Positioning device, stacking device, and stacking method for repeating components of a cell stack for battery cells or fuel cells

Abstract

The invention relates to: a positioning device and a stacking device for positioning repeating components of a cell stack for battery cells or fuel cells, which repeating components are to be placed on top of one another; and a stacking method for forming a cell stack for a battery cell or fuel cell from a plurality of repeating components to be placed on top of one another. This device and this method are intended to be adapted to the properties of the repeating components, allowing both an even greater degree of damage-free alignment of the components and simplified adaptation to component changes. In order to solve this problem, according to the invention the following are provided: at least one elastic element which is designed in such a way that it decelerates a repeating component inserted into the positioning device if, when the latter is inserted into the positioning device transversely to the plane of the repeating components, one edge of the inserted repeating component strikes the at least one elastic element; and at least one positioning element which can be made to vibrate by vibration generators in such a way that the at least one edge of the inserted repeat component is aligned with the corresponding edges of the repeating components already inserted.

Description

[0001] Positioning device, stacking device and stacking method for repeat components of a cell stack for battery or fuel cells

[0002] The invention relates to a positioning device for positioning repeating components of a cell stack for battery or fuel cells that are to be placed on top of one another. Furthermore, the invention relates to a stacking device for forming a cell stack for a battery cell or fuel cell from repeating components that are to be placed on top of one another, comprising at least one such positioning device. Finally, the invention relates to a stacking method using such a stacking device.

[0003] In the field of automated fuel cell production, known as stack assembly, a pick-and-place process is primarily used to manufacture a fuel cell stack. The principle of the pick-and-place process involves stacking repeating units, which comprise bipolar plates and / or membrane electrode assemblies, alternately or alternately, until the required number of cells is reached, by gripping, transporting, positioning, and depositing them on top of one another or layering them onto edge components. Edge components are referred to as end plates, which form the end of the repeating units connected in series or the individual cell layers created thereby. Additional components that may be required for the function of the fuel cell stack can be integrated into these end plates.For example, the additional components may be current collectors and / or unipolar plates and / or pressure distribution plates.

[0004] While pick-and-place systems ensure permanent guidance of repeat components via grippers, they are not suitable for large-scale production due to the requirement to reduce cycle times. Alternative stack formation systems without grippers require devices for the defined alignment and positioning of cell components. EP21197541 A1 discloses a device and method for positioning repeat components to be stacked on top of one another for a battery or fuel cell stack. The device for aligning the components consists of a vibrating jaw that can be set into vibration by a vibration generator and a rigid positioning jaw arranged underneath. The vibrating jaws and positioning jaws each have contact surfaces for contact with an edge of the repeat component to be placed.The vibrating jaw serves to vibrate and center the repeating component to be deposited, while at least one positioning jaw holds the components in position during the continuous stacking process. A disadvantage is that the vibrating and positioning jaws are rigid, and therefore, due to the rigidity of the jaws, damage to the components when they hit the contact surfaces of the jaws cannot be completely ruled out. In addition, the vibrating jaws with vibration generators require a lot of space at the stacking area, and any adjustment, for example, to a different format or material of the repeating components, requires significant conversion work to adapt the jaws and vibration elements.

[0005] The invention is therefore based on the object of providing a device and a method in which the aforementioned disadvantages are overcome by adapting the positioning device and method to the properties of the repeat components and enabling both an even more damage-free alignment of the components and a simplified adaptation to component changes.

[0006] This object is achieved by a positioning device having the features of claim 1 and by a stacking device having the features of claim 9, as well as an associated stacking method having the features of claim 10. Further features of the invention emerge from the subclaims.

[0007] The invention provides a positioning device for positioning repeat components of a cell stack for battery or fuel cells that are to be placed on top of one another. In fuel cell production, these are, in particular, membrane electrode assemblies (also referred to as MEAs) or bipolar plates (BPPs). In battery cell production, these are, in particular, electrodes (anode or cathode) and separators. The individual repeat components can also consist of a composite of these components; for battery cell production, a repeat component can, for example, also consist of a prefabricated stack of electrodes and separators. To form a stack from these components, the repeat components are introduced into the positioning device, aligned by the latter, and held in their position and orientation within a stacking device.The components can be inserted into the positioning device, for example, transversely to the plane of the repeat components that are already in the stack.

