Method of controlling a slurry mixing process for electrode manufacturing, method for electrode manufacturing, slurry mixing 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 slurry mixing apparatus and a method of controlling an electrode manufacturing system are provided. A closed-loop control method of the slurry mixing 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 SLURRY MIXING PROCESS FOR ELECTRODE MANUFACTURING, METHOD FOR ELECTRODE MANUFACTURING, SLURRY

[0002] MIXING APPARATUS AND ELECTRODE MANUFACTURING SYSTEM

[0003] TECHNICAL FIELD

[0004] Embodiments of the present disclosure relate to methods for electrode manufacturing, including controlling a slurry mixing process and controlling an electrode manufacturing process. In particular, methods for closed-loop control of a slurry mixing 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.

[0005] BACKGROUND

[0006] 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.

[0007] 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 (EOL) quality testing forjudging 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.

[0008] 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.

[0009] SUMMARY

[0010] 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.

[0011] According to a first aspect of the present disclosure, a method of controlling a slurry mixing process for electrode manufacturing for an electrochemical energy storage device is provided. The method includes feeding at least one powder material, at least one liquid material, and optionally a previously mixed slurry into a slurry mixer, mixing the at least one powder material, the at least one liquid material and optionally the previously mixed slurry to produce a mixed slurry, the mixing being controlled by at least one mixing process parameter. The method further includes acquiring at least one slurry quality parameter of the mixed slurry, preferably wherein the at least one slurry quality parameter is acquired in-situ, and adjusting the at least one mixing process parameter based on the at least one slurry quality parameter according to a predetermined slurry mixing model. 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 according to the first aspect, and coating the slurry onto an electrode substrate in a coating process to produce the electrode, the coating being controlled based on at least one coating process parameter. The coating includes 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.

[0012] According to a third aspect of the present disclosure, a slurry mixing apparatus for mixing a slurry for an electrode manufacturing system is provided. The slurry mixing apparatus includes a material input for receiving at least one powder material, a liquid input for receiving at least one liquid material, a mixer configured for mixing the at least one powder material and the at least one liquid material to produce a mixed slurry, at least one sensor being configured for acquiring at least one slurry quality parameter of the mixed slurry, preferably wherein the at least one sensor is configured for in-situ acquisition, a material output for loading the mixed slurry into a subsequent process apparatus, and a controller configured for controlling the slurry mixing apparatus by implementing the method according to the first aspect.

[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 being 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 according to the third aspect, the slurry mixing apparatus being configured to mix a slurry of the at least one powder material and the at least one liquid material, a coating apparatus 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 slurry mixing process, so that the desired quality parameters can be obtained. The quality parameters which are influenced by the slurry mixing process, such as quality parameters of the slurry deposition, quality parameters of the resulting electrode and quality parameters of the resulting electrochemical energy storage device having the electrode, can be reached in less time and with improved consistency and repeatability. Further, the slurry mixing 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.

[0015] Those skilled in the art will recognise additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.

[0016] BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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:

[0018] Fig. 1 illustrates a flow chart of an electrode manufacturing process; Fig. 2 illustrates a schematic view of a slurry mixing apparatus according to embodiments of the present disclosure;

[0019] Fig. 3 illustrates a flow chart of a method of controlling a slurry mixing apparatus according to embodiments of the present disclosure; and

[0020] Fig. 4 illustrates a flow chart of a method of manufacturing an electrode according to embodiments of the present disclosure.

[0021] DETAILED DESCRIPTION

[0022] 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.

[0023] 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 slurry mixing systems for preparing a mixed slurry for providing to the next subprocess, it was identified that online data relating to properties of the mixed slurry and / or the raw materials 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.

[0026] The slurry mixing process may further introduce dust and impurities into the powder material feed, such as iron contaminants from equipment and machinery. Impurities such as foreign particles, grains or chips may pierce a separator of the electrochemical energy storage device, causing a short circuit or abnormal discharge performance. Other impurities introduced into the mixed slurry, such as an iron impurity content, may cause reduced cycle life and cell performance.

