WO2022214213A1

WO2022214213A1 - Method and device for producing an electrode stack

Info

Publication number: WO2022214213A1
Application number: PCT/EP2022/025089
Authority: WO
Inventors: Xaver Thum; Frank Neudel; Ralf Linck; Robert Reichel
Original assignee: Giesecke+Devrient Currency Technology Gmbh
Priority date: 2021-04-08
Filing date: 2022-03-08
Publication date: 2022-10-13
Also published as: DE102021001818A1

Abstract

The invention relates to a device for producing an electrode stack with flat electrode elements (1), comprising a stacking wheel (10) that can be rotated about a stacking wheel axis (A) and has a plurality of stacking wheel fingers (11) distributed over the circumference of the stacking wheel, a respective compartment being formed between each pair of stacking wheel fingers in order to receive an electrode element. The device additionally has an ejector (15) which is designed to eject the electrode elements received in the compartments of the stacking wheel out of the respective compartment when the stacking wheel rotates about the stacking wheel axis, wherein the electrode elements are deposited onto an electrode stack by the ejector. For at least one of the compartments of the stacking wheel, a roll pair (12, 13) is provided which has an inner roll (12) and an outer roll (13) that are arranged in the region of the respective compartment such that the rolls act on opposing surfaces of an electrode element received in the compartment in order to influence the movement of the electrode element along the compartment.

Description

Method and device for producing an electrode stack

The invention relates to a method and a device for producing an electrode stack with flat electrode elements.

The stacking of flat electrode elements is known. For example, flat electrode elements are usually stacked to produce electrochemical energy stores, such as lithium-ion batteries, or energy converters, such as fuel cells. Electrode elements are stacked, particularly in the manufacture of pouch cells, a common type of lithium-ion battery. The smallest unit of a lithium-ion cell usually consists of two electrode elements and a separator that separates the electrode elements from one another. Later, after filling, the ion-conductive electrolyte is located in between.

In addition to the other steps in the production of electrochemical energy stores or fuel cells, such as packaging or contacting, the stacking step in production represents a bottle neck for the production throughput. Known methods for stacking the electrode elements rely on a gripper arm of a robot, which grips and places the electrode elements. However, no significant increase in speed is to be expected here.

Other known methods rely on a rotating stacker wheel for stack formation, with which the electrode elements are placed on an electrode stack. WO 2020/212316 A1 describes a method for producing an electrode stack of anodes and cathodes for a lithium-ion battery of an electrically powered motor vehicle, in which the anodes and cathodes are conveyed into compartments of a rotating forklift wheel, and the anodes and cathodes accommodated in the compartments are conveyed to a stacking receptacle by means of the rotation of the stacker wheel. The object of the invention is to provide a method and a stacking device which allow the movement of the electrode elements in the stacker wheel to be influenced.

According to the invention, this object is achieved by a method and a device according to the independent claims. Advantageous embodiments of the invention are the subject of the dependent claims.

In the method according to the invention, an electrode stack with flat electrode elements, in particular an electrochemical energy store or an energy converter, is produced. The following steps are carried out:

- Introducing or transporting one electrode element into each compartment of at least one stacker wheel rotating about a stacker wheel axis, which has several stacker wheel fingers distributed over the circumference of the stacker wheel, between which a compartment for receiving an electrode element is formed, and

- Stripping the electrode elements accommodated in the compartments of the stacker wheel from the respective compartment of the stacker wheel while the stacker wheel rotates about its axis, the electrode elements being deposited on an electrode stack by stripping them out, which in particular is placed on a stack receiving base of a stack receptacle arranged under the stacker wheel rests or is put down.

The device according to the invention for producing the electrode stack has at least one stacker wheel which can be rotated about a stacker wheel axis and has a plurality of stacker wheel fingers distributed over the circumference of the stacker wheel, between which a compartment for receiving an electrode element is formed. In addition, the device has a scraper which is designed to to strip the electrode elements received in the compartments of the stacker wheel from the respective compartment when the stacker wheel rotates about its axis, the electrode elements being deposited on an electrode stack by the stripping. The device according to the invention may also have a stacking device which is designed to accommodate the electrode stack.

For at least one of the compartments of the stacker wheel there is (at least) one pair of rollers, which has an inner and an outer roller, which are arranged (e.g. in the area of the respective compartment) so that they lie on opposite surfaces of a compartment act on the received electrode element in order to influence the movement of the electrode element along the compartment. The effect occurs in particular at a point in time when the electrode element is at least partially introduced into the compartment, e.g. already when the electrode element is being transported into the compartment or only when the electrode element is stripped out of the compartment. In particular, the pair of rollers can influence the movement of the electrode element from the outside to the inside of the stacker wheel (when transporting it into the compartment) and/or the movement of the electrode element from the inside to the outside of the stacker wheel (for stripping it out of the compartment).

