Method for manufacturing accumulators and stacking device for manufacturing accumulators

Abstract

Method for manufacturing accumulators, each comprising at least one cell stack (6), wherein individual sheets (4) are stacked using a stacking device (2) to manufacture the cell stacks (6). - the individual sheets (4) are fed successively to a stacking wheel arrangement (12) of the stacking device (2) by means of a conveyor line (8), wherein the stacking wheel arrangement (12) has two stacking wheels (28) which are arranged in two superimposed planes, - a predetermined number of consecutive single sheets (4) is fed to one of the two stacking wheels (28), wherein the predetermined number corresponds to the number of single sheets (4) in a finished cell stack (6), and - several of the individual sheets (4) following the specified number of individual sheets (4) are fed to the other of the two stacking wheels (28).

Description

[0001] The invention relates to a method for manufacturing accumulators. The invention also relates to a stacking device for manufacturing accumulators.

[0002] Batteries are storage devices for electrical energy and are widely used. In some applications, they consist of multiple battery cells and are used, among other things, in the automotive sector. Here, the batteries serve, for example, as so-called drive or traction batteries to power hybrid or electric vehicles.

[0003] Lithium-ion batteries, that is, batteries made of lithium-ion cells, are currently of particular interest. A wide variety of designs are known regarding their precise construction. The production of lithium-ion cells is outlined, for example, in "Heimes, Heiner Hans; Kampker, Achim; Lienemann, Christoph; Locke, Marc; Offermanns, Christian; Michaelis, Sarah; Rahimzei, Ehsan (2018): Production process of a lithium-ion battery cell, Frankfurt am Main, PEM of RWTH Aachen and VDMA self-published."

[0004] In the production of lithium-ion cells, so-called sheets, also known as individual sheets or electrode elements, are typically manufactured first. In some applications, these are stacked to form electrode stacks. A stacking device is conveniently used for this purpose. Such a stacking device is described in WO 2022 / 199 890 A1 and in DE 10 2021 001 820 A1.

[0005] The invention is based on the objective of providing an advantageous method for the production of accumulators. Furthermore, the invention is based on the objective of providing an advantageous stacking device for the production of accumulators.

[0006] This problem is solved by a method with the features of claim 1 and by a stacking device with the features of claim 10. The advantages and preferred embodiments mentioned with regard to the method are also transferable to the stacking device and vice versa. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims.

[0007] The method according to the invention is designed for the manufacture of accumulators. A corresponding accumulator typically comprises a number of accumulator cells, each of which usually has a cell housing or cell enclosure. Depending on the application, such an accumulator may, for example, consist of a single accumulator cell. However, a corresponding accumulator usually comprises several such accumulator cells and generally forms a battery or a battery module. A corresponding battery, in turn, typically has a battery housing, and a corresponding battery module usually has a module housing or a carrier unit for accumulator cells. If the accumulator is designed as a battery, it may, in some cases, have several of the aforementioned battery modules, i.e., at least one such battery module and typically several.

[0008] Regardless of the above, every accumulator produced by the process has at least one cell stack formed by stacked individual sheets. If the accumulator is built from the aforementioned accumulator cells, each accumulator cell typically has such a cell stack, and in particular exactly one. Furthermore, each of these accumulator cells is then preferably designed as a so-called pouch cell.

[0009] Furthermore, the cell stack advantageously forms a so-called electrode stack. This means that the cell stack contains a layering or stacking of electrode materials. Moreover, the corresponding battery is preferably designed as a lithium-ion battery. Therefore, the layering or stacking in the cell stack typically includes an anode material, a separator material, and a cathode material.

[0010] Suitable individual sheets for manufacturing a corresponding cell stack for a lithium-ion battery, and a possible method for producing such individual sheets, are described, for example, in "Heimes, Heiner Hans; Kampker, Achim; Lienemann, Christoph; Locke, Marc; Offermanns, Christian; Michaelis, Sarah; Rahimzei, Ehsan (2018): Production process of a lithium-ion battery cell, Frankfurt am Main, PEM of RWTH Aachen and VDMA self-published." The corresponding individual sheets are referred to here as sheets.