[0008] The positioning device according to the invention comprises at least one elastic element that decelerates a repeating component introduced into the positioning device when, during insertion into the positioning device transversely to the plane of the repeating components, the repeating component strikes the at least one elastic element with an edge of the inserted repeating component. The elastic element is elastically deformable in such a way that damage to the edge of the inserted repeating component can be avoided. The material and geometry of the elastic element are designed such that it is flexible and dampens the impact of the repeating component on the element. The kinetic energy of the inserted repeating component is dissipated, thereby preventing damage to the component.

[0009] Furthermore, the positioning device has at least one positioning element which can be set into vibration by vibration generators in such a way that at least one edge of the introduced repeat component is aligned with the corresponding edges of the already introduced repeat components.

[0010] According to a further aspect, the invention provides a stacking device for forming a cell stack for a battery cell or fuel cell from repeating components to be placed on top of one another, comprising at least one positioning device according to the above embodiment and a receptacle with a support device movable in the height direction for supporting and adjusting the height of the cell stack during stacking.

[0011] According to a further aspect, the invention provides a stacking method for forming a cell stack for a battery cell or fuel cell from a plurality of repeating components to be placed on top of one another, comprising a) providing a stacking device according to the preceding embodiment, b) depositing a repeating component, c) centering the repeating component by oscillating the vibrating jaw in order to bring it into contact with the positioning jaw contact surface, e) repeating steps a) to c) with further repeating components in order to thus form the cell stack.

[0012] Preferably, the stacking method comprises the step to be carried out after step c): d) moving the support device downwards, wherein in step e) steps a) to d) are repeated with the further repeat components.

[0013] According to an advantageous embodiment of the positioning device according to the invention, the at least one positioning element is simultaneously configured as the at least one elastic element. The positioning element can be controlled by a vibration unit, which causes the positioning element to vibrate, thereby aligning the introduced repeating component with the edges of the already introduced repeating components. At the same time, the positioning element is designed to be elastic, so that the momentum of the introduced repeating component can be reduced. This allows alignment of the repeating components by means of vibration and momentum reduction to be implemented by a single component of the device.The positioning device can thus be used both for operation with an alignment of the repeat components by means of vibrations generated by a vibration unit, and for operation for an alignment solely by the compliance of the elastic elements.

[0014] According to a further advantageous embodiment of the positioning device according to the invention, the at least one positioning element is designed and / or the vibration generator can be controlled such that the at least one positioning element does not oscillate into the envelope of the stacking device at maximum deflection. In order not to impede the feed of the repeat components introduced perpendicularly to the stack into the stacking device, the positioning elements must not come into contact with them, even when oscillating. The geometry and material of the positioning element are therefore designed such that, when excited to oscillate, it does not enter the trajectory of the vertically introduced repeat components. Alternatively, the vibration generator can also be controlled such that the maximum deflection generated by the positioning element does not cause it to oscillate into the feed path of the repeat component.

[0015] According to a further advantageous embodiment of the positioning device according to the invention, several positioning elements can be provided. Each positioning element can be set into vibration by a vibration generator, whereby the vibration generators can be controlled individually to generate different vibration frequencies from the other vibration generators. This allows the repeating components to be aligned at several edge regions by the positioning elements, and the different frequencies allow for flexible adjustment of the positioning to the properties of the repeating component.

[0016] According to a further advantageous embodiment of the positioning device according to the invention, several elastic elements and / or several positioning elements can be provided, wherein at least one elastic element and / or one positioning element has a geometry that differs from other elastic elements or positioning elements. This allows the momentum of the introduced repeat component to be reduced at several points, and additionally, different geometries can be used for different edge regions of the repeat component in order to flexibly respond to the properties of the repeat component. This allows the optimal compliance of the elastic elements to always be used for the respective region of the repeat component.Adaptation to a repeat component with changed properties can be achieved cost-effectively by replacing the positioning elements or the elastic elements with corresponding elements with adapted geometry or material.

