Method of controlling a coating process for electrode manufacturing, method for electrode manufacturing, coating apparatus and electrode manufacturing system

Abstract

Aspects and embodiments of the present invention provide methods for closed-loop control of apparatus and systems for electrode manufacturing. Particularly, a method of controlling a coating apparatus and a method of controlling an electrode manufacturing system are provided. A closed-loop control method of the coating apparatus, which is preferably based on in-line measurement of quality parameters, and a closed-loop overall control method of the electrode manufacturing system, which is preferably based on in-line measurement of quality parameters, allows for improvements in material and energy efficiency, improved accuracy and reliability in achieving quality, performance and safety targets of an electrochemical energy storage device.

Description

[0001] METHOD OF CONTROLLING A COATING PROCESS FOR ELECTRODE MANUFACTURING, METHOD FOR ELECTRODE MANUFACTURING, COATING APPARATUS AND ELECTRODE MANUFACTURING SYSTEM

[0002] TECHNICAL FIELD

[0003] Embodiments of the present disclosure relate to methods for electrode manufacturing, including controlling a coating process and controlling an electrode manufacturing process. In particular, methods for closed-loop control of a coating sub-process and closed-loop control of an overall electrode manufacturing process are provided. Said methods are suitable for manufacturing electrodes for an electrochemical energy storage device, particularly for lithium-ion battery cells.

[0004] BACKGROUND

[0005] The manufacturing of electrochemical energy storage devices, in particular lithium-ion battery cells, typically involves a number of key process steps. One important aspect in the manufacturing process is the electrode manufacturing, which typically involves several subprocesses of powder feeding of powder-form raw materials, liquid feeding of liquid-form raw materials, mixing and preparation of a slurry, coating and drying of at least one layer of the slurry on an electrode substrate, and calendering and slitting of the deposited substrate to produce the final electrode. An electrochemical energy storage device is then assembled and may be tested in an end-of-line (EOL) testing process. The quality of the resulting electrode has a direct impact on the performance of the electrochemical energy storage device, and has a further impact on reaching the desired levels of safety.

[0006] Obtaining electrodes which exhibit the ever-increasing levels of performance and safety is a challenging aspect of electrochemical storage device manufacturing. The precise controlling of the various sub-processes involved in manufacturing the electrode to meet quality targets has been a focus, particularly in battery cell manufacturing, in recent times. In the current state of the art, manufacturers rely on off-line and end-of-line quality testing for judging whether a desired level of quality is reached. However, current methods may result in variable levels of quality, and can result in excessive amounts of scrap material being generated which reduces material and energy efficiency of the manufacturing process. Such deficiencies may be introduced at various sub-processes in the overarching process chain. Identifying sources of defects, sources of quality deficiencies and maintaining quality targets is challenging with current methods.

[0007] In view of the deficiencies in the current state of the art, improved methods for manufacturing electrodes for electrochemical energy storage devices, particularly electrodes for lithium-ion battery cells, are desired.

[0008] SUMMARY

[0009] In view of the above challenges and problems arising in the state of the art, improved methods and apparatus for powder feeding and electrode manufacturing are sought.

[0010] According to a first aspect of the present disclosure, a method of coating an electrode substrate for electrode manufacturing for an electrochemical energy storage device is provided. The method includes providing an electrode substrate, transporting the electrode substrate in a transport direction, feeding at least one mixed slurry, depositing at least one layer of mixed slurry on the electrode substrate with a deposition apparatus, drying the at least one layer with a drying apparatus, and calendering the at least one layer with a calendering apparatus to produce a coated electrode. The depositing, the drying and the calendering are controlled by at least one coating process parameter. The method further includes acquiring at least one coating quality parameter of the at least one layer, preferably wherein the at least one coating quality parameter is acquired in-situ, wherein the at least one coating parameter comprises at least one of a level of electrode mechanical flexibility measured after the drying and / or after the calendering, and a level of electrode layer adhesion measured after the drying and / or after thecalendering. The method further includes adjusting the at least one coating process parameter based on the at least one coating quality parameter according to a predetermined coating model.

[0011] According to a second aspect of the present disclosure, a method for electrode manufacturing for an electrochemical energy storage device is provided. The method includes feeding at least one powder material in a powder feeding process, the feeding being controlled based on at least one powder feeding process parameter, feeding at least one liquid material in a liquid feeding process, the feeding being controlled based on at least one liquid feeding process parameter, mixing a slurry including the at least one powder material and the at least one liquid material in a slurry mixing process, the mixing being controlled based on at least one slurry mixing process parameter, and coating the slurry onto an electrode substrate in a coating process to produce the electrode, the coating being controlled according to the method of the first aspect.

[0012] According to a third aspect of the present disclosure, a coating apparatus for coating an electrode substrate for an electrode manufacturing system is provided. The coating apparatus includes a substrate supply reel for providing an electrode substrate, a mixed slurry input for receiving a mixed slurry, a deposition apparatus configured for depositing at least one layer of the mixed slurry onto the electrode substrate, a drying apparatus configured for drying the at least one layer, a calendering apparatus configured for compressing the at least one layer to produce a coated electrode, at least one sensor configured for acquiring at least one coating quality parameter of the at least one layer, preferably wherein the at least one sensor is configured for in-situ acquisition, and a controller configured for controlling the coating apparatus by implementing the method according to the first aspect. The at least one sensor includes at least one of an in-line electrode flexibility sensor configured for measuring a mechanical flexibility of the at least one layer, the inline electrode flexibility sensor being positioned after the drying apparatus and / or after the calendering apparatus, and an inline electrode layer adhesion sensor configured for measuring the adhesion of the at least one layer to the electrode substrate, the inline electrode layer adhesion sensor being positioned after the drying apparatus and / or after the calendering apparatus.

[0013] According to a fourth aspect of the present disclosure, an electrode manufacturing system for manufacturing electrodes for an electrochemical energy storage device is provided. The system includes at least one powder feeding apparatus configured for feeding at least one powder material, at least one liquid feeding apparatus configured for feeding at least one liquid material, a slurry mixing apparatus configured to mix a slurry of the at least one powder material and the at least one liquid material, a coating apparatus according to the third aspect, the coating apparatus being configured for coating an electrode substrate with at least one layer of the mixed slurry, drying the at least one layer and calendering the at least one layer to produce a coated electrode, and a system controller configured for controlling the electrode manufacturing system according to the method of the second aspect.

[0014] Aspects of the present disclosure provide improved control of the coating process, so that the desired quality parameters can be obtained. The quality parameters which are influenced by the coating process, such as quality parameters of the resulting electrode and quality parameters of an electrochemical energy storage device assembled from the electrode, can be reached in less time and with improved consistency and repeatability. Further, the coating process and / or the overarching electrode manufacturing process can be adapted to varying raw material properties, the amount of scrap material generated from defects or quality deficiencies is reduced, and the improved control system allows for scrap material to be reprocessed, improving the efficiency of the electrode manufacturing system. Those skilled in the art will recognise additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The components in the figures are not necessarily to scale, instead emphasis is being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts. In the drawings:

[0017] Fig. 1 illustrates a flow chart of an electrode manufacturing process;

[0018] Fig. 2 illustrates a schematic view of a coating apparatus according to embodiments of the present disclosure;

[0019] Figs. 3A-3C illustrate sensors for a coating apparatus;

[0020] Fig. 4 illustrates a flow chart of a method of controlling a coating apparatus according to embodiments of the present disclosure; and

[0021] Fig. 5 illustrates a flow chart of a method of manufacturing an electrode according to embodiments of the present disclosure.

[0022] DETAILED DESCRIPTION

[0023] Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with any other embodiment to yield yet a further embodiment. It is intended that the present disclosure includes such modifications and variations. Within the following description of the drawings, the same reference numbers refer to the same or to similar components. Generally, only the differences with respect to the individual embodiments are described. Unless specified otherwise, the description of a part or aspect in one embodiment applies to a corresponding part or aspect in another embodiment as well.

[0024] After investigating the deficiencies in the current state of the art for controlling processes and sub-processes of electrode manufacturing, and particularly with methods for powder feeding, the inventors identified several challenges.

[0025] In present coating systems for depositing, drying and calendering of electrodes, it was identified that online data relating to properties of the mixed slurry being fed to the deposition process was often unavailable, which limits the amount of information on hand for reacting to quality defects or deficiencies and correcting process parameters. This limited online data is typically sourced from offline quality control testing performed in a lab, which may be significantly delayed in time and results in difficult, time-consuming and expensive optimisation of the various sub-processes. As a result, the viscosity, solid content and impurities of the incoming slurry can often not be obtained readily in a control process, which may introduce problems in obtaining an even coating of slurry, affecting the quality of the coating.

[0026] It was further identified that present coating processes have a high energy consumption, particularly with respect to the drying process. Mixed slurry being provided to the coating process may often contain an excessive amount of liquid content, i.e. solvent or water, which requires an increase in energy consumption in the drying process to remove prior to calendering. In some cases, the coating line may consume as much as 2-3 kWh of energy per kWh of battery cells being produced. Thus, improvements in energy efficiency of the coating line are sought.

[0027] Further, in present coating systems, the full characterisation of output quality may typically be difficult to ascertain, and this is particularly challenging in real-time or near-real-time for control systems. The acquisition of quality parameters such as moisture content, porosity and density of the coated layers of an electrode may typically lag behind production by a significant time delay, and any quality defects or deficiencies may result in a high amount of material and / or coated electrodes which are scrapped. Thus, improvements in material efficiency are also sought.

[0028] To address the above-mentioned problems, as a first aspect, the present invention provides a method of coating an electrode substrate. In particular, the solution of the first aspect of the present invention involves a closed-loop control of the coating sub-process, particularly the deposition process, the drying process, the calendering process and optionally the slitting process. The closed-loop control is based on a predetermined model which is used to adjust the process parameters of the coating based on one or more quality parameters acquired from the coating process.

[0029] Further, as a second aspect, the present invention provides a method of controlling the electrode manufacturing process. In particular, the solution of the second aspect of the present invention involves the same closed-loop control of the coating sub-process, which is further contained within an overarching closed-loop control of the electrode manufacturing process. The quality parameters acquired in the coating sub-process may be used as feed-back or feed-forward signals and provided to a previous sub-process or a subsequent sub-process, respectively, so that the process parameters of the respective previous / subsequent sub-process can be adjusted based on a model of said process. Similarly, quality parameters acquired in other sub-processes may be used as a feed-back or feed-forward signal and provided to the coating sub-process of the first aspect, so that process parameters of the coating, e.g. the process parameters of the deposition, drying, calendering and optionally slitting, can be adjusted based on a coating model.