[0011] In this specific example, three different sheets are produced: anode sheets (a) containing an anode material, separator sheets (b) containing a separator material, and cathode sheets (c) containing a cathode material. To produce a corresponding cell stack, these sheets are then conveniently stacked in the sequence abcabc, and so on.

[0012] In an alternative variant, individual sheets are used, which are designed as so-called monocells. Such monocell individual sheets typically have an anode material, a cathode material and a separator material in between.

[0013] Regardless of this, the individual sheets have a length, a width, and a thickness. A typical thickness value is in the range of 0.05 mm to 2.5 mm, and particularly in the range of 0.1 mm to 1.5 mm. For length and width, values ​​that are at least five or ten times greater, respectively, are common.

[0014] In the course of carrying out the process, i.e., the process according to the invention, corresponding individual sheets are stacked into cell stacks. The process for manufacturing accumulators thus comprises at least one stacking step in which the individual sheets are stacked. This stacking step is carried out using the stacking device according to the invention, and in particular, it is fully automated.

[0015] The stacking device, i.e., the stacking device according to the invention, is designed for the production of the previously described accumulators using the method according to the invention and, in particular, for the automatic execution of the stacking process in at least one operating mode. The automatic execution is typically controlled by a control unit of the stacking device. Independently of this, the stacking device, hereinafter also referred to simply as the device, comprises a conveyor belt and a stacking wheel arrangement.

[0016] In the stacking wheel arrangement, two stacking wheels are arranged in two superimposed planes. "Superimposed" here means that the two planes are vertically offset from each other relative to the Earth system. Furthermore, depending on the specific design, the two stacking wheels are either arranged one above the other or, additionally, horizontally offset relative to the Earth system.

[0017] In every case, during the stacking process, the individual sheets are fed sequentially to the stacking wheel assembly via the conveyor. A predetermined number of consecutive individual sheets is then fed to one of the two stacking wheels, and subsequently, several of the individual sheets following the predetermined number are fed to the other of the two stacking wheels. The predetermined number of individual sheets then corresponds to the intended number of individual sheets in a finished cell stack.

[0018] Furthermore, the individual sheets are typically fed continuously to the stacking wheel assembly. This means that the conveyor typically transports the individual sheets at a constant speed, and that the speed preferably remains unchanged, even when switching from feeding individual sheets to one of the stacking wheels to the other. Thus, a continuous flow of individual sheets to the stacking wheel assembly is essentially maintained. Within the stacking wheel assembly, the two stacking wheels are then used alternately to stack individual sheets into cell stacks.

[0019] Furthermore, it is advantageous that the individual sheets fed via the conveyor belt are already arranged in a predetermined sequence on the conveyor belt, at least if different individual sheets are to be stacked, and / or the individual sheets are aligned and oriented in a predetermined manner, i.e., in particular, that they lie with a predetermined side on the conveyor belt.

[0020] It is further advantageous if the stacking device includes a distribution unit positioned between the conveyor and the stacking wheel assembly. This distribution unit has two branches: a first branch and a second branch. Each of the two stacking wheels is assigned a branch, with the first branch being assigned to the first stacking wheel and the second branch to the second stacking wheel. During the execution of the process, individual sheets are fed to each of the two stacking wheels via one of the two branches. Preferably, depending on the position of a switch in the distribution unit, the individual sheets are conveyed either into the first branch or the second branch.

[0021] If the distribution unit has a previously mentioned diverter, this is preferably designed by means of a distribution roller. The distribution roller is preferably displaceable in the vertical direction relative to the ground system, or it is displaceable to a good approximation in the vertical direction. "To a good approximation" here means that the actual direction preferably deviates by no more than 40°, more preferably by no more than 25°, and particularly by no more than 15° from the vertical direction.

[0022] Preferably, the distributor roller is movable between two vertical positions, namely between a first position and a second position. In the first position, the individual sheets fed to the switch are conveyed via the switch into the first branch, and in the second position, the individual sheets fed to the switch are conveyed via the switch into the second branch.

[0023] According to an advantageous embodiment, the distributor roller is supplemented by a pair of rollers, which are also part of the diverter. This pair of rollers is then formed by two rollers that are typically arranged offset from each other in the aforementioned vertical direction.

