Method for coating an electrode coil

Abstract

A method for coating an electrode coil comprising a provision step in which a coating system (1), an electrode coil (3) and raw materials are provided, a mixing step in which a batch of raw materials is mixed in the coating system (1) to form coating material of a coating material batch, and a coating step in which the coating material is applied to the electrode coil (3) in the coating system (1) to form a first coating (5), wherein in the mixing step at least one of the raw materials of the raw material batch is mixed or blended with a marking agent (6), characterized in that the marking agent (6) can be uniquely assigned or is uniquely associated with the raw material batch or with a raw material of the raw material batch or with the coating material batch.

Description

The invention relates to a method for coating an electrode coil according to the preamble of claim 1. In an exemplary process for coating an electrode coil, raw materials are first fed into a coating system in batches and then mixed together to form a coating material. In a coating step, the coating material is then applied to the electrode coil, forming a coating. This method has the disadvantage that the material composition of the coating can only be determined by means of a relatively complex material analysis. Furthermore, the analyzed material composition does not allow for the determination of which batch, or—due to residual quantities in the coating system—which batches the raw materials underlying the coating were sourced from. Therefore, it is not possible to trace individual batches of raw materials back to specific batches, or at least only with very low temporal resolution. Due to the low temporal resolution, quality assurance measures, such as recalls, can only be implemented with significant safety margins. This means that, in case of doubt, considerably more batteries or coated electrode coils will have to be recalled than the number of electrode coils that actually fail to meet quality requirements. Furthermore, process optimization is difficult to achieve with this method, as the low temporal resolution makes it impossible to establish a clear causal relationship between the resulting product characteristics, such as the cell capacity of the battery cell, and individual raw material batches. DE 10 2004 007 583 A1 discloses a method for determining the spatial distribution of polymeric additives and / or ionomers in fuel cells. DE 10 2011 116 046 A1 discloses the recycling of products. CN 112966836 A discloses a method and a system for tracing the recycling process in battery manufacturing based on the Internet of Things. DE 10 2013 020 391 A1 discloses a generic method for coating an electrode coil. WO 2010 / 066237 A1 discloses a method for authenticating and / or identifying an object. The object of the invention is to provide a method by which it is possible to deduce the raw material batches underlying the coating or contained in the coating with minimal effort. This problem is solved by the features of the independent claim. Preferred embodiments of the invention are disclosed in the dependent claims. The invention proposes a method for coating an electrode coil, comprising a provisioning step in which a coating system, an electrode coil, and raw materials are provided; a mixing step in which a batch of raw materials is mixed in the coating system to form a coating material from a batch of coating material; and a coating step in which the coating material is applied to the electrode coil in the coating system to form a first coating. According to the invention, in the mixing step, at least one of the raw materials from the raw material batch is mixed or blended with a marker. Thus, one or more markers are added to the first coating, enabling a unique assignment of the first coating to specific raw material batches. Depending on the quality of the coated electrode coil or the battery cells produced with it, it is possible, due to the assignment via the marking agent, to determine a minimum layer thickness of the first coating in a material-efficient manner and still achieve the desired properties of the battery cell. Preferably, the electrode coil is made of a metal, preferably copper or aluminum. Alternatively, the electrode coil may be made of a metal alloy, preferably a copper or aluminum alloy. Alternatively, the electrode coil may be formed from a copper or aluminum foil. The electrode coil thus exhibits the lowest possible electrical resistance. The resulting battery cell therefore has a particularly high efficiency. It is particularly preferred that the raw material batch comprises, preferably, an active material, an additive, a binder, and a solvent, wherein it is particularly preferred that the active material is formed by a mixture or blend of, preferably, nickel, manganese, and cobalt. This raw material combination results in a particularly durable coating of the electrode coil. Alternatively or additionally, the active material can be a powder mixture of nickel powder, manganese powder, and cobalt powder. This powder mixture can be easily mixed evenly and / or homogeneously and emptied from the raw material containers with virtually no residue. Alternatively or additionally, it can be provided that the raw