The inner and outer rollers of the respective pair of rollers are arranged in such a way that, as soon as an electrode element transported into the compartment is located between the inner and outer roller of the respective pair of rollers, they contact the relevant electrode element by friction.

The inner and outer rollers of the respective pair of rollers can be slightly spaced apart perpendicularly to the transport direction (the distance being less than the thickness of the electrode element) so that they do not touch one another. This can be beneficial to reduce wear on the rollers. Alternatively, the inner and an outer roller can be arranged in such a way that they touch one another, eg can roll on one another. In particular, the inner and outer rollers can touch one another in a contact area and, with this contact area, come into engagement with the electrode element introduced into the respective compartment. The inner and outer rollers of the respective pair of rollers can frictionally contact one another even when there is no electrode element between them. As a result, the rollers can also be driven by means of a drive wheel without an electrode element located in between, for example in order to set them in rotation before the electrode element arrives. In order to be able to avoid the thickness of the electrode element transported through between them, the inner and outer rollers can be designed to be correspondingly elastic, or the shaft on which they are fastened can be fastened in a correspondingly elastically displaceable or spring-loaded manner.

With regard to the electrode element located between them, the respective inner and outer rollers can be directly opposite one another. When the electrode element is brought into the compartment, both rollers come into engagement with the electrode element at the same time. Alternatively, the respective inner and outer rollers can also be arranged slightly offset from one another along the transport direction of the electrode element. A targeted offset of the two rollers along the transport direction can be used, for example,

- When threading the electrode element between the pair of rollers, it may be easier to thread in excess of the electrode element that is pre-bent in one direction, or

- When threading the electrode element between the pair of rollers to increase the braking effect by additional slight deflection of the electrode element, or

- When stripping the electrode element from the stacker wheel through the inner roller, an additional one. generate downward force on the electrode element, to support a faster laying down of the rear edge of the electrode element on the electrode stack.

The inner and outer rollers are arranged in such a way that the inner roller - in relation to the stacker wheel - is radially further inwards than the outer roller. The inner roller then acts on the radially inwardly facing surface of the respective electrode element and the outer roller on its radially outwardly facing surface. The inner roller and the outer roller act on the opposing surfaces of the respective electrode element. The outer and inner rollers of the respective pair of rollers are arranged along the respective compartment from the outside inwards, preferably at a position which corresponds to 20%-80% of the compartment length. This ensures that the electrode element can be influenced not only when it arrives in the compartment but also when it is located further inside the compartment.

Preferably, there is at least one pair of rollers for each compartment of the stacker wheel. Exactly one pair of rollers can be present for each compartment of the stacker wheel, but there can also be several pairs of rollers per compartment of the stacker wheel. These can be located at various positions along the shelf. However, two pairs of rollers can also be arranged in the same position along the respective compartment, but offset from one another along the stacker wheel axis (viewed in the direction of transport of the electrode element to the right and left of the stacker wheel), i.e. the stacker wheel is then located between the two pairs of rollers offset along the stacker wheel axis .

The outer and inner rollers of the respective pair of rollers that are available for the respective compartment are attached to the device in such a way that they rotate with the stacker wheel. For example, for this purpose they can be attached to the fingers of the stacker wheel delimiting the respective compartment. The inner roller is attached to that finger which faces the compartment on the axis of the stacking wheel Limited side, and the outer roller on that finger that limits the tray on the side facing away from the stack wheel axis. Alternatively, the outer and inner rollers available for the respective subject can also be fastened to a separate element (eg a wheel) which rotates with the stacker wheel and which, for example, is mounted on the shaft of the stacker wheel in an axially offset manner with respect to the stacker wheel.

The device can be designed to (actively) drive the inner and/or outer roller of the pair of rollers to rotate. In particular, the inner and/or outer roller of the pair of rollers can be driven to rotate directly, e.g. by means of appropriate motors, or they can be driven to rotate indirectly, using the rotational movement of the stacker wheel, in particular by means of a drive wheel arranged on the stacker wheel. The drive wheel can either be designed in such a way that it is rotatable (e.g. by means of a motor) or it can be designed in such a way that it is non-rotatable.

Alternatively, it can also be provided that the inner and outer roller of the pair of rollers are used to act on the electrode element accommodated in the compartment without being (actively) driven to rotate, ie without being driven to rotate by an element different from the electrode element to become. In this case, the inner and outer rollers of the pair of rollers are rotated at most by the friction of the electrode element transported through between them. For example, the inner and outer rollers can be mounted in such a way that they are free-running in order to merely guide the incoming electrode element during its movement and, if necessary, to brake it slightly. Alternatively, the inner and outer rollers of the pair of rollers can also be rotated against a resistance in order to brake the incoming electrode element more strongly. For this purpose, the rollers of the pair of rollers can be mounted, for example, by a plain bearing each. The device can be designed such that the movement of the electrode element entering the compartment, directed from the outside to the inside of the stacker wheel, is braked along the compartment by the engagement of the pair of rollers. The inner and/or outer rollers can be driven for this purpose, but they do not have to be driven for this purpose.