[0027] Further, the slurry mixing process may be susceptible to variations in properties of the incoming raw materials. For example, the incoming powder material and / or liquid material introduced to the slurry mixing process in a powder feeding process and / or a liquid feeding process, respectively, may be of unexpected quality, sourced from a different supplier, or sourced from a batch which has varying properties. Variations in raw material properties may result in quality deficiencies in the slurry mixing process, particularly in often-seen situations where the slurry mixing recipe may be fixed. As a result, the electrodes produced from the mixed slurry, and electrochemical energy storage devices having said electrodes, may have compromised quality, performance and safety, including a reduced battery capacity, increased internal resistance, and reduced cycle life.

[0028] To address the above-mentioned problems, as a first aspect, the present invention provides a method of controlling a slurry mixing apparatus. In particular, the solution of the first aspect of the present invention involves a closed-loop control of the slurry mixing sub-process. The closed-loop control is based on a predetermined model which is used to adjust the process parameters of the slurry mixing based on one or more quality parameters acquired from the slurry mixing process. 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 slurry mixing sub-process, which is further contained within an overarching closed-loop control of the electrode manufacturing process. The quality parameters acquired in the slurry mixing 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 powder feeding sub-process of the first aspect, so that process parameters of the powder feeding can be adjusted based on a slurry mixing model.

[0029] The closed-loop control systems of the aspects and embodiments described herein allow for the desired quality parameters of a slurry, a deposited slurry layer or a final deposited electrode to be obtained quickly and reliably. Further, the closed-loop control systems allow for variations in powder materials to be accounted for quickly and reliably, and may also be used to control the slurry mixing for other needs such as the reprocessing of scrap slurry.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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. 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.

[0035] 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.

[0036] Concluding the method 100 is the optional process of 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.

[0037] 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 (Li4Ti50i2), 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. The present invention has a particular focus on the slurry mixing process 130. Particularly, aspects of the present invention relate to methods of controlling a slurry mixing process so that accurate and reliable mixing of the appropriate amounts of powder material and liquid material is carried out and an optimised mixed slurry can be provided to a subsequent process. By providing methods of control according to aspects and embodiments described herein, the targeted quality parameters as measured in the slurry mixing process 130, and the quality parameters as measured in subsequent processes such as the coating processes and EOL testing processes, 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.

[0038] Reference will now be made to Fig. 2, which shows a schematic block diagram of a slurry mixing apparatus 200 according to aspects and embodiments described herein. The slurry mixing apparatus 200, which includes a mixing container 201 and optionally a lid 202 for sealing the mixing container 201, is configured for receiving at least one powder material P from a powder material input 210 and at least one liquid material L from a liquid material input 220, mixing the powder material P and the liquid material L into a slurry S, and outputting the mixed slurry via a slurry output 240.

[0039] The respective inputs and outputs as illustrated are shown as an example. The powder material input 210 is shown as a powder chute e.g. directly connected to powder material feeding process, but may alternatively include any means of providing powder material P into the mixing container 201, such as a powder feed conveyor, a powder hopper, or the powder material P may simply be poured into the mixing container 201 from another container. Similarly, the liquid material input 220 is shown as a liquid pipe e.g. directly connected to a liquid material feeding process, but may alternatively include any means of providing liquid material L into the mixing container 201, such as a liquid tank, or the liquid material L may simply be poured into the mixing container 201 from another container. The slurry output 240 is shown as a discharge pipe provided at a bottom side of the mixing container, but may alternatively include any means of outputting the mixed slurry, such as a pouring mechanism configured for pouring the slurry S from the mixing container. Any one of the powder material input 210, the liquid material input 220 and the slurry output 240 may be provided with one or more valves, gates or closures so that the respective inputs / outputs can be closed off and the mixing container 201 can be sealed.

[0040] Optionally, the slurry mixing apparatus 200 may include an additional input for providing a previously mixed slurry. For example, in the case where the slurry mixing process is adapted for repairing or reprocessing a scrap slurry, or in the case where the slurry mixing process is adapted for reprocessing a slurry which has been stored in a slurry storage process, the previously mixed slurry may be provided into the mixing container 201 via an input which is separate to the powder and liquid inputs. Alternatively, the previously mixed slurry may be provided into the mixing container 201 via the liquid material input 220.

