Laminating device for laminating multiple layers of continuous webs for producing energy cells

Abstract

The invention relates to a laminating device for producing a multilayer continuous web (3) for an energy cell, consisting of at least one separating web (4, 6) and at least one electrode, comprising a pressing device which laminates the multilayer continuous web (3) by means of a pressing surface under pressure. The pressing surface has a plurality of sections with different elastic rigidities.

Description

Technical Field

[0001] The invention relates to a laminating device for laminating multilayer continuous webs for producing energy cells having the features of the preamble of claim 1 . Background Art

[0002] Energy cells or energy storage devices within the meaning of the present invention are used, for example, in motor vehicles, other land vehicles, ships, aircraft or in stationary installations such as photovoltaic installations in the form of battery cells or fuel cells, where very large amounts of energy must be stored over relatively long periods of time.

[0003] For this purpose, such an energy cell may have a structure consisting of a large number of stacked segments. These segments are respectively formed by alternating anode sheets and cathode sheets, which are separated from each other by separator sheets that are also manufactured as segments. These segments are pre-cut in the manufacturing process and are then stacked in a predetermined order for stacking and connected to each other by lamination. Here, the anode sheets and cathode sheets are first cut out from the continuous web and then placed in a dispersed manner and spaced apart on the corresponding continuous web of the separator material. Then, in a second step, the subsequently formed "double-layer" continuous web made of the separator material with the placed anode sheets or cathode sheets is cut into segments again using a cutting device, wherein, in this case, these segments are formed in a double layer by the separator sheet together with the anode sheets or cathode sheets arranged thereon. As long as this is feasible or necessary in terms of production technology, the continuous web of separator material with the anode and cathode sheets placed thereon can also be stacked before cutting, so as to form a continuous web having a separator material with a first continuous layer of anode sheets or cathode sheets placed thereon and a separator material with a second continuous layer of anode sheets or cathode sheets placed thereon. Then, this "four-layer" continuous web is cut into sections with the help of a cutting device, and the sections are formed in the form of four layers with a first separator, an anode sheet, a second separator and a cathode sheet attached thereto. The advantage of this solution is that one cutting can be saved. In addition, the cut electrodes can also be placed on a continuous separating web and stacked into a three-layer continuous web through another continuous separating web, and then a three-layer section with a separator, an electrode sheet and another separator is cut therefrom. Therefore, the section in the sense of the present invention is a single-layer section of separator material, anode material or cathode material, or also a double-layer, three-layer or four-layer section of the above structure.

[0004] Furthermore, the above-mentioned “two-layer” or “four-layer” continuous webs can also be supplemented by placing a further separating web on the electrodes to form “three-layer” or “five-layer” continuous webs, which then each have a separating web on both sides.

[0005] Alternatively, the electrode can also be present as a continuous web, i.e. in an uncut form in a "two-layer", "three-layer", "four-layer" or "five-layer" continuous web, which is then cut into significantly longer lengths and then, for example, rolled up. Alternatively, the continuous web can also be first wound up and then cut after the winding is completed. In this case, the electrode is not present in the continuous web in spaced-apart sections, but in the form of a single section which extends without interruption in the intermediate space between the separating webs.

[0006] Furthermore, electrodes in the form of copper webs or copper foils or similar carrier materials with intermittent coatings can also be provided in the continuous web, wherein the coatings each form segmented, spaced-apart elevations in the electrode.

[0007] In order to laminate "double-layer", "triple-layer", "quadruple-layer" or "quintuple-layer" continuous webs, these are passed between two pressing devices, which exert pressure on the continuous web. In this case, the electrodes are pressed together with the separating webs in these continuous webs. In principle, the electrodes and the separating webs are connected to each other and laminated by means of the pressing devices by exerting pressure. In addition, the lamination can be supported by the heat generated by the pressure. Furthermore, additional heating zones or cooling zones can also be provided, which regulate the temperature of the continuous web during lamination. In order to achieve a high-quality connection, it is desirable that the continuous web is subjected to pressure that is as uniform as possible in its longitudinal extension and in its transverse extension.

[0008] If the electrodes in the continuous web are already arranged in the form of cut-out sections at a distance from one another, the electrodes, due to their spacing, additionally form the intermediate spaces in the continuous web, wherein the electrodes, due to their thickness in the intermediate spaces, additionally keep the separating webs at a certain distance from one another. The electrodes thus have additional free edges at the edges delimiting the intermediate spaces. Furthermore, the continuous web thus has additional thickness fluctuations.