Alternatively or additionally, the device can be designed to drive the inner and/or outer roller in such a way that through the engagement of the pair of rollers, the movement of the electrode element (entering the compartment) directed from the outside inward of the stacker wheel continues through the engagement of the pair of rollers is guided (constantly, more slowly or possibly accelerated) in order to transport the electrode element entering the compartment further into the compartment (towards the inner end of the compartment) through the engagement of the pair of rollers.

Alternatively or additionally, the device can be designed to drive the inner and/or outer roller of the pair of rollers in such a way that the engagement of the pair of rollers causes or accelerates a movement of the electrode element accommodated in the compartment from the inside outwards of the stacker wheel to transport the electrode element accommodated in the compartment out of the compartment (towards the outer end of the compartment), in particular for stripping out of the stacker wheel.

The device is preferably designed to drive the inner and/or outer roller of the pair of rollers to rotate using the rotational movement of the stacker wheel. For this purpose, the device preferably has a drive wheel in the area of the stacker wheel, which is arranged in such a way that the driving of the inner/outer roller of the roller pair is achieved by a (direct or indirect) interaction of the inner/outer roller with the drive wheel, in particular using the rotational movement of the stacker wheel. The respective other non-driven outer/inner roller is then, for example, free-running. For example, the inner roller can directly interact with the drive wheel by rolling the inner roller of the pair of rollers on a smooth outer contour of the drive wheel.

The impeller may be circular or ring-shaped, such as in the form of a disk. The drive wheel can have a full circumference. This is particularly preferred in the case of a rotatable drive wheel. Even in the case of a non-rotatable drive wheel, the drive wheel can have a full circumference, but it does not have to have a full circumference; it is sufficient if the outer/inner contour of the drive wheel has at least one circle segment. The center point of the circular segment lies on the forklift wheel axle. A drive wheel is therefore also understood to be a drive element whose outer/inner contour has at least one circular segment on which the drive wheel interacts (directly or indirectly) with the inner/outer roller. The outer/inner contour of the drive wheel can be smooth or have teeth.

It is also possible to use a drive wheel which has two or more circular segments, the common center of which lies on the stacker wheel axis and which interact with the inner/outer roller of the pair of rollers one after the other as the stacker wheel rotates. The inner roller can, for example, roll on an outer contour of a segment of a circle or the outer roller on an inner contour of a (ring-shaped) segment of a circle. The circular segments are preferably arranged azimuthally offset from one another with respect to the rotation of the forklift wheel in such a way that at any time preferably only one of these circular segments interacts with the respective inner/outer roller of the respective pair of rollers in order to drive them. For example, the inner/outer roller can be driven by a first segment of a circle in such a way that an electrode element running into the stacker wheel moves in the direction of the interior of the compartment by the action of the roller pair is transported further (and possibly decelerated) and is driven by a second circular segment in the opposite direction in order to transport the same electrode element located in the compartment in the direction of the exterior of the compartment for stripping.

Indirect interaction of the inner/outer roller with the drive wheel can be achieved via an auxiliary element, e.g. an auxiliary wheel mechanically coupled (e.g. seated on the same shaft) to the inner/outer roller of the pair of rollers, the auxiliary wheel being driven directly by the drive wheel (e.g. rolls on the drive wheel) and drives the inner/outer roller of the pair of rollers via the common shaft. If the drive wheel is a drive gear, this can be done analogously via an auxiliary gear whose teeth mesh with the teeth of the drive gear to drive the auxiliary gear, the auxiliary gear being associated with the inner or outer roller of the roller pair is mechanically coupled (e.g. seated on the same shaft and this shaft is driven by the auxiliary gear).

For example, the drive wheel is offset along the forklift wheel axis to the respective forklift wheel, e.g. at such a small distance from the respective forklift wheel that it can interact directly with the inner/outer roller attached to the forklift wheel (compact arrangement).

The device preferably has at least two forklift wheels, which are offset from one another along the forklift wheel axis, preferably by at least 10 cm. For mutually corresponding (along the stacker wheel axis to each other offset) compartments of these stacker wheels is (at the corresponding Po position along the compartment) preferably in each case a separate pair of rollers available. These pairs of rollers, which are each assigned to the corresponding compartment of the various stacker wheels and are each arranged at the corresponding position along the compartment, are offset from one another along the stacker wheel axis, preferably by at least 10 cm. So that a torque the electrode elements influenced by the engagement of the pairs of rollers are avoided. The corresponding inner/outer rollers of the corresponding roller pairs can be mounted on a common shaft so that these inner/outer rollers all rotate in the same direction at the same speed and can be driven by a common drive wheel.

