, in which the blowing device has at least one air outlet opening and/or a nozzle for discharging the air stream.

5. _Stacking device according to one of the preceding claims, in which the air outlet opening or the nozzle is arranged next to a plane of rotation in which the stacking compartments move during rotation.

6. _Stacking device according to one of the preceding claims, which further has a further stacking wheel which can be rotated in the specified direction and which has stacking compartments for receiving one of the planar elements in each case, and in which the blowing device is designed so that the blowing area between the stacking wheels lies.

7. Stacking device according to one of the preceding claims, further comprising a stripper for stripping the flat element out of the stacking compartment and/or a tray on which flat elements that have emerged from the stacking compartments can be stacked.

8. _Stacking device according to one of the preceding claims, which further comprises a transport device for transporting separated planar elements into the receiving area, wherein the transport device and the at least one stacking wheel are arranged in relation to one another such that a planar element brought in by the transport device enters one of the Stacking compartments is transported when it moves through the receiving area.

9. Stacking device according to one of the preceding claims, which further includes a sensor for detecting a point in time when the planar element enters the stacking compartment and/or a sensor for determining a position of the stacking wheel and a sensor connected to the blowing device and the sensor or sensors Control device connected to signal connections, which emits signals to the blower device in order to control the strength of the air flow as a function of a rotational speed of the stacking wheel and/or a point in time when the planar element enters the stacking compartment and/or a position of the stacking wheel.

10. A method for forming a stack of flat elements, for example electrodes, for an electrochemical energy store or a fuel cell, using a stacking wheel that can be rotated in a specified direction of rotation and has stacking compartments for receiving one of the flat elements, in which a single one of the flat elements is transported to the stacking wheel rotating in the predetermined direction of rotation and enters one of the stacking compartments of the stacking wheel, the flat element is transported further in the stacking compartment by rotating the stacking wheel, and in a predetermined phase of the rotary movement out of the stacking compartment is removed, whereby during the entry of the flat element into the stacking compartment and/or during transport in the stacking compartment in a specified blowing area through which the flat element passes, an air flow is directed onto the flat element, so that onto the respective flat element exerted a force t will.

11. The method according to claim 10, in which the stacking compartments have opposite walls and the air flow exerts a force on the planar element in the direction of one of the walls of the stacking compartment and/or in the direction away from one of the walls of the stacking compartment.

12. The method as claimed in claim 10 or 11, in which the air flow is directed onto the planar element in such a way that it also exerts a force along one of the walls of the stacking compartment on the planar element.

13. The method according to any one of claims 10 to 12, wherein the air flow is generated adjacent to a plane of rotation in which the stacking compartments move during rotation.

14. The method according to any one of claims 10 to 13, in which another stacking wheel that can be rotated in the predetermined direction is used, which has stacking compartments for receiving one of the flat elements, the stacking wheel and the other stacking wheel are rotated synchronously, and in which the blowing area between the stacking wheels.

15. The method according to any one of claims 10 to 14, wherein the strength of the air flow is controlled as a function of a rotational speed of the stacking wheel and/or a point in time when the planar element enters the stacking compartment and/or a position of the stacking wheel.