Rollers used in the dry coating process for electrode manufacturing

Abstract

The present invention relates to a roller (1) for use in a dry coating process for manufacturing electrodes, the roller comprising a roller core (3) made of a core material and a roller shell (4) made of a shell material, the roller shell surrounding the roller core at least in a section, the shell material having a greater hardness than the core material, and the roller core comprising a device for tempering the roller shell.

Description

[Technical field]

[0001] The present invention relates to a roller for use in a dry coating process for manufacturing electrodes, the roller including a roller core made of a core material and a roller shell made of a shell material, the roller shell surrounding the roller core at least in section.

[0002] Up to now, battery and supercapacitor electrodes (anodes and cathodes) have been mainly processed using wet chemical methods. For this purpose, the respective active material, conductive additives and binders are dispersed in a liquid phase (water- or solvent-based) and then the resulting paste is applied to a current collector (film or foam structure). A further process step involves drying the electrodes. The dryer lines used are long and consume a lot of energy to operate. Furthermore, in order to comply with the applicable environmental regulations, essential peripheral equipment is also required to separate the sometimes toxic solvents from the exhaust air.

[0003] A new manufacturing technology for battery electrodes is the dry coating process. This does not require the use of solvents and consumes less energy. The dry coating process therefore has the potential to significantly reduce production costs. The dry coating process includes two key steps. First, the powders of active material, additives and binders are mixed in a dry mixing process. The decisive factor here is the structure and distribution of the polymer binder. An optimal distribution of the polymer fibrils results in a mechanically stable free-standing film even at low binder contents of less than 5 weight percent. In the second process step, the powder material obtained in the mixing process can be pressed to form an electrode film with a thickness of about 50-100 μm, either free-standing or on a current collector as a substrate. A uniform distribution of the powder material is crucial here. Especially when different starting powders are used, the challenge is to process them successively into a wound electrode film.

[0004] A major challenge in the field of electrode manufacturing using dry coating processes is to produce electrodes accurately while minimizing thickness variations. The large overall size of the rollers required to economically produce electrodes, combined with the thermal expansion of the roller material, allows the roller diameter to vary significantly, directly affecting the thickness and other dimensions of the electrode. However, the precise thickness of the electrode is a critical quality feature during the manufacture of electrochemical cells such as lithium ion batteries. The thickness of the electrode must be uniform across its entire length and width. During the manufacture of lithium ion batteries, such as cylindrical, prismatic, or pouch batteries, the electrode foil is prepared and laminated with other layers, such as separators and current collectors, and then the entire laminated continuous foil is cut to specific lengths. The cut composite film is wound into a lithium ion battery. Variations in either thickness across the length or width of the electrode can cause the size of the wound film layers resulting from the above process to vary, resulting in inaccurate windings. For these reasons, improved systems, processes, and devices are needed to ensure accuracy in electrode thickness.

[0005] Another problem in the field of electrode manufacturing using dry coating processes is the possibility of damage to the roller surface by dirt, particles, or for example agglomerated electrode coating material. When particles are deposited on the surfaces of rollers that are in contact with each other during machine operation, they are pressed between the rollers. When such particles are pressed between the rollers, they are subjected to large localized forces on the roller surface, which can damage the roller if the allowable surface pressure is exceeded. This is known as contact fatigue and is manifested in the form of fatigue holes on both surfaces of the rollers where the roller gap is formed. Contact fatigue has a negative impact on the quality of the electrode, since it results in surface defects on the rollers. In a live manufacturing environment, it is necessary to prevent the formation of pits, surface deformations, and other undesirable microstructural features that accumulate on the surface of the rollers. Since the surface of the electrodes needs to be precise and uniform, even small damage caused by inclusions can affect the function of the electrodes when they are assembled and used in the final product. Therefore, it is necessary to increase the hardness of the rollers to prevent damage due to pressure concentrations of impurities.

[0006] It is therefore necessary to provide a roller for producing electrodes which, on the one hand, ensures a uniform thickness of the material web passing through the roller gap and, on the other hand, is resistant to damage to the roller surface.

[0007] That is, the roller gap must remain constant, regardless of the load and the external environment, for example by maintaining a precise and uniform temperature across the roller gap, while the surface of the rollers must be as hard as possible.

[0008] SUMMARY OF THE PRESENT EMBODIMENT It is therefore an object of the present invention to provide a roller for producing electrodes, which is capable of producing electrodes of uniform thickness and quality.