The drive wheel is preferably designed and/or arranged in such a way that it only interacts with the inner or outer roller of the pair of rollers in a limited angular section of the rotation of the stacker wheel, in particular in an angular section of no more than 270°, in particular no more than 180° of the rotation of the forklift wheel . This angular section overlaps (at least for the most part) with that angular section of the rotation of the stacker wheel in which the electrode elements are present in the stacker wheel. This ensures that the inner and outer rollers, which rotate due to the interaction with the drive wheel, are no longer driven after the end of the above-mentioned angular section of the action and can brake again through friction (in their bearing) in order to be able to move without or with reduced rotation speed to be available for the next electrode element. Braking takes place in the remaining azimuthal section (of at least 90° or at least 180°) (on 360° of the forklift wheel rotation). In order to ensure the driving of the inner/outer roller by means of the drive wheel over a large angular section, the inner/outer roller or the drive wheel can be suspended in a spring-loaded manner so that they can be displaced perpendicularly to their axis.

The interaction of the inner roller or the outer roller with the drive wheel allows the rotation of the inner and/or outer roller to be started or stopped in a targeted manner in a specific angular position of the truck wheel rotation. In addition, the rotation speed of the inner and/or the outer roller can be specifically varied through the interaction with the drive wheel.

In a variant of the drive wheel, the drive wheel is attached to the device in such a way that it can be rotated about an axis, in particular about the axis of the forklift wheel or about an axis that is offset from the axis of the forklift wheel. The drive wheel is designed as a ring gear, for example. The drive wheel can be connected to a drive motor, by means of which the drive wheel can be rotated about its axis, the rotation of the drive wheel being able to be controlled independently of the rotation of the forklift wheel. If the drive wheel has its own drive motor, its direction of rotation and its rotational speed can be freely adjusted, regardless of the rotation of the forklift wheel. A targeted speed profile for the rotation of the inner/outer roller of the pair of rollers can thus be set, with which the movement of the electrode element located between the inner and outer roller is influenced. This means that the running-in and/or stripping process of the respective electrode element can be actively supported and carried out in a defined manner.

In particular, the drive wheel is attached to the device in such a way that it can be rotated about an axis which is offset from the forklift wheel axis. The offset between the axis of the drive wheel and the axis of the forklift wheel is preferably selected in such a way that the outer/inner contour of the drive wheel (only) interacts with the inner/outer roller of the pair of rollers in the limited angular section of the rotation of the forklift wheel to drive them. The offset between the axis of the drive wheel and the stacker wheel axis and the diameter of the drive wheel are preferably so small that the drive wheel lies radially completely within the circumference of the stacker wheel. The axis of the drive wheel can be arranged, for example, below the stacker wheel axis and possibly laterally offset thereto, the lateral offset being such that the axis of the drive wheel, viewed in the transport direction of the electrode elements arriving at the stacker wheel, lies behind the stacker wheel axis. It is thus possible to influence the movement of the electrode elements received in the compartment, directed out of the compartment, for/during stripping out of the stacker wheel. Accordingly, the drive wheel is referred to as a stripping drive wheel.

Alternatively, the axis of the drive wheel can also be arranged above the stacker wheel axis and, if necessary, offset laterally thereto, the lateral offset being such that the axis of the drive wheel, viewed in the transport direction of the electrode elements arriving at the stacker wheel, lies behind the stacker wheel axis. In this way, the movement of the electrode elements entering the compartment can be influenced. Accordingly, the drive wheel is referred to as the inlet drive wheel. For example, the apparatus comprises at least two stripping drive wheels rotatable about a common axis and/or at least two infeed drive wheels rotatable about a common axis A' (different from the stripping drive wheels).

In another variant of the drive wheel, the drive wheel is fastened to the device in a non-rotatable manner, and it can be designed, for example, as a so-called sun wheel. The outer contour of the drive wheel is in particular formed in such a way that the drive wheel only interacts with the inner/outer roller of the pair of rollers in the limited angular section of the rotation of the forklift wheel in order to drive them. For example, the non-rotatable drive wheel is arranged with its center approximately on the forklift wheel axis and has an outer contour that is set back radially inward in that angle section in which no interaction should take place. However, the non-rotatable drive wheel can also have the shape of a circular segment, for example a semicircular segment.