[0030] The closed-loop control systems of the aspects and embodiments described herein allow for the desired quality parameters of a deposited wet slurry layer, a deposited dry slurry layer, a calendered electrode and / or a final deposited electrode to be obtained quickly and reliably. Further, the closed-loop control systems allow for variations in raw material quality, mixed slurry quality and other variables to be accounted for quickly and reliably, and may also be used to control the coating process for other needs such as the reprocessing of scrap electrodes.

[0031] Referring firstly to Fig. 1, which shows a flowchart of an exemplary method for an electrode manufacturing process for an electrochemical energy storage device. The method 100 includes a plurality of sub-processes, some of which are denoted by solid lines as being included in aspects and embodiments described herein, and others of which are denoted by dashed lines as being optional and / or of reduced relevance in aspects and embodiments described herein.

[0032] The method 100 begins with the feeding of raw materials. In one sub-process, the feeding of at least one liquid material is carried out in box 110. The method 100 is exemplarily shown as including one liquid feeding process 110. However, the present disclosure is not limited thereto, and a plurality of liquid feeding processes 110 may be provided for feeding liquid materials of a different composition, or a single liquid feeding process 110 may be provided for feeding a mixture of different liquid materials which have been mixed in a previous process.

[0033] In at least one other sub-process, the feeding of at least one powder material is carried out in box 120. Optionally, additional powder feeding processes may be included. A serial arrangement may be provided by including an optional powder feeding process 121 which feeds one or more powder materials into the subsequent powder feeding process 120. For example, the powder feeding process 121 may be configured for feeding a first powder material of a first composition, and the subsequent powder feeding process 120 may be configured for feeding a second powder material of a second composition at the same time as the first powder material to produce a powder mixture. Alternatively, in the serial configuration, the powder feeding process 121 may be configured for feeding a powder material using a first set of process parameters, while the subsequent powder feeding process 120 may be configured to feed the same powder material from the powder pre-feeding process 121 using a second set of process parameters, e.g. with different inline sieve size.

[0034] A parallel arrangement may be provided by including an optional powder feeding process 122 which feeds one or more powder materials into the same process as which the powder feeding process 120 feeds. As with the serial arrangement described above, the multiple powder feeding processes 120, 122 may feed powder materials having different compositions, or may feed the same powder materials with different process parameters.

[0035] The at least one liquid feeding process 110 and the at least one powder feeding process 120, 121, 122 feed the respective raw materials into the slurry mixing process 130. Here, the at least one liquid material and the at least one powder material are mixed together according to a mixing recipe to produce a mixed slurry. Optionally, the mixed slurry may be stored for a predetermined time frame. An optional slurry storage process 131 may be included, wherein the mixed slurry is stored according to specific storage conditions for later use.

[0036] The mixed slurry is subsequently fed from the slurry mixing process 130, or optionally from the slurry storage process 131, into a coating process 140 where the mixed slurry is deposited onto an electrode substrate to produce a coated electrode. In the context of the present disclosure, the term “coating process” refers to the process wherein the final deposited electrode is produced, and typically includes a plurality of sub-processes therein. The coating process 140 includes a deposition process 141, a drying process 142, a calendering process 143 and optionally a slitting process 144. In the deposition process 141, the mixed slurry is deposited onto an electrode substrate to form at least one layer of the mixed slurry. In the drying process 142, the at least one layer is dried so that all solvents and other liquid components of the at least one layer of mixed slurry is evaporated to leave a dried layer of electrode material. Thereafter, the at least one layer is calendered in a calendering process 143, such that the at least one layer is compressed to the target thickness and density to produce the coated electrode comprising an electrode substrate and at least one layer of deposited electrode material thereon. Optionally, the coating process 140 may additionally include a slitting process 144, where the at least one layer and / or the electrode substrate is partitioned into separate electrode regions or completely separate electrode units ready for assembly into an electrochemical energy storage device.

[0037] Once the coated electrode has been produced in the coating process 140, further manufacturing processes 150 are carried out to produce a completed electrochemical energy storage device. These further manufacturing processes 150 are typical of the current state of the art, and are outside of the scope of the present disclosure. The further manufacturing processes 150 may include, at a minimum, layering of a plurality of the coated electrodes and providing the plurality of coated electrodes within an enclosure or housing to form the electrochemical energy storage device having at least one of the electrodes produced according to aspects and embodiments described herein. For example, the electrochemical energy storage device may include any one of a battery cell, particularly a lithium-ion battery cell, an ultracapacitor or a supercapacitor.

[0038] Concluding the method 100 is the optional process of end-of-line (EOL) testing 160 of the electrochemical energy storage device. The quality of the final device is evaluated by measuring a plurality of quality parameters and comparing said quality parameters to one or more target values. For example, in the case of the electrochemical energy storage device being a battery cell, the quality parameters which may be measured during EOL testing 160 may include any one of cell capacity, cell volumetric energy density, cell gravimetric energy density, cell DC internal resistance, cell AC internal resistance, cell open-circuit voltage value and cell weight.

[0039] The apparatuses and methods of the present disclosure are related to the manufacturing of electrodes for electrochemical energy storage devices. Particularly, the electrochemical energy storage device is a battery cell, more particularly a lithium-ion battery cell. Accordingly, the materials involved with the various processes and sub-processes described herein are materials typical to the manufacture of battery cell electrodes depending on the cell chemistry. For example, the at least one powder material being fed by one or more powder feeding processes may be an active cathode material, e.g. lithium nickel manganese cobalt oxide (Li-NMC), lithium iron phosphate (LiFePO4) or lithium cobalt oxide (LiCoO2), an active anode material, e.g. graphite or lithium titanate (Li4Ti5O12), or additives such as binders, e.g. polyvinylidene fluoride, or carbon black. Further, the at least one liquid material being fed by one or more liquid feeding processes may be a solvent, e.g. N-methyl-2-pyrrolidone, or water. Further, mixtures of said powders and / or liquids may be provided. However, the present disclosure is not limited thereto, and any powder and / or liquid materials in the state of the art which are suitable for the manufacture of cell electrodes, including mixtures thereof, may be used in the apparatuses and methods of the present disclosure.

[0040] The present invention has a particular focus on the coating process 140. Particularly, aspects of the present invention relate to methods of coating an electrode substrate so that accurate and reliable coating, drying, calendering and optionally slitting of the coated electrode can be achieved. By providing methods of control according to aspects and embodiments described herein, the targeted quality parameters as measured in the coating process 140, and the quality parameters as measured in subsequent processes such as an EOL testing process, can be quickly optimised so as to guarantee performance, quality and safety targets of the final electrode and of the electrochemical energy storage device in which the final electrode is to be assembled.

[0041] Reference will now be made to Fig. 2, which shows a schematic block diagram of a coating apparatus 200 according to aspects and embodiments described herein. The coating apparatus 200 is configured for coating an electrode substrate S with at least one layer L of mixed slurry to produce a coated electrode E. The coating apparatus 200 includes, at a minimum, a deposition apparatus 220, a drying apparatus 230, a calendering apparatus 240 and a coating controller 260. Optionally, the coating apparatus may further include a slitting apparatus 250. The coating apparatus 200 includes a deposition apparatus 220 which is configured for depositing at least one layer L of mixed slurry onto an electrode substrate S. The deposition apparatus 220 as exemplarily shown in Fig. 2 includes a slurry input 210, which may be in the form of a slurry hopper or a discharge tube from a slurry mixing apparatus, which is provided with the mixed slurry to be deposited, and the slurry input 210 provides the mixed slurry to a deposition feed screw 221. The deposition feed screw 221, which is actuated by the deposition drive motor 223, may controllably feed a precise amount of slurry to a deposition head 222. The deposition head 222 is shaped so as to deposit a precise layer L of mixed slurry onto the electrode substrate S. Although the deposition apparatus 220 is exemplarily shown as including an auger-type slurry feeding mechanism 221, the present disclosure is not limited thereto, and the deposition apparatus 220 may instead use an alternative form of slurry feeding of any type suitable for providing the mixed slurry to the deposition head 222. Further, the deposition head 222 may be configured to be controllable such that a width and / or a thickness of the mixed slurry layer L deposited onto the electrode substrate may be controllably adjusted.

[0042] Next, the coating apparatus 200 includes a drying apparatus 230. The drying apparatus 230 is exemplarily shown in Fig. 2 as including at least one heating element 231 which his configured to generate heat to dry the at least one layer L deposited on the electrode substrate S. For example, the at least one heating element 231 may include infrared heating elements provided above and below the substrate. However, the present disclosure is not limited thereto, and any heating and / or drying means known in the state of the art may be used. For example, the drying apparatus 230 may be further provided with one or more fans, one or more resistive heating elements, or one or more heated rollers. The drying apparatus 230 is configured to be controllable, such that the drying process may be automatically adjusted. For example, a plurality of heating elements 231 may be selectively switched to lengthen or shorten the drying zone, or the voltage, current or power applied to the heating elements 231 may be controlled so that a drying speed or drying power may be automatically adjusted.

[0043] Next, the coating apparatus 200 includes a calendering apparatus 240. The calendering apparatus 240 is exemplarily shown in Fig. 2 as including two pairs of opposing upper / lower calendering rollers 241a, 241b through which the electrode substrate S passes, so that the at least one layer L deposited thereon is precisely compressed to achieve the desired target thickness and / or density. Although the calendering apparatus 240 is shown as including two pairs of rollers, the present disclosure is not limited thereto, and any amount of roller pairs may be provided. The upper and lower calendering rollers 241a, 241b are movably controlled by an upper calendering actuator 242a and a lower calendering actuator 242b, respectively, so that the precise distance between the upper and lower calendering rollers 241a, 241b can be adjusted, thus controlling the compressed layer thickness of the coated electrode. Further, the upper and lower calendering rollers 241a, 241b may be configured for applying an adjustable roller load to the coated electrode, particularly so that the precise density or porosity of the at least one layer L can be controlled.

[0044] Next, the coating apparatus 200 may optionally include a slitting apparatus 250. The slitting apparatus 250 is configured for cutting the coated electrode into separate electrodes, particularly precisely cutting the coated electrode into strips of a specific width. The slitting apparatus 250 may include a plurality of cutting elements, e.g. cutting blades or cutting discs, which may be mounted in a fixed position or, alternatively, may be mounted to at least one actuator for adjusting their width-wise spacing and / or relative positions so that the width of the separated electrodes can be precisely controlled. Further, the slitting apparatus 250 may be further configured for cutting the coated electrode in the transverse direction. The present disclosure, however, is not limited thereto, and any slitting / cutting means known in the state of the art may be used. For transporting the electrode substrate S, and subsequently the coated electrode E, the coating apparatus 200 is further provided with a substrate transport apparatus. Although the substrate transport apparatus illustrated in Fig. 2 may be a simplified arrangement, the substrate transport includes at a minimum, a substrate supply reel 201, a substrate tension roller 202 and at least one coated electrode output reel 204a, 204b, with one or more guide rollers provided along the transport path so as to guide the sub strate / el ectrode throughout the coating apparatus 200. The substrate tension roller 202 may be controllable such that the tension applied to the electrode substrate can be adjusted for optimal coating. Generally, the substrate transport apparatus may include any typical substrate transport apparatus used in coating apparatuses of the state of the art.

