Method for treating tension creases after continuous coating

Abstract

The invention relates to a method for treating at least one tab region of a carrier layer coated with at least one material, the at least one tab region running parallel to the applied material, wherein pressure and heat are simultaneously applied to the at least one tab region by at least one pair of rollers. The invention further relates to a device for treating at least one tab region of a carrier layer coated with at least one material.

Description

[0001] Cellforce Group GmbH MSP Ref: 49293 PT-WO CB / gro

[0002] METHOD FOR TREATING STRESS WRINKLES AFTER CONTINUOUS COATING

[0003] The invention relates to a method for treating at least one conductive area of ​​a substrate coated with at least one material, wherein the at least one conductive area runs parallel to the material. The invention further relates to a device for treating at least one conductive area of ​​a substrate coated with at least one material.

[0004] In the production of electrochemical storage devices, such as lithium-ion batteries, anode layers, cathode layers, and separators are typically assembled in alternating sequences. The anode and cathode layers are called electrode layers and consist of an electrically conductive substrate layer coated with an active material. The electrode layers are produced in a continuous process by coating the substrate layer with the active material. The edges of the substrate layer remain uncoated and later serve as conductors for the electrical contact of the electrode layers within a battery cell.

[0005] The continuous application of the active material in the form of a dry or wet coating by calender rolling requires high pressures. This results in local surface area increases of the substrate layer in the coated area and waviness in the uncoated areas or the conductive areas of the substrate layer. Due to the resulting waviness in the conductive areas, subsequent folding or cutting of the electrode layers cannot be carried out precisely. 49293 PT-WO CB / gro

[0006] The present invention therefore aims to provide a method for correcting wave formation in conductor areas as a result of coating processes. This objective is achieved by the features specified in claim 1. Further advantageous embodiments of the invention are part of the dependent claims.

[0007] According to one aspect of the invention, a method is provided for treating at least one conductive area of ​​a carrier layer coated with at least one material configured as an active material. The at least one conductive area of ​​the carrier layer extends parallel to the active material along a conveying direction in which the carrier layer can have its longest extent. The carrier layer with the applied active material serves as the basis for the production of electrode layers or electrode foils for electrochemical storage devices. For example, due to a continuous manufacturing process, the carrier layer can be configured as an electrically conductive strip that has a greater length in the conveying direction of the manufacturing process than perpendicular to the conveying direction. A conductive area can be arranged on one or both sides of an area with an active material applied to the carrier layer.

[0008] The process is not limited to the production of electrodes for battery cells or electrochemical energy storage devices. Rather, the at least one material can, in principle, be any coating designed as an active material, applied under pressure, for example by calendering, onto an electrically conductive or non-conductive substrate.

[0009] According to the invention, the at least one discharge area is simultaneously subjected to pressure and heat by at least one pair of rollers. For this purpose, the at least one discharge area of ​​a carrier layer already coated or provided with the active material is used. 49293 PT-WO CB / gro

[0010] In particular, at least one discharge area is subjected to pressure and heat following coating and optional cutting of the carrier layer.

[0011] The pressure is applied by at least one pair of rollers specifically to the discharge area perpendicular to the conveying direction or at an angle to the conveying direction.

[0012] The process according to the invention can be carried out independently of the coating of the carrier layer with the active material and, in particular, downstream of this coating. Alternatively, the process according to the invention can be carried out downstream in the conveying direction as part of a continuous processing process for the regular application of the active material to the carrier layer.

[0013] The at least one pair of rollers for carrying out the process can therefore be part of a continuous processing plant for producing carrier layers coated with the active material or be arranged downstream of such a continuous processing plant in the conveying direction.

[0014] The carrier layer coated with the active material can be used as an electrode foil after being cut to the appropriate length. Depending on the design, further coating processes and / or treatments can be carried out. The carrier layer can, for example, be made of aluminum foil, copper foil, or similar materials.

[0015] According to a further aspect of the invention, a device for treating at least one current collector area of ​​a carrier layer coated with at least one material, for example, designed as an active material, is provided. The device can be configured as a manufacturing device for producing electrodes for an electrical energy storage device or as part of such a manufacturing device. 49293 PT-WO CB / gro

[0016] At least one pair of rollers of the device is designed to subject the at least one discharge area to pressure and temperature simultaneously in a continuous process.

[0017] By simultaneously applying pressure and temperature to the draft tube area, such as hot pressing, a so-called ironing effect or a heat and pressure process can be created which can permanently eliminate the wrinkles or waves that have formed in the draft tube area.

[0018] In one embodiment, the at least one discharge tube section is guided along a conveying direction by the at least one pair of rollers. This allows the discharge tube section to be treated parallel to the active material-coated section of the carrier layer. The rollers of the at least one pair of rollers are arranged in a straight line or offset from each other along the conveying direction. This allows for precise control of the heating and the direction of the pressure application.

[0019] The discharge area can be subjected to temperature at the same time as the pressure is applied, which is particularly easy from a technical point of view, if at least one roller of the at least one pair of rollers is heated directly.