[0017] According to a further advantageous embodiment of the positioning device according to the invention, the at least one positioning element and the at least one vibration generator are mounted on a base plate that is positioned vertically above the stacking device, wherein the base plate is designed to be detachable from the stacking device. The positioning elements and vibration generators are not connected to the stacking device, but are fixed to a base plate that can be arranged above the stacking device.

[0018] Due to the possibility of detaching the base plate with the positioning elements and vibration generators from the stacking device, the stacking device can be removed from the stacking position in order to be able to carry out further process steps in the cell stack formation, such as pressing the stack, or to be able to use the stacking device as a workpiece carrier for the cell stack in the further process.

[0019] According to a further advantageous embodiment of the positioning device according to the invention, a protective element is arranged in a gap between the stacking device and the base plate to prevent jamming of repeating components. This prevents the repeating component from entering the gap between the base plate and the stacking device. Multiple protective elements can also be arranged, for example, each adjacent to a positioning element or an elastic element.

[0020] According to a further advantageous embodiment of the positioning device according to the invention, the at least one positioning element can be set into vibration by a vibration generator such that it oscillates at its natural frequency. This allows comparatively large vibration amplitudes to be generated with a small vibration generator, thus minimizing the space required for the vibration mechanism.

[0021] Some embodiments are explained in more detail below with reference to the attached drawings. They show:

[0022] Fig. 1 : A stacking device according to the invention in a schematic representation in side view

[0023] Fig. 2: An embodiment of the positioning device for arrangement above the stacking device

[0024] Fig. 3: A design of the base plate for arrangement above the stacking device in which positioning elements are simultaneously designed as elastic elements.

[0025] Figure 1 shows a schematic side view of a manufacturing device 1 according to the invention. First repeat components 2, in the present example membrane electrode assemblies of a fuel cell, are arranged in a stack 10 in a magazine-shaped repeat component supply device 3. Second repeat components 4, in the present example bipolar plates for a fuel cell, are provided in a stacking device 5 (in the illustrated embodiment, a gravity magazine). The first repeat components 2 are separated and transported to a stacking device 7 by means of a conveying device 6, here a vacuum overhead conveyor belt, and inserted into the stacking device from the side. From above, the second repeat components 4 are fed individually from the stacking device 5 to the stacking device 7.The first and second repeat components 2, 4 are alternately stacked on top of one another in the stacking device 7 and thus stacked to form a fuel cell stack. For this purpose, the stacking table 8 of the stacking device 7 is designed to be vertically movable and moves successively downwards during the stacking process. At the end of the stacking process, the stack 11 is removed from the stacking device 7, and further production steps are carried out to produce a fuel cell stack. In principle, the device shown can also be used to produce battery cells, whereby separators and electrodes are alternately stacked on top of one another instead of membrane-electrode assemblies and bipolar plates. It is also possible to stack prefabricated stacks, for example consisting of electrodes and separators, which together form a repeating component.

[0026] The alignment of the repeat components for storage in the stacking device takes place in a positioning device 9. The positioning device 9 is arranged above the stacking device 7. In the positioning device 9, the first repeat components 2 transported from the conveyor device to the stacking device are braked and aligned to the stack 11.

[0027] Fig. 2 shows a possible embodiment of the positioning device 9. A base plate 12 for arrangement above the stacking device 7 has a recess 13 which is positioned above the stacking device 7 and whose dimensions are adapted to the size of the repeat components 2, 4 in order to enable the repeat components 2, 4 to be passed through. Elastic elements 14 are attached to the base plate 12, which in the present embodiment are designed as lamellar, curved dampers made of a material with elastic properties; for example, materials such as rubber or thermoplastic polyamide elastomers (TPA) can be used. If the repeat component 2 is introduced laterally from the conveyor device 6 into the positioning device 9, its edge strikes at least one of the elastic elements 14, which decelerate the repeat component 2 due to their flexible properties without damaging it.When the repeat component 2 impacts, the elastic lamellae of the elastic elements 14 are pressed in and thus dampen the impact of the repeat component 2.

