Abstract
A method is proposed for manufacturing dry electrodes on a current collector with the aid of a roller system. The roller system includes at least three rollers and the current collector. A first roller and a second roller are rotated in opposite rotational directions. Powder is poured into a calender gap formed by the first rotating roller and the second rotating roller, the powder being carried on the second roller. A signal is triggered with the aid of a control unit for setting a laminating gap between the second roller and the third roller, the third roller and/or the first roller and the second roller moving toward each other in the direction of the current collector. At least the third roller is rotated in the opposite direction of the second roller. The current collector is moved through the laminating gap.
Claims
1. A method for manufacturing dry electrodes on a current collector with the aid of a roller system, the roller system comprising at least three rollers, the current collector is arranged between a second roller of the at least three rollers and a third roller of the at least three rollers, the method comprising: rotating a first roller of the at least three rollers and the second roller in opposite rotational directions; pouring powder into a calender gap formed by the first rotating roller and the second rotating roller, the powder being carried on the second roller; triggering a signal with the aid of a control unit for setting a laminating gap between the second roller and the third roller, the third roller and/or the first roller and the second roller moving toward each other in a direction of the current collector; rotating at least the third roller of the at least three rollers in the opposite direction of the second roller; and moving the current collector through the laminating gap, the laminating gap being set such that the powder is applied as a thin layer to the current collector for forming the dry electrodes.
2. The method according to claim 1, wherein the method further comprises: ascertaining a thickness of the powder that has become a thin layer on the second roller; and triggering the signal with the aid of the control unit, based on the ascertained thickness.
3. The method according to claim 1, wherein the method further comprises: removing the powder carried on the second roller, in particular the powder which has become a defective thin layer, via a removal device, which is arranged downstream from the laminating gap in the rotational direction.
4. The method according to claim 1, wherein the rotational speed of the first roller, the second roller, the third roller, and/or the pass-through speed of the current collector is/are controlled with the aid of the control unit based on the ascertained thickness of the powder which has become a thin layer.
5. The method according to claim 1, wherein the powder is collected and/or sucked off by the removal device during the removal of the powder carried on the second roller, in particular the powder which has become a defective thin layer.
6. The method according to claim 1, wherein the signal for setting a laminating gap between the second roller and the third roller is triggered after a predetermined time.
7. The method according to claim 1, wherein the method further comprises: ascertaining a powder quantity which has been poured into the calender gap; ascertaining a completed rotation of the second roller; and/or triggering the signal with the aid of the control unit based on the ascertained powder quantity and/or the ascertained completed rotation of the second roller.
8. A roller system for manufacturing dry electrodes on a current collector, the roller system comprising: a control unit; at least three rollers; a current collector arranged in a laminating gap, which is designed to collect powder which has become a thin layer, the laminating gap defining a distance between a first roller of the at least three rollers and a second roller of the at least three rollers; a pouring device to pour powder into the calender gap, the calender gap defining a distance between a first roller and the second roller; and a removal device to remove the powder carried on the second roller, the removal device being arranged downstream from the laminating gap in the rotational direction, wherein the control unit is configured to trigger a signal for setting a laminating gap, in particular a thickness of the laminating gap.
9. The roller system according to claim 8, further comprising a layer thickness sensor, which is configured to ascertain the thickness of the powder which has become a thin layer on the second roller upstream from the laminating gap in the rotational direction.
10. A dry electrode, which is manufactured according to the method according to claim 1.
11. A computer program product, comprising commands, which, when executed, prompt a control unit of a roller system to carry out the method according to claim 1.
12. A computer-readable medium, on which the computer program product according to claim 11 is stored.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
[0055] FIG. 1 schematically shows a side view of a roller system according to an example;
[0056] FIG. 2 schematically shows a top view of a roller system according to an example;
[0057] FIG. 3 schematically shows a side view of a roller system according to an example;
[0058] FIG. 4 schematically shows a side view of a roller system according to an example;
[0059] FIGS. 5 and 6 schematically show a roller of a roller system according an example; and
[0060] FIGS. 7 through 9 schematically show side views of roller systems according to examples.
