Method and rolling apparatus for operating a rolling mill for manufacturing electrode webs

Abstract

To provide a method for operating a rolling device for manufacturing an electrode web.SOLUTION: Provided is a method in which a rolling device 2 has a rolling machine 16 and 18 including a roll pair 20 and an adhering roll 22 which is formed separately for the roll pair or is a part of the roll pair for forming a material film 14 for an electrode web 4; base material 12 for the electrode web is supplied to the adhering roll; the rolling machine has a film forming gap 24 formed by the roll pair; the film forming gap discharges a predetermined amount of material 26 and forms the material film based on this; the material film is adhered to the adhering roll and transferred from the adhering roll to the base material; the material film has basis weight G and film thickness D; the basis weight and / or the film thickness are adjusted to a target value, and for that purpose, the rolling device is controlled according to the basis weight and / or the film thickness. In addition, a corresponding rolling device is provided.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for operating a rolling device for manufacturing an electrode web and a corresponding rolling device. Thus, in particular, the present invention also relates to the manufacture of electrode webs and corresponding electrode webs.

[0002] Electrode webs are typically used for manufacturing batteries. In this case, the battery is used, for example, to supply energy to an electric drive device of a vehicle such as a passenger car or a truck. Electrode webs are typically manufactured as endless webs, which are then finished into individual electrodes. One or more electrodes are then stacked or wound and assembled into cells. One or more such cells are then properly interconnected and housed within a common housing to form a battery.

[0003] In the manufacture of electrode webs, first, a substrate, generally a foil made of a conductive material such as copper or aluminum, is prepared. Then, a material film, which consists of an active material and contains, for example, lithium or a lithium compound, is deposited on the substrate to manufacture a lithium battery. The manufacture of the electrodes can in principle be carried out dry or wet, depending on the composition of the active material for the material film.

[0004] WO 2018 / 210723 describes a method for manufacturing a dry film. In this case, a dry powder mixture is processed into a dry film by a rolling device having a first roll and a second roll. The first roll has a higher rotational peripheral speed than the second roll, and the resulting dry film is placed on the first roll.

[0005] U.S. Patent Application Publication No. 2022 / 0006071 describes a dry electrode manufacturing process in which the thickness of a self-supporting film and the degree of compression of the film are controlled by repeated calendering. This limits the degree of control over basis weight and film thickness, unlike in wet electrode manufacturing.

[0006] See also U.S. Patent Application Publication No. 2020 / 0144591.

[0007] Given this background, the object of the present invention is to improve the manufacture of electrode webs, particularly dry manufacturing. To this end, there is a need to provide an improved method for operating a rolling mill and a corresponding rolling mill.

[0008] According to the present invention, this problem is solved by a method having the features of claim 1 and a rolling mill having the features of claim 10. Advantageous embodiments, improved forms and variations are the subject of the dependent claims. Descriptions relating to the method also apply to the rolling mill, and vice versa. Where steps of the method are described implicitly or explicitly below, advantageous embodiments of the rolling mill arise, in particular, by having at least one control unit configured to perform one or more of these steps.

[0009] This method is used to operate a rolling mill. A preferred rolling mill is described in International Publication No. 2018 / 210723, mentioned at the beginning, and such a rolling mill will be assumed hereafter without limitation of generality. The rolling mill is also called a calendar. The rolling mill is used to manufacture electrode webs. The electrode webs are used in particular to manufacture batteries, which are then preferably used to supply energy to the electric drive systems of vehicles, such as passenger cars or trucks. The electrode webs are first manufactured by the rolling mill, in particular as endless webs, and then, as may be, finished as needed.

[0010] In the manufacture of electrode webs, a substrate and at least one material film are assembled. The combination of the substrate and the material film forms the electrode web. The rolling apparatus has a rolling mill having a roll pair and a workpiece roll for forming the material film for the electrode web. The workpiece roll is either formed individually with respect to the roll pair or is part of the roll pair, i.e., one of the two rolls of the roll pair. In either case, the rolling mill has at least two rolls for forming the material film, and the rolling apparatus is correspondingly also called a multi-roll system or multi-roll calendar. In some cases, the rolling apparatus has multiple rolling mills for coating the substrate on both sides with the material film.

[0011] A rolling mill has a film-forming gap formed by a pair of rolls; that is, the film-forming gap is formed between both rolls of the roll pair and therefore has a gap width corresponding to the distance between both rolls. The film-forming gap releases a predetermined amount (i.e., an amount per unit time) of material, thereby forming a material film. In other words, the material film is also initially formed by the film-forming gap. In this process, the gap width of the film-forming gap has a significant influence on the formation of the material film. The material for this is supplied to the rolling mill, specifically to a gusset, by a metering device, which is formed between both rolls of the roll pair and is connected to the film-forming gap. In addition to the gap width, the relative speed of both rolls (and similarly the corresponding shear speed) also affects the formation of the material film.