material batch comprises as raw materials, preferably exactly, a predefined quantity of active material, a predefined quantity of additives, a predefined quantity of binders and a predefined quantity of solvents. According to the invention, the marking agent is uniquely identifiable or assigned to a raw material batch, a raw material within a raw material batch, or a coating material batch, particularly with regard to the type of marking agent, its concentration, and / or its molar mass in the raw material and / or the coating material. The assignment of the marking agent to a specific raw material batch or a specific coating material batch allows, for example, inferences to be made about the production date and / or the recycled content. Additionally, relevant recycling instructions can be issued to an operator of the coating system via the coating system. For example, it can be provided that in the mixing step, preferably first, one, preferably exactly one, raw material from the raw material batch, preferably the active material, is mixed or blended with the marking agent, preferably to form a marked raw material, and that, preferably subsequently, the marked raw material is mixed or blended with the remaining raw materials of the raw material batch to form the coating material, preferably in a mixing container. Thus, based on the marking agent used or its properties, it is possible to unambiguously identify not only a specific coating material batch, but also a specific active material batch. For example, it can be provided that in the mixing step all raw materials of the raw material batch and the marking agent are placed in a mixing container, and that all raw materials of the raw material batch and the marking agent are mixed or blended together, preferably only in the mixing container. This simplifies the process in that the addition of the marking agent takes place in the mixing container in which a mixing process, specifically the blending of the raw materials, is already taking place. In this single mixing process, the raw materials are thus mixed with each other, and the marking agent is mixed with the raw materials. For example, the coating material may be formed from a heterogeneous mixture of all raw materials in the raw material batch, or from a homogeneous or heterogeneous mixture of all raw materials in the raw material batch. It should also be noted that the coating system may contain residual quantities of previously processed raw material or coating material batches, which may unintentionally mix or blend with the raw materials or coating material. For precisely this reason, it is a particular advantage that the process allows for precise identification of raw materials and coating material from different raw material and / or coating material batches based on the marker agent added. Preferably, the marking agent is formed by a modified polymer or by a mixture of several modified polymers, and / or the marking agent comprises fluorescent particles and / or color particles and / or magnetic particles and / or metallic particles and / or silicate-encapsulated deoxyribonucleic acid. In particular, the use of silicate-encapsulated deoxyribonucleic acid enables a particularly high information content of the marking agent. It is particularly preferred that the marking agent in one of the raw materials of the raw material batch has a marking agent concentration in the range of 1 ppm to 10 ppm, or in the range of 10 ppm to 100 ppm, or in the range of 100 ppm to 1000 ppm, and / or that the marking agent in the coating material of the coating material batch has a marking agent concentration in the range of 1 ppm to 10 ppm, or in the range of 10 ppm to 100 ppm, or in the range of 100 ppm to 1000 ppm. At these concentrations, it is particularly reliably ensured that the properties of the electrode coil coating are not negatively affected by the marking agent. For example, the marking agent may be provided, preferably completely, to be thermally and / or chemically stable. This means that the marking agent is present in the coating in a chemically and / or physically unchanged form. This advantageously ensures that the marking agent is reliably detectable within the coating. For example, the method may include a control step in which a detection device is used to determine the material composition of the first coating of the electrode coil, preferably determining the material composition of the coating in the coating system and / or non-destructively. In this way, the marking agent(s) in the coating can be identified. Preferably, the detection device may be arranged on a conveyor belt or on one of the tank outlets of the raw material containers and / or the mixing containers and / or the buffer containers. For example, the detection device may consist of a mass spectrometer and an evaluation unit connected to the mass spectrometer via a signal. The evaluation unit then uses the marker(s) contained in the material composition to determine the raw material batch(es) or the coating material batch(es) from which the raw materials contained in and / or underlying the coating originate. The mass spectrometer offers the advantage that the material composition analysis can be performed non-invasively and in a very short time. The coating process can therefore