DETAILED DESCRIPTION
[0061] FIG. 1 schematically shows a side view of a roller system 100 according to an example. A roller system 100 of this type may be used to carry out a method for manufacturing dry electrodes 10 on a current collector 12. Roller system 100 in FIG. 1 includes four rollers. A gap is provided between first roller 13 and second roller 14, which is referred to as calender gap 20. First roller 13 may be referred to as an application roller. The gap between third roller 15 and fourth roller 16 is also referred to as calender gap 20. A contact pressure roller unit of this type may include one or more rollers. A gap is also provided between second roller 14 and third roller 15, which, however, is referred to as laminating gap 18. A current collector 12 is arranged in laminating gap 18. Second roller 14 and third roller 15 may be part of a contact pressure roller unit. Second roller 14 and third roller 15 may therefore be referred to as contact pressure rollers. Laminating gap 18, which may also be referred to as a contact pressure gap, may be designed to transfer powder 11 which has become a thin layer from a roller of the contact pressure roller unit, i.e., from second roller 14 and/or from third roller 15, to one side and possible to two sides of current collector 12 with the aid of a contact force. For the sake of completeness, it is noted that the rollers a provided with a cylindrical design and are preferably arranged in parallel to each other with regard to their axial axes.
[0062] Roller system 100 in FIG. 1 is essentially formed symmetrically around current collector 12. This means that powder 11 which has become the thin layer may be applied to both sides of current collector 12. It should be noted that elements and/or components described in reference to one side of current collector 12 of roller system 100 in FIG. 1 may also be situated mirror-symmetrically on the other side of current collector 12 of roller system 100 in FIG. 1. The efficiency of dry electrode 10 may be improved by the application of the thin layer to both sides of current collector 12. Manufactured dry electrode 10 is made up of the thin layer and current collector 12. One may speak of a one-sided dry electrode 10 or a two-sided dry electrode 10, depending on whether the thin layer is applied to both sides of current collector 12. Asymmetrical examples are also conceivable (cf. FIG. 7).
[0063] In roller system 100 in FIG. 1, two rollers, first roller 13 and second roller 14, are arranged on a first side of current collector 12 or on the left side of current collector 12. A pouring device 26, which is designed to pour powder 11, may be arranged at least partially in the two calender gaps 20 of roller system 100. Pouring device 26 may be referred to as a dosing unit. Removal devices 22 may also be provided on one of the two sides of current collector 12 in each case. The two rollers arranged the closest to current collector 12 may be provided with a removal device 22 of this type. Removal device 22 may include a scraper 23 and a collecting device 24.
[0064] First roller 13 and second roller 14 are configured to rotate in opposite rotational directions. Powder 11 may be poured into calender gap 20 between first roller 13 and second roller 14 with the aid of a pouring device 26. Powder 11 is then carried on second roller 14.
[0065] Roller system 100 in FIG. 1 is in operation, in particular, in started mode. This may be apparent from FIG. 1, since laminating gap 18 is set in such a way that powder 11 poured into particular calender gaps 20 becomes a thin layer and is applied as a thin layer to current collector 12 for the purpose of forming a dry electrode 10. This means that laminating gap 18 is small enough to permit powder 11 which has become a thin layer to be applied to current collector 12.