The stacker wheel has (e.g. a disk-like) around the stacker wheel axis rotatable stacker wheel body, distributed over the circumference of which the stacker wheel fingers are arranged, the stacker wheel fingers being formed at the radial outer end of the stacker wheel body. The compartments of the forklift wheel are each delimited by two forklift wheel fingers. The stacker wheel fingers can be designed so that the pockets are arcuate, e.g., spiral, or have a straight shape, e.g., slot-like. The device preferably has two or more similar stacker wheels on the same axis of rotation, which are axially offset from one another and, for example, rotate synchronously with one another.

The scraper can be in one piece or in several pieces, e.g. engage like a rake between the forklift wheels so that it meshes with the forklift wheel(s). The stripper can be stationary or movable relative to the forklift wheel.

To produce the electrode stack, the electrode elements stripped out of the stacker wheel are placed on a stack receiving base of a stack receptacle, which is arranged horizontally or at an angle to the horizontal, in particular arranged at an angle such that the gravity of the electrode elements placed on the stack receiving base has a force component , which is directed in the direction of one of the rear walls of the stack receptacle, on which the front edges of the electrode elements of the electrode stack are aligned.

The invention also relates to a device for transporting and depositing the electrode elements, which has the device according to the invention for producing an electrode stack and at least one transport device for transporting electrode elements one after the other to the forklift wheel of the device and for introducing one of the electrode elements into one of the compartments of the forklift wheel, and if necessary a stacking floor, which is arranged and designed under the forklift wheel in such a way that the from the forklift wheel Stiffened electrode elements can be placed on the stack receiving floor. Two or more than two transport devices can also be used per stacking device, which are connected to the stacker wheel of the stacking device at different angular positions, e.g. to feed cathodes and anodes separately to the same stacker wheel, with the compartments of the stacker wheel alternating between the ver various transport facilities land transported electrode elements (eg cathodes and anodes).

The preferred embodiments presented with reference to the method according to the invention and their advantages apply correspondingly to the stacking device according to the invention and vice versa. Further features of the invention emerge from the claims, the figures and the description of the figures.

Embodiments of the invention are explained in more detail with reference to a schematic drawing. show:

Fig. 1 A first embodiment with a non-rotatable to drive wheel in 3D view (Fig. La) and in side view (Fig. Lb),

Fig. 2 A second embodiment with a rotatable drive wheel for the running-in process of the electrode elements and with a rotatable drive wheel for the stripping process of the electrode elements in a 3D view (Fig. 2a) and in a top view (Fig. 2b) as well as in a sectional view along the lines AA (Fig. 2c) and along lines BB (Fig. 2d) in Figure 2b. Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 and 2 each show an exemplary embodiment of a device for transporting and depositing electrode elements with a stacking device which is designed to produce an electrode stack which contains flat electrode elements (and possibly other elements). The electrode elements are, for example, cathodes, based, for example, on aluminum foil, and/or anodes, based, for example, on copper foil, or a combination of both. During the stacking process, e.g. anode, separator, cathode, separator, etc. are stacked in a repeating cycle. The electrode elements can also be battery cells or fuel cells.

A plurality of electrode elements 1 are transported individually one after the other by means of a transport device to the stacking device (transport direction T). The transport device can be formed by belts 20 running around rollers, between which the electrode elements are guided. Alternatively, pairs of rollers can be used to transport the elec- trode elements forward, between which the elec- trode elements are guided. A guide plate 22 can be used to insert the electrode elements into the respective compartment.

The stacking device has in both embodiments two to a common stacker wheel axis A rotatable stacker wheels 10, each distributed over the circumference of the stacker wheel having a plurality of stacker wheel fingers 11, between which rule a compartment for receiving an electrode element 1 is formed. The stacker wheels 10 are rotated about their axis A in the direction of rotation R by means of a motor 14 (cf. FIG. 2b) in such a way that, by means of the transport device, one electrode element is inserted into one compartment of the respective stacker wheel 10. to be led. The electrode element 1 accommodated in the respective compartment is stripped out of the stacker wheel 10 by a stripper 15 in order to deposit it on a stack receiving base 30 . In order to reduce the height of fall of the stripped electrode elements after stripping, the stack receiving base 30 can be guided away downwards during the stack production.

The stacker wheel fingers 11 and compartments here run spirally around the axis of rotation A, but can alternatively also be straight, e.g. radial, and possibly have a larger compartment width than shown, so that the electrode elements are not bent too much by the shape of the compartment . The stacker wheel fingers are shown relatively thin in the figures, but they can also have a much greater azimuthal width.