[0012] The material exists in particular in powder form. This material is a battery powder mixture in particular. This material contains at least one active material. The active material contains, for example, lithium or a lithium compound. Furthermore, the material preferably contains a binder and / or a conductive additive. The material preferably does not contain any liquid components or contains up to 3% by weight, particularly preferably up to 1% by weight, of liquid components. Such materials are also referred to as “dry materials,” and the method in which such materials are used is referred to as “dry processes for manufacturing electrode webs” or equivalently “dry electrode manufacturing.” The liquid components are particularly solvents and / or lubricants, and therefore the material preferably does not contain solvents and / or lubricants, or solvents and / or lubricants are contained in the material in amounts of no more than those described.

[0013] In particular, both rolls of a roll pair are operated at different peripheral speeds to form the material film. This generates a shear force in the film-forming gap, and this shear force acts on the material, correspondingly affecting the formation of the material film. In this case, the shear force depends on the difference in peripheral speeds between the two, i.e., the relative speed of one roll of the roll pair to the other roll of the roll pair. The roll with the slower peripheral speed is also called the shear roll. The other roll is called the adherend roll or transfer roll. The material film is formed particularly on the roll with the faster peripheral speed, i.e., on the adherend roll or transfer roll, depending on the embodiment.

[0014] Within the scope of this method, the material film is applied to a deposition roll. When the deposition roll is part of a roll pair, the material film is preferably applied directly to the deposition roll, starting from the film formation gap. In contrast, when the deposition roll is formed individually for a roll pair, the material film is preferably applied directly to a transfer roll, starting from the film formation gap. The material film is then transferred from the film formation gap to the deposition roll via the transfer roll, indirectly or directly transferring the material film to the deposition roll.

[0015] The substrate is, in particular, a foil made of a conductive material, such as copper or aluminum. Here, the substrate for the electrode web is supplied to the adherend roll, and the material film is transferred from the adherend roll onto the substrate, i.e., the substrate is coated with the material film. It is preferable that the substrate is coated with an adhesion promoter or similar substance to ensure that the material film is securely fixed onto the substrate. The transfer of the material film onto the substrate is also called "lamination".

[0016] Although the material film is not particularly self-supporting, it is continuously supported by one or more rolls from the film formation gap to the substrate. Therefore, the material film is also called a "roll-supported material film."

[0017] To transfer the material film onto the substrate, the rolling apparatus is appropriately provided with opposing rolls to the load rolls. The opposing rolls are either separate rolls similar to those already described in the (i.e., first) rolling mill, or load rolls of the second rolling mill. A gap is then formed between the opposing rolls and the load rolls, through which the substrate is conveyed and the material film is transferred onto the substrate. At the time of transfer onto the substrate, the material film is preferably not compressed or only slightly compressed, i.e., compressed by a maximum of 5%. In this case, the gap is also referred to as the "lamination gap." This case will be assumed below without limitation of generality.

[0018] If a transfer roll is not present, the material film in the lamination gap is preferably compressed to the target density, and therefore no further calendering is necessary or performed. However, if compression to the target density in the lamination gap is not possible, for example, when a transfer roll is used, it is preferable for the material film to be further compressed downstream of the lamination gap, particularly to the target density, using a calender.

[0019] As is quite common, material films have a basis weight and film thickness. Film thickness is the minimum dimension, measured perpendicular to the width and length of the material film (and therefore perpendicular to the surface of the roll and perpendicular to the substrate). Film thickness is typically in the range of 30 μm to 200 μm, preferably 40 μm to 150 μm. Basis weight indicates how much mass the material film has per unit area, and the unit area extends in the direction of the length and width of the material film. Basis weight is typically 50 g / m². 2 ~300g / m 2 This is within the range. Basis weight is also called load or area load. When the basis weight of the material film is constant, the film thickness is equivalent to the film density of the material film, that is, the mass of the material film per unit volume.

[0020] Unlike film thickness, after the material film is delivered to the substrate, the basis weight is no longer adjustable because no further material is added or removed. Only the film thickness can still be adjusted by additional calendering, but only to a lower value. However, the basis weight is maintained during calendering. However, both the basis weight and the film thickness can be adjusted by appropriately controlling the rolling equipment before the material film is delivered to the substrate. In this invention, the basis weight and / or film thickness are adjusted to target values ​​(in particular, target values ​​from the ranges mentioned above), and for this purpose, the rolling equipment is controlled according to the basis weight and / or film thickness. This is understood to mean that either the basis weight or the film thickness is adjusted to a target value, or both occur simultaneously, i.e., the basis weight and film thickness are adjusted to their respective target values. In the case of basis weight, the target value is also referred to as the target load, and in the case of film thickness, it is correspondingly referred to as the target thickness. An important advantage of the present invention is that the manufacture of the electrode web is particularly precise, and the specifications regarding basis weight and / or film thickness are particularly easy and accurate to implement. Since the basis weight is no longer changeable after the material film has been transferred onto the substrate, as described, embodiments that adjust the basis weight are particularly preferred.