[0024] Preferably, at least one of these two rollers is driven, so that the two rollers form a so-called conveyor roller pair. This means that these rollers rotate in opposite directions during operation and thereby convey the supplied individual sheets, which are guided between the rollers.

[0025] In the diverter, the distributor roller also preferably forms such a conveyor roller pair either together with one roller of the roller pair or together with the other roller of the roller pair, depending on the vertical position of the distributor roller.

[0026] It is also advantageous if the first branch of the distribution unit for conveying the individual sheets has at least one pair of conveying rollers. Other designs are typical in which the first branch has at least two pairs of conveying rollers: one pair of a first type and one pair of a second type. The two types differ, for example, in the diameter of the rollers that form the respective pairs of conveying rollers.

[0027] It is also advantageous if the first branch has at least one pair of guide plates, preferably arranged one above the other. These guide plates serve to guide the individual leaves during transport over the first branch. That is, the individual leaves transported over the first branch are guided between the two guide plates of the guide plate pair.

[0028] In some applications, the guide plates described above also have openings, in particular slots. For conveying the individual sheets, projections on the rollers of a previously mentioned pair of conveying rollers preferably extend through these openings, so that the conveying of the individual sheets is accomplished by means of these projections.

[0029] Such projections are, for example, designed in a ring shape. In this configuration, the ring-shaped projections of each roller are arranged around an axis of the roller and, viewed along this axis, are spaced apart in a row. In profile, this results in a rectangular tooth pattern on the rollers.

[0030] Depending on the application, the second branch of the distribution unit may have none, one, or several of the previously described features of the first branch of the distribution unit.

[0031] According to at least one embodiment, the rollers of the previously described switch also have such projections. In the case of the distributor roller, however, the ring-shaped projections are preferably arranged alternately, once offset in a transverse direction perpendicular to the axis of the distributor roller and once offset in the opposite transverse direction.

[0032] In an advantageous further development, a guide plate is also attached to the distributor roller, which has a V-shape formed by two legs.

[0033] Both legs typically have openings, and the distributor shaft is conveniently located between the two legs.

[0034] Furthermore, one of the stacking wheels, namely the first stacking wheel, has an axle. A further advantage is a design in which the first stacking wheel is configured as a driven stacking wheel and thus rotates around the axle in one direction during operation.

[0035] Independently of this, the first stacking wheel preferably has several fingers arranged in a row spaced apart from one another along the axis. Furthermore, the first stacking wheel preferably has several such rows distributed around the axis. Typical designs have more than two fingers per row and more than ten rows. A single sheet fed to the first stacking wheel is then typically inserted into a space between two consecutive rows in the circumferential direction or in the aforementioned direction of rotation.

[0036] Furthermore, the fingers are preferably curved. In particular, the fingers are bent in the opposite direction to the previously mentioned rotation.

[0037] The second stacking wheel of the two stacking wheels, depending on the embodiment, has none, one, or several of the features described above of the first stacking wheel. Preferably, the stacking wheels of the stacking wheel arrangement are identical.

[0038] It is also advantageous if each stacking wheel is assigned a stacking table on which individual sheets are stacked into cell stacks using the respective stacking wheel. Preferably, a common gripper of the stacking device is then assigned to the stacking tables, with which the finished cell stacks are removed from the stacking tables.

[0039] Depending on the design variant, the finished stacked cell stacks are also turned over using the gripper.

[0040] Regardless of this, it is advantageous if the stacked cell piles are fed into a continuous furnace using a gripper. In the continuous furnace, the stacked cell piles then undergo heat treatment. During this heat treatment, pressure is preferably applied to the piles, typically in the stacking direction. In this case, the continuous furnace essentially performs a hot pressing process.

[0041] The advantages and further training described in connection with the process can also be applied analogously to the stacking device and vice versa.

[0042] In summary, the underlying idea of ​​the inventive method and the inventive stacking device can also be formulated as follows: To manufacture a battery, single-cell units are stacked. Stacking wheels are suitable for this purpose. Since the bundle is complete after a certain number of single-cell units have been stacked, the flow of single-cell units is then diverted to a different path and thus to a different stacker / stacker wheel. Subsequently, a continuous flow of bundles is generated again by means of a gripping mechanism. For this purpose, two stackers are alternately loaded with the desired number of single-cell units using a tandem principle. A manipulator designed as a gripper then picks up the bundles from the stacker that is currently finishing. A double conveyor belt with heated belts acts as a continuous oven for the removal and lamination of the bundle.