In both exemplary embodiments, two identical forklift wheels 10 are attached to a common axle shaft and are offset from one another along the forklift wheel axis A, but there can also be more than two. A pair of rollers, which is formed by an inner roller 12 and an outer roller 13, is arranged on each compartment of the stacker wheel 10, see FIGS. The pairs of rollers are attached to the respective forklift wheel 10 so that they rotate with the forklift wheel 10 . The inner and outer rollers 12, 13 touch one another in a contact area K, see FIG. For example, the two rollers 12, 13 have an elastomer on their surface. The compartments of the stacker wheel have a taper 19 immediately in front of the pair of rollers 12, 13, so that the front edge of the electrode element 1 easily enters the contact area K of the pair of rollers, cf.

Fig. lb. If necessary, several pairs of rollers per compartment can be used, which are arranged at different positions along the compartment.

In the first exemplary embodiment from FIG so-called sun gear is formed. The drive wheel 16 is stationary and not rotatable. The drive wheel 16 is not continuously circular, but has a circular segment that is set back radially and does not act on the inner roller 12 . The drive wheel 12 acts on the inner roller 12 only in the preceding circle segment. When the stacker wheel 10 rotates about its axis A, the inner rollers 12 come men only in the limited angular portion of the stacker wheel rotation into engagement with the drive wheel 16 in which the vorste existing circular segment of the drive wheel 16 is located. This limited Winkelab section is denoted by W in Fig. lb and includes about 160 ° of the stacker wheel rotation. Due to the friction of the inner roller 12 on the stationary drive wheel 16, the inner roller 12 is set in rotation (here clockwise). It therefore rolls on the outer contour of the drive wheel 16 . Since the inner roller 12 and the outer roller 13 are in frictional contact, this also causes the outer roller 13 to rotate (in this case counterclockwise). The electrode element 1 inserted into the respective compartment comes into contact with the pair of rollers 12, 13 in the contact area K.

If the electrode element 1 by the transport device with a - is introduced significantly increased Ge speed - compared to the rotational speed of the stacker wheel 10, the electrode element 1 is slowed down by the engagement of the rotating pair of rollers 12, 13. Braking allows damage to the electrode elements, which would possibly occur if they hit the inner compartment end of the forklift wheel, to be avoided. Since the limited angular section in which the inner roller 12 is driven is relatively large, the pair of rollers not only acts on the electrode elements 1 in the entry area of the electrode elements 1, but also afterwards, until shortly before reaching the stripper 15. The engagement of the The pair of rollers therefore also causes the movement of the electrode elements to continue in the direction of the inner end of the compartment. With approximately comparable inlet speed of the electrode elements compared to the rotational speed of the stacker wheel rotation is by the Effect of the pair of rollers, if necessary, no braking of the incoming electrode elements achieved, but only a continuation of the movement of the incoming electrode elements.

In the area of the scraper 15, the drive wheel 16 is set back radially inwards, so that it no longer acts on the respective inner roller 12. Each respective pair of rollers 12, 13 is in the angular section in which the element 1 ELEMENT meets the stripper 15, free of drive. In this way, the stripper can strip the electrode element 1 out of the respective compartment without resistance.

Depending on the angle at which the set back or the projecting circle segment begins and ends, it can be adjusted when the pair of rollers 12, 13 influence the movement of the respective electrode element 1 within the compartment. The angle is selected depending on the properties of the electrode elements and/or depending on the transport speed of the electrode elements that they have when entering the stacker wheel.

In the first embodiment, the inner roller 12 is set in rotation by means of friction on the outer contour of the drive wheel 16 when the stacking wheel moves around the drive wheel. Alternatively, the surface of the drive wheel can also have a toothing in which a corresponding toothing of an auxiliary gear wheel co-rotating on the shaft of the inner roller 12 engages in a form-fitting manner.

As an alternative to the first exemplary embodiment, the outer roller 13 of the pair of rollers or an auxiliary roller co-rotating on the shaft of the outer roller 13 could also be driven by a circular segment-shaped inner contour of an annular, non-rotierba ren drive wheel when the forklift wheel moves around this be. This could be used, for example, for the grazing movement of the electrode elements. In the second exemplary embodiment from Fig. 2a-d, the inner roller 12 of the respective pair of rollers comes into contact with two different drive wheels 17 and 18, which can be rotated about different axes A', which are each offset from axis A of the stacker wheel 10 are arranged, cf. Fig. 2c, d. The drive wheels 17, 18 are ring-shaped or designed as a so-called ring gear. The ring gears 17, 18 have, for example, a toothing on the inside, which on the one hand serves as a bearing for the ring gear and on the other hand is used for driving by a drive motor 25, see FIG.