[0021] In dry electrode manufacturing, it is possible to achieve a predetermined basis weight ("target load") and a predetermined film thickness ("target thickness") by operating the rolling mill with various operating parameters, thereby manufacturing an electrode web, along which the basis weight and film thickness vary. Subsequently, only the area of ​​the electrode web having the predetermined basis weight and film thickness is further processed, and the remaining area is discarded. However, this inevitably results in waste and is correspondingly inefficient and costly. The present invention enables automatic adjustment and adaptation (i.e., adjustment) of the rolling mill, thereby ensuring that the predetermined basis weight and / or predetermined film thickness are formed continuously or at least substantially over the entire area. This results in correspondingly less waste in the manufacture of electrode webs.

[0022] In this invention, the electrode web is not processed retrospectively, i.e., only after the material film is delivered to the substrate, in order to adjust the basis weight and film thickness. Instead, the material film is appropriately formed in accordance with the requirements before delivery to the substrate. This makes it possible to adjust the basis weight for the first time. Regarding the adjustment of film thickness, retrospective calendering of the electrode web is unnecessary, and at the very least, the rolling equipment is simplified accordingly.

[0023] To adjust the basis weight and / or film thickness to their respective target values, the rolling mill has, in particular, a control unit, as well as at least one measuring unit and at least one regulator, which are connected to or part of the control unit. The measuring unit measures the adjustment amount, and based on this, an actual value is determined and this value is transmitted to the regulator. Furthermore, a target value is sent to the regulator. Depending on the deviation of the actual value from the target value (adjustment deviation), the regulator controls the rolling mill, i.e., the corresponding working amount. Various suitable embodiments for this purpose are described below. These embodiments differ, in particular, in the selection of the adjustment amount and its measurement, as well as the working amount, i.e., how the rolling mill is specifically controlled. In this regard, basically, only various embodiments, or their individual aspects, can be combined with one another.

[0024] In terms of working parameters, the gap width of the film-forming gap and the relative speed of the rolls in a roll pair are particularly appropriate, as already mentioned above. Accordingly, in a suitable embodiment, the rolling apparatus is controlled by adjusting the gap width of the film-forming gap. Alternatively or additionally, a roll pair has two rolls that are operated at different peripheral speeds to form the material film, as described above, and the rolling apparatus is controlled by adjusting the difference in peripheral speeds. By either means, the amount of material released from the film-forming gap (per unit time) is adjusted directly, and consequently, the basis weight and film thickness of the material film are also adjusted. When both the gap width and relative speed are controlled accordingly, it is advantageous that the basis weight and film thickness are adjusted independently of each other. It is convenient that the basis weight is adjusted by controlling the gap width of the film-forming gap, and the film thickness, and consequently the density of the material film, is adjusted by controlling the gap width of the lamination gap or the gap width between the transfer roll and the adherend roll. If it is not possible to measure the basis weight on one of the rolls, the film thickness is appropriate to use to compare both sides of the electrode web and especially for process monitoring. However, even then, advantageously, the basis weight measured, especially on the substrate, is adjusted as a target amount, i.e., adjusted specifically to a target value.

[0025] Preferably, basis weight or film thickness or both are measured and used directly as actual values. Then, a corresponding target load or target thickness is used as the target value. However, embodiments are also possible and appropriate in which the actual value (and likewise the target value) is simply derived from basis weight or film thickness or both together and, if applicable, is appropriately abstracted, for example, not stated in units of basis weight or film thickness. In a convenient embodiment, basis weight is derived from a measured value of film thickness. For this purpose, film thickness is measured particularly on the adherend roll (or similarly on the transfer roll), and then, in combination with the peripheral speed of the adherend roll (equivalent to rotational speed and roll diameter) and the amount of material released from the film-forming gap, an actual value of basis weight is calculated, and thereafter, adjustment of basis weight based on the measured value of film thickness is carried out. Alternatively or additionally, basis weight is measured downstream of the lamination gap, and film thickness is preferably used to control the uniformity of both sides of the electrode web, i.e., in particular whether the film thickness is the same on both sides.