[0009] It is therefore provided that the shell material has a greater hardness than the core material and that the roller core has a device for tempering the roller shell. This configuration has the advantage that the roller has a high hardness, since the roller shell is on its surface to produce the electrode, and that the core is relatively soft and therefore shows good processability, so that the roller core can be easily machined, in particular machined to accommodate a device for tempering the roller shell. This provides a solution to the problem that the shaft must have the greatest possible hardness on the one hand and have a device for influencing the roller gap on the other hand. The invention therefore meets the contradictory requirements of both properties. A hard shaft alone is difficult to machine and therefore the tempering function cannot be realized. On the other hand, a soft shaft alone is not suitable for the manufacture of dry electrodes.

[0010] For example, it may be provided that the roller core or substrate is made of a slightly hardened steel, for example a tempered steel such as 42CrMo4, thus having good workability and facilitating milling. The roller core or substrate may also consist of or contain a nickel-based alloy. It may further be provided that the roller shell is made of a hard material, such as a hardened cold-worked steel, having maximum resistance. Good workability of the shell material is not necessary and is obviously undesirable. The shell may be shrunk or clamped on the roller core. A further advantage of this arrangement is that solid shafts made from pre-forged cold-worked steel cannot be manufactured in the size and hardness required for the manufacture of electrodes. To manufacture batteries, roller bodies with large diameters are required. Bodies such as these can only be hardened from the outside using a water shower or an oil bath. However, solid shafts of this size have a very high heat capacity. When they are heated in a hardening furnace, the roller surface is repeatedly relaxed due to the heat flow from inside the roller body, so they cannot be hardened to the desired extent. In this way, a toughened structure can be achieved only within the range of up to 3-4 mm deep into the roller surface. It is therefore advantageous to design the roller shell as a tubular structure and mount it on the roller core, since in this way the roller shell can be heated and quenched simultaneously from the inside and outside and does not have as large a heat capacity as a solid shaft, so that the heat flow from the inside of the roller shell during quenching is correspondingly less than in the case of a solid shaft. This allows through-hardening of tubes up to 20 mm and more. The configuration of a shaft with a soft roller core and a hard roller shell in the form of a tubular structure mounted on the roller core has two major advantages. Firstly, as mentioned above, with the roller shell a better through-hardening can be achieved, since it can be quenched especially simultaneously from both the inside and the outside. This makes it possible to increase the thickness of the hardened zone. On the other hand, there is no need to introduce cooling channels in the hard roller shell. Instead, they can be provided only in the softer core.

[0011] The invention further relates to a roller for use in a dry coating process for producing electrodes, the roller comprising a roller core made of a core material and a roller shell made of a shell material, the roller shell surrounding the roller core at least in a section, the shell material having a greater hardness than the core material, the roller shell and the roller core being designed as separate components, the essentially tubular roller shell being fastened to the roller core in a pressure locking and / or form locking manner, the roller shell being made of a hardenable steel, such as a cold work steel, the surface of which is through-hardened to a depth of at least 5 mm. However, if the shell material is through-hardened to a depth of a few millimeters, for example to at least 5 mm, this has the advantage of preventing hard particles from penetrating the hardened coating. On the other hand, if the coating is thin, it may happen that, instead of the coating itself being damaged by local pressure peaks, the softer roller core material underneath the coating is damaged if the surface pressure in the roller gap is too high. This effect can be avoided by providing a minimum thickness of the coating or hardened roller shell.

[0012] The present invention also relates to a roller for use in a dry coating process for producing an electrode, the roller comprising a roller core made of a core material and a roller shell made of a shell material, the roller shell surrounding the roller core at least in a section, the roller core having a device for tempering the roller shell, the device for tempering the roller shell having a plurality of tempering zones independently segmented in the axial direction of the roller, and can be set to individual temperatures in each tempering zone. During electrode production, temperature fluctuations or material distribution fluctuations across the roller gap can occur. This can lead to local irregularities in the size of the roller gap. For example, due to certain operating fluctuations, the roller gap in the center of the roll can be temporarily narrower than the roller gap in the outer region of the roll pair. This difference can be compensated for by controlling the tempering zones in the edge regions in response to generating higher temperatures in the edge regions of the roller gap, such that the rollers in the corresponding regions further expand and the roller gap decreases due to the generation of higher temperatures. On the other hand, if the roller gap is larger in the center region than in the edge regions, the tempering zone in the center roller region can be controlled such that the roller gap in the center region decreases as a result of the higher temperature.