[0041] The slurry mixing apparatus 200 includes the mixing container 201, which is configured to hold the slurry, particularly the raw materials for mixing the slurry, while the mixing is carried out. The mixing container 201 may further be provided with a lid 202 which allows for the mixing container 201 to be sealed such that the atmosphere within the mixing container 201 can be controlled. For example, the pressure within the mixing container 201 may be adjusted, e.g. to a vacuum, so that the conditions in which the slurry is mixed can be optimised. Further, the mixing container 201 may include a heating element which allows the temperature inside the mixing container 201, particularly the temperature of the raw materials and / or slurry to be raised or lowered according to the prescribed slurry mixing recipe. Optionally, the mixing container 201 may further include a vacuum pump for controlling a level of vacuum within the mixing container 201, or for carrying out a de-aeration process of the slurry undergoing mixing within the mixing container 201.

[0042] The slurry mixing apparatus 200 further includes the mixer 230, which is configured to mix the at least one powder material P and the at least one liquid material L into a slurry. The mixer 230 includes a mixer motor 231 which is mechanically connected to a mixer blade 232. The mixer motor 231 is exemplarily shown as being located outside of the mixing container 201, however the mixer motor 231, particularly the entire mixer 230, may alternatively be provided within the mixing container 201. The mixer 230 is exemplarily shown with the mixer blade 232 connected to a rotating shaft. However, the mixer 230 may include a mechanism which modifies the rotation and / or movement of the mixer blade 232. For example, the mixer 230 may include a planetary mixer.

[0043] The slurry mixing apparatus 200 is provided with at least one sensor for acquiring at least one quality parameter of the slurry undergoing mixing, or of the mixed slurry. Preferably, the at least one sensor is configured for acquiring the at least one quality parameter in-situ.

[0044] 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.

[0045] 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. 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] The at least one sensor may be provided at one or more positions in the slurry mixing apparatus 200. As illustrated in Fig. 2, a slurry quality sensor 230a may be provided in the top side of the mixing container 201, or in the lid 202, above the top level of the slurry undergoing mixing. In other words, a slurry quality sensor 203a may be provided at a position in the inner atmosphere of the mixing container 201. For example, a slurry quality sensor 203a may be placed in this position for observing the slurry using optical means. The sensor in this position could also be a sensor configured for measuring a parameter related to the process, such as a pressure sensor which is configured to measure a level of vacuum or pressure within the mixing container 201.

[0050] Further, a slurry quality sensor 203b may be provided in the side or bottom of the mixing container below the top level of the slurry undergoing mixing. In other words, a slurry quality sensor 203b may be provided at a position directly in the slurry undergoing mixing. For example, a slurry quality sensor 203b may be placed in this position for directly measuring parameters of the slurry as it is mixed, such as slurry viscosity, slurry pH, slurry volume resistivity, content of magnetic impurities in the slurry, or any other parameter which may be measured by direct contact with the slurry. The sensor in this position could also be a sensor configured for measuring a parameter related to the process, such as a temperature sensor which is configured to measure a mixing temperature of the slurry within the mixing container 201.

[0051] Further, a slurry quality sensor 203c may be provided in the slurry output 240. In other words, a slurry quality sensor 203c may be provided at a position directly in the mixed slurry after it has undergone mixing. For example, a slurry quality sensor 203b may be placed in this position for directly measuring parameters of the slurry after mixing, such as slurry viscosity, slurry pH, slurry volume resistivity, content of magnetic impurities in the slurry, or any other parameter which may be measured by direct contact with the slurry.

[0052] The at least one sensor may include a refractometer configured for measuring a solid content of the mixed slurry, an inline viscometer configured for measuring a viscosity of the mixed slurry, a hydrometer or densitometer for measuring a density of the mixed slurry, a pH sensor for measuring a pH level of the mixed slurry, an inline grindometer for measuring a level of coarseness of the mixed slurry, an inline voltage or current sensor for measuring a volume resistivity of the mixed slurry, and an optical, magnetic field or hall effect sensor for estimating a content of magnetic impurities in the mixed slurry.

[0053] The sensor types discussed above are only examples of possible sensors which may be included in the slurry mixing apparatus 200. The present disclosure is not limited thereto, however, and any slurry quality sensor which is known in the state of the art may be incorporated into the slurry mixing apparatus 200 either as an in-line sensor or as an on-line sensor.