[0043] This offers several advantages: "Taping" with adhesive tape for temporary fixation of the stack is no longer necessary, as the fixing takes place immediately after the stacking process in the oven. Continuous fixing is achieved through clamping. The packages are correctly oriented again at the end, after the cells have been temporarily turned over during the stacking process. The two material streams temporarily generated by the tandem operation are ultimately merged into one. The required temperature exposure time for lamination and the number of cells per stack determine the length of the continuous oven.

[0044] Further advantages, features, and details of the invention will become apparent from the claims, the following description of preferred embodiments, and the schematic drawings. These show: Fig. 1 a stacking device comprising a conveyor, a distribution unit, a stacking wheel arrangement and a gripper, Fig. 2 enlarges a lower branch of the distribution unit, Fig. 3 enlarges a pair of rollers of the distributor unit, Fig. 4 enlarges a switch of the distribution unit, Fig. 5 enlarges a stacking wheel of the stacking arrangement, Fig. 6 enlarges two gripper jaws of the gripper, and Fig. 7 a single sheet for a cell stack of an accumulator.

[0045] Corresponding parts are marked with the same reference symbols in all figures.

[0046] A stacking device 2, described below as an example, serves for the automatic execution of a stacking process step in which individual sheets 4 are stacked to form cell stacks 6. The stacking process step is part of a process for manufacturing lithium-ion batteries (not shown), each battery having at least one such cell stack 6. The automatic execution is typically controlled by a control unit of the stacking device 2 (not shown).

[0047] The stacking device 2 now comprises a conveyor 8, a distributor 10, a stacking wheel arrangement 12, and preferably also a gripper 14. Furthermore, the stacking device 2 preferably comprises a continuous oven 16. An embodiment with a gripper 14, namely with a first gripper 14, and with a continuous oven 16 is described in Fig. 1 shown. Fig. 2 to Fig. 6 give different excerpts of Fig. 1 enlarges again.

[0048] During operation of the stacking device 2, and thus during the execution of the stacking process, the individual sheets 4 are continuously fed to the distribution unit 10 via conveyor 8. In the case of the design variant according to... Fig. 1 designed as a simple conveyor belt which transports the individual sheets 4 in a conveying direction.

[0049] As an example, all the individual sheets supplied are designed in the same way. Fig. Figure 7 shows an example of such a single sheet 4. It is designed as a so-called monocell and has a layer of an anode material 18, a layer of a cathode material 20, and an intermediate layer of a separator material 22. The single sheet 4 also has two electrically conductive current collectors 24, one of which is in contact with the anode material 18 and the other with the cathode material 20. Each of these current collectors 24 forms a so-called current collector tab 26, with the two current collector tabs 26 protruding from opposite sides of the single sheet 4. Fig. In 7, only the conductor flag 26 of the conductor foil 24, which protrudes from the plane of the drawing, is visible on the anode material 18.

[0050] On the in Fig. On the conveyor belt shown in Figure 1, several of these individual sheets 4 are already arranged one behind the other in the conveying direction. These individual sheets 4 are all aligned and oriented in the same way. In this manner, the individual sheets 4 are then fed to the distribution unit 10 during operation of the stacking device 2. The conveyor 8 typically transports the individual sheets 4 at a predetermined speed, which is preferably kept constant at least for a certain period of time, while several cell stacks 6 are being stacked.

[0051] The cell stacks 6 are further stacked by means of the stacking wheel assembly 12 of the stacking device 2, which has two stacking wheels 28 for this purpose. To distribute the individual sheets 4 fed via the conveyor 8 onto the stacking wheels 28, the distribution unit 10 is positioned between the conveyor 8 and the stacking wheel assembly 12, the distribution unit 10 having a branch 30 for each stacking wheel 28. Thus, each stacking wheel 28 is assigned a branch 30 via which individual sheets 4 can be fed to the corresponding stacking wheel 28.