be carried out without interruption during the determination of the material composition. Preferably, the mass spectrometer can be part of a mass spectrometer arrangement comprising several, preferably identical, mass spectrometers, which are in signal communication with the evaluation unit, and a first mass spectrometer of the mass spectrometer arrangement determines the material composition of the first coating of the electrode coil, and a second mass spectrometer of the mass spectrometer arrangement determines the material composition of a second coating of the electrode coil. For example, the first mass spectrometer and / or the second mass spectrometer could be a DESI mass spectrometer. A DESI mass spectrometer is a mass spectrometer that operates on the principle of desorption electrospray ionization. Preferably, a batch of raw materials may contain several raw materials, preferably each in different, predefined quantities. The described methods are applicable to any process for battery cell manufacturing, e.g. also for the manufacturing of a housing. The following are descriptions of embodiments of the invention with reference to the accompanying figures. Figure 1 shows a schematic flowchart of a method for coating an electrode coil in which a marking agent is added to an active material; Figure 2 shows a schematic flowchart of the method for coating an electrode coil in which the marking agent is added to a coating material; Figure 3 shows a schematic flowchart of the method according to Figure 1, wherein two coating devices are supplied with coating material; and Figure 4 shows a rough schematic side view of a coating system with a detection device. Figure 4 shows a section of a coating system 1. In a coating step of a process for coating an electrode coil, an electrode coil 3 is conveyed continuously on a conveyor belt (not shown) and coated with a coating 5 in a continuous coating process. The coating system 1 includes a mass spectrometer 7, which forms a detection device of the coating system 1. Using the mass spectrometer 7, the material composition of the coating 5 is determined at predefined time intervals in a control step of the process. The coating 5 is formed by applying a coating material. The coating material comprises raw materials from different raw material batches as well as a marker 6 that can be precisely assigned to each raw material batch. This means that at least one raw material from each raw material batch or each coating material batch of the coating material contains a marker 6 that differs from the markers 6 of preceding or subsequent raw material or coating material batches, for example, with regard to the type of marker 6 and / or with regard to the marker concentration in the coating material or the marker concentration in a mixture of at least one raw material and the marker 6. To be able to unambiguously assign the material composition determined by mass spectrometer 7 to the raw materials of the different raw material batches, the procedure includes a preparation step, a mixing step, a coating step, and a control step. The mixing step is carried out after the preparation step. The coating step is carried out after the mixing step, and the control step is carried out after the coating step. In the setup step, the coating system 1 is set up first. This includes the raw material containers: an active material container 9, an additive container 11, a binder container 13, and a solvent container 15. A mixing container 17, a buffer container 19, and a coating device 21 are also set up. The coating step is carried out in the coating device 21, where the coating material is applied to the electrode coil 3, forming the coating 5. The raw material containers are connected to the mixing tank 17 via pipelines. The mixing tank 17 is connected to the buffer tank 19 via a pipeline. The buffer tank 19 is connected to the coating device 21 via a pipeline. In addition, a predefined quantity of raw materials, i.e., a raw material batch, is provided during the provisioning step. The raw materials are, for example, active material 10, additives, binders, and solvents. Active material 10 is a powder mixture consisting of nickel powder, manganese powder, and cobalt powder. The marker 6 can, for example, comprise one or more modified polymers. Alternatively or additionally, the marker 6 can comprise fluorescent particles and / or color particles and / or magnetic particles and / or metallic particles and / or silicate-encapsulated deoxyribonucleic acid (i.e., silicate-encapsulated DNA). The marker 6 is thermally stable and / or resistant to the process temperatures occurring during the procedure. The marker 6 does not affect the material properties, in particular those of the active material 10. The marker 6 is optically and / or chemically and / or mass spectroscopically and / or physically detectable. Furthermore, the marker 6 offers a high information content. That is, a large number of generable codes can be realized using the marker 6. For the following description of the method, it is assumed only by way of example that the marking agent 6 has exactly one modified polymer, and that the marking agent 6 can be detected by mass spectrometry using the mass spectrometer 7. In the process illustrated with reference to Fig. 1, the marking