The drive wheels 17, 18 are stationary and can be rotated about the respective axis A'. Due to its offset axis A', the respective inner roller 12 comes into engagement with the outer contour of the respective drive wheel 17 or 18 only in the limited angular section of the truck wheel rotation, see the two angular sections W in Figures 2c and 2d. In the case of the drive wheel 18 from FIG. 2c and the drive wheel 17 from FIG. 2d, this limited angular section comprises approximately 90° of the rotation of the forklift wheel, but can also comprise a larger or smaller angle. The drive wheel 18 from FIG. 2c is arranged in the lower area of the stacker wheel 10 and serves to support the process of stripping the electrode elements 1 out of the stacker wheel 10. It is also called stripping drive wheel 18 in the following. The drive wheel 17 from FIG. 2d is arranged in the upper area of the stacker wheel 10 and serves to support the running-in process of the electrode elements 1 into the stacker wheel 10. It is also called the run-in drive wheel 17 in the following.

If the infeed drive wheel 17 is not rotated, it acts similarly to the non-rotatable drive wheel 16 of the first exemplary embodiment: the inner roller 12 rubbing against the infeed drive wheel 17 causes the inner roller 12 to rotate (clockwise). It rolls on the outer contour of the infeed drive wheel 17 . When the inner roller 12 and the freewheeling outer Touching roller 13 by friction means that the outer roller 13 can also be rotated (counterclockwise). The electrode element 1 introduced into the compartment is braked by the engagement of the pair of rollers 12, 13 (at a high infeed speed) and/or transported further along the compartment.

However, the infeed drive wheel 17 can be rotated about its axis A' if required. This makes it possible to control the movement of the electrode element along the compartment. Depending on the direction of rotation and rotational speed of the infeed drive wheel 17, the electrode elements 1 can be slowed down, accelerated or transported further.

The inlet drive wheel 17 is preferably rotated in the same direction of rotation R (clockwise) as the stacker wheel 10. If the angular speed of the inlet drive wheel 17 is selected to be significantly lower than that of the stacker wheel 10, the result is that the roller 12 with a - in Compared to the case of the non-rotating inlet drive wheel 17 - rotated at a lower rotational speed (roller 12 clockwise). This results in a slower further movement of the respective electrode element 1 in the direction of the interior of the compartment than in the case of the non-rotating infeed drive wheel 17. In the case of a significantly greater angular speed of the infeed drive wheel 17 compared to the stacker wheel 10, the direction of rotation of the roller 12 vice versa (counterclockwise roller 12), so that it exerts a force on the electrode elements 1, which is directed towards the outside of the compartment. This can be used to strongly decelerate the electrode elements 1 entering the compartment.

On the other hand, if the inlet drive wheel 17 rotates opposite to the direction of rotation R like the stacker wheel 10, ie counterclockwise here, a greater rotational speed of the roller 12 is achieved, and thus a - compared to the case of the non-rotated inlet drive wheel 17 faster further movement of the respective electrode element 1 in the direction of the interior of the compartment.

The stripping drive wheel 18 only acts on the rollers 12 in the lower area of the stacker wheel, just before they reach the stripper 15 during their rotation. Preferably, the stripping drive wheel 18 is rotated about its axis A', in the same direction of rotation R (clockwise) as the stacker wheel 10, preferably at a significantly greater angular velocity than the stacker wheel 10. The direction of rotation of the roller 12 is thus reversed (counterclockwise) so that it exerts a force on the electrode elements 1, which is directed towards the outside of the compartment. The electrode element 1 located in the respective compartment is moved in the direction of the outside of the compartment by the engagement of the pair of rollers 12, 13 even before the stripper 15 is reached. This supports the stripping process and/or prevents the electric elements 1 from hitting the stripper 15 too hard.

In the second embodiment, the device for each of the two Stap lerräder 10 each have a stripping drive wheel 18 and an inlet drive wheel 17.

In other exemplary embodiments, the device has on each of the two stacker wheels 10 only one infeed drive wheel 17, but no stripping drive wheel 18 or vice versa, only one stripping drive wheel 18, but no infeed to drive wheel 17. In addition to those with pairs of rollers and Stacker wheels equipped with drive wheel/wheels, additional stacker wheels 10 can also be mounted on the same axle shaft and used for stacking the electrode elements, but they are not equipped with pairs of rollers and for which there is also no drive wheel.

Claims

patent claims

1. A method for producing an electrode stack, comprising the steps:

- Insertion of one electrode element (1) in each case, at least one forklift wheel (10) rotating about a forklift wheel axis (A), which has several forklift wheel fingers (11) distributed over the circumference of the forklift wheel, between which the compartment for receiving an elec roden elements is formed,

- Stripping the electrode elements accommodated in the compartments of the stacker wheel from the respective compartment of the stacker wheel while the stacker wheel rotates about its stacker wheel axis (A), the electrode elements being placed on an electrode stack by the stripping, characterized in that for at least one of the Compartments of the stacker wheel have a pair of rollers comprising an inner roller (12) and an outer roller (13) arranged to act on opposite faces of an electrode element (1) received in the compartment to prevent movement of the electrode element along the compartment.