[0054] Further, the slurry mixing apparatus 200 may be provided with additional sensors, particularly additional in-line sensors, so that accurate control of the slurry mixing apparatus 200 based on the desired process parameters may be carried out. For example, the powder material input 210 and / or the liquid material input 220 may be provided with a load cell or a rate of flow sensor configured for measuring a mass or rate of flow of the powder material P and / or the liquid material L being fed into the slurry mixing apparatus 200. Said load cells and rate of flow sensors allow for more accurate control of the slurry mixing apparatus 200 in response to quality parameters. Further, the mixer 230 may be provided with a torque sensor on the mixer shaft which may be configured to measure a mixing shear force. Measuring the shear force, which can indicate a viscosity of the slurry, allows for more accurate control of the operation of the mixing motor 231 so that the optimal shear rate and shear force applied to the slurry is achieved. The slurry mixing apparatus 200 may be further provided with a magnetic filter 260. The magnetic filter 260 is configured for capturing foreign ferromagnetic materials, such as iron filings, which may inadvertently arise in the slurry mixing. The magnetic filter 260 may be configured as a passive filter which only has a capture function. However, the magnetic filter 260 may alternatively be provided as an active filter which may be selectively activated to filter the slurry, and / or in-line sensor which is configured to measure a mass of foreign ferromagnetic materials which have been captured. For example, the magnetic filter 260 may be an electromagnet which can be activated or deactivated to filter iron impurities from the slurry. As a further example, the magnetic filter 260 may be provided with a load cell so that a mass of foreign ferromagnetic materials captured by the magnetic filter 260, particularly the rate of mass accumulation, may be used as an indication of an iron impurity content of the slurry, and a corresponding quality parameter of the slurry may be estimated. The magnetic filter 260 is exemplarily shown as being provided directly in the slurry undergoing mixing, e.g. in a side or in the bottom of the mixing container 201. However, the present disclosure is not limited thereto, and the magnetic filter 260 may be provided at other positions in the slurry mixing apparatus 200, such as in the powder material input 210 or in the slurry output 240.

[0055] Alternatively, instead of or in addition to a magnetic filter 260, the slurry mixing apparatus 200 may include an impurity filter which is configured for capturing and removing impurities from the slurry undergoing mixing and / or from the mixed slurry after mixing. The same features described above for the magnetic filter 260 are also applicable to the impurity filter, in that the impurity filter may be configured as a passive filter, as an active filter, and / or as a sensor for detecting the content of impurities in the slurry. Particularly, the slurry mixing apparatus 200 may include an in-line impurity sensor configured for detecting a content of impurities in the slurry, wherein the in-line impurity sensor includes an optical sensor, a magnetic field sensor or a hall effect sensor, or a sensor configured for spectroscopic analysis. Further, the slurry mixing apparatus 200 includes a mixing controller 250 which is configured to control the slurry mixing apparatus 200 according to the control methods described in the present disclosure. The mixing controller 250 is in communication with the at least one sensor so that at least one quality parameter acquired by said sensors can be input into the mixing controller 250. Further, the mixing controller 250 is in communication with one or more actuators for controlling the slurry mixing apparatus 200, particularly a mixer motor 231, so that the mixing controller 250 may instruct the mixing. The mixing controller 250 may further be in communication with other sensors, such as load cells or torque sensors for more accurate control of a material feed rate and / or a mixing shear rate or shear force.

[0056] The mixing controller 250 may be a microprocessor, a programmable logic controller (PLC), or a digital signal processor (DSP). Particularly, the mixing controller 250 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 mixing controller 250 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.

[0057] The mixing controller 250 may further include a network interface for connecting to a data network, in particular a global data network. In this arrangement, the mixing controller 250 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 mixing controller 250 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 mixing controller 250 may be adapted for sending status information to the data network. Particularly, the mixing controller 250 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 mixing controller 250 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.

[0058] The mixing controller 250 is further provided with a control algorithm and a slurry mixing model which are implemented for realising a closed-loop control method of the slurry mixing apparatus 200. Referring now to Fig. 3, which shows a flowchart of a method of controlling a slurry mixing process according to aspects and embodiments of the present invention, the control methods of the present disclosure will be described in the following.

[0059] According to the first aspect of the present invention, a method of controlling a slurry mixing process for electrode manufacturing for an electrochemical storage device. The method includes feeding at least one powder material, at least one liquid material, and optionally a previously mixed slurry into a slurry mixing apparatus, mixing the at least one powder material, the at least one liquid material and optionally the previously mixed slurry to produced a mixed slurry, the mixing being controlled by at least one slurry mixing process parameter. The method further includes acquiring at least one slurry quality parameter of the mixed slurry, preferably wherein the at least one slurry quality parameter is acquired in-situ, and adjusting the at least one mixing process parameter based on the at least one slurry quality parameter according to a predetermined slurry mixing model.