[0026] Measuring basis weight and film thickness is possible and advantageous at various points in the rolling apparatus. In a suitable embodiment, the basis weight and / or film thickness of the material film are measured while the material film is being deposited on the deposition roll, i.e., measured on the deposition roll. Alternatively or additionally, the basis weight and / or film thickness of the material film are measured while the material film is being deposited on the substrate, i.e., measured downstream of the deposition roll and on the substrate. The basis weight is measured, for example, by absorptiometry, where the absorption of, for example, X-rays or ultrasound in the material film is measured, for example, by transmission. This is particularly easy for material films on a substrate because the material film on the substrate is always self-supporting downstream of the deposition roll. However, fundamentally, the basis weight can also be measured for roll-supported material films before delivery to the substrate. For example, the film thickness is measured optically by reflection, compared to a reference. A combination in which the film thickness is measured while the material film is being deposited on the deposition roll and the basis weight is measured while the material film is being deposited on the substrate is particularly preferred. Both of these measurements are particularly straightforward. In embodiments where material films are deposited onto a substrate on both sides, the basis weight measurement provides only one value (an actual value) for both material films combined. By additionally measuring the film thickness of each material film before transfer to the substrate, this value is divided between both material films in proportion to the ratio of the two film thicknesses, and thus, the basis weight for each material film is determined at least approximately correctly.

[0027] Similar to the gap width of the film-forming gap and the relative speed of the rolls of the roll pair, in a rolling apparatus having a transfer roll, it is also advantageous, alternatively or additionally, on the one hand, to use the gap width of the gap between the transfer roll and the receiving roll as an operating variable, and / or on the other hand, to use the relative speed between the transfer roll and the receiving roll as an operating variable. As already described, the rolling apparatus, in a preferred embodiment, has a transfer roll which is arranged upstream of the receiving roll, via which transfer roll the material film is delivered from the film-forming gap to the receiving roll. In this context, the terms "upstream" (similarly "downstream") are understood to relate to the conveying direction of the material film. The rolling apparatus is then controlled by adjusting the gap width of the gap between the transfer roll and the receiving roll and / or by adjusting the difference in the peripheral speeds of the transfer roll and the receiving roll (i.e., the relative speed).

[0028] Similarly, similar to the measurement of the basis weight and / or film thickness on the receiving roll, alternatively or additionally, for this purpose, in a suitable embodiment, the basis weight and / or film thickness in the material film is measured while the material film is being deposited on the transfer roll, i.e., this is measured at the transfer roll.

[0029] Various configurations are possible for the rolling apparatus, all of which are suitable for the method described herein. The optional use of transfer rolls has already been described. Furthermore, coating of one or both sides of the substrate is also possible, with the latter being preferred. Accordingly, in a suitable embodiment, the substrate is coated on both sides by the rolling apparatus, i.e., the material films are each applied to both sides of the substrate as described. The (first) material film, already described, is then applied to the first surface of the substrate, and the rolling apparatus has a further (second) rolling mill to form a further (second) material film to be applied to the second surface of the substrate on the opposite side. The second material film also has a basis weight and film thickness. The formation of both material films and their transfer onto the substrate preferably proceeds in the same manner, i.e., the rolling apparatus has a rolling mill for each material film. The measurements and adjustments described herein are conveniently performed identically for both the rolling mill and the material films, in accordance with the preceding and following descriptions. The rolling mill is positioned either offset with respect to the substrate transport direction so that both material films are delivered onto the substrate successively, or positioned in the same location so that both material films are delivered onto the substrate simultaneously. In the latter case, both loading rolls are simultaneously the opposing rolls of the other loading roll. When both material films are loaded successively, it is advantageous that the basis weight and / or film thickness of each material film can be measured while each individual material film is already loaded onto the substrate. In the advantageous embodiment, the basis weight and / or film thickness of the material film are measured accordingly while the material film is loaded onto the substrate, but before the second material film is loaded onto the opposite side of the substrate. The basis weight and / or film thickness are measured accordingly downstream of the loading roll of the first rolling mill and upstream of the loading roll of the second rolling mill.

[0030] In the case of a substrate coated on both sides, both rolling mills are preferably controlled such that the difference in the film thickness of both sides is minimized, i.e., the material films are automatically formed with the same thickness. This is particularly advantageous in combination with the measurement of the basis weight in a substrate coated on both sides, as already described above.

[0031] Optionally, in a convenient embodiment, the filling level of the material in front of the film-forming gap is adjusted to a target value of the filling level according to the actual value of the filling level or according to the basis weight and / or the film thickness, i.e., the filling level is adjusted. Thereby, it is ensured that neither the roll pair runs out of gusset nor overflows. The adjustment of the filling level is particularly carried out in a decentralized manner by simply measuring the actual value of the filling level and then controlling the supply of the material to the gusset accordingly, and thus independently of the adjustment of the basis weight and / or the film thickness. Alternatively, the adjustment of the filling level is particularly carried out in a centralized manner by controlling the supply according to the basis weight and / or the film thickness.

[0032] Also, embodiments in which the lamination gap is additionally controlled particularly according to the basis weight and / or the film thickness are advantageous. It is appropriate that the gap width of the lamination gap is adjusted according to the film thickness, particularly the film thickness of the material film on the substrate.

[0033] The rolling device according to the invention is configured to carry out the method described above and has a control unit which is also particularly constructed. In this case, the control unit particularly takes over one or more of the above control tasks and adjustment tasks. All control tasks and adjustment tasks are either implemented centrally within an individual control unit or divided in a decentralized manner among a plurality of corresponding control units. For example, the adjustment of each of the film thickness and the basis weight is implemented independently of each other in separate control units.