[0020] In a further embodiment, the at least one discharge section is guided along the conveying direction by at least two pairs of rollers offset from each other along the conveying direction. This allows the process to be carried out in several steps.

[0021] The heat sink area is subjected to a first temperature by at least one roller of the first roller pair and to a second temperature by at least one roller of the second roller pair. This allows the treatment of the at least one heat sink area to be carried out, for example, in several smaller steps. This avoids the effects of large temperature fluctuations on the heat sink area and the adjacent active material, so that 49293 PT-WO CB / gro

[0022] A particularly optimal improvement of the damage can be achieved in small steps.

[0023] Multiple treatments of the surge arrester area can be achieved by subjecting at least one section of the arrester to a temperature equal to the second temperature. This allows for the particularly effective removal of any deformations or creases introduced into the surge arrester area through repeated application of a heat and pressure process.

[0024] According to a further embodiment, the at least one heat sink section is exposed to the first temperature, which exceeds the second temperature. This measure enables a gradual and controlled cooling of the heat sink section after it has passed the first pair of rollers.

[0025] In a further embodiment, the at least one draft tube section is cooled by being exposed to the second temperature. This accelerates the cooling of the draft tube section after treatment by the heat and pressure process compared to natural cooling.

[0026] In addition to the heating of the at least one roller, heat input can be achieved due to friction if the rollers of the at least one pair of rollers are rotated in opposite directions or in the same directions.

[0027] According to a further embodiment, the at least one roller of the first pair of rollers is heated to the first temperature by radiant heat and / or by induction and / or by conduction. The at least one roller of the second pair of rollers is cooled to the second temperature by conduction and / or convection.

[0028] Depending on the design, at least one roller of the second pair of rollers can also be heated to a second temperature, which is below the first, by means of radiant heat and / or induction and / or conduction.

[0029] The temperature can be either at or above the initial temperature. This allows for a particularly versatile heating and / or cooling of the rollers.

[0030] Several embodiments of the invention are explained in more detail below with reference to the drawings. The drawings show:

[0031] Fig. 1 shows a schematic representation of a device for treating at least one drain area according to a first embodiment of the invention,

[0032] Fig. 2 shows a schematic representation of a device for treating at least one drain area according to a second embodiment of the invention.

[0033] Fig. 3 shows a schematic representation of a device for treating at least one drain area according to a third embodiment of the invention, and

[0034] Fig. 4 is a schematic diagram illustrating a method for treating at least one current collector area of ​​an electrode foil coated with at least one active material according to an embodiment of the invention.

[0035] In the illustrations, identical reference numbers denote the same elements or structural components. The sizes and relative positions of the elements in the illustrations are not necessarily drawn to scale, and some of these elements are shown enlarged and repositioned for clarity. Furthermore, the distinctive shapes of the drawn elements are not intended to convey information about the actual shape of the individual elements but were chosen solely for easier identification in the illustrations. 49293 PT-WO CB / gro

[0036] Fig. 1 shows a schematic representation of a device 10 for treating at least one conductor area 21 of a carrier layer 20 according to a first embodiment of the invention.

[0037] The carrier layer 20 is designed as a ribbon-shaped metal foil and is coated, by way of example, with a material 22 designed as an active material. The coating with the active material 22 is implemented centrally between two edge-side discharge tube areas 21.

[0038] In the illustrated embodiment, the carrier layer 20 is made of copper. The two current collector areas 21 are uncoated and function as current collectors and current connectors, respectively. A section of the carrier layer 20 coated with the active material 22 is shown schematically in Fig. 1.

[0039] In the illustrated embodiment, the device 10 is designed as a manufacturing device for producing electrodes 30 for an electrical energy storage device (not shown). The device 10 has a first carrier roller 11 on which the carrier layer 20 is wound in pre-coated form. After passing through a web tension control 12, the carrier layer 20 is fed to a first pair of rollers 13.

[0040] The first pair of rollers 13 of the device 10 is configured to simultaneously apply pressure and temperature to the at least one discharge area 21 in a continuous process. For this purpose, two first rollers 41, 42 exert pressure on the discharge areas 21. The pressure is directed towards the discharge areas 21 opposite to the conveying direction F. The rollers 41, 42 of the first pair of rollers 13 are arranged in alignment with each other along the conveying direction F.

[0041] The two rollers 41, 42 of the first pair of rollers 13 are also heated, thus enabling the simultaneous application of heat to the discharge areas 21. The first pair of rollers 13 heats the discharge areas 21 in addition to applying pressure. 49293 PT-WO CB / gro

[0042] In the illustrated embodiment, a pair of rollers 13 is provided for each discharge area 21. The first two pairs of rollers 13 can be connected to each other by common drive shafts. Alternatively, one pair of rollers 13 can apply pressure and temperature to both discharge areas 21, with a central section recessed to prevent contact with the active material 22 of the carrier layer 20.