2. The method as claimed in claim 1, characterized in that the inner and outer rollers of the pair of rollers (12, 13) are used to act on the electrode element (1) accommodated in the compartment without being driven for rotation.

3. The method according to claim 1, characterized in that the inner and/or the outer roller of the pair of rollers are driven, preferably indirectly, in particular using the rotational movement of the stacker wheel, for example with the aid of a drive wheel (16, 17, 18) .

4. Device for producing an electrode stack, with - at least one forklift wheel (10) rotatable about a forklift wheel axis, which has several forklift wheel fingers (11) distributed over the circumference of the forklift wheel, between which a compartment for receiving an electrode element (1) inserted in the compartment is formed, and

- a stripper (15), which is designed to strip the electrode elements received in the compartments of the stacker wheel from the respective compartment when the stacker wheel rotates about its stacker wheel axis (A), the electrode elements being deposited on an electrode stack by the stripping, characterized in that the device comprises, for at least one of the compartments of the stacker wheel, a pair of rollers comprising an inner roller (12) and an outer roller (13) arranged to lie on opposite surfaces of a in the compartment accommodated electrode element (1) can act to influence the movement of the electrode element along the compartment.

5. Apparatus according to claim 4, characterized in that the outer and inner rollers of the respective pair of rollers (12, 13) provided for the respective compartment are arranged at a position along the respective compartment from the outside inwards which is 20% - corresponds to 80% of the compartment length.

6. Device according to one of claims 4 to 5, characterized in that the device is designed to drive the inner and/or outer roller of the pair of rollers (12, 13), preferably indirectly, to rotate, in particular using the rotational movement of the forklift wheel (10).

7. Device according to one of claims 4 to 6, characterized in that the device in the region of the stacker wheel has a drive wheel (16, 17, 18) which is arranged such that driving the inner roller (12) / outer Role of the pair of rollers is achieved by interaction of the inner roller (12)/external roller (13) with the drive wheel (16, 17, 18), in particular using the rotational movement of the stacker wheel.

8. The device according to claim 7, characterized in that the drive wheel (16, 17, 18) is constructed and/or arranged in such a way that it interacts only in a limited angular section (W) of the rotation of the stacker wheel (10). the inner/outer roller of the pair of rollers occurs, in particular in an angular section of at most 270° of the forklift wheel rotation.

9. Device according to one of claims 7 to 8, characterized in that the drive wheel (17, 18) is attached to the device in such a way that it is rotatable about an axis, in particular about the stacker wheel axis (A) or about a ver the forklift wheel axis lying axis (A '), wherein the drive wheel preference, is designed as a ring gear.

10. Device according to one of claims 7 to 9, characterized in that the drive wheel (17, 18) is attached to the device in such a way that it is rotatable about an axis (A') which is offset from the stacker wheel axis (A). is, the offset between the axis (A') of the drive wheel (17) and the stacker wheel axis (A) being selected in particular in such a way that the outer/inner contour of the drive wheel in the limited angular section (W) of the rotation of the stacker wheel in Interacts with the inner/outer roller of the pair of rollers (12, 13) to drive them.

11. The device according to claim 10, characterized in that the axis (A') of the drive wheel (18) is arranged below the forklift wheel axis (A) and is optionally arranged laterally offset thereto, the lateral offset being such that the axis of the drive wheel, viewed in the transport direction (T) of the electrode elements arriving at the stacker wheel, is behind the stacker wheel axis (A).

12. The device according to claim 10, characterized in that the axis (A') of the drive wheel (17) is arranged above the forklift wheel axis (A) and is optionally arranged laterally offset thereto, the lateral offset being such that the axis of the drive wheel, viewed in the transport direction (T) of the electrode elements arriving at the stacker wheel, is behind the stacker wheel axis (A).

13. Device according to one of claims 7 to 8, characterized in that the drive wheel (16) is non-rotatably attached to the device, the outer / inner contour of the drive wheel being shaped in particular such that the drive wheel only in the limited angular section (W) of the rotation of the truck wheel interacts with the inner/outer roller of the pair of rollers (12, 13) to drive them.

14. Device according to one of claims 4 to 5, characterized in that the device is designed to use the inner and/or outer roller (12, 13) of the pair of rollers to act on the electrode element (1) received in the compartment , without driving them to rotate.

15. Device for transporting and storing electrode elements, marked by

- a device for producing an electrode stack according to any one of claims 4 to 14, and

- at least one transport device (20) for transporting electrode elements (1) one after the other to the stacker wheel (10) of the device and for introducing one of the electrode elements into one of the compartments of the stacker wheel (10).