[0045] The coating apparatus 200 is provided with at least one sensor for acquiring at least one quality parameter of the at least one layer L, and more generally, at least one quality parameter of the coated electrode E. Preferably, the at least one sensor is configured for acquiring the at least one quality parameter in-situ.

[0046] In the context of the present disclosure, the terms “in-line” and “in-situ” are used interchangeably, and refer to the arrangement of a sensor in a process. The acquisition of a quality parameter may be achieved in a number of ways, including “in-line” or “in-situ” acquisition, “on-line” acquisition, “at-line” acquisition and “off-line” acquisition.

[0047] An “in-line” or “in-situ” acquisition of a quality parameter refers to the observation, measurement or estimation of a quality parameter which is integrated directly into the process. In other words, the quality parameter is observed, measured or estimated by the analysis of a material, a mixture, a slurry or a deposited layer moving or being operated on within a process line. In-line or in-situ acquisition is carried out by in-line sensors installed on the process line.

[0048] An “on-line” acquisition of a quality parameter refers to the observation, measurement or estimation of a quality parameter which is taken from a separate area adjacent to the process line. In other words, the quality parameter is observed, measured or estimated by the analysis of a material, a mixture, a slurry or a deposited layer which has been diverted from the process line into a parallel sampling line. On-line acquisition is carried out by on-line sensors installed on a sampling line parallel to or split off from the process line.

[0049] In contrast to in-line / in-situ and on-line acquisition, an “at-line” acquisition and an “off-line” acquisition of a quality parameter is performed outside of a process line. In both at-line and offline acquisition, the quality parameter is observed, measured or estimated by the analysis of a material, a mixture, a slurry or a deposited layer which has been sampled and removed from the process line for outside analysis. An at-line analysis may be performed at the site of the process apparatus, while an off-line analysis may be performed in a laboratory.

[0050] Although at-line and off-line analyses of quality parameters may result in more accurate measurements, the nature of at-line or off-line analyses is such that automatic control based on those parameters is difficult due to the time delay in obtaining the parameter, as well as the requirement for the parameter to be manually entered back into the system so that requisite adjustments to process parameters can be carried out.

[0051] On the other hand, in-line / in-situ and on-line measurements have the advantage of generating real-time measurements and estimations of quality parameters and, particularly in the case of in-line / in-situ acquisition, do not require diversion of material from the process line into a sampling line. With recent improvements in sensor technology, in-line / in-situ measurement of a wide variety of quality parameters in real-time has become possible. The real-time acquisition afforded by in-line / in-situ and on-line measurement allows for the closed-loop control methods of the present disclosure to be realised. The present disclosure is not limited only to in-line / in- situ and on-line acquisition of quality parameters, and the incorporation of parameters acquired at-line or off-line is possible. However, it is preferable that the at least one quality parameter is acquired in-situ so that real-time closed-loop control can be implemented. Particularly, a mixture of a plurality of quality parameters which are acquired in-line / in-situ and a plurality of quality parameters which are acquired on-line, at-line or off-line is possible.

[0052] Referring now to Figs. 3A-3C, some examples of in-line sensors for acquiring at least one quality parameter are provided. Fig. 3 A exemplarily shows an in-line electrode layer adhesion sensor 270, Fig. 3B exemplarily shows an in-line electrode flexibility sensor 280, and Fig. 3C exemplarily shows an in-line four-terminal conductivity sensor.

[0053] The in-line electrode layer adhesion sensor 270 of Fig. 3 A includes a pair of movable rollers which may be selectively moved into contact with the coated electrode when acquisition is to be carried out. The pair of rollers includes an upper sensor roller 272a and a lower sensor roller 272b, wherein the upper sensor roller 272a is provided on the coated side of the coated electrode so that the at least one layer is contacted. The upper sensor roller 272a includes at least one surface portion having an adhesive layer 273. An imaging system 271 is provided for detecting whether the at least one layer peels from the electrode substrate or not, and is configured to generate a quality parameter corresponding to the level of adhesion.

[0054] In one arrangement, the adhesive layer 273 has a predetermined peel strength, such that the force required to peel the coated layer away from the upper sensor roller 272a is known. As shown in the right-hand side of Fig. 3 A, if the coated layer peels away from the electrode substrate and remains adhered to the upper roller 272a, the predetermined peel strength of the adhesive layer 273 is not exceeded, and the level of adhesion of the at least one layer to the electrode substrate is deficient. On the other hand, if the at least one layer separates from the upper roller 272a, the predetermined peel strength of the adhesive layer 273 is exceeded, and the level of adhesion of the at least one layer to the electrode substrate is sufficient.

[0055] In another arrangement, the upper roller 272a may be provided with a plurality of adhesive layers 273 each with a different predetermined peel strength. Thus, it can be determined if the at least one layer peels from the electrode substrate on one or more of the plurality of adhesive layers 273, and does not peel on others of the plurality of adhesive layers 273. The imaging system 271 may sense which of the predetermined peel strengths are exceeded, allowing an estimation of a level of adhesion to be generated.

[0056] In another arrangement, the upper roller 272a may be configured to have a pulling tension applied thereto in a direction away from the coated electrode. The upper roller 272a may be brought into contact with the at least one layer such that the at least one layer adheres thereto, and the upper roller 272a may subsequently be pulled away from the at least one layer. A sensor, such as a load sensor, may be provided to detect the pulling force, and the point at which the at least one layer separates from the upper roller 272a indicates a minimum level of adhesion which has been achieved. Alternatively, the point at which the at least one layer separates from the electrode substrate indicates a maximum level of adhesion which has been achieved.

[0057] The in-line electrode flexibility sensor 280 of Fig. 3B includes a sensor tension roller 283 which applies a predetermined tension to the coated electrode, e.g. by applying force to the coated electrode between two guide rollers 282, where the sensor tension roller 283 has a specific radius. According to one arrangement, the force applied by the sensor tension roller 283 is measured, and the force required to achieve the bend radius around the specific radius of the sensor tension roller 283 indicates a level of mechanical flexibility or mechanical stiffness of the coated electrode. According to an alternative arrangement, an imaging system 281 may be further provided to observe the at least one layer deposited on the electrode substrate. The imaging system 281 is configured to monitor the surface of the at least one layer to observe whether cracking develops in the at least one layer, indicating a level of mechanical flexibility or mechanical stiffness of the coated electrode.

[0058] The in-line four-terminal conductivity sensor 290 of Fig. 3C includes two pairs of movable rollers which may be selectively moved into contact with the coated electrode when acquisition is to be carried out. The rollers are configured to measure electrode conductivity and / or resistance according to four-terminal sensing, otherwise known as Kelvin sensing. Each pair of the rollers includes an upper sensor roller 291a, 293a and a lower sensor roller 291b, 293b, and each of the rollers is electrically conductive. The first pair of sensor rollers including upper sensor roller 291a and lower sensor roller 291b are connected to a current source and current sensor for measuring a current across the coated electrode, and the second pair of sensor rollers including upper sensor roller 293a and lower sensor roller 293b are connected to a voltage sensor for measuring a voltage drop across the coated electrode. Using the four-terminal sensing, the electrode conductivity and / or resistance can be accurately determined, eliminating contact resistance between the coated electrode and the rollers.

[0059] The rollers 291a, 291b, 293a, 293b of the in-line four-terminal conductivity sensor 290 may be rollers of another apparatus in the coating apparatus 200. For example, one or more of the rollers may be a transport roller for transporting / guiding the coated electrode, or may a calendering roller of the calendering apparatus 240.

[0060] At least one of the in-line electrode layer adhesion sensor 270, the in-line electrode flexibility sensor 280 and the in-line four-terminal conductivity sensor 290 exemplarily shown in Figs. 3A-3C may be arranged to acquire an in-line coating quality parameter at a position after the drying apparatus, and / or at a position after the calendering apparatus. Referring once again to Fig. 2, said sensors 270, 280, 290 may be arranged to acquire the respective coating quality parameter at in-line sensor positions 203.

[0061] The sensor types discussed above are only examples of possible sensors which may be included in the coating apparatus 200. The present disclosure is not limited thereto, however, and any coating quality sensor which is known in the state of the art may be incorporated into the coating apparatus 200, preferably as an in-line sensor. For example, the at least one sensor may further include a laser or optical sensor configured for measuring a thickness of the at least one layer, an optical sensor, particularly a camera system, configured for detecting a crack density of the at least one layer, a density sensor, particularly an X-ray diffraction sensor, configured for measuring a density and / or a porosity of the at least one layer, a moisture sensor for measuring a moisture level of the at least one layer, and an optical sensor, particularly a camera system, configured for measuring a width and / or deposition accuracy of the at least one layer.

[0062] Further, the coating apparatus 200 may be provided with additional sensors, particularly additional in-line sensors, so that accurate control of the coating apparatus 200 based on the desired process parameters may be carried out. For example, the slurry input 210 may be provided with a load cell 211 configured for measuring a mass of the mixed slurry being fed into the deposition apparatus 220. Said load cell 211 allows for more accurate determination of the rate of mixed slurry being fed to the deposition apparatus 220, and allows for more accurate control of the coating apparatus 200 in response to quality parameters.

[0063] The coating apparatus 200 further includes a coating controller 260 which is configured to control the coating apparatus 200 according to the control methods described in the present disclosure. Particularly, the coating controller 260 is configured to control the deposition apparatus 220, the drying apparatus 230, the calendering apparatus 240 and optionally the slitting apparatus 250 based on at least one coating process parameter. The coating controller 260 is in communication with the at least one sensor, particularly at least one in-line sensor, more particularly at least one in-line electrode flexibility sensor 280 and at least one in-line electrode adhesion sensor 270, so that at least one quality parameter acquired by said sensors can be input into the coating controller 260. Further, the coating controller 260 is in communication with one or more actuators for controlling the coating apparatus 200 so that the coating controller 260 may instruct a coating of an electrode substrate. Particularly, the coating controller may be in communication actuators of the deposition apparatus 220, such as the controllable deposition head 222 and / or the deposition feed screw 221, for instructing a deposition of at least one layer of mixed slurry. More particularly, the coating controller 260 may be in communication with actuators of the drying apparatus 230, such as one or more fans and / or one or more heating elements 231, for instructing a drying of the at least one layer. More particularly, the coating controller 260 may be in communication with actuators of the calendering apparatus 240, such as one or more upper / lower calendering actuators 242a, 242b for controlling the spacing and / or force of the upper / lower calendering rollers 241a, 241b, respectively, for instructing a calendering of the at least one layer. Optionally, the coating controller 260 may be in communication with actuators of the slitting apparatus 250, such as an actuator for adjusting the width-wise spacing between cutting elements of the slitting apparatus 250, for instructing a slitting of the coated electrode. The coating controller 260 may further be in communication with other sensors, such as load cell 211 provided on the slurry input 210, for more accurate control of a slurry feed rate.