[0060] In the flowchart illustrated in Fig. 3, the method 300 is outlined as follows. An input is provided to the slurry mixing input 310, which may be an input of a powder material P or a liquid material L, or may be an input from a previous process 400, e.g. a slurry storage process. A control algorithm 330 is provided for carrying out the method 300 based on at least one mixing process parameter PMprovided by the set of mixing process parameters 320. Based on the control algorithm 330 and the process parameters, the slurry mixing apparatus 340 is controlled, i.e. by commanding one or more actuators of the slurry mixing apparatus, to produce an output. The output of the method 300 is provided to a subsequent process 500, e.g. a coating process or a slurry storage process.

[0061] The slurry mixing apparatus is continuously monitored by at least one slurry quality sensor 350 of the slurry mixing apparatus, and said sensor(s) acquire at least one slurry quality parameter Qs of the slurry undergoing mixing in the slurry mixing apparatus or of the mixed slurry being output from the slurry mixing apparatus. The at least one slurry quality parameter Qsis provided to the slurry mixing model 360 which includes a plurality of correlations between slurry quality parameters Qsand mixing process parameters PM. Using the slurry mixing model 360, at least one adjusted mixing process parameter APMis generated in the process parameter adjustment 370 based on the slurry quality parameter Qs. The at least one adjusted mixing process parameter APMis then used to update the set of mixing process parameters 320 so that the control algorithm 330 is automatically adjusted in a closed-loop fashion.

[0062] Through continuous monitoring and closed-loop control of the slurry mixing process, particularly based on quality parameters acquired in-situ, the mixing process parameters PMof the slurry mixing process can be specifically tuned to account for variations in slurry quality. For example, the desired target quality of a mixed slurry can be assured by optimising the slurry mixing process based on an in-line solid content measurement or an in-line viscosity measurement.

[0063] 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.

[0064] 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.

[0065] According to embodiments, 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 (in other words, the slurry mixing recipe), 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 mixing apparatus. According to further embodiments, the at least one powder quality parameter Qsmay 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 mixing process parameter PMmay be any process parameter typical for operating a slurry mixing apparatus, and the at least one slurry quality parameter Qsmay be any quality parameter for which a suitable sensor is available, which preferably can be acquired in-situ.

[0066] According to an embodiment, which may be combined with other embodiments described herein, the slurry mixing model 360 is based on at least one correlation between the at least one mixing process parameter PMand the at least one slurry quality parameter Qs.

[0067] Preferably, the slurry mixing 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 slurry mixing 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 slurry mixing 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 slurry mixing model 360 may be replaced with an empirical model. As a further alternative, the slurry mixing 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.

[0068] The closed-loop control method 300 for controlling the slurry mixing process as described implements the closed-loop control based on quality parameters Qsacquired within the slurry mixing 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 Qsacquired in the slurry mixing 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 500.

[0069] 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.

[0070] 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 slurry quality parameter Qsof the slurry mixing 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 slurry quality parameter Qs. For example, the slurry mixing process may come before a subsequent process 500 which corresponds to a coating process in which the slurry material being mixed in the slurry mixing process is coated on an electrode substrate. The slurry mixing process may acquire a quality parameter Qs, such as a slurry viscosity or a slurry density, and the process parameters of the coating process may be automatically adapted based thereon. If the slurry viscosity, for example, indicates that the mixed slurry being fed has a higher viscosity than expected, the coating process, or more particularly the deposition process, can be adapted to suit so that the desired coating thickness can be achieved. 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 slurry quality parameter Qsbased on a model 560 of the subsequent process 500.

[0071] 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 slurry quality parameter Qsof the slurry mixing 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 slurry quality parameter Qs. For example, the slurry mixing process may come after a previous process 400 which corresponds to a powder feeding process in which at least one powder material is fed into the slurry mixing process. The slurry mixing process may acquire a quality parameter Qs, such as grind fineness of the slurry, and the process parameters of the powder feeding in the previous process 400, e.g. the mesh size of the in-line sieve in the powder feeding process, may be automatically adapted to optimise the quality parameter Qs. 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 slurry quality parameter Qsbased on a model 460 of the subsequent process 400.