[0009] The continuous web to be laminated thus has a fluctuating thickness which is caused only by unavoidable production inaccuracies of the electrodes and the separating webs in their thickness and / or by the spacing of the electrodes. Furthermore, the electrodes can be designed to be narrower than the separating webs, so that additionally due to the arrangement of the electrodes in the continuous web, different thicknesses of the continuous web are produced in the region of the edge sections of the continuous web.

[0010] These thickness fluctuations of the continuous web can lead to dynamic stresses on the pressing device in the laminating device. In addition, the thickness fluctuations lead to fluctuations in the pressing force applied by the pressing device to the continuous web and increase the pressure load at the free edge, with the risk of damaging the edge. Summary of the invention

[0011] Against this background, the invention is based on the object of providing a laminating device which enables lamination of continuous webs with a contour-adapted contact pressure and reduced dynamic loading of the pressing device.

[0012] To achieve this object, according to the invention, a laminating device is proposed having the features of claim 1. Further preferred embodiments can be derived from the dependent claims, the drawings and the associated description.

[0013] According to the basic idea of ​​the invention, it is proposed that the pressing surface has a plurality of sections with different elastic stiffnesses. By means of the different elastic stiffnesses, the pressing surface can be designed in a targeted manner so that it is harder in a predetermined section and thus transmits a higher pressure, while it transmits a lower pressure in a section with a lower elastic stiffness. Thus, the thickness differences in the continuous web caused by the arrangement of the electrodes in the continuous web can be compensated in particular by the pressing surface being intentionally more bent and elastically compressed in the sections with a lower elastic stiffness than in the sections with a higher elastic stiffness. As a result, the thickness fluctuations thus have a smaller influence on the pressing force, because the thickness fluctuations are compensated again by the contour-adapted pressing force, so that lamination is carried out with a substantially more constant pressing force acting on the continuous web. By means of a pressing force that is segmented synchronously with the thickness fluctuations of the continuous web, zones of higher and lower pressure can be produced and thus the bonding force as a result of the lamination can be influenced in a targeted manner. In particular, in areas with free edges, the pressing force can be reduced synchronously with the thickness fluctuations and the free edges to avoid damage to the free edges without increasing the dynamic load on the entire system by the pressing surface being specifically bent and elastically compressed more in sections with lower elastic stiffness than in sections with higher elastic stiffness.

[0014] It is further proposed that the pressing device laminates the multi-layer continuous web in the laminating device under the introduction of heat. The lamination (i.e. connection) of the continuous webs of the separator material to each other and to the electrodes is achieved by the penetration of the polymer from one layer to another, which in turn is caused by adhesion forces acting at the interface. It is precisely these adhesion forces that can be easily achieved by the introduction of heat. However, it must be ensured that the material at the interface should not be compressed to such an extent that the ion exchange that is important for the functioning of the energy cell is prohibited when heat is introduced and pressure is applied.

[0015] The different spring rates can preferably be achieved by sprung support of the pressing surface in the pressing device. The different spring rates achieved by sprung support of the pressing surface can be achieved by a single sprung supported section of the otherwise non-sprung pressing surface or by a plurality of sprung supported sections with different spring rates.

[0016] Furthermore, different elastic stiffnesses can be achieved additionally or alternatively by different elastic stiffnesses of the material of the pressing surface. This can be achieved, for example, by arranging the reinforcement material portions in different parts of the pressing surface or combining different materials in different parts and / or by determining different thicknesses of the pressing surface.

[0017] It is further proposed that the electrode has a smaller width than the separating web in the longitudinal direction of the continuous web and that the pressing surface has a higher or lower elastic stiffness in the region where it covers at least one protruding edge of the separating web than in the region where it covers the electrode. With the proposed solution, the continuous web is laminated with a higher pressure in at least one edge region than in the region of the electrode. This results in a stronger bond of the continuous web in the edge region and at the same time a lower load on the electrode. In addition, the elastic stiffness can also be designed to be lower instead of higher, so that the pressing surface is intentionally bent more strongly in the region of the protruding edge of the separating web. Since the continuous web itself is constructed to be "softer" in the region of the edge of the separating web due to the absence of a resistance surface that is otherwise formed by the electrode, the pressing surface applies a lower pressing force in these sections in a targeted manner.

[0018] It is further proposed that a plurality of electrodes are arranged regularly spaced apart from one another in the continuous web. The continuous web is thus preconfigured for producing individual multilayer sections, each of which has an electrode or an electrode pair. To produce these sections, the continuous web then only has to be cut into individual sections by a cutting process. If the continuous web has a continuous web with intermittent coatings, the coated sections correspond to the electrodes and the spacings between the coatings correspond to the spacings of the electrodes.