agent 6 is added to the active material 10 manually or automatically during the mixing step and mixed with it, preferably uniformly and / or homogeneously, to form a marked active material in which the marking agent 6 is uniformly distributed. Particularly for the automated addition of the marking agent, the coating system 1 can have an actuator (not shown) by means of which a predefined quantity of marking agent 6 is added to the active material 10, preferably depending on the quantity of active material 10 provided in the raw material batch. In the marked active material, the marking agent 6 can be present in a concentration ranging from 1 ppm to 10 ppm, from 10 ppm to 100 ppm, or from 100 ppm to 1000 ppm.For the following description of the process, it is merely assumed by way of example that the marking agent 6 is present in the marked active material at a concentration of 10 ppm. The marked active material is then poured into active material container 9, the additive into additive container 11, the binder into binder container 13, and the solvent into solvent container 15. The pouring of the materials is illustrated in Figures 1 and 2 by the arrows pointing into the containers. The labeled active material, the additive, the binder, and the solvent, which are fed into mixing vessel 17, are then mixed in the mixing vessel 17 to form a coating material. After mixing, the coating material is in the form of a suspension. Such a suspension can also be referred to as a slurry. The coating material is then fed into buffer tank 19 and temporarily stored there. From buffer tank 19, the coating material is fed as needed to the coating device 21, by means of which the electrode coil 3 is continuously coated in the coating step. In the control step, the coating 5 is analyzed at predefined time intervals and thus at predefined positions on the coating 5 using the mass spectrometer 7. The mass spectrometer 7 determines the respective proportion and properties of the marking agents 6 contained in the coating 5. In an evaluation unit (not shown) of the coating system 1, which is connected to the mass spectrometer 7 via signal processing, it is then determined which raw material batches, in particular which active material batches of active material 10, were processed in the coating 5. Thus, residual quantities of active materials from raw material batches other than the raw material batch can also be easily determined in coating 5. In other words: In the evaluation unit, the active material batch underlying or used for coating 5 can be precisely determined based on the detected marker(s) 6 and / or the concentration(s) of the detected marker(s). The method illustrated in Fig. 1 is essentially identical to the method illustrated in Fig. 2, with the sole difference being that in the method of Fig. 2 the marking agent 6 is not first mixed or blended with the active material 10, but is first fed to the mixing container 17, in which the marking agent 6 is mixed or blended together with all raw materials, namely the active material 10, the additive, the binder and the solvent, preferably uniformly and / or homogeneously. Unlike the method of Fig. 1, the method of Fig. 2 allows conclusions to be drawn about one or more specific batches of the coating material that were used locally in the coating 5 at a predefined position. It should also be noted that in the two described procedures, material samples of the coating material can be taken from the mixing vessel 17 or the buffer vessel 19 in the control step, either as an alternative or in addition to the analysis with the mass spectrometer 7 (which can also be referred to as inline measurement) (which can also be referred to as offline measurement). In the control step, the material composition of the material samples can then be determined, for example, using a mass spectrometer installed in a materials laboratory. Determining the material composition of the coating 5 itself and the material composition of the material samples can be used, in particular, to validate and / or optimize a simulation model (= digital twin) of the electrode coil coating process and / or to support the commissioning of the coating system 1. In this respect, taking material samples can increase the predictive accuracy, since not only the final result based on the coating 5, but also the intermediate steps for obtaining the coating material can be traced and validated. As shown in Fig. 3, two or more mixing containers 17 and 23, two or more buffer containers 19 and 25, and two or more coating devices 21 and 27 can also be fed from the raw material containers 9 to 15. The coating system 1 then has a mass spectrometer arrangement formed by the mass spectrometer 7 and at least one further mass spectrometer 29. The mass spectrometers 7 and 29 are in signal communication with the evaluation unit, with the mass spectrometer 7 determining the material composition of the coating 5 of the electrode coil 3, and the mass spectrometer 29 determining the material composition of a coating 31 of the electrode coil 3. Using this method, in the control step, it is possible to determine, based on any coating, whether applied to one or more surfaces of an electrode coil or to surfaces of several electrode coils, which raw material batch or which raw material batches or which coating material batch or which coating material batches are contained in and / or form the basis of the coatings. Reference symbol list 1 Coating system 3 Electrode coil 5 Coating 6 Marker 7 Mass spectrometer 9 Active material container 10 Active material 11 Additive material container 13 Binder container 15 Solvent container 17 Mixing container 19 Buffer container 21 Coating device 23 Mixing container 25 Buffer container 27 Coating device 29 Mass spectrometer 31 Coating