Brief Description of the Drawings

[0034] The embodiments of the present invention will be described in more detail below with reference to the drawings. The following are schematically shown: [Figure 1] This is a schematic diagram of the vehicle. [Figure 2] This is a schematic diagram of a rolling mill. [Figure 3] This is a schematic diagram of a modified rolling mill. [Figure 4] This is a schematic diagram of a further modified form of the rolling mill. [Figure 5] This is a schematic diagram of a further modified form of the rolling mill. [Figure 6] This is a schematic diagram of the adjustment of the filling level in the rolling mill.

[0035] The method according to the present invention is used to operate a rolling mill 2. Figures 2 to 5 show embodiments of the rolling mill 2, and the method will be described below with reference to these embodiments. The rolling mill 2 is used to manufacture an electrode web 4. The electrode web 4 is used, for example, to manufacture a battery 6, which is then used to supply energy to a vehicle 10, for example, an electric drive unit 8 of a passenger car as shown in Figure 1. Here, the electrode web 4 is first manufactured by the rolling mill 2, particularly as an endless web, and then, optionally, as needed, finished (not shown).

[0036] In the manufacture of the electrode web 4, a substrate 12 and at least one material film 14 are assembled. The rolling apparatus 2 has rolling mills 16, 18, each having a pair of rolls 20 and a workpiece roll 22, for forming the material film 14. The workpiece roll 22 is either formed individually with respect to the pair of rolls 20 (see Figures 3 and 5) or is part of the pair of rolls 20 (see Figures 2 and 4). Here, the rolling apparatus 2 shown in Figures 2 to 5 has multiple rolling mills 16, 18, each for coating the substrate 12 on both sides with the material film 14. However, embodiments having only one rolling mill 16, 18 are also possible.

[0037] The rolling mills 16 and 18 have a film-forming gap 24 formed by a pair of rolls 20, that is, the film-forming gap 24 is formed between both rolls of the pair of rolls 20 and therefore has a gap width B1 corresponding to the distance between both rolls. The film-forming gap 24 releases a predetermined amount (i.e., an amount per unit time) of material 26, thereby forming a material film 14. In this process, the gap width B1 has a significant influence on the formation of the material film 14. Here, the material 26 is supplied by a metering device 28, i.e., to a gusset 30, which is formed between both rolls of the pair of rolls 20 and is connected to the film-forming gap 24.

[0038] Here, material 26 exists in powder form and contains no liquid components, or at most a small amount of liquid components. Such materials are also called "dry materials" and are solvent-free.

[0039] Both rolls of the roll pair 20 are operated at different peripheral speeds U1 and U2 to form the material film 14. This generates a shear force in the film-forming gap 24, which acts on the material 26 and accordingly affects the formation of the material film 14. The shear force depends on the difference between the two peripheral speeds U1 and U2, i.e., the relative speeds of both rolls of the roll pair 20. The roll with the slower peripheral speed U1 is also called the shear roll 32. The other roll is called the adherend roll 22 or the transfer roll 34. The material film 14 is formed on the roll with the faster peripheral speed U2, i.e., on the adherend roll 22 or the transfer roll 34.

[0040] Within the scope of this method, the material film 14 is applied to the adherend roll 22. If the adherend roll 22 is part of a roll pair 20, as shown in Figures 2 and 4, the material film 14 is applied directly to the adherend roll 22, starting from the film formation gap 24. In contrast, if the adherend roll 22 is formed separately from the roll pair 20, as shown in Figures 3 and 5, the material film 14 is applied directly to the transfer roll 34, starting from the film formation gap 24. The material film 14 is then transferred from the film formation gap 24 to the adherend roll 22 via the transfer roll 34. The transfer roll 34 then transfers the material film 14 to the adherend roll 22 indirectly (not shown) or directly, as shown in Figures 3 and 5.

[0041] Here, the substrate 12 is a foil made of a conductive material. The substrate 12 is supplied to the adhesion roll 22, and the material film 14 is transferred from the adhesion roll 22 onto the substrate 12. Optionally, the substrate 12 is coated with an adhesion promoter or similar substance to securely fix the material film 14. The transfer of the material film 14 onto the substrate 12 is also referred to as "lamination."

[0042] As can be seen in Figures 2 to 5, the material film 14 is not self-supporting, but is continuously supported by one or more rolls from the film formation gap 24 to the substrate 12. Therefore, the material film 14 is also referred to as a "roll-supported material film".