[0028] Furthermore, positioning elements 15, which are designed here as thin metal sheets, are attached to the base plate 12. Vibration generators 16 (Fig. 3) are attached to the positioning elements 15, which cause the positioning elements 15 to vibrate. If the repeating component 2 touches one or more of the positioning elements 15, their vibration guides it to the recess 13 in the base plate. Due to the circumferential arrangement of the positioning elements 15 around the recess 13, the repeating component 2 is centered by the positioning elements 15 and deposited on the stack 11.

[0029] Fig. 3 shows a further possible embodiment of the positioning device 9, in which the positioning elements 15 simultaneously form the elastic elements 14. The positioning elements 15 are fastened to the base plate 12 and, in the present embodiment, are designed as thin metal sheets. The thin metal sheets are flexible and are therefore suitable for braking the repeating components 2. If the repeating component 2 is introduced laterally from the conveyor device 6 into the positioning device 9, its edge strikes at least one of the positioning elements / elastic elements 15, which, due to their resilient properties, brake the repeating component 2 without damaging it. Furthermore, in this embodiment, each positioning element 15 is equipped with a vibration generator 16, which can be controlled in such a way that it can cause the positioning element 15 to vibrate.By oscillating the positioning elements 15, the repeat component is aligned and placed on the stack 11.

[0030] The positioning elements 15 also have protective elements 17, which are located in a gap between the stacking device 7 and the base plate 12 and prevent the repeat components 2, 4 from becoming jammed in the gap.

Claims

Patent claims 1. A positioning device for positioning repeat components of a cell stack for battery or fuel cells that are to be placed one on top of the other, comprising at least one elastic element that is designed such that it decelerates a repeat component introduced into the positioning device when, upon introduction into the positioning device transversely to the plane of the repeat components, the repeat component strikes the at least one elastic element with an edge of the introduced repeat component, wherein the at least one elastic element is further designed such that it is elastically deformable in such a way that damage to the edge of the introduced repeat component can be avoided, and wherein the device further comprises at least one positioning element, wherein the at least one positioning element can be set into vibration by vibration generators in such a way,that at least one edge of the inserted repeat component is aligned with the corresponding edges of the already inserted repeat components.

2. Positioning device according to claim 1, wherein the at least one positioning element is simultaneously designed as the at least one elastic element.

3. Positioning device according to claim 1 or 2, characterized in that the at least one positioning element is designed and / or the vibration generator can be controlled in such a way that the at least one positioning element does not oscillate into the envelope curve of the stacking device according to claim 9 at maximum deflection.

4. Positioning device according to one of the preceding claims, characterized in that a plurality of positioning elements are provided, each of which can be set into vibration by a vibration generator, wherein the vibration generators can be controlled individually in order to generate different vibration frequencies from the other vibration generators.

5. Positioning device according to one of the preceding claims, characterized in that a plurality of elastic elements and / or a plurality of positioning elements are provided, wherein at least one elastic element and / or one positioning element has a geometry different from other elastic elements or positioning elements.

6. Positioning device according to one of the preceding claims, characterized in that the at least one positioning element and the at least one vibration generator are fastened to a base plate which is positioned in the vertical direction above the stacking device according to claim 9, wherein the base plate is designed to be detachable from the stacking device.

7. Positioning device according to one of the preceding claims, characterized in that a protective element is arranged in a gap between the stacking device and the base plate to prevent jamming of repeat components.

8. Positioning device according to one of the preceding claims, characterized in that the at least one positioning element is set into vibration by vibration generators such that it oscillates at its natural frequency.

9. Stacking device for forming a cell stack for a battery cell or fuel cell from repeating components to be placed on top of one another, comprising at least one positioning device according to one of the preceding claims and a receptacle with a support device movable in the height direction for supporting and adjusting the height of the cell stack during stacking.

10. Stacking method for forming a cell stack for a battery cell or fuel cell from a plurality of repeating components to be placed on top of one another, comprising a) providing a stacking device according to claim 9, b) depositing a repeating component, c) centering the repeat component by oscillating the at least one positioning element to align it with the edges of the repeat components already laid, e) repeating steps a) to c) with further repeat components to form the cell stack.

11. Stacking method according to claim 10, characterized by the step to be carried out after step c): d) moving the support device downwards, wherein in step e) steps a) to d) are repeated with the further repeat components.

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