[0013] It may be provided that the shell material is applied as a coating to the roller core or roller shell. The coating may comprise chromium, diamond-like carbon (DLC), tungsten carbide, or a metal matrix composite such as a tungsten carbide / cobalt alloy or a chromium carbide / nickel chromium composite. DLC coatings and PVD coatings including tungsten carbide can be CVD-coated onto the calender roll to increase the hardness of the roller and prevent damage caused by impurities exerting high pressure on the roll. The thickness of the coating may be between 1 μm and 50 μm.

[0014] It may be provided that the coating of the roller is carried out in a vacuum environment. In the negative pressure environment, the uncoated roller may be exposed to a volatile precursor. The volatile precursor may comprise one or more of tungsten hexachloride (WCl6) with hydrogen (H2) and methane (CH4), or alternatively WCL6 with H2 and methanol (C3OH). In this way, a tungsten carbide layer may be deposited. As mentioned above, tungsten carbide may be deposited by chemical vapor deposition, although other CVD processes such as plasma activated chemical vapor deposition (PACVD) may also be used. Once deposition is complete, the roller may be removed from the low pressure environment.

[0015] Additionally, a primer layer can be provided between the roller surface and the coating to improve the protection or surface adhesion of the coating. The primer layer can include one or more of diamond-like coating (DLC), tungsten carbide (WC), or copper (Cu). The composition and microstructure of the diamond-like coating can be customized according to the requirements of surface hardness, chemical resistance, toughness, and other desired properties. The diamond-like coating can include one or more of the following forms: ta-C (tetrahedrally bonded hydrogen-free amorphous carbon), aC:H (hydrogen-containing amorphous carbon), aC:H:Me (Me=W, Ti, metal-doped amorphous carbon with hydrogen), aC:H:Si (Si-doped amorphous carbon with hydrogen), aC:H:X (nonmetal-doped amorphous carbon with hydrogen), aC:Me (Me=Ti, metal-doped hydrogen-free amorphous carbon), ta-C:H (tetrahedrally bonded amorphous carbon with hydrogen).

[0016] It can also be provided that the roller shell has a hardness of at least 53 HRC, preferably at least 57 HRC, particularly preferably at least 62 HRC.

[0017] It can further be provided that the roller shell and the roller core are designed as separate components and that the essentially tubular roller shell is attached to the roller core in a force-fit and / or form-fit manner.

[0018] The roller shell can be fixed to the roller core by shrinkage and / or cold expansion. In case of heat shrinkage or cold expansion, the roller shell and roller core need to be designed to be oversized at room temperature. When the roller shell is heated or the roller core is cooled, a clearance is created between the two components so that the roller shell can be pressed onto the roller core. During cold stretching, the diameter of the roller core decreases upon cooling due to the shrinkage process. The roller shell shrinks as it cools and tightly encapsulates the roller core. This therefore results in a shrinkage interlock between the two components after they return to normal temperature.

[0019] It may also be provided that the roller shell is fixed to the roller core by a clamp connection.

[0020] It can also be envisaged that the roller shell has a wall thickness of at least 10 mm, preferably at least 15 mm, particularly preferably at least 20 mm. Furthermore, it can be provided that the roller shell is provided with a coating.

[0021] It may be provided that the roller shell consists of a hardenable steel, such as cold work steel, and at least its surface is through hardened to a depth of at least 5 mm.

[0022] In particular, it can be provided that the roller shell is through-hardened over the entire cross section of the pipe wall.

[0023] It may further be provided that the roller core consists of a heat treatable steel such as 42CrMo4, or a machinable steel such as a case hardening steel.

[0024] It can also be envisaged that the device for tempering the roller shell has at least one heating and / or cooling element integrated in the roller core. It can also be provided that the device for tempering the roller shell is an induction heating element. The device for tempering the roller shell can be configured to be able to maintain a predetermined operating temperature of the roller during the production run. By setting a predetermined operating temperature, it is possible to adjust the thermal expansion of the roller during operation that correlates to the operating temperature. The device for tempering the roller shell can be a resistive element. For example, the device for tempering the roller shell can be a resistive coil. Alternatively, the device for tempering the roller shell can be inductive. It can also be envisaged that several types of heating elements can be combined to set the roller to a specific temperature. The device for tempering the roller shell can be embedded in the roller at a certain depth below the roller surface to heat the roller surface uniformly. For example, the device for tempering the roller shell can be arranged on the central axis of the roller or in a cavity around the central axis of the roller.