[0043] To transfer the material film 14 onto the substrate 12, the rolling apparatus 2 in the shown embodiment has a counter roll 36 relative to the adherend roll 22. The counter roll 36 is either a separate roll (see Figures 4 and 5) similar to that of the (i.e., first) rolling mill 16 (see Figures 2 and 3) already described, or the adherend roll 22 of the second rolling mill 18. A gap 38 is then formed between the counter roll 36 and the adherend roll 22, through which the substrate 12 is conveyed and the material film 14 is transferred onto the substrate 12. Here, upon transfer onto the substrate 12, the material film 14 is not compressed, or at most only slightly compressed. In this case, the gap 38 is also referred to as the “laminated gap”.

[0044] As is quite common, the material film 14 has a basis weight G and a film thickness D. The film thickness D is the minimum dimension of the material film 14, measured perpendicular to its width (perpendicular to the plane of the drawing in Figures 2-5) and length (in the plane of the drawing in Figures 2-5, along the material film 14, i.e., along the transport direction of the material film 14). The basis weight G indicates how much mass the material film has per unit area, and the unit area extends in the direction of the length and width of the material film 14.

[0045] The basis weight G and, similarly, the film thickness D can be adjusted by appropriately controlling the rolling mill 2 before the material film 14 is delivered onto the substrate 12. Here, the basis weight G and / or film thickness D are adjusted to target values, and for that purpose, the rolling mill 2 is controlled according to the basis weight G and / or film thickness D. This is understood to mean that either the basis weight G or the film thickness D is adjusted to a target value, or both occur simultaneously, i.e., the basis weight G and film thickness D are adjusted to their respective target values. Here, automatic adjustment and adaptation (i.e., adjustment) of the rolling mill 2 is achieved, thereby ensuring that a predetermined basis weight ("target load") and / or a predetermined film thickness ("target thickness") are formed continuously or at least substantially over time.

[0046] Therefore, the electrode web 4 is not processed retrospectively, i.e., only after the material film 14 has been delivered onto the substrate 12, in order to adjust the basis weight G and film thickness D. Rather, the material film 14 is appropriately formed in accordance with these conditions before it is delivered onto the substrate 12.

[0047] To adjust the basis weight G and / or film thickness D to their respective target values, the rolling mill 2 in the embodiments shown herein has a control unit 40, as well as at least one measuring unit 42 and at least one regulator 44, which are connected to or part of the control unit 40. Each measuring unit 42 measures the adjustment amount, and based on this, an actual value is determined, which is then transmitted to one or more regulators 44. Furthermore, a target value is sent to the regulators 44. Depending on the deviation of the actual value from the target value (adjustment deviation), the regulators 44 control the rolling mill 2, i.e., the corresponding working amount. Various suitable embodiments for this purpose are described below. These embodiments differ, in particular, in the selection of the adjustment amount and its measured value, as well as the working amount, i.e., how the rolling mill 2 is specifically controlled. In this regard, basically, only various embodiments, or their individual aspects, can be combined with one another.

[0048] In particular, the gap width B1 of the film-forming gap 24 and the relative speed Δ(U1,U2) of the rolls in the roll pair 20 are suitable as working parameters. Accordingly, in possible embodiments, the rolling mill 2 is controlled by adjusting the gap width B1. Alternatively or additionally, the rolling mill 2 is controlled by adjusting the difference between the peripheral speeds U1 and U2. By either means, the amount of material 26 released from the film-forming gap 24 (per unit time) is directly adjusted, and consequently, the basis weight G and film thickness D of the material film 14 are also adjusted. When both the gap width B1 and the relative speed are controlled accordingly, the basis weight G and film thickness D are also adjusted independently of each other.

[0049] In one embodiment, basis weight G or film thickness D or both are measured and used directly as actual values. Then, a corresponding target load or target thickness is used as the target value. However, embodiments are also possible in which the actual value (and likewise the target value) is simply derived from basis weight G or film thickness D or both together, and, if applicable, is abstracted accordingly. In a further embodiment, basis weight G is derived from a measured value of film thickness D. To this end, film thickness D is measured, for example, on the adherend roll 22, and then, in combination with the peripheral speed U2 of the adherend roll 22 and the amount of material 26 released from the film forming gap 24, an actual value of basis weight G is calculated, and thereafter, adjustment of basis weight G based on the measured value of film thickness D is performed.

[0050] The basis weight G and film thickness D can be measured at various points on the rolling mill 2, as can be seen in Figures 2 to 5. Here, the basis weight G and / or film thickness D are measured while the material film 14 is being applied to the application roll 22, or alternatively or additionally, while the material film 14 is being applied to the substrate 12. Figures 2 to 5 show corresponding measuring units 42 for measuring either the basis weight G, the film thickness D, or both, respectively. As can be seen in Figures 2 to 5, the basis weight G can be measured, for example, on the material film 14 on the substrate 12, since the material film 14 on the substrate 12 is always self-supporting downstream of the application roll 22. However, basically, the basis weight G can also be measured on the roll-supported material film 14 before delivery onto the substrate 12. In one embodiment, the film thickness D is measured while the material film 14 is being applied to the application roll 22, and the basis weight G is measured while the material film 14 is being applied to the substrate 12. In an embodiment in which material films 14 are deposited onto a substrate 12 on both sides, the basis weight G measurement provides only one value (actual value) for both material films 14 combined. By additionally measuring the film thickness D of each material film 14 before delivery onto the substrate 12, this value is divided between both material films 14 in proportion to the ratio of the two film thicknesses D, and thus, for each material film 14, the respective basis weight G is determined at least approximately correctly.