[0019] In this case, it is further proposed that the pressing surface has a higher or lower elastic stiffness in the section of the continuous web in the area of ​​the interval of the electrodes than in the section of the continuous web in the area of ​​the electrodes. Through the higher elastic stiffness in the area of ​​the interval of the electrodes, the continuous web is subjected to a relatively higher pressing force in these sections than in the area of ​​the electrodes. Thus, the pressing surface can be bent more consciously in the area of ​​the electrodes than in the area of ​​the intermediate space or the interval of the electrodes, so that the electrodes are protected in the lamination and the separating webs are laminated in an improved manner in the area of ​​the intermediate space. Therefore, the pressing surface has a distribution of sections with higher elastic stiffness corresponding to the arrangement of the intermediate space and a distribution of sections with lower elastic stiffness corresponding to the distribution of the electrodes. In addition, the elastic stiffness can be designed to be lower rather than higher, so that the pressing surface is bent more consciously in the section of the continuous web in the area of ​​the interval of the electrodes. Because the continuous web itself is constructed "thinner" in the area of ​​the interval due to the non-existent resistance surface formed by the electrodes in other cases, the pressing surface is consciously applied with a lower pressing force in these sections.

[0020] It is further proposed that the pressing device comprises at least one pressing roller with a circular cross section and that the pressing surface is formed by the outer surface of the pressing roller. By means of the proposed embodiment of the pressing device, the laminating device can be preferably integrated into a roller operation, which in turn enables a very high production capacity. Furthermore, the outer surface of the pressing roller forms a particularly advantageous pressing surface, since it can be produced very precisely and enables linear pressing of a continuous web over the entire width by rolling on the continuous web.

[0021] In this case, at least one outer cover segment which is resiliently supported in the radial direction can be arranged in the outer cover surface, the radial outer surface of which forms part of the pressing surface. As a result, the pressing surface is locally elastically compressed in the region of the outer cover segments, so that the pressure for laminating the continuous web is lower in these sections. For this purpose, the outer cover segments can be arranged and dimensioned in such a way that they cover the electrodes when rolling on the continuous web, so that the electrodes are intentionally relieved of load during lamination, or in other words, the continuous web is laminated in the region of the intermediate space with a higher pressure than in the region of the electrodes. Furthermore, the resilient outer cover segments can also be arranged in such a way that the electrodes are deliberately relieved of load in the region of their edges.

[0022] It is further proposed that the pressing device has at least one pressing belt and that the pressing surface is formed by the surface of the pressing belt with which the pressing belt bears against the continuous web when pressure is applied. The pressing surface realized by the pressing belt in the pressing device has the advantage that the pressure during lamination can be generated by any desired pressure generating device and can be distributed to the continuous web by the pressing belt in a distribution on the continuous web that is defined by the shape and construction of the pressing belt. The pressing belt has the advantage, due to its belt-like form, that the force transmission surface can be expanded over a greater length of the continuous web.

[0023] In this case, the press belt can have different elastic stiffnesses along its longitudinal extension in the direction of the applied pressure. The press belt thus has harder areas and areas that are deliberately softer. The press belt can thus be adapted to the thickness differences of the continuous web, so that the continuous web is less stressed in the areas of greater thickness. In those areas where the electrodes are arranged (for example, areas that are in contact with the continuous web), the press belt can bend in an improved manner, so that the pressure peaks during lamination can be reduced.

[0024] Here, the pressure roller can preferably abut against the free side of the pressing belt and can press the pressing belt against the continuous web when pressure is applied. In this case, the pressure roller is a pressure generating device with the above-mentioned advantages, which is then combined with the advantages of using a pressing belt to form a further improved solution.

[0025] According to an advantageous embodiment, it is provided that the press roller and / or the press belt are moved and / or driven synchronously with the continuous web.

[0026] By the synchronous movement of the continuous web and the pressure roller and / or the pressing belt, the bonding force can be influenced in a targeted manner accordingly. In this way, the pressing force can be reduced synchronously with the thickness fluctuation and the free edge in the region with the free edge, for example. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Hereinafter, the present invention will be explained based on preferred embodiments with reference to the accompanying drawings.