[0052] The stacking wheels 28 are arranged in two superimposed planes. This means that the stacking wheels 28 are arranged offset from each other in the vertical direction relative to the Earth system, or at least to a good approximation in the vertical direction. "To a good approximation" here means that the actual direction preferably deviates from the vertical direction by no more than 40°, more preferably by no more than 25°, and particularly by no more than 15°.

[0053] In contrast, the stacking wheels 28 are preferably not offset in the horizontal direction relative to the Earth system, or at least to a good approximation in the horizontal direction. "To a good approximation" here means that the actual direction preferably deviates from the horizontal direction by no more than 40°, more preferably by no more than 25°, and in particular by no more than 15°.

[0054] The stacking wheels 28 are therefore preferably arranged one above the other, as is the case in Fig. 1 is indicated. Therefore, one of the stacking wheels 28, namely the one in Fig. 1 shown above, designated as the upper stacking wheel 28, and that the other stacking wheel 28, namely the one in Fig. 1 shown below, as lower stacking wheel 28. The branch 30 assigned to the upper stacking wheel 28 is additionally referred to as upper branch 30 and the branch 30 assigned to the lower stacking wheel 28 as lower branch 30.

[0055] To enable the distribution of the individual leaves 4 to the two branches 30, the distribution unit 10 typically has a switch. The switch is preferably designed by means of a distribution roller 32, as is the case in Fig. Figure 4 shows the arrangement. The distributor roller 32 is adjustable in the aforementioned vertical direction, or at least to a good approximation in the vertical direction, and in particular, is displaceable between two vertical positions. In the upper vertical position, the individual sheets 4 fed to the switch are conveyed via the switch into the upper branch 30, and in the lower vertical position, the individual sheets 4 fed to the switch are conveyed via the switch into the lower branch 30.

[0056] In the exemplary embodiment, the distributor roller 32 is supplemented by a pair of rollers, which are also part of the diverter. This pair of rollers consists of two rollers 34 arranged one above the other. Thus, the pair of rollers has an upper roller 34 and a lower roller 34.

[0057] Furthermore, at least one of the two rollers 34 is driven, so that they form a so-called conveying roller pair. This means that these rollers 34 rotate in opposite directions during operation and thereby convey the supplied individual sheets 4, so that these are guided between the rollers 34.

[0058] In the diverter, the distributor roller 32 also expediently forms such a conveyor roller pair either together with the upper roller 34 of the roller pair or together with the lower roller 34 of the roller pair, depending on the vertical position of the distributor roller 32.

[0059] Furthermore, the aforementioned 30 figures typically each have pairs of rollers designed as conveyor roller pairs. In the exemplary embodiment according to Fig. In this case, each branch 30 has a pair of rollers 36 of a first type and a pair of rollers 38 of a second type. The two types differ in the diameter of the rollers 36 and 38.

[0060] Furthermore, an embodiment of the stacking device 2 is preferred in which the distributor unit 10, as in the case of the embodiment variant according to Fig. 1, comprising at least two guide plates 40, which are arranged in a manner that is superimposed and thus forms a guide plate pair. In this case, the individual leaves 4 are then expediently guided between the guide plates 40 of the guide plate pair.

[0061] In the exemplary embodiment according to Fig. 1 The guide plates 40 also have openings 42, in particular slots. This is at least evident in Fig. 3 indicated. To transport the individual sheets 4, projections 44 on the rollers 36, 38 then engage through the openings 42, so that the transport of the individual sheets 4 is accomplished with the help of the projections 44.

[0062] Those projections 44 are in the embodiment according to Fig. 1. The projections 44 of each roller 36, 38 are guided around an axis 46, 48 of the roller and, viewed along the axis 46, 48, are arranged in a row with a distance between them. In profile, the rollers 36, 38 thus exhibit a rectangular tooth pattern.

[0063] According to the design variant Fig. Furthermore, the rollers of the previously described switch also exhibit such projections 44. In the case of the distributor roller 32, however, the annular projections 44 are arranged alternately along an axis 50 of the distributor roller 32, first offset in a transverse direction perpendicular to the axis 50 and then offset in the opposite transverse direction. Fig. 4 is recognizable.