[0064] The coating controller 260 may be a microprocessor, a programmable logic controller (PLC), or a digital signal processor (DSP). Particularly, the coating controller 260 may include a processing element, at least one input and at least one output, such that a data processing operation is performed on the at least one input and output to the at least one output. The coating controller 260 may further include at least one storage means, which may include random access memory (RAM), read-only memory (ROM) and external data storage means such as hard disks, flash storage or network-attached storage.

[0065] The coating controller 260 may further include a network interface for connecting to a data network, in particular a global data network. In this arrangement, the coating controller 260 is operatively connected to the network interface for carrying out commands received from the data network. The commands may include sending and / or receiving at least one of the process parameters or quality parameters, i.e. the parameters described above. The commands may further include carrying out a command received from the data network. In this case, the coating controller 260 is adapted for carrying out the task in response to the control command. The commands may include a status request. In response to the status request, or without prior status request, the coating controller 260 may be adapted for sending status information to the data network. Particularly, the coating controller 260 may be adapted for sending status information to the network interface, and the network interface is then adapted for sending the status information over the data network. The commands may include an update command including update data. In this case, the coating controller 260 is adapted for initiating an update in response to the update command and using the update data. The data network may be an Ethernet network using TCP / IP such as LAN, WAN or Internet. The data network may comprise distributed storage units such as the Cloud. Depending on the application, the Cloud can be in the form of a public, private, hybrid or community Cloud.

[0066] The coating controller 260 is further provided with a control algorithm and a coating model which are implemented for realising a closed-loop control method of the coating apparatus 200. Referring now to Fig. 4, which shows a flowchart of a method of controlling a coating process according to aspects and embodiments of the present invention, the control methods of the present disclosure will be described in the following.

[0067] According to the first aspect of the present invention, a method of coating an electrode substrate for electrode manufacturing for an electrochemical energy storage device is provided. The method 300 includes providing an electrode substrate, transporting the electrode substrate in a transport direction, feeding at least one mixed slurry, depositing at least one layer of mixed slurry on the electrode substrate with a deposition apparatus 341, drying the at least one layer with a drying apparatus 342, and calendering the at least one layer with a calendering apparatus 343 to produce a coated electrode. The depositing 341, drying 342 and calendering 343 are controlled by at least one coating process parameter Pc. The method 300 further includes acquiring 350 at least one coating quality parameter Qcof the at least one layer, preferably wherein the at least one coating quality parameter Qcis acquired in-situ, and adjusting 370 the at least one powder feeding process parameter Pcbased on the at least one powder quality parameter Qcaccording to a predetermined coating model 360. The at least one coating parameter Qcincludes at least one of a level of electrode mechanical flexibility measured after the drying 342 and / or after the calendering 343, and a level of electrode layer adhesion measured after the drying 342 and / or after the calendering 343.

[0068] In the flowchart illustrated in Fig. 4, the method 300 is outlined as follows. An input is provided to the coating input 310, which may be an input of at least one mixed slurry, particularly an input from a previous process 400, e.g. a slurry mixing process. A control algorithm 330 is provided for carrying out the method 300 based on at least one process parameter Pcprovided by the set of coating process parameters 320. Based on the control algorithm 330 and the process parameters, the coating apparatus 340 is controlled, i.e. by commanding one or more actuators of the powder feeding apparatus, to produce an output. In particular, the deposition apparatus 341, the drying apparatus 342, the calendering apparatus 343 and optionally the slitting apparatus 344 are controlled by commanding one or more actuators of the respective apparatuses. The output of the method 300 is provided to a subsequent process 500, e.g. a further manufacturing / assembly process or an EOL testing process.

[0069] The coating apparatus, particularly the deposition apparatus, the drying apparatus, the calendering apparatus and optionally the slitting apparatus, is continuously monitored by at least one coating sensor 350 of the coating apparatus, and said sensor(s) acquire at least one quality parameter Qcof the at least one layer of deposited slurry and / or the completed electrode output from or being transported through the coating apparatus. The at least one coating quality parameter Qcis provided to the coating model 360 which includes a plurality of correlations between quality parameters Qc and process parameters Pc. Using the coating model 360, at least one adjusted coating process parameter APCis generated in the process parameter adjustment 370 based on the quality parameter Qc. The at least one adjusted coating process parameter APCis then used to update the set of coating process parameters 320 so that the control algorithm 330 is automatically adjusted in a closed-loop fashion.

[0070] Through continuous monitoring and closed-loop control of the coating process, particularly based on quality parameters acquired in-situ, the process parameters Pcof the coating process can be specifically tuned to account for variations in material quality and variations in mixed slurry quality. For example, the desired target porosity or density of the at least one layer of deposited material on the electrode can be assured by optimising the depositing and / or calendering based on an in-line porosity or density measurement.

[0071] In the context of the present disclosure, the term “process parameter” refers to a parameter which defines an aspect of the process to be carried out. The process parameter may constitute a process state, e.g. an on / off condition, but typically constitutes a variable state which may be adjusted to achieve a desired process outcome. For a certain process, one or more process parameters may be initialised with a predefined set of values and may be automatically adjusted, updated or modified by a control method. For example, a process parameter may include an actuator on / off state, an actuator speed, a temperature, a pressure, or any other parameter which is used to control an aspect of a process.

[0072] On the other hand, a “quality parameter” refers to a parameter which defines an aspect of a process ingredient, material, intermediate product or final product of a process which is obtained, measured or estimated by some form of analysis. A quality parameter constitutes a value of a property of the process ingredient, material, intermediate product or final product which may be measured, for example, by one or more sensors or one or more analyses. Typically, a quality parameter, particularly of an intermediate product or a final product, is influenced by the process parameters which define the process used to generate said intermediate product or final product. A quality parameter may be compared to a threshold or a target range in order to determine whether a defect or quality deficiency has occurred. According to embodiments, the at least one coating process parameter Pcmay include one or more parameters from the group containing a coating transport speed of the electrode substrate through the deposition apparatus, a tension of the electrode substrate at the deposition apparatus, a diameter of a coating roller of the deposition apparatus, a feed rate of the mixed slurry, a drying transport speed of the electrode substrate past the drying apparatus, a drying power, a transport length of the drying apparatus, a drying temperature, particularly a drying temperature profile along a transport length of the drying apparatus, a calendering transport speed of the electrode substrate through the calendering apparatus, a calendering pressure, and a calendering height, particularly a distance between a pair of calendering rollers. According to further embodiments, the at least one coating quality parameter Qcmay include one or more parameters from the group containing a wet coating thickness of the at least one layer measured before the drying, a dry coating thickness of the at least one layer measured after the drying, a calendered coating thickness of the at least one layer measured after the calendering, a width of the at least one layer, the width being measured in a direction transverse to the transport direction, a moisture content of the at least one layer, a porosity of the at least one layer, a conductivity of the at least one layer, an area capacity of the at least one layer, a coating density of the at least one layer, a coating weight of the at least one layer, a coating accuracy of the at least one layer, and a crack density of the at least one layer measured after the calendering. However, the present disclosure is not limited thereto. The at least one coating process parameter Pcmay be any process parameter typical for operating a coating apparatus, particularly a deposition apparatus, a drying apparatus, a calendering apparatus and / or a slitting apparatus, and the at least one coating quality parameter Qcmay be any quality parameter for which a suitable sensor is available, which preferably can be acquired in-situ. According to an embodiment, which may be combined with other embodiments described herein, the coating model 360 is based on at least one correlation between the at least one coating process parameter Pcand the at least one coating quality parameter Qc.

[0073] Preferably, the coating model 360 includes a predetermined empirical model. Empirical data can be generated through operation of the electrode manufacturing system, or through prior knowledge of similar electrode manufacturing systems implemented previously. Alternatively, the coating model 360 may include a number of correlations obtained from simulation, estimation, extrapolation or calculation. For example, for at least an initial “training” period of operating the electrode manufacturing process, there may be insufficient empirical data on hand to build a comprehensive model. The coating model 360 may be operated based on a simulated, estimated, extrapolated or calculated model for a period of time while collecting empirical data, until sufficient data has been generated so that the coating model 360 may be replaced with an empirical model. As a further alternative, the coating model 360 may include a machine learning model which, when presented with an initial set of training data, is adapted to automatically improve the correlations during ongoing operation of the electrode manufacturing system.

[0074] The closed-loop control method 300 for controlling the coating process as described implements the closed-loop control based on quality parameters Qcacquired within the coating process. However, the method 300 may be further improved by accounting for parameters from other sub-processes of the electrode manufacturing process, such as a previous process 400 or a subsequent process 500. Similarly, the quality parameters Qcacquired in the coating process can also be provided to other sub-processes of the electrode manufacturing process for similar closed-loop control of said sub-process, such as a previous process 400 or a subsequent process

[0075] 500. In the context of the present disclosure, the terms “previous process” and “subsequent process” refers to separate sub-processes of the electrode manufacturing process which are carried out prior to or subsequent to the present sub-process, respectively. The previous process or subsequent process is considered to be an “external process” in view of the present sub-process under consideration. Further, the “external process” may be considered as a parallel sub-process which is being carried out in parallel to the present sub-process, and any disclosure relating to a previous process or subsequent process is also applicable to a parallel process. Accordingly, process parameters which govern the external process or quality parameters which are acquired in the external process are referred to as “external parameters” in view of the present subprocess under consideration.