[0025] The device for tempering the roller shell may include several heating elements. The heating elements may be wrapped in an electrical insulator to ensure that the current remains within the heating element and is not conducted through the roller. The electrical insulator may be electrically insulating and thermally conductive. The electrical insulator may include ceramics such as silica, alumina, steatite (a magnesium silicate mineral), cordierite (a mineral that contains iron, magnesium, aluminum and silicon, but does not contain iron in synthetic form), as well as polymers. If a polymer is used, it may contain components that are thermally conductive but electrically insulating, such as aluminum oxide or boron nitride. Since the roller may undergo uniform cyclic bending during operation, the insulator may be flexible, such as fiberglass or polymer, or may be omitted if an induction heating element is used.

[0026] The roller core may be hollow and may contain a gas such as air. An electric heating element may be located within the core. The core may have openings that allow a gas or fluid to circulate to control the temperature of the roller.

[0027] The heating element may be electrically connected to a power source external to the roller. For example, the power interface may consist of electrical contacts at both ends of the roller. Alternatively, the roller has electrical contacts at only one end of the roller.

[0028] The roller may also include one or more air cooling channels. The cooling channels may extend through the roller core. The channels may be passively or actively cooled by a cooling gas or liquid, such as compressed air, nitrogen, or other substances, using a system external to the roller. The cooling channels may be supplied with a cooling medium by an active component, such as a fan, blower, pump, or compressor. The cooling medium may be circulated during operation to further control the temperature of the roller. The cooling gas may be provided at ambient temperature (e.g., about 18° C. to about 24° C., or about 20° C.), at a temperature greater than ambient temperature, or at a temperature less than ambient temperature.

[0029] The roller may also include one or more sensors for measuring temperature. The temperature sensor may be a resistive temperature sensor. For example, a single temperature sensor may be located either in the center of the roller or near the running surface of the roller, i.e. near the roller surface. It is also possible that one or more temperature sensors are attached to the outside of the roller to measure the temperature dissipated by the roller.

[0030] The heating elements, active cooling elements, and / or temperature sensors may be integrated into a control circuit or regulation circuit outside of the roller. The control circuit may include one or more processors, a storage medium for storing data and programming instructions / settings, and a communication interface.

[0031] It can also be provided that the device for tempering the roller shell comprises a plurality of tempering zones that are independently segmented in the axial direction of the roller, each tempering zone being able to be set to an individual temperature.

[0032] By using individual tempering zones, it is possible to vary the outer diameter of the roller at various points across its width to produce an electrode of as uniform a thickness as possible across the entire width of the roller gap, depending on the local variations in operating parameters.

[0033] Each tempering zone may include one or more heating elements that do not overlap with the other zones. Each heating element may have a separate power source. For example, a device for tempering a roller shell may include multiple axially adjacent inductors housed in the roller core. Each inductor may include separate electrical contacts or a separate power source. Furthermore, each inductor may be assigned a separate temperature sensor to detect the temperature locally. Data from the temperature sensors may be transmitted to a higher-level control device via a data cable on one end face.

[0034] It may be provided that the roller core has an axial bore, in which at least one heating and / or cooling element is accommodated.

[0035] Alternatively, it can be provided that the device for tempering the roller shell is a temperature radiator housed in the axial bore of the roller core.

[0036] It may further be provided that the roller core has functional holes in the form of fluid channels extending in at least a section on the outer surface of the roller core.

[0037] The invention further relates to a roller assembly for use in a dry coating process for producing electrodes, the roller assembly comprising two rollers forming a roller gap between them, at least one of which is designed as a roller according to any one of the preceding claims, and further comprising at least two detection devices spaced apart from each other orthogonally to the conveying direction of the electrode for detecting a thickness of the electrode produced in the roller gap, the roller assembly further comprising a control device designed to compare the at least two detected actual thicknesses with a target thickness, wherein upon detection of a deviation of one of the actual thicknesses from the target thickness, the tempering zones assigned to the respective detection devices are controlled by the control device in such a way that the respective actual thickness approaches the target thickness.