[0066] FIG. 2 schematically shows a top view of a roller system 100 according to an example. Roller system 100 in FIG. 2 may be, for example, roller system 100 in FIG. 1. Unless otherwise described, roller system 100 in FIG. 2 includes the same elements and features as roller system 100 in FIG. 1. The two thin layers, which are each applied to second roller 14 and to third roller 15, are then applied to current collector 12. To be able to set a predetermined width of dry electrode 10, at least one marginal edge section 30 is provided, preferably two marginal edge sections 30 for each roller. Marginal edge section 30 may precisely define or truncate the edge or margin of dry electrode 10. The width of electrode(s) 10 may be set with the aid of marginal edge section 30. A removal unit 28 is preferably arranged directly next to marginal edge section 30 to remove material or powder 11 extending beyond the edge or powder 11 which has become a layer. Removal unit 28 may remove or collect the material. Removal unit 28 may include a collecting container. In addition, removal unit 28 may include a scraper 23, with the aid of which the corresponding roller may be cleaned.
[0067] Powder 11 supplied to second roller 14 and to third roller 15 forms a thin layer. Once the thin layer has been applied to current collector 12, the thin layer may be referred to as dry electrode 10. To be able to manufacture a functioning dry electrode 10, the thin layer must be formed as homogeneously as possible. The thin layer must be formed free of defects or free of flaws. Cracks, holes, and/or fractures in the layer may be viewed, for example, as defects. The thin layer also preferably has a predefined minimum layer thickness. The thin layer or dry electrode 10 in FIG. 2 does not have any defects. It may be inferred therefrom that roller system 100 in FIG. 2 is also in operation, in particular, in started mode. After all, roller system 100 according to the invention is configured to be able to collect powder 11 which has become a thin layer with the aid of current collector 12 only in a started mode.
[0068] FIG. 3 schematically shows a side view of a roller system 100 according to an example. Unless otherwise described, roller system 100 in FIG. 3 includes the same elements and features as roller system 100 in FIGS. 1 and 2.
[0069] In contrast to roller systems 100 in FIGS. 1 and 2, roller system 100 in FIG. 3 is in a starting mode, i.e., not yet in the started mode. The gap, namely laminating gap 18, between second roller 14 and third roller 15 is larger in starting mode than in started mode. Laminating gap 18 of roller system 100 in FIG. 3 is set in such a way that powder 11 and/or powder 11 which has partially become a thin layer, may not be applied to current collector 12. In starting mode, it may therefore prove to be advantageous, for example to save energy, to not move current collector 12 through laminating gap 18.
[0070] Clumps 19 or particles of powder 11 are shown on second roller 14 and on third roller 15 of roller system 100 in FIG. 3. Clumps 19 may form a defective layer. Powder 11 poured into calender gap 20 has not yet become a thin layer in starting mode. Instead, the thin layer only just begins to form, which results in the creation of clumps 19 or particles of powder 11. Powder 11 has only partially become a thin layer in starting mode. In other words, the quality of the thin layer is not yet sufficient to turn it into a dry electrode 10. It is therefore advantageous to remove clumps 19 or particles of powder 11. This is implemented with the aid of a removal device 22. Removal device 22 may be configured to remove powder 11 on second and/or on third roller 15, preferably downstream from laminating gap 18 in the rotational direction. It may also be provided that removal device 22 cleans the corresponding roller during the removal of powder 11 or clumps 19. Removal device 22 may include a scraper 23 for this purpose. Removal device 22 preferably includes a collecting device 24 to remove the material, i.e. powder 11 and/or clumps 19, from the corresponding roller. Collecting device 24 may mechanically collect the material and/or suck off the material.
[0071] Roller system 100 in FIG. 3 also includes a layer thickness sensor 17. Layer thickness sensor 17 is preferably situated upstream from laminating gap 18 in the rotational direction. It is also conceivable that a further layer thickness sensor 17 is arranged on third roller 15 of roller system 100 in FIG. 3. After all, powder 11 which has become the thin layer is also carried on third roller 15.
[0072] The thickness of powder 11 which has at least partially become the thin layer may be ascertained or measured with the aid of layer thickness sensor 17. If the thickness of powder 11 and/or powder 11 which has at least partially become the thin layer is ascertained, it may be decided, or a control unit may decide, whether the ascertained thickness meets a predefined criterion. If the ascertained thickness meets the predefined criterion, the control unit may trigger a signal for setting laminating gap 18. During the setting of laminating gap 18, third roller 15, in particular together with fourth roller 16 and/or first roller 13 and second roller 14, may be moved toward each other in the direction of current collector 12.