[0076] According to an embodiment, which may be combined with other embodiments described herein, the method 300 according to the first aspect may further include providing the at least one coating quality parameter Qcof the coating process to a subsequent process 500 of the electrode manufacturing as a feed-forward signal, such that at least one process parameter of the subsequent process is adjusted based on the at least one coating quality parameter. For example, the coating process may come before a subsequent process 500 which corresponds to a binning process in which the electrode being produced by the coating process is sorted based on its quality for assembly into a battery cell. The coating process may acquire a quality parameter Qc, such as an electrode coating density, and the process parameters of the binning process may be automatically adapted based thereon. If the electrode coating density, for example, indicates an electrode with a high density, the binning process can select the electrodes intended for assembly into a high-capacity battery cell and sort said electrodes accordingly. Particularly, as shown in the figure by the optional dashed lines, the process parameters of the subsequent process 500 may be adjusted based on the coating quality parameter Qcbased on a model 560 of the subsequent process 500. According to a further embodiment, which may be combined with other embodiments described herein, the method 300 according to the first aspect may further include providing the at least one coating quality parameter Qcof the powder feeding process to a previous process 400 of the electrode manufacturing as a feed-back signal, such that at least one process parameter of the previous process is adjusted based on the at least one coating quality parameter Qc. For example, the coating process may come after a previous process 400 which corresponds to a slurry mixing process. The coating process may acquire a quality parameter Qc, such as an electrode porosity or an electrode moisture content, and the process parameters of the slurry mixing in the previous process 400 may be automatically adapted to optimise the quality parameter Qc. Particularly, as shown in the figure by the optional dashed lines, the process parameters of the previous process 400 may be adjusted based on the powder feeding quality parameter Qcbased on a model 460 of the subsequent process 400.

[0077] According to a further embodiment, which may be combined with other embodiments described herein, the method 300 according to the first aspect may further include acquiring at least one external parameter Qx, QY of a previous process 400 or a subsequent process 500 and adjusting the at least one coating process parameter Pcbased on the at least one external parameter Qx, QY according to the coating model 360. As exemplarily shown in the figure by the optional dashed lines, an external quality parameter Qxwhich is acquired by the at least one sensor 450 in a previous process 400 may be provided, as an external parameter, to the coating process 300 so that one or more coating process parameters Pccan be adjusted based on the external parameter using the coating model 360. Similarly, an external quality parameter QYwhich is acquired by the at least one sensor 550 in a subsequent process 500 may be provided, as an external parameter, to the coating process 300 so that one or more coating process parameters Pc can be adjusted based on the external parameter using the coating model 360. According to a further embodiment, which may be combined with other embodiments described herein, the at least one external parameter of the electrode manufacturing may be at least one quality parameter acquired in a previous or subsequent process, or at least one process parameter set to control a previous or subsequent process. For example, the coating process 300 may be adjusted based on the process parameters of a previous slurry mixing process. If the slurry mixing recipe was adjusted for some known reason, e.g. to account for variations in raw materials sourced from different suppliers, the process parameters of the slurry mixing recipe can be made known to the coating process so that at least one coating process parameter Pcmay be automatically adjusted using the coating model 360.

[0078] According to a further embodiment, which may be combined with other embodiments described herein, the method 300 according to the first aspect may further comprise slitting the deposited electrode. Particularly, the deposited electrode, after the calendering process, is cut into separated electrodes according to the final desired size for assembly into a battery cell. The slitting is particularly performed in the transport direction so that the deposited electrode is cut into strips of a prescribed width, and may be further trimmed along at least one edge of the deposited electrode. The at least one coating process parameter Pcmay further include an electrode cutting speed and / or an electrode cutting width tolerance. For example, after the deposition apparatus has coated at least one layer of mixed slurry on the electrode substrate, a coating quality parameter Qccorresponding to the deposited width of the at least one layer and / or an electrode coating accuracy may be acquired, and the process parameters of the slitting apparatus, e.g. the width-wise positions of one or more cutting elements, may be adjusted so that the target width of the separated electrodes may be accurately achieved.

[0079] Reference will now be made to Fig. 5, which illustrates a flow chart of a method for electrode manufacturing for an electrochemical storage device. In particular, Fig. 5 relates to a closed- loop control system for the overall electrode manufacturing process described herein, wherein a holistic system is employed to control each sub-process of the electrode manufacturing process based on parameters of one sub-process being used as feed-back or feed-forward signals in the control of other sub-processes. By implementing a closed-loop overall control system which encapsulates the respective closed-loop control systems of each sub-process, the process parameters of each sub-process can be adjusted based on quality parameters measured at any point in the electrode manufacturing process using an overall system model. Such an overall control system not only allows for improvements in reaching quality, safety and performance targets more reliably, but allows for further possibilities such as allowing for the source tracing of defects or quality deficiencies, reduced scrap generation, and repair / recycling of previously scrapped materials.

[0080] According to the second aspect of the present invention, a method for electrode manufacturing for an electrochemical energy storage device is provided. The method includes feeding at least one powder material in a powder feeding process 120, the feeding being based on at least one powder feeding process parameter PP, feeding at least one liquid material in a liquid feeding process 110, the feeding being controlled based on at least one liquid feeding process parameter PL, mixing a slurry comprising the at least one powder material and the at least one liquid material in a slurry mixing process 130, the mixing being controlled based on at least one slurry mixing process parameter PM. The method further includes coating the slurry onto an electrode substrate in a coating process 140 to produce the electrode, the coating being controlled according to the first aspect described above.

[0081] In a general sense, the method may define an overall closed-loop control system which encapsulates the closed-loop control methods of each sub-process of the electrode manufacturing process, wherein the overall closed-loop system can adjust process parameters of each sub-process based on quality parameters acquired in other sub-processes. Similar to the first aspect, the control method of each sub-process is based on process parameters which are internal to that sub-process, and which may be adjusted based on quality parameters acquired internally to that sub-process, using a model which may be internal to that sub-process. However, in the second aspect, the control method of each sub-process may further be based on one or more external parameters from other sub-processes, that is, parameters which are acquired externally to a specific sub-process. Thus, the adjusting of the internal process parameters of each sub-process based on the one or more external parameters may be performed by an overall control system according to the second aspect. Such an over-arching control system allows for sub-processes to be reactive to quality parameters in other subprocesses, allowing for quality targets to be achieved quickly and quality targets to be reliably maintained, while reduced the amount of material scrap generated.

[0082] Beginning with the powder feeding process 120, a powder feeding controller 126, which may be included in the powder feeding apparatus, is configured to carry out a powder feeding control method to feed at least one powder material into the subsequent slurry mixing process 130 according to at least one powder feeding process parameter PP. At least one powder quality sensor 125 is provided for acquiring at least one powder quality parameter QPwhich, within the closed-loop control system of the powder feeding process 120, is fed back to the powder feeding controller 126. Further, the at least one powder quality parameter QPis provided to the overall system controller 600.

[0083] The at least one powder feeding process parameter PPmay include one or more parameters from the group containing a powder volume rate of the powder material into or out of the powder feeding apparatus, a powder mass rate of the powder material into or out of the powder feeding apparatus, and a mesh size of an in-line mesh of the powder feeding apparatus. The at least one powder quality parameter QPmay include one or more parameters from the group containing an average particle size, a particle size range, a content of magnetic components, a tapped density and a content of impurities. However, the present disclosure is not limited thereto. The at least one powder feeding process parameter PPmay be any process parameter typical for operating a powder feeding apparatus, and the at least one powder quality parameter QPmay be any quality parameter for which a suitable sensor is available, which preferably can be acquired in-situ.

[0084] Next, in the liquid feeding process 110, a liquid feeding controller 116, which may be included in a liquid feeding apparatus, is configured to carry out a liquid feeding control method to feed at least one liquid material into the subsequent slurry mixing process 130 according to at least one liquid feeding process parameter PL. At least one liquid quality sensor 115 may be provided for acquiring at least one liquid quality parameter QLwhich, within the closed-loop control system of the liquid feeding process 110, may be fed back to the liquid feeding controller 116. Further, the at least one liquid quality parameter QLis provided to the overall system controller 600.

[0085] The at least one liquid feeding process parameter PLmay include one or more parameters from the group containing a liquid volume rate of the liquid material into or out of the liquid feeding apparatus, a liquid mass rate of the liquid material into or out of the liquid feeding apparatus. The at least one liquid quality parameter QLmay include one or more parameters from the group containing a viscosity of the liquid material, a content of impurities in the liquid material and, if the liquid is water, a pH measurement of the liquid material. However, the present disclosure is not limited thereto. The at least one liquid feeding process parameter PLmay be any process parameter typical for operating a powder feeding apparatus, and the at least one powder quality parameter QLmay be any quality parameter for which a suitable sensor is available, which preferably can be acquired in-situ.

[0086] Next, a slurry is mixed using the powder material fed from the powder feeding process 120 and the liquid material fed from the liquid feeding process 110 in a slurry mixing process 130. A mixing controller 136 is configured to carry out the slurry mixing control method to mix the slurry based on at least one mixing process parameter PM. The at least one mixing process parameter PMmay be prescribed based on one or more slurry recipes. At least one slurry quality sensor 135 may be provided for acquiring at least one slurry quality parameter Qswhich, within the closed-loop control system of the mixing process 130, may be fed back to the mixing controller 136. Further, the at least one slurry quality parameter Qsis provided to the overall system controller 600.

[0087] The at least one mixing process parameter PMmay include one or more parameters from the group containing a mixing, feeding and / or dispersing sequence of the at least one powder material and / or the at least one liquid material, a mixing duration, a mixing rate, a mixing shear rate and / or a mixing shear force, a mixing temperature, and a vacuum level of an atmosphere inside the slurry mixer. The at least one liquid quality parameter QLmay include one or more parameters from the group containing a solid content of the mixed slurry, a viscosity of the mixed slurry, a density of the mixed slurry, a pH level of the mixed slurry, a level of coarseness of the mixed slurry, a volume resistivity of the mixed slurry, and a content of magnetic impurities in the mixed slurry. However, the present disclosure is not limited thereto. The at least one liquid feeding process parameter PLmay be any process parameter typical for operating a powder feeding apparatus, and the at least one powder quality parameter QLmay be any quality parameter for which a suitable sensor is available, which preferably can be acquired in-situ.

[0088] Finally, the coating process 140 is carried out so that a coated electrode may be produced. The coating process 140 is according to the first aspect as described above. The coating process 140 includes, at a minimum, a deposition process which may be controlled by a deposition controller 146, a drying process which may be controlled by a drying controller 147, and a calendering process which may be controlled by a calendering controller 148. Optionally, the coating process 140 may further include a slitting process which may be controlled by a slitting controller. However, the present disclosure is not limited thereto, and a single coating controller may be provided which is configured for controlling all methods in the coating process 140. The respective processes included in the coating process 140 are carried out based on at least one coating process parameter Pc. The at least one coating process parameter Pcmay be a plurality of coating process parameters which relate to parameters of the deposition process, the drying process, the calendering process, and optionally the slitting process. At least one coating quality sensor 145 may be provided for acquiring at least one coating quality parameter Qc which, within the closed-loop control system of the coating process 140, may be fed back and / or fed forward to one of the deposition controller 146, the drying controller 147, the calendering controller 148 and optionally the slitting controller. Further, in addition to the first aspect and embodiments described above, the at least one coating quality parameter Qcis provided to the overall system controller 600.