[0038] It may be provided that each tempering zone is assigned at least one detection device. The detection device may be a sensor for detecting the thickness of the electrode. The sensors for measuring the thickness of the produced electrode are arranged at regular intervals across the width of the roller gap and may be part of a control system, which controls the individual tempering zones in response to the individual thickness measurements recorded in the different tempering zones so as to successively bring the thickness of the produced electrode closer to a target value. The detection device may also be a temperature sensor, which detects the respective temperature in each tempering zone. It may be provided that when the temperature is detected in a tempering zone, the thickness of the produced electrode in this area is known or can be derived from the detected temperature, since the thickness of the produced electrode is known as a function of temperature.

[0039] Using a tempering zone, it is possible to control the temperature expansion of the roller body so that the roller gap between two rollers can be adjusted as evenly as possible over the entire roller width, or crowning can be avoided or corrected.

[0040] The present invention further relates to a method of manufacturing an electrode, the method comprising the step of contacting an electrode precursor material with a roller, the roller comprising a roller core comprising a core material and a roller shell comprising a shell material, the roller shell surrounding the roller core at least in a section, the roller material having a greater hardness than the core material, and the roller core comprising a tempering device for tempering the roller shell.

[0041] The device for tempering the roller shell may include a plurality of tempering zones independently segmented in the axial direction of the roller, each tempering zone being set to a separate temperature, and the method may further include setting the temperature in at least one tempering zone independently from the other tempering zones.

[0042] The present invention further relates to a method of manufacturing an electrode, the method comprising the steps of: a roller assembly having two rollers forming a roller gap therebetween and at least two detection devices for detecting thickness; contacting an electrode precursor material with a roller assembly; detecting a thickness of the electrode formed in the roller gap by at least one detection device; and adjusting a temperature of at least one of the rollers based on the detected electrode thickness.

[0043] The present invention further relates to an electrochemical laminate comprising at least one electrode layer formed by calendering an electrode precursor material with a roller, the roller comprising: A roller core made of a core material; a roller shell made of a shell material and surrounding the roller core in at least a section; Including, the shell material has a greater hardness than the core material; The roller core includes a device for tempering the roller shell. [Brief description of the drawings]

[0044] Exemplary embodiments of the invention are described with reference to the following drawings. [Figure 1] 1 shows a cross-sectional view of an embodiment of a roller according to the present invention. [Diagram 2] 1 illustrates a perspective view of an embodiment of a roller in a half section according to the present invention. [Diagram 3] 1 shows a perspective view of an embodiment of a roller according to the present invention. [Figure 4] 1 shows a schematic cross-sectional view of an embodiment of a roller according to the present invention. [Diagram 5] FIG. 2 shows a detailed view of an embodiment of the tempering zone of a roller according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] FIG. 1 shows a cross-sectional view of an embodiment of a roller 1 according to the invention, which can be used in a dry coating process for manufacturing electrodes. The roller 1 has a roller body formed by a roller core 3 and a roller shell 4. The roller core 3 consists essentially of a soft core material. The roller core 3 is surrounded by a roller shell 4, which consists essentially of a shell material. The roller core is provided with an axial bore 8, which defines a cavity in the roller core 3. A device 5 for tempering the roller shell 4 is accommodated in the axial bore. The device 5 for tempering the roller shell 4 has a plurality of independently segmented tempering zones 6 in the axial direction X of the roller 1, each tempering zone 6 being able to be set to an individual temperature. In the illustrated embodiment, the device 5 for tempering the roller shell 4 has a total of 12 tempering zones 6, each tempering zone 6 being formed by a separate inductor 9. All inductors 9 have the same dimensions and are spaced apart by the same distance. Furthermore, each inductor 9 has a separate voltage contact 20 and each inductor is assigned a separate temperature sensor 15. The recorded temperature data are transmitted via a data cable 23 to a higher-level control unit, which compares the received actual values ​​with the respective target values ​​and adjusts the power supply to the individual inductors 9 accordingly. This allows each tempering zone 6 to be set to an individual temperature. With an increase in temperature, the material of the roller core 3 and the roller shell 4 expands, so that the outer diameter of the roller 1 increases accordingly, and as a result the roller gap between the two rollers 1 through which the electrode material passes is reduced. By providing several individually controllable tempering zones 6, it is possible to influence the outer diameter of the roller 1 and thus the roller gap individually over the entire width of the roller gap in the sections of the individual tempering zones 6. The inductors 9 are mounted at a fixed distance from each other on a support shaft 18, which is accommodated in the axial bore 8 of the roller 1. The support shaft 18 is mounted in the axial bore 8 via a spherical roller bearing 24, so that the support shaft 18 together with the inductors 9 mounted thereon can rotate relative to the roller body.During operation, the roller body, i.e. the roller core 3, together with the roller shell 4 surrounding it, rotates around a stationary support shaft 18, on which the inductors 9 are attached. The support shaft 18 also has an axial hole itself, which is used to pass cooling air to protect the inductors 9 or their electrical contacts 20 from overheating. At one end of the roller 1, the support shaft 18 has a compressed air connection 22 for supplying cooling air to the axial hole of the support shaft 18. At the opposite end, the cooling air duct has a radial hole, which serves as an air outlet 19 for the compressed air. At the axial opposite sides of the roller body are the bearing points 14, through which the roller 1 is attached. In both cases, the journals 17 protrude beyond this point. Furthermore, slip rings 21 are attached to one of the journals 17, shown on the right side of the figure, ensuring the transmission of power or signals between the components rotating relative to each other. Connected to the slip rings are the power supply connections 25 between the control unit and the individual inductors 9, as well as data cables 23 for the transmission of signals between the temperature sensors and the control unit. The roller core 3 also comprises cooling holes 16 which extend in the region of the roller body approximately parallel to the roller axis X. In the region of the bearing points 14 the cooling holes 16 extend a shorter distance from the roller axis X. Between the cooling holes 16 of the roller core 3 and the cooling holes 16 of the bearing points 14 an obliquely extending connecting channel is provided which connects the cooling holes 16 of the roller core 3 with the cooling holes 16 of the bearing points 14.