[0051] Similar to the gap width B1 of the film-forming gap 24 and the relative speed of the rolls in the roll pair 20, the rolling mill 2 having a transfer roll 34 also alternatively or additionally uses, on the one hand, the gap width B2 of the gap 38 as a workpiece, and / or on the other hand, the relative speed between the transfer roll 34 and the workpiece roll 22 as a workpiece. As already described, each rolling mill 2, in Figures 3 and 5, has a transfer roll 34, which is located upstream of the workpiece roll 22, through which the material film 14 is transferred from the film-forming gap 24 to the workpiece roll 22. The rolling mill 2 is then controlled by adjusting the gap width B2 of the gap 38 and / or by adjusting the difference in peripheral speeds U2,U3 of the transfer roll 34 and the workpiece roll 22 (i.e., relative speed Δ(U2,U3)).

[0052] Similarly, as with the measurement of basis weight G and / or film thickness D on the adherend roll 22, in a suitable embodiment, the basis weight G and / or film thickness D are measured while the material film 14 is adhered to the transfer roll 34, either or additionally.

[0053] As can be seen in Figures 2 to 5, various configurations are possible for the rolling mill 2, but all are suitable for the method described herein. The optional use of the transfer rolls 34 has already been described. Furthermore, single-sided or double-sided coating of the substrate is also possible, and only the latter is shown in Figures 2 to 5. Here, the substrate 12 is coated on both sides by each rolling mill 2. Next, the (first) material film 14, which has already been described, is applied to the first surface of the substrate 12, and the rolling mill 2 has a further (second) rolling mill 18 to form a further (second) material film 14 to be applied to the second surface of the substrate 12 on the opposite side. The second material film 14 also has a basis weight G and a film thickness D. The formation of both material films 14 and their transfer onto the substrate 12 proceed in the same manner, i.e., the rolling mill 2 has rolling mills 16, 18 for each material film 14. The measurements and adjustments described are performed identically for both the rolling mills 16, 18 and the material film 14, in accordance with the preceding and following descriptions. The rolling mills 16, 18 are positioned either offset with respect to the transport direction of the substrate 12 so that both material films 14 are delivered onto the substrate 12 successively (see Figures 4 and 5), or positioned in the same location so that both material films 14 are delivered onto the substrate 12 simultaneously (see Figures 2 and 3). In the latter case, both load rolls 22 are simultaneously the opposing rolls 36 of the other load roll 22. Furthermore, in Figures 4 and 5, the basis weight G and / or film thickness D are measured downstream of the load roll 22 of the first rolling mill 16 and upstream of the load roll 22 of the second rolling mill 18.

[0054] In the case of a substrate 12 coated on both sides, both rolling mills 16 and 18 are further controlled so that the difference between the two film thicknesses D is minimized, i.e., so that the material film 14 is automatically formed to the same thickness.

[0055] Optionally, in one embodiment, the filling level of the material 26 upstream of the film-forming gap 24 is further adjusted to a target value of the filling level, i.e., the filling level is adjusted, according to the actual value F of the filling level, or according to the basis weight G and / or film thickness D. This is illustrated in Figure 6 and is applicable to the embodiments in Figures 2 to 5. This ensures that the gusset 30 of the roll pair 20 is neither empty nor overflowing. The filling level adjustment is performed decentrally, and thus independently of the adjustment of the basis weight G and / or film thickness D, in particular by simply measuring the actual value F of the filling level and then controlling the supply of material 26 to the gusset 30 accordingly. Alternatively, the filling level adjustment is performed centrally, in particular by controlling the supply according to the basis weight G and / or film thickness D.

[0056] Optionally, the lamination gap 38 is also controlled, for example, according to the basis weight G and / or film thickness D.