[0089] For process parameters related to the deposition process, the at least one coating process parameter Pcmay include one or more parameters from the group containing a coating transport speed of the electrode substrate through the deposition apparatus, a tension of the electrode substrate at the deposition apparatus, a diameter of a coating roller of the deposition apparatus, and a feed rate of the mixed slurry. For process parameters related to the drying process, the at least one coating process parameter Pcmay include one or more parameters from the group containing a drying transport speed of the electrode substrate past the drying apparatus, a drying power, a transport length of the drying apparatus, and a drying temperature, particularly a drying temperature profile along a transport length of the drying apparatus. For process parameters related to the calendering process, the at least one coating process parameter Pcmay include one or more parameters from the group containing a calendering transport speed of the electrode substrate through the calendering apparatus, a calendering pressure, and a calendering height, particularly a distance between a pair of calendering rollers. However, the present disclosure is not limited thereto, and the at least one coating process parameter Pcmay be any process parameter typical for operating a deposition apparatus, a drying apparatus, a calendering apparatus or an electrode slitting apparatus.

[0090] The at least one coating quality parameter Qcmay include one or more parameters from the group containing a wet coating thickness of the at least one layer measured before the drying, a dry coating thickness of the at least one layer measured after the drying, a calendered coating thickness of the at least one layer measured after the calendering, a width of the at least one layer, the width being measured in a direction transverse to the transport direction, a moisture content of the at least one layer, a porosity of the at least one layer, a conductivity of the at least one layer, an area capacity of the at least one layer, a coating density of the at least one layer, a coating weight of the at least one layer, a coating accuracy of the at least one layer, and a crack density of the at least one layer measured after the calendering. However, the present disclosure is not limited thereto, and the at least one coating quality parameter Qcmay be any quality parameter for which a suitable sensor is available, which preferably can be acquired in-situ.

[0091] The overall system controller 600 is provided with the quality parameters QP, QL, Qs, Qc which, for brevity, will be referred to as a plurality of quality parameters QALL- The overall system controller 600 may be configured to automatically generate adjusted process parameters based on the plurality of quality parameters QALL using an overall system model 610. The overall system controller 600, based on an overall control algorithm 620, may then provide a plurality of adjusted process parameters APALL to the requisite sub-processes.

[0092] The overall system model 610 is an over-arching model of the electrode manufacturing process. In one exemplary form, the overall system model 610 may include a plurality of correlations between quality parameters and process parameters. The plurality of correlations may be based on empirical data, or may be configured to be automatically generated during operation. In a further exemplary form, the overall system model 610 may include a machine learning model. The machine learning model may be trained on a subset of correlations formed from empirical data, and may generatively build a more comprehensive set of correlations based on said subset.

[0093] The overall system model 610 is exemplarily shown as being a single model contained within the overall system controller 600. However, the present invention is not limited thereto. The overall system model 610 may include a plurality of sub-models. For example, the overall system model 610 may include one or more sub-models related to the generating of adjusted process parameters for a specific sub-process.

[0094] The plurality of adjusted process parameters AP LL may include one or more of the group containing an adjusted powder feeding process parameter APP, an adjusted liquid feeding process parameter APL, an adjusted mixing process parameter APM, and an adjusted coating process parameter APC. Each one of the adjusted process parameters is provided to the controller 116, 126, 136, 146, 147, 148 of the liquid feeding process 110, the powder feeding process 120, the mixing process 130 and the coating process 140, respectively, so that one or more of said processes can be automatically adjusted based on any quality parameter sourced from the sub-processes, wherein said quality parameter is fed back or fed forward through the overall control system.

[0095] For example, a slurry quality parameter Qswhich indicates a slurry density may, using the overall system model 610 and the correlations included therein, indicate that a feed-forward adjustment may be required in the coating process 140 so that a desired coating density is achieved, and the overall system controller 600 may generate an adjusted coating process parameter APCto correct and / or take account for the slurry density. Similarly, a slurry quality parameter Qswhich indicates a slurry viscosity may, using the overall system model 610 and the correlations included therein, indicate that a feed-back adjustment may be required in the liquid feeding process 110 so that a desired slurry viscosity is achieved, and the overall system controller 600 may generate an adjusted liquid feeding process parameter APLto correct and / or take account for the slurry viscosity.

[0096] According to an embodiment, which may be combined with other embodiments described herein, in the method according to the second aspect the at least one powder feeding process parameter PP, the at least one liquid feeding process parameter PL, and / or the at least one slurry mixing process parameter PMis adjusted based on the at least one coating quality parameter Qc. In other words, process parameters which are external to the coating process 140 may be adjusted based on a quality parameter which is internal to the coating process 140.

[0097] Particularly, the at least one liquid feeding process parameter PLmay be adjusted based on the at least one coating quality parameter Qcusing a liquid feeding model. For example, in the case where the at least one coating quality parameter Qcincludes an electrode moisture measurement, the value of the electrode moisture of the at least one layer of coated slurry material, either measured before the drying process or after the drying process, may require a decreased volume of solvent or water to be added by the liquid feeding process 110 so that the desired electrode moisture targets are achieved. Using the liquid feeding model or the overall system model 610, which may include a correlation between an electrode moisture of the at least one deposited layer (quality parameter) and a solvent or water volume (process parameter), the liquid feeding process parameter PLcorresponding to the volume of solvent or water being fed may be automatically adjusted to suit.

[0098] Further, the at least one powder feeding process parameter PPmay be adjusted based on the at least one coating quality parameter Qcusing a powder feeding model. For example, in the case where the at least one coating quality parameter Qcincludes an electrode porosity measurement, this may indicate that the mesh size of the in-line sieve in the powder feeding process may need to be adjusted so that the particle size range of the at least one powder material being fed into the slurry mixing process 130 is optimised. Accordingly, in the powder feeding process 120, said process parameter may be automatically adjusted.

[0099] Further still, the at least one slurry mixing process parameter PMmay be adjusted based on the at least one coating quality parameter Qcusing a slurry mixing model. For example, in the case where the at least one coating quality parameter Qcincludes an electrode adhesion, the value of the electrode adhesion of the at least one layer to the electrode substrate, as measured by an electrode adhesion sensor either after the drying apparatus or after the calendering apparatus, may require that the slurry mixing is performed with a modified slurry recipe, e.g. with a higher binder content, so that electrode adhesion targets are achieved, and said process parameter may be automatically adjusted.

[0100] According to an embodiment, which may be combined with other embodiments described herein, in the method according to the second aspect the at least one coating process parameter Pcis adjusted based on at least one external parameter of the liquid feeding process 110, the powder feeding process 120, and / or the slurry mixing process 130 according to the coating model. In other words, process parameters which are internal to the coating process 140 may be adjusted based on a quality parameter which is external to the coating process 140. Said external parameter may be at least one liquid quality parameter QL, at least one powder feeding quality parameter QP, and / or at least one slurry quality parameter Qs.

[0101] Particularly, at least one coating process parameter Pcmay be adjusted based on the at least one liquid quality parameter QLusing the coating model. For example, in the case where the at least one liquid quality parameter QLincludes an in-line solvent concentration measurement being fed by the liquid feeding, parameters for controlling the drying apparatus may need to be changed so that the desired drying quality parameters are achieved, e.g. electrode moisture content. Said process parameters for controlling the drying apparatus may be automatically adjusted, e.g. the drying power and / or drying time may be adjusted to suit. Further, at least one coating process parameter Pcmay be adjusted based on the at least one powder quality parameter QPusing the coating model. For example, in the case where the at least one powder quality parameter QPincludes an in-line tapped density measurement of the powder material being fed, the calendering roller force in the calendering apparatus may need to be adjusted so that the desired coating density targets are achieved.

[0102] Further still, at least one coating process parameter Pcmay be adjusted based on the at least one slurry quality parameter Qsusing the coating model. For example, in the case where the at least one slurry quality parameter Qsincludes an in-line solid content measurement of the slurry, the mass of mixed slurry being fed into the deposition apparatus may need to be adjusted so that the desired coating quality targets such as coating width and coating thickness are achieved.

[0103] According to an embodiment, which may be combined with other embodiments described herein, the method according to the second aspect further includes at least one of storing the mixed slurry 131 after the slurry mixing process 130 and before the coating process 140 or before a further slurry mixing process 130, and / or testing the electrochemical energy storage device having the electrode in an end-of-line testing process 160.

[0104] Storage of a mixed slurry 131 may occur in situations where a coating process 140 is not ready for feeding the mixed slurry therein, e.g. in cases where the coating process 140 is offline or in the process of coating an electrode substrate with a different mixed slurry. In other situations, a mixed slurry may be required to be stored for a certain period of time under prescribed conditions, such as a storage temperature, storage pressure or storage humidity, in order to achieve desired quality targets of a deposited electrode. The storage of a mixed slurry 131 may be carried out in a storage apparatus, particularly a storage apparatus with a means to control at least one storage process parameter. Optionally, said storage apparatus may be equipped with at least one sensor for acquiring at least one storage quality parameter. The at least one storage process parameter and / or the at least one storage quality parameter may be provided to the overall system controller 600 so that one or more process parameters, particularly the at least one coating process parameter Pc, may be automatically adjusted based on the storage conditions and / or storage quality. Particularly, the overall system model 610 may include a plurality of correlations between storage quality parameters, storage process parameters, and process parameters of other sub-processes.

[0105] As an example of a feed-forward arrangement, a mixed slurry which has been stored at a specific temperature for a specific storage time may have a higher density than a slurry which has more recently been mixed, necessitating an adjustment to at least one coating process parameter Pcto generate, based on the overall system model 610, an adjusted coating process parameter APCso that the increased slurry density can be taken into account and the resulting deposited electrode exhibits the desired properties after coating, drying and calendering. As a further example of a feed-back arrangement, the mixed slurry which has been stored at a specific temperature for a specific storage time may be required to be re-mixed in the slurry mixing process, e.g. to increase the content of solvent, necessitating an adjustment to at least one liquid feeding process parameter PLand at least one mixing process parameter PMto generate, based on the overall system model 610, an adjusted liquid feeding process parameter APLand an adjusted mixing process parameter APMso that the stored slurry can be re-mixed and the desired slurry quality parameters can be achieved.

[0106] According to an embodiment, which may be combined with other embodiments described herein, in the method according to the second aspect the at least one coating process parameter Pcis adjusted based on at least one external parameter of the end-of-line testing process 160 according to the coating model. For example, if the EOL testing indicates that the final cell weight is insufficient, this may indicate that the mass of slurry material being fed to the deposition apparatus and being coated onto the electrode substrate is required to be increased so that the desired cell capacity is achieved. For the next batch of electrode manufacturing, the coating process may be adjusted to suit.