[0064] Furthermore, the distributor roller 32 is in the version variant according to Fig. 1 is combined with a guide plate 52, which has a V-shape formed by two legs. Both legs have openings similar to the openings 42 (not shown in detail), and the distributor roller 32 is positioned between the two legs. Individual sheets 4 are then guided via the upper leg into the upper branch 30 and via the lower leg into the lower branch 30.

[0065] The stacking wheels 28 of the stacking wheel arrangement 12 are preferably designed identically. Typically, each stacking wheel 28 is designed as a driven stacking wheel 28 and thus rotates in a rotational direction 54 around an axis 56 during operation. Furthermore, it preferably has several fingers 58 arranged in a row spaced apart from one another along the axis 56. This stacking wheel 28 also preferably has several such rows distributed around the axis 56. Typical designs have more than two fingers 58 per row and more than ten rows. A stacking wheel 28 designed in this way is described in Fig. 5 shown. A single sheet 4 is then inserted into a space between two rows that follow each other in the direction of rotation.

[0066] Furthermore, the fingers 58 are preferably shaped in an arc shape, as in the exemplary embodiment according to Fig. 1 is the case. The fingers 58 are then preferably bent in the opposite direction to the rotation 54.

[0067] It is also useful if each stacking wheel 28 of the stacking wheel arrangement 12 is assigned a stacking table 60 on which the individual sheets 4 supplied to the corresponding stacking wheel 28 are stacked into cell stacks 6.

[0068] The stacking device 2 is preferably designed and configured such that the two stacking wheels 28 of the stacking wheel arrangement 12 alternately stack individual sheets 4 into cell stacks 6. This means that initially, enough individual sheets 4 for a cell stack 6 are conveyed into one of the branches 30. Then, the switch position of the distributor unit 10 is changed, specifically the vertical position of the distributor roller 32, so that the subsequent individual sheets are fed to the other branch 30. Consequently, cell stacks 6 are then also alternately stacked on the stacking tables 60.

[0069] Furthermore, the stacking device 2 preferably has the previously mentioned first gripper 14, as in the exemplary embodiment according to Fig. 1. This first gripper 14 is typically assigned to both stacking tables 60 of the stacking wheel arrangement 12, so that the first gripper 14 removes fully stacked cell stacks 6 from both stacking tables 60. If, preferably, the stacking device 2 also includes the aforementioned continuous oven 16, the first gripper expediently feeds the fully stacked cell stacks 6 to the continuous oven 16. During this process, the cell stacks 6 are turned over according to at least one embodiment.

[0070] Several designs are suitable for the first gripper 14. In the case of the design according to Fig. In the first gripper 14, two gripping jaws 62 are movable towards and away from each other, thus enabling a grasping action. The two gripping jaws 62 are further connected via a telescopic arm 64 to a rotational axis 66, about which the telescopic arm 64 can rotate. The rotational axis 66 is, in the exemplary embodiment, Fig. 1 vertically slidable on a rail 68.

[0071] The two gripping jaws 62 are, in the case of the design according to Fig. 1. They are further designed in the same manner and each has a shape reminiscent of a comb. To form such a comb shape, several parallel ridges 70 are arranged next to each other. This is due to Fig. 6. To grip a fully stacked cell stack 6 from one of the stacking tables 60, the strips 70 of the lower gripper jaw 62 are inserted into appropriately formed grooves 72 on the stacking table 60, so that the corresponding strips 70 are positioned below the bottommost individual sheet 4 before gripping the cell stack 6. The grooves 72 are in Fig. 5 clearly visible.

[0072] As previously explained, the first gripper 14 is preferably used to feed pre-stacked cell stacks 6 to the aforementioned continuous oven 16. In this embodiment, at least the continuous oven 16 has the following features: Fig. 1. Another gripper 74, namely a second gripper 74. The second gripper 74 is formed by two gripping jaws 76. Each of these gripping jaws 76 is designed in the manner of a simple conveyor belt with two deflection rollers, but instead of a single wide belt, several narrow belts 78 are stretched between the two deflection rollers and arranged side by side. As this Fig. Figure 6 shows that a gap is left between the belts 78, allowing the bars 70 of the gripping jaws 62 of the first gripper 14 to be positioned between the belts 78. Furthermore, the two gripping jaws 76 of the second gripper 74 are each pivotally mounted about an axis, so that they can move like the two jaws of a pair of pliers.