Claims

A method for coating an electrode coil comprising a provision step in which a coating system (1), an electrode coil (3) and raw materials are provided, a mixing step in which a batch of raw materials is mixed in the coating system (1) to form coating material of a coating material batch, and a coating step in which the coating material is applied to the electrode coil (3) in the coating system (1) to form a first coating (5), wherein in the mixing step at least one of the raw materials of the raw material batch is mixed or blended with a marking agent (6), characterized in that the marking agent (6) can be uniquely assigned or is uniquely associated with the raw material batch or with a raw material of the raw material batch or with the coating material batch. The method according to claim 1, characterized in that the raw material batch comprises as raw materials, preferably exactly, an active material, an additive, a binder and a solvent, wherein it is preferably provided that the active material is formed by a mixture or a blend of, preferably exactly, nickel, manganese and cobalt. Method according to claim 1 or 2, characterized in that the marking agent (6) can be clearly assigned or is uniquely associated with the raw material batch or with a raw material of the raw material batch or of the coating material batch with regard to the type of marking agent (6) and / or with regard to the concentration and / or with regard to the molar mass of the marking agent (6) in the raw material and / or the coating material. Method according to one of claims 1 to 3, characterized in that in the mixing step, first one, preferably exactly one, raw material of the raw material batch, preferably the active material, is mixed or blended with the marking agent (6), preferably to form a marked raw material, and that subsequently the marked raw material is mixed or blended with the remaining raw materials of the raw material batch to form the coating material, preferably in a mixing container (17; 23). Method according to one of claims 1 to 3, characterized in that in the mixing step all raw materials of the raw material batch and the marking agent (6) are placed in a mixing container (17; 23), and that all raw materials of the raw material batch and the marking agent (6) are mixed or blended together, preferably only in the mixing container (17; 23). Method according to one of the preceding claims, characterized in that the marking agent (6) is formed by a modified polymer or by a mixture of several modified polymers, and / or that the marking agent (6) comprises fluorescent particles and / or color particles and / or magnetic particles and / or metallic particles and / or silicate-encapsulated deoxyribonucleic acid. Method according to one of the preceding claims, characterized in that the marking agent (6) in one of the raw materials of the raw material batch has a marking agent concentration in a range of 1 ppm to 10 ppm or in a range of 10 ppm to 100 ppm or in a range of 100 ppm to 1000 ppm, and / or that the marking agent (6) in the coating material of the coating material batch has a marking agent concentration in a range of 1 ppm to 10 ppm or in a range of 10 ppm to 100 ppm or in a range of 100 ppm to 1000 ppm. Method according to one of the preceding claims, characterized in that the method includes a control step in which a material composition of the coating (5) of the electrode coil (3) is determined by means of a detection device, wherein it is preferably provided that the material composition of the coating (5) is determined in the coating system (1) and / or non-destructively. Method according to claim 8, characterized in that the detection device is formed by a first mass spectrometer (7) and by an evaluation unit connected to the first mass spectrometer (7) via a signal, and that the evaluation unit determines, on the basis of the marker agent (6) contained in the material composition or on the basis of the marker agents (6) contained in the material composition, the raw material batch or raw material batches or the coating material or coating material batches from which the raw materials contained in and / or underlying the coating (5) originate. Method according to claim 9, characterized in that the first mass spectrometer (7) is part of a mass spectrometer arrangement comprising several, preferably identical, mass spectrometers, which are in signal communication with the evaluation unit, and that the first mass spectrometer (7) of the mass spectrometer arrangement determines the material composition of the first coating (5) of the electrode coil (3), and that a second mass spectrometer (29) of the mass spectrometer arrangement determines the material composition of a second coating (31) of the electrode coil (3).

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