[0107] The present invention according to the second aspect and embodiments allows for defect and / or quality deficiency source tracing. In other words, in the case where a quality parameter may indicate a defect or a deficiency, the quality parameter can be used to indicate the sub-process or specific process step in which the defect or deficiency has arisen. The defect source tracing 630 may be carried out by the overall system control 600, in particular using the overall system model 610, as indicated in the figures. However, the present disclosure is not limited thereto, and the defect source tracing may be carried out by the respective sub-process controllers 116, 126, 136, 146, 147, 148 within each sub-process, and / or the EOL testing controller 166.

[0108] According to an embodiment, which may be combined with other embodiments described herein, the method according to the second aspect further includes comparing at least one quality parameter from one of the powder feeding process, the liquid feeding process, the slurry mixing process and the coating process to a predetermined defect threshold and, if the comparing indicates a defect, further identifying a source of the defect, based on the at least one quality parameter, using one of the powder feeding model, a liquid, feeding model, a slurry mixing model and a coating model. Optionally, the powder feeding model, liquid feeding model, slurry mixing model and coating model may be incorporated into an overall system model 610, and the further identifying of the source of the defect is based on the at least one quality parameter using the overall system model 610.

[0109] In the above embodiment, which will be referred to as the defect source tracing, the one or more models included in the control method may include a plurality of correlations which indicate the effects of specific process parameters on the probability of generating a defect. For example, in the slurry mixing process 130, a slurry mixing process parameter PMmay, if set to certain values, result in some probability of generating a specific defect in the coating process 140. With sufficient empirical data, a correlation can be produced and provided in one or more models in the control system, particularly in the overall system model 610. The defect source tracing may then, based on a coating quality parameter Qcwhich indicates the specific defect, identify with a level of probability that the specific defect was caused by the specific value of the slurry mixing process parameter PM. As a further example, it may be known that setting the slurry mixing temperature to a particular temperature may have a certain probability of resulting in a density of a deposited layer of slurry on an electrode substrate to exceed a defect threshold, and the defect source tracing may thus be able to identify the likelihood of the defective density parameter in the coating process 140 to have originated from the slurry mixing temperature, and the defect may be avoided by adjusting the slurry mixing temperature to suit.

[0110] The identifying step may further include the comparing the at least one quality parameter to one or more additional quality parameters which do not indicate a defect. Further optionally, the identifying step may include comparing the at least one quality parameter to one or more process parameters. By basing the identifying on additional parameters, the defect source tracing may be able to indicate with more precision as to the source of the defect.

[0111] The defect source tracing 630 may further be used to determine whether one or more materials, intermediate products or final products should be removed from the electrode manufacturing process as scrap material. Depending on the type of defect and / or the quality of the scrap material, the scrap material may be disposed of. However, preferably, since the defect source tracing 630 indicates why said scrap material may have been removed from the process, a scrap repair and / or re-use process 640 may be carried out so that the scrap material is reprocessed or repurposed in such a way as to minimise waste. By reprocessing or repurposing scrap material, such as scrap slurry or scrap electrodes which may have been in various stages of coating, drying and calendering, the material efficiency and energy efficiency of the manufacturing process can be significantly improved. According to an embodiment, which may be combined with other embodiments described herein, the method according to the second aspect may further include, if the identifying indicates that the source of the defect is in the slurry mixing process, removing the mixed slurry as a scrap slurry and optionally removing the electrode as a scrap electrode, and / or if the identifying indicates that the source of the defect is in the coating process, removing the electrode as a scrap electrode. The scrap material, i.e. the scrap slurry and / or the scrap electrode, may be removed from the electrode manufacturing process and optionally stored under prescribed storage conditions.

[0112] The closed-loop control methods for controlling the electrode manufacturing system as described herein thus have a significant advantage in that the respective processes and subprocesses may be adapted from their usual control schemes of pure manufacturing of electrodes to other modes according to control schemes for repairing and reprocessing. Accordingly, aspects and embodiments of the present disclosure achieve further improvements in energy and material efficiency.

[0113] According to an embodiment, which may be combined with other embodiments described herein, the method according to the second aspect may further include reprocessing the scrap slurry and / or reprocessing the scrap electrode.

[0114] In particular, the scrap slurry may be reprocessed by adjusting the at least one mixing process parameter PMbased on the at least one quality parameter, i.e. at least one quality parameter of the scrap slurry, feeding the scrap slurry into the slurry mixing process 130, optionally feeding at least one powder material and / or at least one liquid material into the slurry mixing process 130, and re-mixing the scrap slurry. For example, a scrap slurry mixture may have been scrapped and removed from the electrode manufacturing process due to an insufficient solid content of the mixed slurry. In this case, the scrap slurry is re-introduced into the slurry mixing process 130, and adjusted process parameters APPof the powder feeding process 120 are generated by the overall system controller 600 for feeding a correcting or repairing amount of powder material so that the scrap slurry can be re-mixed with more powder, resulting in a repaired slurry which meets the desired quality target for solid content.

[0115] Similarly, the scrap electrode may be reprocessed by adjusting the at least one coating process parameter Pcbased on the at least one quality parameter, i.e. at least one quality parameter of the scrap electrode, feeding the scrap electrode into the coating process 140, and re-depositing, re-drying and / or re-calendering the scrap electrode. For example, a scrap electrode may have been scrapped and removed from the electrode manufacturing process due to insufficient coating thickness of one or more layers of slurry. In this case, the scrap electrode is reintroduced into the coating process 140, and adjusted process parameters APCof the coating process 140, particularly the deposition process, are generated by the overall system controller 600 for re-depositing a correcting or repairing layer of slurry onto the scrap electrode, resulting in a repaired electrode which meets the desired quality target for layer thickness.

[0116] Further aspects and embodiments of the present disclosure relate to the apparatus for carrying out the above-described methods according to the first and / or second aspect.

[0117] Referring once again to Fig. 2, according to the third aspect of the present disclosure, a coating apparatus 200 for coating an electrode substrate S is provided. The coating apparatus 200 includes a substrate supply reel 201 for providing an electrode substrate S, a mixed slurry input 210 for receiving a mixed slurry, a deposition apparatus 220 configured for depositing at least one layer L of the mixed slurry onto the electrode substrate S, a drying apparatus 230 configured for drying the at least one layer L, a calendering apparatus 240 configured for compressing the at least one layer L to produce a coated electrode E, at least one sensor configured for acquiring at least one coating quality parameter Qcof the at least one layer L, preferably wherein the at least one sensor is configured for in-situ acquisition, and a controller configured for controlling the coating apparatus 200 by implementing the method according to the second aspect. The at least one sensor comprises at least one of an inline electrode flexibility sensor 280 configured for measuring a mechanical flexibility of the at least one layer L, the inline electrode flexibility sensor 280 being positioned after the drying apparatus 230 and / or after the calendering apparatus 240, and an inline electrode layer adhesion sensor 270 configured for measuring the adhesion of the at least one layer L to the electrode substrate S, the inline electrode adhesion sensor being positioned after the drying apparatus 230 and / or after the calendering apparatus 240. Further embodiments according to features, aspects and modifications of the coating apparatus 200 as described earlier in the present disclosure are possible.

[0118] In particular, according to an embodiment which may be combined with other embodiments described herein, the at least one sensor may further include an in-line four-terminal conductivity sensor 290 configured for acquiring a measurement of an electrode conductivity and / or resistance of the coated electrode. The terminals of the four-terminal conductivity sensor 290 may include one or more rollers, and the one or more rollers may be one or more of rollers of a substrate transport apparatus or one or more rollers of the calendering apparatus.

[0119] Further, according to an embodiment which may be combined with other embodiments described herein, the at least one sensor may further include a laser or optical sensor configured for measuring a thickness of the at least one layer, an optical sensor, particularly a camera system, configured for detecting a crack density of the at least one layer, a density sensor, particularly an X-ray diffraction sensor, configured for measuring a density and / or a porosity of the at least one layer, a moisture sensor for measuring a moisture level of the at least one layer, and an optical sensor, particularly a camera system, configured for measuring a width and / or deposition accuracy of the at least one layer. However, the sensor types discussed above are only examples of possible sensors which may be included in the coating apparatus 200. The present disclosure is not limited thereto, however, and any coating quality sensor which is known in the state of the art may be incorporated into the coating apparatus 200 either as an inline sensor or as an on-line sensor.

[0120] Further, the coating apparatus 200 may be provided with additional sensors, particularly additional in-line sensors, so that accurate control of the coating apparatus 200 based on the desired process parameters may be carried out. For example, the slurry input 210 may be provided with a load cell 211 configured for measuring a mass of the mixed slurry being fed into the deposition apparatus 220.

[0121] The controller of the coating apparatus 200, i.e. the coating controller 260, may be a microprocessor, a programmable logic controller (PLC), or a digital signal processor (DSP). Particularly, the coating controller 260 may include a processing element, at least one input and at least one output, such that a data processing operation is performed on the at least one input and output to the at least one output. The coating controller 260 may further include at least one storage means, which may include random access memory (RAM), read-only memory (ROM) and external data storage means such as hard disks, flash storage or network-attached storage, and may further include a network interface for connecting the coating controller 260 to a data network, in particular a global data network.

[0122] According to a fourth aspect of the present disclosure, an electrode manufacturing system for manufacturing electrodes for an electrochemical energy storage device is provided. The system includes at least one powder feeding apparatus 200 configured for feeding at least one powder material M, at least one liquid feeding apparatus configured for feeding at least one liquid material, and a slurry mixing apparatus configured to mix a slurry of the at least one powder material M and the at least one liquid material. The system further includes a coating apparatus according to the third aspect described above, the coating apparatus being configured for coating an electrode substrate with at least one layer of the mixed slurry, drying the at least one layer and calendering the at least one layer to produce a coated electrode, and a system controller configured for controlling the electrode manufacturing system according to the method of the second aspect.

[0123] The system controller of the electrode manufacturing system, i.e. the overall system controller 600, may be a microprocessor, a programmable logic controller (PLC), or a digital signal processor (DSP). Particularly, the overall system controller 600 may include a processing element, at least one input and at least one output, such that a data processing operation is performed on the at least one input and output to the at least one output. The overall system controller 600 may further include at least one storage means, which may include random access memory (RAM), read-only memory (ROM) and external data storage means such as hard disks, flash storage or network-attached storage, and may further include a network interface for connecting the overall system controller 600 to a data network, in particular a global data network.

[0124] Although various exemplary embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that various changes and modifications can be made which will achieve some of the advantages of the invention without departing from the spirit and scope of the invention. It will be obvious to those reasonably skilled in the art that other components performing the same functions may be suitably substituted. It should be mentioned that features explained with reference to a specific figure may be combined with features of other figures, even in those cases in which this has not explicitly been mentioned.