[0028] Figure 1 shows a cut-out of a laminating device having four layers of continuous webs and a pressing device with two pressing rollers; and

[0029] Figure 2 A detail of a laminating device with a three-layer continuous web and a pressing device with two press rollers and two press belts is shown. DETAILED DESCRIPTION

[0030] exist Figure 1, a section of a laminating device according to the invention can be seen, wherein the continuous web 3 is formed by a "four-layer" continuous web 3, which has a separating web 4 on the upper side and a separating web 6 in the middle, a plurality of anodes 5 arranged between the separating webs 4 and 6, and a plurality of cathodes 7 arranged below the intermediate separating web 6. The anodes 5 are designed to be larger than the cathodes 7, so that the anodes 5, when arranged in pairs with the cathodes 7, have a smaller end-side spacing A from each other than the cathodes 7. The laminating device also includes a pressing device with two pressing rollers 1 and 2, which are designed as cylindrical rollers with a circular cross section. The pressing rollers 1 and 2 are oriented parallel to each other with their rotation axes and are arranged so that there is a gap S between their outer shell surfaces 12 and 13, which has a constant gap width SW in the direction of the rotation axis (i.e. perpendicular to the display plane).

[0031] The gap width SW of the gap S is dimensioned to be smaller than the thickness D of the continuous web 3, so that the continuous web 3 is slightly pressed and laminated when passing through the gap S. The thickness D2 of the separating webs 4 and 6 is 15 to 25 μm, respectively, while the electrode 5 has a thickness D1 of 150 to 400 μm. Therefore, a thickness D of the electrode web 3 of about 330 μm to 850 μm is obtained. The gap width SW is 20 to 100 μm smaller than the thickness D of the continuous web 3, preferably 40 to 60 μm smaller, so that the continuous web 3 is slightly compressed by 5 to 10 μm when passing through the gap S. The intermediate space 8 is formed by the spacing of the electrodes and has a height corresponding to the thickness D1 of the electrode 5 (i.e. 150 to 400 μm). Furthermore, the intermediate space 8 has a length in the conveying direction which corresponds to the spacing A of the electrodes 5, which is 3 mm between the anodes and 6 mm between the cathodes, wherein it is desirable to dimension the spacing A between the electrodes 5 as small as possible in order to increase the material utilization of the continuous web 3 and the number of electrodes 5 in a predetermined length of the continuous web 3.

[0032] The continuous web 3 is transported in the conveying direction T and pulled through the gap S. The pressure rollers 1 and 2 can themselves be actively driven, for example by separate drives in the form of servomotors, to perform counter-rotating movements directed in the arrow direction P, so that they also actively transport the continuous web 3 by friction locking. Alternatively, the pressure rollers 1 and 2 can also be mounted only in a rotatable manner, so that they themselves are driven by the continuous web 3 by friction locking to perform a rotational movement. In this case, the pressure rollers 1 and 2 only roll passively on the surface of the continuous web 3.

[0033] The outer surfaces 12 and 13 of the pressure rollers 1 and 2 form the pressure surfaces of the pressure device. The outer surface 12 of the upper pressure roller 2 is spring-loaded by a plurality of springs F1 to F5 with different spring rates, so that it bends to different degrees depending on the rotational angle position of the pressure roller 2 and the contact position on the continuous web 3 defined thereby. The same applies to the lower pressure roller 1 in the figure with the springs F6 to F10, which act on the outer surface 13.

[0034] exist Figure 2 In FIG. 1 , an alternative embodiment of the invention can be seen. Here, the pressing device comprises, in addition to the two pressing rollers 1 and 2, two pressing belts 20 and 21, which are in contact with the top and bottom of the continuous web 3. The pressing rollers 1 and 2 are connected to the Figure 1 The pressing rollers 1 and 2 are of identical design and rest against the free surfaces of the two pressing belts 20 and 21 .

[0035] Furthermore, a continuous web 3 to be laminated is provided, which passes through the gap S and has a thickness D. The continuous web 3 is formed by a "three-layer" continuous web 3 having a separating web 4 on the upper side and a separating web 6 on the lower side and an anode 5 arranged therebetween. The anodes 5 are arranged at the same spacing A relative to one another with intermediate spaces 8 and have a smaller width than the separating webs 4 and 6, so that the separating webs 4 and 6 protrude laterally beyond the anode 5.

[0036] Since the anode 5 is in principle larger than the cathode 7 in the energy cell, the separating webs 4 and 6 are identical and serve to arrange the anode 5 and the cathode 7. Figure 1 The cathodes 7 are visible in the anode 5, so the spacing A of the intermediate spaces 8 between the cathodes 7 and the free side edge areas in the cathodes 7 are particularly large. In contrast, the spacing A of the intermediate spaces 8 in the anode 5 and the free side edge areas are smaller.

[0037] The springs F1 to F10 in the pressure rollers 1 and 2 are dimensioned such that the pressing surface formed by the outer surfaces 12 and 13 is designed to be harder in certain sections of the circumference and softer in other sections in such a way that the springs F1 to F10 have different spring rates. The pressing surface can thus bend to different degrees in the event of unavoidable thickness fluctuations of the continuous web 3 (e.g. due to the intermediate space 8). The continuous web 3 can thus be laminated with smaller pressure peaks and reduced load on the electrode 5, in particular in the region of the edges adjoining the intermediate space 8.