[0046] FIG. 2 shows a perspective view of an embodiment of a roller in a half section according to the invention from FIG. 1. The roller 1 has a journal 17 at each of its outer ends, which journals are connected to the bearing points 14 directly adjacent to the roller body. The lower journal 17 shown in the figure is fitted with a slip ring 21, to which wiring for transmitting power or signals is connected. Also visible is a support shaft 18 extending through the roller body, on which twelve inductors 9 are fitted. It can be seen that the inductors 9 each surround the support shaft 18 in the shape of a ring. The support shaft 18 extends to the end face on the side of the roller 1 that has the slip ring 21 and protrudes from the journal 17. Here, in the axial bore of the support shaft 18 provided for the air guide, an air connection 22 is arranged for supplying cooling air for cooling the inductors 9. It can also be seen that the bearing points 24 of the support shaft 18 are respectively arranged between the roller body and the bearing points 14 in the axial direction X. It can also be seen that the support shaft 18 has a plurality of air outlets 19 near the bearing point 24 of the support shaft 18, which are radially aligned in different directions.

[0047] FIG. 3 shows a perspective view of an embodiment of a roller 1 according to the invention. It basically has a roller body consisting of a roller core 3 and a roller shell 4, the latter being made of a harder material than the roller core 3. The roller shell 4 is provided with a roller surface and is used to generate electrodes in the roller gap. The roller body is axially connected to bearing points 14 by means of which the roller 1 can be supported in rotation. One of the bearing points 14 is connected to a journal 17 by means of which the roller 1 can be driven. The other bearing point 14 is connected to a slip ring 21 to which the connections for power and signal transmission lead. On the one hand, a data cable 23 leads to the slip ring, by means of which the data cable 23 is connected to a control unit. On the other hand, the slip ring is connected to a power cable 25 by means of which the inductors 9 inside the roller body can be individually powered.

[0048] FIG. 4 shows a schematic cross-section of a roller 1 used in a dry coating process for producing an electrode 2. This roller basically comprises a roller core 3 which on the one hand consists of a core material which is a machinable steel. The steel of the core material can also be a heat-treatable steel, for example, in particular 42CrMo4, or a case-hardened steel. On the other hand, the roller 1 comprises a roller shell 4 which surrounds the roller core 3 in the form of a ring. The roller shell 4 consists of a shell material which has a greater hardness than the core material. The hardness of the roller shell 4 is at least 53 HRC (hardness according to Rockwell, scale C), preferably at least 57 HRC, particularly preferably at least 62 HRC. For example, the roller shell 4 can be made of a hardenable steel, such as a cold-work steel. The surface of the roller shell is through-hardened to a depth of at least 5 mm. In the illustrated embodiment, the roller shell 4 and the roller core 3 are designed as separate components, the tubular roller shell 4 being friction-locked to the roller core 3. The roller shell 4 is fixed to the roller core 3 by shrinkage of the roller shell 4 and / or cold expansion of the roller core 3. The roller shell 4 has a wall thickness D of at least 10 mm, preferably at least 15 mm, particularly preferably at least 20 mm. The roller shell 4 is preferably through-hardened over the entire cross section of the tube wall.