[0072] 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 mixing process parameter PMbased on the at least one external parameter Qx, QY according to the slurry mixing 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 slurry mixing process 300 so that one or more mixing process parameters PMcan be adjusted based on the external parameter using the slurry mixing 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 slurry mixing process 300 so that one or more mixing process parameters PMcan be adjusted based on the external parameter using the slurry mixing model 360.

[0073] According to a further embodiment, which may be combined with other embodiments described herein, the at least one external parameter is selected from the group which includes a storage time corresponding to an amount of time the previously mixed slurry has been in storage, a storage temperature at which the previously mixed slurry was stored and a storage humidity at which the previously mixed slurry was stored. However, the present disclosure is not limited thereto, and any other external parameter, including external process parameters and external quality parameters, may be used to adjust the mixing process parameters PMof the slurry mixing process.

[0074] For example, the slurry mixing process 300 may acquire, as an external parameter QY, a quality parameter which corresponds to an electrode moisture content of a dried electrode layer after the mixed slurry has been provided to a subsequent coating process and has been deposited on an electrode substrate and dried. The electrode moisture content of the dried electrode layer may then be further optimised by generating one or more adjusted mixing process parameters APMbased on the electrode moisture content using the slurry mixing model 360, e.g. by adjusting a feed rate of liquid material or by adjusting the mixing temperature.

[0075] According to an embodiment, which may be combined with other embodiments described herein, the method 300 according to the first aspect may further include acquiring a content of magnetic components in the mixed slurry and, if the content of magnetic components exceeds a predetermined threshold, filtering the mixed slurry using a magnetic filter. The acquiring of the content of magnetic components and subsequent filtering of the mixed slurry may be performed using the magnetic filter 260 described previously. According to an embodiment, which may be combined with other embodiments described herein, the method 300 according to the first aspect may further include acquiring a content of impurities in the mixed slurry and, if the content of impurities exceeds a predetermined threshold level, filtering the mixed slurry using an impurity filter. The acquiring of the content of impurities and subsequent filtering of the mixed slurry may be performed using the impurity filter and / or impurity sensors described previously.

[0076] By actively filtering magnetic components and / or other impurities, the quality of the subsequently deposited layers in the coated electrodes is improved, resulting in electrochemical energy storage devices having said electrodes exhibiting improved performance, quality and safety levels. In particular, the active removal of iron impurities, particularly larger iron particles which may have been introduced into the slurry from equipment wear, are removed from the slurry, and the risk of a coated electrode being punctured by a neighbouring electrode is reduced, which specifically improves safety of the final device.

[0077] According to an embodiment, which may be combined with other embodiments described herein, the method 300 according to the first aspect may further include acquiring a level of aeration of the mixed slurry and, if the level of aeration exceeds a predetermined threshold, subjecting the mixed slurry to a de-aeration process. For example, a vacuum pump connected to the mixing container may be activated during mixing of the slurry so that any air bubbles trapped in the slurry are removed. By de-aerating the mixed slurry, the porosity of a subsequently deposited layer of the mixed slurry is reduced, and the density of the coated electrode can be improved. Improved performance of the electrochemical energy storage device having said electrode, particularly cell capacity and discharge performance, can be achieved.

[0078] Reference will now be made to Fig. 4, which illustrates a flow chart of a method for electrode manufacturing for an electrochemical storage device. In particular, Fig. 4 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.

[0079] 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 controlled based on at least one powder feeding process parameter PP, and 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. The method further includes 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 according to the first aspect described above. The method further includes coating the slurry onto an electrode substrate in a coating process 140 to produce the electrode, the coating being controlled based on at least one coating process parameter Pc, wherein the coating comprises 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.

[0080] 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.

[0081] 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. 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 method of controlling the slurry mixing process 130 is according to the first aspect and embodiments described above. 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, in addition to the first aspect and embodiments described above, the at least one slurry quality parameter Qsis provided to the overall system controller 600.

[0086] 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. Finally, the coating process 140 is carried out so that a coated electrode may be produced. 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 Qcwhich, 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, the at least one coating quality parameter Qcis provided to the overall system controller 600.

[0087] 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.

[0088] 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.

[0089] 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. 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.

[0090] 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.

[0091] The plurality of adjusted process parameters APALL 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.

[0092] 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.

[0093] 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 coating process parameter Pcis adjusted based on the at least one slurry quality parameter Qs. In other words, process parameters which are external to the slurry mixing process 130 may be adjusted based on a quality parameter which is internal to the slurry mixing process 130.