[0125] Spatially relative terms such as “under”, “below”, “lower”, “over”, “upper” and the like are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc. and are also not intended to be limiting. Like terms refer to like elements throughout the description. As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise. With the above range of variations and applications in mind, it should be understood that the present invention is not limited by the foregoing description, nor is it limited by the accompanying drawings. Instead, the present invention is limited only by the following claims and their legal equivalents.

[0126] Reference numbers

[0127] 100 Method of manufacturing an 166 End-of-line (EOL) testing electrochemical energy storage controller device 200 Coating apparatus

[0128] 110 Liquid material feeding process 201 Substrate supply reel

[0129] 115 Liquid quality parameter 202 Substrate tension roller

[0130] 116 Liquid feeding controller 203 In-line sensor

[0131] 204a, 204b Electrode output reel

[0132] 120-122 Powder material feeding

[0133] 210 Slurry input process

[0134] 211 Slurry input load cell

[0135] 125 Powder quality sensor

[0136] 220 Deposition apparatus

[0137] 126 Powder feeding controller

[0138] 221 Deposition feed screw

[0139] 130 Slurry mixing process

[0140] 222 Deposition head

[0141] 131 Slurry storage process 223 Deposition drive motor

[0142] 135 Mixing quality sensor 230 Drying apparatus

[0143] 136 Mixing controller 231 Heating element

[0144] 140 Coating process 240 Calendering apparatus

[0145] 141 Deposition process 241a Upper calendering roller

[0146] 142 Drying process 241b Lower calendering roller

[0147] 143 Calendering process 242a Upper calendering actuator

[0148] 242b Lower calendering actuator

[0149] 144 Slitting process

[0150] 250 Slitting apparatus

[0151] 145 Coating quality sensor

[0152] 260 Coating controller

[0153] 146 Deposition controller

[0154] 270 In-line electrode layer adhesion

[0155] 147 Drying controller sensor

[0156] 148 Calendering controller

[0157] 150 Further manufacturing 271, 281 Imaging system processes 272a Upper sensor roller

[0158] 160 End-of-line (EOL) testing 272a Lower sensor roller process

[0159] 273 Adhesive layer

[0160] 165 End-of-line (EOL) testing

[0161] 280 In-line electrode flexibility sensor sensor Guide roller 610 Overall system model

[0162] Sensor tension roller 620 Overall control algorithm

[0163] In-line four-terminal 630 Defect source tracing conductivity sensor 640 Scrap repair and / or reusea, 293a Upper sensor roller E Electrode b, 293b Lower sensor roller L Deposited layer

[0164] Current sensor S Electrode substrate

[0165] Voltage sensor Pc Coating process parameter

[0166] Coating method APALL Adjusted system process parameters

[0167] Coating input

[0168] APCAdjusted coating process

[0169] Coating process parameters parameter

[0170] Coating control algorithm

[0171] APMAdjusted mixing process

[0172] Coating apparatus parameter

[0173] Deposition apparatus

[0174] APPAdjusted powder feeding

[0175] Drying apparatus process parameter

[0176] Calendering apparatus QALL System quality parameters

[0177] Slitting apparatus Qc Coating quality parameter

[0178] Coating sensor QEOL EOL testing quality parameter

[0179] Coating model Qs Slurry quality parameter

[0180] Process parameter adjustment QP Powder quality parameter

[0181] Previous process Qx Quality parameter from previous process

[0182] Previous process sensor

[0183] QyQuality parameter from

[0184] Previous process model subsequent process

[0185] Subsequent process

[0186] Subsequent process sensor

[0187] Subsequent process model

[0188] Overall system controller

Claims

Claims1. A method of coating an electrode substrate for electrode manufacturing for an electrochemical energy storage device, the method comprising: providing an electrode substrate; transporting the electrode substrate in a transport direction; feeding at least one mixed slurry; depositing at least one layer of mixed slurry on the electrode substrate with a deposition apparatus; drying the at least one layer with a drying apparatus; and calendering the at least one layer with a calendering apparatus to produce a coated electrode, wherein the depositing, the drying and the calendering are controlled by at least one coating process parameter, wherein the method further comprises: acquiring at least one coating quality parameter of the at least one layer, preferably wherein the at least one coating quality parameter is acquired in-situ, wherein the at least one coating parameter comprises at least one of: a level of electrode mechanical flexibility measured after the drying and / or after the calendering; and a level of electrode layer adhesion measured after the drying and / or after the calendering, and adjusting the at least one coating process parameter based on the at least one coating quality parameter according to a predetermined coating model.

2. The method according to claim 1, wherein the coating model is based on at least one correlation between the at least one coating process parameter and the at least one coatingquality parameter, preferably wherein the coating model comprises a predetermined empirical model.

3. The method according to any one of claims 1 to 2, wherein at least one further coating quality parameter is selected from the group comprising: a wet coating thickness of the at least one layer measured before the drying; a dry coating thickness of the at least one layer measured after the drying; a calendered coating thickness of the at least one layer measured after the calendering; a width of the at least one layer, the width being measured in a direction transverse to the transport direction; a moisture content of the at least one layer; a porosity of the at least one layer; a conductivity of the at least one layer; an area capacity of the at least one layer; a coating density of the at least one layer; a coating weight of the at least one layer; a coating accuracy of the at least one layer; and a crack density of the at least one layer measured after the calendering.

4. The method according to any one of claims 1 to 3, wherein the at least one coating process parameter is selected from the group comprising: a coating transport speed of the electrode substrate through the deposition apparatus; a tension of the electrode substrate at the deposition apparatus; a diameter of a coating roller of the deposition apparatus; a feed rate of the mixed slurry; a drying transport speed of the electrode substrate past the drying apparatus; a drying power;a transport length of the drying apparatus; a drying temperature, particularly a drying temperature profile along a transport length of the drying apparatus; a calendering transport speed of the electrode substrate through the calendering apparatus a calendering pressure; and a calendering height, particularly a distance between a pair of calendering rollers.

5. The method according to any one of claims 1 to 4, further comprising: providing the at least one coating quality parameter of the coating process to a subsequent process of the electrode manufacturing as a feed-forward signal, such that at least one process parameter of the subsequent process is adjusted based on the at least one coating quality parameter; and / or providing the at least one coating quality parameter of the coating process to a previous process of the electrode manufacturing as a feed-back signal, such that at least one process parameter of the previous process is adjusted based on the at least one coating quality parameter.

6. The method according to any one of claims 1 to 5, further comprising: acquiring at least one external parameter of a previous process or of a subsequent process; and adjusting the at least one coating process parameter based on the at least one external parameter according to the coating model.

7. The method according to claim 6, wherein the at least one external parameter of the electrode manufacturing is at least one quality parameter acquired in a previous or subsequent process, or at least one process parameter set to control a previous or subsequent process.

8. The method according to any one of claims 1 to 7, the method further comprising slitting the deposited electrode, and wherein the at least one coating process parameter further comprises an electrode cutting speed and / or an electrode cutting width tolerance.

9. A method for electrode manufacturing for an electrochemical energy storage device, the method comprising: feeding at least one powder material in a powder material feeding process, the feeding being controlled based on at least one powder feeding process parameter; feeding at least one liquid material in a liquid feeding process, the feeding being controlled based on at least one liquid feeding process parameter; mixing a slurry of the at least one powder material and the at least one liquid material in a slurry mixing process, the mixing being controlled based on at least one slurry mixing process parameter; and coating the mixed slurry onto an electrode substrate in a coating process to produce the electrode, the coating being controlled according to the method of any one of claims 1 to 8.

10. The method according to claim 9, further comprising at least one of: storing the slurry after the slurry preparation process and before the coating process or before a further slurry mixing process; and / or testing the electromechanical energy storage device having the electrode in an end-of- line testing process.

11. The method according to any one of claims 9 to 10, further comprising: comparing at least one quality parameter from one of the powder feeding process, the liquid feeding process, the slurry mixing process and the coating process to a predetermined defect threshold; and if the comparing indicates a defect, further identifying a source of the defect, based on the at least one quality parameter, using one of a powder feeding model, a liquid feeding model, a slurry mixing model and the coating model.

12. The method according to claim 11, further comprising: if the identifying indicates that the source of the defect is in the slurry mixing process, removing the mixed slurry as a scrap slurry and optionally removing the electrode as a scrap electrode; and / or if the identifying indicates that the source of the defect is in the coating process, removing the electrode as a scrap electrode.

13. The method according to claim 12, further comprising reprocessing the scrap slurry and / or reprocessing the scrap electrode.

14. The method according to any one of claim 9 to 13, wherein the at least one powder feeding process parameter, the at least one liquid feeding process parameter and / or the at least one slurry mixing process parameter are adjusted based on the at least one coating quality parameter.

15. The method according to any one of claims 9 to 14, wherein the at least one coating process parameter is adjusted based on at least one external parameter of the powder feeding process, the liquid feeding process and / or the slurry mixing process according to the coating model.

16. The method according to any one of claims 10 to 15, wherein the at least one coating process parameter is adjusted based on at least one external parameter of the end-of-line testing process according to the coating model.

17. A coating apparatus for coating an electrode substrate for an electrode manufacturing system, the coating apparatus comprising: a substrate supply reel for providing an electrode substrate; a mixed slurry input for receiving a mixed slurry;a deposition apparatus configured for depositing at least one layer of the mixed slurry onto the electrode substrate; a drying apparatus configured for drying the at least one layer; a calendering apparatus configured for compressing the at least one layer to produce a coated electrode; at least one sensor configured for acquiring at least one coating quality parameter of the at least one layer, preferably wherein the at least one sensor is configured for in-situ acquisition; and a controller configured for controlling the coating apparatus by implementing the method according to any one of claims 1 to 8, wherein the at least one sensor comprises at least one of an inline electrode flexibility sensor configured for measuring a mechanical flexibility of the at least one layer, the inline electrode flexibility sensor being positioned after the drying apparatus and / or after the calendering apparatus; and an inline electrode layer adhesion sensor configured for measuring the adhesion of the at least one layer to the electrode substrate, the inline electrode layer adhesion sensor being positioned after the drying apparatus and / or after the calendering apparatus.

18. An electrode manufacturing system for manufacturing electrodes for an electrochemical energy storage device, the electrode manufacturing system comprising: at least one powder feeding apparatus configured for feeding at least one powder material; at least one liquid feeding apparatus configured for feeding at least one liquid material; a slurry mixing apparatus configured to mix a slurry of the at least one powder material and the at least one liquid material; a coating apparatus according to claim 17, the coating apparatus being configured for coating an electrode substrate with at least one layer of the mixed slurry, drying the at least one layer and calendering the at least one layer to produce a coated electrode; and a system controller configured for controlling the electrode manufacturing system according to the method of any one of claims 9 to 16.

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