[0038] exist Figure 2 In the embodiment of the present invention, in addition to the pressing rollers 1 and 2, two pressing belts 20 and 21 are additionally provided. Figure 1Corresponding to the embodiment of the present invention, a plurality of springs F1 to F10 with different spring rates are provided in the pressure rollers 1 and 2. Alternatively or additionally, the pressing belts 20 and 21 can also be constructed to have different spring rates in the direction of applying the pressing force to the continuous web 3. For this purpose, the pressing belts 20 and 21 can be realized, for example, as textile belts with local fiber reinforcement or other combinations of different materials. In addition, individual casing segments can also be provided in the outer covering surfaces 12 and 13 of the pressure rollers 1 and 2, which form sections of the outer covering surfaces 12 and 13 with their surfaces and are supported individually in an elastic manner. It is also conceivable to use a rod blanket (Stangenteppich), a piston-cylinder unit, a pneumatically operated pressure device (for example with an inflatable cushion) as a pressure generating device instead of the pressure rollers 1 and 2. As the pressing belts 20 and 21, in particular, fiber-reinforced textile belts, steel belts or even very finely divided chain link belts can be used.

[0039] Here, the laminating device can be constructed so that the pressing device has an elastic stiffness distribution in the pressing surface that is adapted to the thickness distribution of the continuous web 3 to be laminated, wherein in particular the size of the electrodes 5 (including the spacing A of the electrodes in the intermediate space 8) and the orientation of the intermediate space 8 are taken into account.

Claims

1. A laminating device for producing a multilayer continuous web (3) for producing an energy cell, the multilayer continuous web consisting of at least one separating web (4, 6) and at least one electrode, the laminating device comprising: a pressing device which laminates the multilayer continuous web (3) by means of a pressing surface under pressure, It is characterized in that The pressing surface has a plurality of sections with different elastic stiffness.

2. The laminating device according to claim 1, characterized in that The pressing device laminates the multi-layer continuous web (3) while introducing heat.

3. The laminating device according to claim 1 or 2, characterized in that: The different spring rates are achieved by resiliently supporting at least one section of a pressing surface in the pressing device.

4. The laminating device according to any one of claims 1 to 3, characterized in that The different elastic stiffnesses are achieved by different elastic stiffnesses of the material of the pressing surfaces.

5. The laminating device according to any one of claims 1 to 4, characterized in that - the electrodes have a smaller width in the longitudinal direction of the continuous web than the separating webs (4, 5), and The pressing surface has a higher or lower elastic stiffness in its region covering at least one protruding edge of the separating web (4, 5) than in its region covering the electrode.

6. The laminating device according to any one of claims 1 to 5, characterized in that A plurality of cut-out electrodes are arranged in the continuous web (3) and are regularly spaced apart from one another.

7. The laminating device according to claim 6, characterized in that The pressing surface has a higher or lower elastic stiffness in the section of the continuous web (3) in the region of the interval in which it abuts against the electrodes than in the section of the continuous web (3) in the region in which it abuts against the electrodes.

8. The laminating device according to any one of claims 1 to 7, characterized in that - the pressing device comprises at least one pressing roller (1, 2) having a circular cross section, and The pressing surface is formed by the outer cover surfaces (12, 13) of the pressing rollers.

9. The laminating device according to claim 8, characterized in that - at least one casing segment which is resiliently supported in radial direction is arranged in the casing surface (12, 13), the radial outer surface of which forms part of the pressing surface.

10. The laminating device according to any one of claims 1 to 7, characterized in that The pressing device has at least one pressing belt (20, 21), and the pressing surface is formed by the surface of the pressing belt (20, 21), with which the pressing belt bears against the continuous web (3) under application of pressure.

11. The laminating device according to claim 10, characterized in that The pressing belts (20, 21) have different elastic stiffnesses along their longitudinal extension in the direction of the applied pressure.

12. Laminating device according to claim 8 or 9 and in accordance with any one of claims 10 or 11, characterized in that The pressure rollers (1, 2) bear against the free sides of the pressure belts (20, 21) and, under application of pressure, press the pressure belts (20, 21) against the continuous web (3).

13. Laminating device according to any one of claims 8 or 9 and according to any one of claims 10 to 12, characterized in that The press rollers (1, 2) and / or the press belts (20, 21) are moved and / or driven synchronously with the continuous web (3).

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