[0043] After applying pressure and temperature to the discharge tube areas 21, the carrier layer 20 can, for example, be used as an electrode 30. For this purpose, the ribbon-shaped electrode 30 is wound onto a second carrier roll 15 after a further web tension check 12.

[0044] Figure 2 shows a schematic representation of a device 10 for treating at least one draft tube section 21 according to a second embodiment of the invention. In contrast to the embodiment shown in Figure 1, a second pair of rollers 14 is used.

[0045] The second rollers 43, 44 or the rollers 43, 44 of the second pair of rollers 14 can be thermally conditioned in such a way that the deflector areas 21 are reheated and pressed or cooled after passing the first pair of rollers 13.

[0046] Furthermore, the first rollers 41, 42 of the first roller pair 13 and the second rollers 43, 44 of the second roller pair 14 are arranged offset from each other along the conveying direction F.

[0047] Fig. 3 shows a schematic representation of a device 10 for treating at least one deflector area 21 according to a third embodiment of the invention. In contrast to the embodiment shown in Fig. 2, the first rollers 41, 42 of the first roller pair 13 and the second rollers 43, 44 of the second roller pair 14 are arranged in alignment along the conveying direction F, so that the pressure force resulting on the deflector areas 21 is exerted exclusively vertically. 49293 PT-WO CB / gro

[0048] Fig. 4 shows a schematic diagram illustrating a method 50 for treating at least one drain area 21 of a carrier layer 20 coated with at least one active material 22 according to an embodiment of the invention.

[0049] The at least one drainage area 21 of the carrier layer 20 runs parallel to the active material 22 along the conveying direction F, in which the carrier layer 20 has its longest extent.

[0050] In particular, the carrier layer 20 with the applied active material 22 can serve as a basis for the production of electrode layers or electrode foils 30. For example, due to a continuous manufacturing process, the carrier layer 20 can be designed as an electrically conductive strip which has a greater length in the conveying direction F of the manufacturing process than perpendicular to the conveying direction F.

[0051] In a first step 51 of the process 50, a carrier layer 20 is provided. Subsequently, the carrier layer 20 can be coated with one or more active materials 52. The current collector areas 21 on both sides of the active material 22 remain unchanged.

[0052] Due to the coating of the carrier layer 20 with the active material 22, wrinkles or waves can form in the discharge areas 21. In a further step 53, these undesirable deformations are smoothed at the edges of the active material 22. For this purpose, at least one pair of rollers 13 is used to apply pressure and heat to the discharge areas 21.

[0053] In a further step 54, the edge-treated carrier layer 20 is used as an electrode 30 or at least wound onto a carrier roll 15.

Claims

49293 PT-WO CB / gro REQUIREMENTS 1. Method (50) for treating at least one discharge area (21) of a carrier layer (20) coated with at least one material (22) designed as an active material as a basis for the production of electrode foils (30) of electrochemical storage devices, wherein the at least one discharge area (21) runs parallel to the applied material (22), wherein the at least one discharge area (21) is simultaneously subjected to pressure and heat by at least one pair of rollers (13).

2. Method according to claim 1, wherein the at least one deflector section (21) is guided along a conveying direction (F) through the at least one pair of rollers (13), wherein the rollers (41, 42) of the at least one pair of rollers (13) are arranged in a straight line or offset from each other along the conveying direction (F).

3. Method according to claim 1 or 2, wherein at least one roller (41 , 42) of the at least one pair of rollers (13) is heated directly or indirectly.

4. Method according to one of claims 1 to 3, wherein the at least one deflector section (21) is guided along the conveying direction (F) by at least two pairs of rollers (13, 14) offset from one another along the conveying direction (F), wherein the deflector section (21) is exposed to a first temperature by at least one roller (41, 42) of the first pair of rollers (13) and to a second temperature by at least one roller (43, 44) of the second pair of rollers (14).

5. The method of claim 4, wherein the at least one drain area (21) is exposed to the first temperature, which is equal to the second temperature. 49293 PT-WO CB / gro 6. Method according to claim 4, wherein the at least one drain area (21 ) is exposed to the first temperature which exceeds the second temperature.

7. Method according to claim 6, wherein the at least one drain area (21 ) is cooled by exposure to the second temperature.

8. Method according to any one of claims 1 to 7, wherein the rollers (41 , 42) of the at least one pair of rollers (13, 14) are rotated in opposite directions or in the same directions.

9. Method according to any one of claims 5 to 8, wherein the at least one roller (41, 42) of the first pair of rollers (13) is heated to the first temperature by radiant heat, by induction and / or by conduction, and / or wherein the at least one roller (43, 44) of the second pair of rollers (14) is cooled to the second temperature by conduction and / or by convection.

10. Device (10) for treating at least one discharge area (21) of a carrier layer (20) coated with at least one material (22), comprising at least one pair of rollers (13, 14) which is configured to subject the at least one discharge area (21) to pressure and temperature simultaneously in a continuous process.

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