[0073] FIG. 4 schematically shows a side view of a roller system 100 according to an example. Unless otherwise described, roller system 100 in FIG. 4 includes the same elements and features as roller system 100 in FIGS. 1 through 3.
[0074] It is apparent in FIG. 4 that a dry electrode 10, or a thin layer, has not been applied to current collector 12. It may thus be recognized thereby that roller system 100 in FIG. 4 is still in starting mode. However, in contrast to FIG. 3, powder 11 carried on second roller 14 and on third roller 15 forms a homogeneous thin layer. In other words, roller system 100 was operated in starting mode long enough and thus ready to transition into started mode. The control unit of roller system 100 may therefore trigger a signal to set laminating gap 18 in such a way that powder 11 which has become the thin layer may now be applied to current collector 12. To set laminating gap 18, the rollers may be moved in pairs, i.e., first and second roller 14 together and/or third and fourth roller 16 together, toward current collector 12 in the radial direction. A movement of the rollers in pairs makes it possible to keep particular calender gap 20 constant. In an asymmetrical example of roller system 100, it is conceivable that, for example, only the two rollers on one side of current collector 12 are moved in the direction of current collector 12. The corresponding rollers are moved radially in the direction of current collector 12 until powder 11 which has become the thin layer may be applied to current collector 12. The radial movement or radial movements are illustrated with the aid of arrows in FIG. 4.
[0075] FIGS. 5 and 6 schematically show a roller of a roller system 100 according to an example. The rollers illustrated in FIGS. 5 and 6 may be third roller 15. If the rollers in FIGS. 5 and 6 are viewed in a mirror-inverted manner, they may also be second roller 14 of a roller system 100.
[0076] As described with reference to FIGS. 1 through 4, a removal device 22 may be arranged on second roller 14 and alternatively also on third roller 15. Removal device 22 may be used to remove material on the corresponding roller, on the one hand, and to clean the corresponding roller, on the other hand. Removal device 22 may include a brush 25 to clean the corresponding roller. Brush 25 may be a rotating brush. A cleaning device 34 may furthermore be provided downstream from removal device 22 in the rotational direction of the roller. Cleaning device 34 may clean the surface of the roller in addition to removal device 22. Cleaning device 34 may include one or multiple cleaning rollers 38, which are configured to apply a fibrous material or a non-woven fabric to the surface of the corresponding roller or to press it onto the rollers. A greater cleaning effect may be achieved thereby. The fibrous material may be wound off from one spool 33 to another spool 33 via cleaning roller 38 and be subsequently wound on again. In the example in FIG. 6, it may furthermore be provided that a cleaning agent is applied to the fibrous material and/or to the surface of the corresponding roller. In the example in FIG. 5, the cleaning of the roller may be carried out in a dry manner.
[0077] FIGS. 7 through 9 schematically show side views of roller systems 100 according to further examples. Unless otherwise described, roller system 100 in FIGS. 7 through 9 includes the same elements and features as roller system 100 in FIGS. 1 through 4.
[0078] In principle, any configuration of rollers may be conceivable which makes it possible to apply a thin layer to one or to both sides of current collector 12. It is also conceivable to manufacture a dry electrode 10 which is only one-sided. In this case, roller system 100 may include only three rollers. For example, only the lower three rollers of roller system 100 in FIG. 7 may be provided. In FIG. 9, four rollers may also be provided for transferring the thin layer to current collector 12. In other words, it is conceivable that a contact pressure roller unit is provided, which includes for contact pressure rollers. Powder 11, which is pressed on evenly, is therefore carried on two second rollers 14, 14 and also on two third rollers 15, 15 in the example in FIG. 9.
[0079] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