[0049] FIG. 5 shows a detailed view of an embodiment of the roller 1 in a half section according to the invention. In particular, a cross section through the inductor 9 as well as the support shaft 18 and its bearing 24 is shown. It can be seen that the copper coil or inductor 9 has several copper wires. The number and thickness of the copper wires per inductor can be determined so as to be able to achieve the necessary heating power to adjust the roller gap. Since each inductor 9 has its own electrical contact 20, each inductor 9 has its own power source, so that the resulting different tempering zones 6 can be used to control the deflection of the roller 1. A small distance is provided between each inductor. It can be seen that the support shaft 18, housed in the axial bore 8 of the roller 1, is mounted to the roller 1 via a spherical roller bearing 24. An air duct formed in the support shaft 18 has several air outlets 19 extending radially from the air duct and opening into the interior of the roller 1 housing the inductors 9. The air outlets 19 serve to cool this interior.

[0050] The features of the invention disclosed in the above description, in the drawings and in the claims may be essential for the realization of the invention both individually and in any combination. [Explanation of symbols]

[0051] (List of reference numbers) 1 Roller 2 electrodes 3 Roller Core 4 Roller Shell 5. Device for tempering roll shells 6 Tempering Zone 7 Heating or cooling elements 8 Axial hole 9. Inductors 10 Fluid Channels 11 Roller Assembly 12 Roller gap 13 Detection device for detecting electrode thickness 14 Bearing points 15 Temperature Sensor 16 Cooling hole section 17 Journals 18 Support shaft 19 Air outlet 20 Electrical Contacts 21 Slip ring 22 Air connection 23 Data Cable 24 Spherical roller bearing 25 Power Cable 26 Air Duct

Claims

1. A roller (1) for use in a dry coating process for producing an electrode (2), comprising: A roller core (3) made of a core material; a roller shell (4) made of a shell material, said roller shell (4) surrounding said roller core (3) at least in a section; Including, the shell material has a greater hardness than the core material; The roller, wherein the roller core (3) has a device (5) for tempering the roller shell (4).

2. A roller (1) for use in a dry coating process for producing an electrode (2), comprising: A roller core (3) made of a core material; a roller shell (4) made of a shell material, said roller shell (4) surrounding said roller core (3) at least in a section; Including, the shell material has a greater hardness than the core material; said roller shell (4) and said roller core (3) being designed as separate components, said essentially tubular roller shell (4) being attached to said roller core (3) in a force-fit and / or form-fit manner, The roller, wherein the roller shell (4) is made of hardenable steel, such as cold work steel, and at least its surface is through-hardened to a depth of at least 5 mm.

3. A roller (1) for use in a dry coating process for producing an electrode (2), comprising: A roller core (3) made of a core material; a roller shell (4) made of a shell material, said roller shell (4) surrounding said roller core (3) at least in a section; Including, The roller core (3) has a device (5) for tempering the roller shell (4), The device (5) for tempering the roller shell (4) has a plurality of independently segmented tempering zones (6) in the axial direction (X) of the roller (1), each of the tempering zones (6) being capable of being set to an individual temperature.

4. The roller (1) according to any one of the preceding claims, wherein the shell material is applied as a coating to the roller core (3) or to the roller shell (4).

5. 5. The roller (1) of claim 4, wherein the coating comprises chromium, diamond-like carbon, tungsten carbide, or a metal matrix composite such as a tungsten carbide / cobalt alloy or a chromium carbide / nickel chromium composite.

6. 10. The roller (1) according to any one of the preceding claims, wherein the roller shell (4) has a hardness of at least 53 HRC, preferably at least 57 HRC, particularly preferably at least 62 HRC.

7. 10. The roller (1) according to any one of the preceding claims, wherein the roller shell (4) and the roller core (3) are designed as separate components, and the essentially tubular roller shell (4) is attached to the roller core (3) in a pressure-locking and / or form-locking manner.

8. 8. The roller (1) according to claim 7, wherein the roller shell (4) is fixed to the roller core (3) by shrinkage and / or cold expansion.