[0057] The control unit 40 undertakes one or more of the control and adjustment tasks described above. All control and adjustment tasks are either centrally implemented within individual control units 40 or distributed among multiple corresponding control units 40, as shown in Figures 2 to 5. For example, the adjustments of the film thickness D and basis weight G are implemented independently of each other in separate control units 40. [Explanation of symbols]

[0058] 2. Rolling mill 4 Electrode Web 6 batteries 8. Drive system 10 vehicles 12 Base material 14. Material Film 16 (First) Rolling Mill 18 (Second) Rolling Mill 20 Rolls vs. 22 Roll to be attached 24 Film formation gap 26 Material 28 Metering device 30 gussets 32 Shear Rolls 34 Transfer Rolls 36 Opposing Roll 38 Gap (Lamination gap) 40 Control Units 42 measuring units 44 Regulator B1 Gap width (film formation gap) B2 Gap width (laminated gap) D Film thickness Actual value of F filling level G Basis weight U1,U2,U3 Circumferential speed

Claims

1. A method for operating a rolling mill (2) for manufacturing an electrode web (4), a. The rolling apparatus (2) has a rolling mill (16, 18) which comprises a pair of rolls (20) and adherend rolls (22) that are individually formed with respect to the pair of rolls (20) or are part of the pair of rolls (20), for forming a material film (14) for the electrode web (4), b. The substrate (12) for the electrode web (4) is supplied to the adherend roll (22), c. The rolling mill (16, 18) has a film-forming gap (24) formed by the roll pair (20), and the film-forming gap (24) releases a predetermined amount of material (26), thereby forming the material film (14). d. The material film (14) is attached to the adherend roll (22), and then transferred from the adherend roll (22) to the substrate (12). e. The material film (14) has a basis weight (G) and a film thickness (D), f. The basis weight (G) is adjusted to a target value, and for that purpose, the rolling mill (2) is controlled according to the basis weight (G). g. In order to adjust the basis weight (G) to a target value, the rolling mill (2) has a control unit (40), and at least one measuring unit (42) and at least one regulator (44), wherein the at least one measuring unit (42) and at least one regulator (44) are connected to or part of the control unit (40), h. Before handing over to the substrate (12), the basis weight (G) is measured on the roll-supported material film (14). The roll pair (20) has two rolls which are operated at different peripheral speeds (U1, U2) to form the material film (14), The rolling mill (2) is controlled by adjusting the difference in peripheral speeds (U1, U2) according to the target value of the basis weight (G). The basis weight (G) is adjusted before the material film (14) is delivered onto the substrate (12). method.

2. The method according to claim 1, wherein the rolling apparatus (2) is controlled by adjusting the gap width (B1) of the film forming gap (24).

3. The method according to claim 1, wherein the basis weight (G) of the material film (14) is measured while the material film (14) is attached to the attachment roll (22).

4. A method for operating a rolling mill (2) for manufacturing an electrode web (4), a. The rolling apparatus (2) has a rolling mill (16, 18) which comprises a pair of rolls (20) and adherend rolls (22) that are individually formed with respect to the pair of rolls (20) or are part of the pair of rolls (20), for forming a material film (14) for the electrode web (4), b. The substrate (12) for the electrode web (4) is supplied to the adherend roll (22), c. The rolling mill (16, 18) has a film-forming gap (24) formed by the roll pair (20), and the film-forming gap (24) releases a predetermined amount of material (26), thereby forming the material film (14). d. The material film (14) is attached to the adherend roll (22), and then transferred from the adherend roll (22) to the substrate (12). e. The material film (14) has a basis weight (G) and a film thickness (D), f. The basis weight (G) is adjusted to a target value, and for that purpose, the rolling mill (2) is controlled according to the basis weight (G). g. In order to adjust the basis weight (G) to a target value, the rolling mill (2) has a control unit (40), and at least one measuring unit (42) and at least one regulator (44), wherein the at least one measuring unit (42) and at least one regulator (44) are connected to or part of the control unit (40), h. Before handing over to the substrate (12), the basis weight (G) is measured on the roll-supported material film (14). The rolling apparatus (2) has a transfer roll (34), the transfer roll (34) is positioned upstream of the adhered roll (22), and the material film (14) is transferred from the film forming gap (24) to the adhered roll (22) via the transfer roll (34). The rolling mill (2) By adjusting the difference in peripheral speeds (U2, U3) between the transfer roll (34) and the adherend roll (22) according to the target value of the basis weight (G), Control, The basis weight (G) is adjusted before the material film (14) is delivered onto the substrate (12). method.

5. The method according to claim 4, wherein the basis weight (G) of the material film (14) is measured while the material film (14) is attached to the transfer roll (34).

6. The method according to claim 1 or 4, wherein the substrate (12) is coated on both sides by the rolling mill (2).

7. The material film (14) is attached to the first surface of the substrate (12). The rolling apparatus (2) has further rolling mills (16, 18) which are attached to the second surface of the substrate (12) on the opposite side and form a further material film (14) having a film thickness (D), Both rolling mills (16, 18) are controlled so that the thickness (D) of both films is the same. The method according to claim 1 or 4.

8. The method according to claim 1 or 4, wherein the material (26) does not contain any liquid components or contains up to 3% by weight of liquid components.

9. The method according to claim 1 or 4, wherein the film thickness (D) is adjusted to a target value, and for that purpose, the rolling apparatus (2) is controlled according to the film thickness (D).

10. It has a control unit (40), The control unit (40) is configured to carry out the method described in claim 1 or 4. Rolling mill (2).

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