[0073] The second gripper 74 of the continuous furnace 16 is connected according to the design. Fig.1. A heated conveyor line 80 of the continuous furnace 16 is described. In the exemplary embodiment, this is formed by two conveyor belts arranged one above the other, between which the cell stacks 6 are guided. Preferably, pressure is exerted on the cell stacks 6 by the two conveyor belts, acting both vertically and against the vertical direction. Reference symbol list 2 stacking device 4 single sheets 6 cell stacks 8 Conveyor road 10 distribution unit 12 stacking wheel arrangement 14 first grabber 16 continuous oven 18 Anode material 20 cathode materials 22 Separator material 24 Conductor foil 26 drain tabs 28 stacking wheel 30 branch 32 Distributor roller 34 rollers 36 rollers 38 roller 40 guide plate 42 Breakthrough 44 lead 46 axle 48 axle 50 axle 52 Guide plate 54 Direction of rotation 56 axle 58 fingers 60 stacking table 62 Gripping jaw 64 telescopic arm 66 Rotation axis 68 rail 70 bar 72 Nut 74 second grabber 76 Gripping jaw 78 belts 80 Conveyor road

Claims

[1] Method for manufacturing accumulators, each comprising at least one cell stack (6), wherein individual sheets (4) are stacked using a stacking device (2) to manufacture the cell stack (6), by - the individual sheets (4) are fed successively to a stacking wheel arrangement (12) of the stacking device (2) by means of a conveyor line (8), wherein the stacking wheel arrangement (12) has two stacking wheels (28) which are arranged in two superimposed planes, - a predetermined number of consecutive single sheets (4) is fed to one of the two stacking wheels (28), wherein the predetermined number corresponds to the number of single sheets (4) in a finished cell stack (6), and - several of the individual sheets (4) following the specified number of individual sheets (4) are fed to the other of the two stacking wheels (28). [2] Method according to claim 1, wherein the two stacking wheels (28) are used alternately to stack individual sheets (4) into cell stacks (6). [3] Method according to claim 1 or 2, wherein - the stacking device (2) has a distributor unit (10) positioned between the conveyor (8) and the stacking wheel arrangement (12), - the distribution unit (10) has two branches (30), namely a first branch (30) and a second branch (30), - each of the two stacking wheels (28) is fed individual sheets (4) via one of the two branches (30) and - the individual leaves (4) are fed either to the first branch (30) or to the second branch (30) depending on the vertical position of a distributor roller (32). [4] Method according to claim 3, wherein the first branch (30) has a pair of rollers (36, 38) by means of which individual sheets (4) are conveyed over the first branch (30). [5] Method according to claim 4, wherein - the first branch (30) has a pair of guide plates with two guide plates (40) arranged one above the other, between which the individual leaves (4) conveyed over the first branch (30) are guided, - each of the rollers (36) of the roller pair is designed as a roller (36) with an axis (46) and with annular projections (44), - the ring-shaped projections (44) are formed running around the axis (46) and are arranged in a row at a distance from each other along the axis (46) and - the individual leaves (4) guided over the first branch (30) are conveyed by means of the projections (44) of the rollers (36), which for this purpose extend through openings (42) in the guide plates (40) of the guide plate pair. [6] Method according to one of claims 1 to 5, wherein one of the two stacking wheels (28) has an axle (46) and several fingers (58) distributed around the axle (46) and wherein a single sheet (4) supplied to this stacking wheel (28) is guided into a space between two fingers (58) following one another in a direction of rotation (54). [7] Method according to any one of claims 1 to 6, wherein each of the stacking wheels (28) is assigned a stacking table (60) of the stacking wheel arrangement (12), on which individual sheets (4) are stacked to form cell stacks (6) with the respective stacking wheel (28), and wherein a common gripper (14) of the stacking device (2) is assigned to the stacking tables (60), with which finished stacked cell stacks (6) are removed from the stacking tables (60). [8] Method according to claim 7, wherein the finished stacked cell stacks (6) are turned over with the gripper (14). [9] Method according to claim 7 or 8, wherein the finished stacked cell stacks (6) are fed to a continuous furnace (16) by means of the gripper (14). [10] Stacking device (2) for the production of accumulators by a method according to one of the preceding claims.

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