9. 8. The roller (1) according to claim 7, wherein the roller shell (4) is fixed on the roller core (3) by a clamp connection.

10. 10. The roller (1) according to any one of the preceding claims, wherein the roller shell (4) has a wall thickness (D) of at least 10 mm, preferably at least 15 mm, particularly preferably at least 20 mm.

11. 2. A roller (1) according to any one of the preceding claims, wherein the roller shell (4) is made of hardenable steel, such as cold work steel, the surface of which is through-hardened to a depth of at least 5 mm.

12. 12. The roller (1) according to claim 11, wherein the roller shell (4) is through-hardened over the entire tube wall cross section.

13. 10. The roller (1) according to any one of the preceding claims, wherein the roller core (3) is made of a heat treatable steel such as 42CrMo4 or a machinable steel such as a case hardening steel.

14. The roller (1) according to any one of claims 1 or 3 to 13, wherein the device (5) for tempering the roller shell (4) comprises at least one heating and / or cooling element (7) integrated in the roller core (3).

15. The roller (1) according to any one of claims 1, 2 or 4 to 14, wherein the device (5) for tempering the roller shell (4) provides a plurality of independently segmented tempering zones (6) in the axial direction (X) of the roller (1), each of the tempering zones (6) being able to be set to a separate temperature.

16. 16. The roller (1) according to claim 14 or 15, wherein the roller core (3) has an axial bore (8) in which the heating and / or cooling element (7) is accommodated.

17. The roller (1) according to any one of claims 1, 2 or 4 to 16, wherein the device (5) for tempering the roller shell (4) is an induction heating element (9).

18. The roller (1) according to any one of claims 1, 2 or 4 to 16, wherein the device (5) for tempering the roller shell (4) is a temperature radiator received in the axial bore (8) of the roller core (3).

19. The roller (1) according to any one of claims 1, 2 or 4 to 18, wherein the roller core (3) has functional holes formed as fluid channels (10), the functional holes extending within at least a section on an outer surface of the roller core (3).

20. A roller assembly (11) for use in a dry coating process for producing an electrode (2), comprising: It comprises two rollers (1) forming a roller gap (12) between the two rollers, at least one roller (1) of the two rollers being designed as a roller according to any one of the preceding claims, at least two detection devices (13) spaced apart perpendicular to the conveying direction of the electrode (2) for detecting the thickness of the electrode (2) produced in the roller gap (12), The roller assembly (11) also includes a control device (14) designed to compare the at least two detected actual thicknesses with a target thickness, and when a deviation of one of the actual thicknesses from the target thickness is detected, the tempering zone (6) assigned to each of the detection devices (13) is activated by the control device (14) so ​​that each of the actual thicknesses approaches the target thickness.

21. 21. A roller assembly (11) according to claim 20, wherein each tempering zone (6) is assigned at least one respective detection device (13).

22. 1. A method of manufacturing an electrode, comprising the steps of: contacting an electrode precursor material with a roller (1), The roller (1) is A roller core (3) made of a core material; a roller shell (4) made of a shell material, said roller shell (4) surrounding said roller core (3) at least in a section; Including, the roller material has a greater hardness than the core material; The method, wherein the roller core (3) has a tempering device for tempering the roller shell (4).

23. said device (5) for tempering said roller shell (4) has a plurality of tempering zones (6) independently segmented in the axial direction (X) of said roller (1), each of said tempering zones (6) being capable of being set at a separate temperature; 23. The method according to claim 22, further comprising the step of setting the temperature in at least one tempering zone (6) independently from the other tempering zones (6).

24. 1. A method of manufacturing an electrode, comprising the steps of: by a roller assembly (11) having two rollers (1) forming a roller gap (12) therebetween and at least two detection devices (13) for detecting thickness, contacting an electrode precursor material with said roller assembly (11); detecting the thickness of the electrode formed in the roller gap (12) by at least one of the detection devices (13); adjusting the temperature of at least one of the rollers (1) based on the detected electrode thickness; The method comprising:

25. 1. An electrochemical laminate comprising at least one electrode layer formed by calendering an electrode precursor material with a roller (1), said roller (1) comprising: A roller core (3) made of a core material; a roller shell (4) made of a shell material, said roller shell (4) surrounding said roller core (3) at least in a section; Including, the shell material has a greater hardness than the core material; The electrochemical laminate, wherein the roller core (3) has a device (5) for tempering the roller shell (4).

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