[0094] Particularly, the at least one liquid feeding process parameter PLmay be adjusted based on the at least one slurry quality parameter Qsusing a liquid feeding model. For example, in the case where the at least one slurry quality parameter Qsincludes a slurry viscosity, the value of the slurry viscosity may require an increased or decreased volume of solvent to be added so that the desired slurry quality targets are achieved. Using the liquid feeding model or the overall system model 610, which may include a correlation between a slurry viscosity of the mixed slurry (quality parameter) and a solvent volume (process parameter), the liquid feeding process parameter PLcorresponding to the volume of solvent being fed may be automatically adjusted to suit.

[0095] Further, the at least one powder feeding process parameter PPmay be adjusted based on the at least one slurry quality parameter Qsusing a powder feeding model. For example, in the case where the at least one slurry quality parameter Qsincludes a slurry fineness of grind, the value of the slurry fineness in the slurry mixing process 130 may require that the sieving in the powder feeding process 120 is performed with an adjusted mesh size so that the desired slurry quality targets are achieved, and said process parameter may be automatically adjusted.

[0096] Further still, the at least one coating process parameter Pcmay be adjusted based on the at least one slurry quality parameter Qsusing a coating model. For example, in the case where the at least one slurry quality parameter Qsincludes a slurry density measurement, the slurry density from the slurry mixing process 130 may require that the calendering is performed with an adjusted calendering roller load so that the desired quality targets of the deposited layer are achieved, and said process parameter may be automatically adjusted.

[0097] 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 mixing process parameter PMis adjusted based on at least one external parameter of the liquid feeding process 110, the powder feeding process 120 and / or the coating process 140 according to the slurry mixing model. In other words, process parameters which are internal to the slurry mixing process 130 may be adjusted based on a quality parameter which is external to the slurry mixing process 130. Said external parameter may be at least one liquid quality parameter QL, at least one powder quality parameter QP, and / or at least one coating quality parameter Qc.

[0098] Particularly, at least one mixing process parameter PMmay be adjusted based on the at least one liquid quality parameter QLusing the slurry mixing model. For example, in the case where the at least one liquid quality parameter QLincludes an in-line pH measurement of water being fed by the liquid feeding, the slurry mixing recipe, e.g. the mixing and dispersion sequence or the amounts of materials to be loaded, may need to be adjusted so that the desired slurry pH level targets are achieved, and said process parameter may be automatically adjusted.

[0099] Further, at least one mixing process parameter PMmay be adjusted based on the at least one powder quality parameter QPusing the slurry mixing model. For example, in the case where the at least one powder quality parameter QPincludes an in-line tapped density of the powder material, the mixing shear rate and / or shear force may need to be adjusted so that the desired slurry density targets are achieved.

[0100] Further still, at least one mixing process parameter PMmay be adjusted based on the at least one coating quality parameter Qcusing the slurry mixing model. For example, in the case where the at least one coating quality parameter Qcincludes a wet or dry thickness of the coating deposited in the coating process 140, the the mixing time and rate and / or the mixing temperature may need to be adjusted so that the desired slurry viscosity is achieved, and so that the coating thickness targets are achieved.

[0101] 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 EOL testing process 160.

[0102] 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.

[0103] 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.

[0104] 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 slurry mixing process parameter PMis adjusted based on at least one external parameter of the EOL testing process 160 according to the slurry mixing model. For example, if the EOL testing indicates that the final cell weight is insufficient, this may indicate that the solid content of the mixed slurry is required to be increased so that the desired cell capacity is achieved. For the next batch of electrode manufacturing, the slurry mixing may be adjusted to suit.

[0105] 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.

[0106] 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.

[0107] 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 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 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.

[0108] The identifying step may further include 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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. 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.

[0114] 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.

[0115] Referring once again to Fig. 2, according to the third aspect of the present disclosure, a slurry mixing apparatus 200 for mixing a slurry S for an electrode manufacturing system is provided. The slurry mixing apparatus 200 includes a material input 210 for receiving at least one powder material P, a liquid input 220 for receiving at least one liquid material, a mixer 230 configured for mixing the at least one powder material P and the at least one liquid material L to produce a mixed slurry S, at least one sensor 203a, 203b, 203c being configured for acquiring at least one slurry quality parameter Qsof the mixed slurry S, preferably wherein the at least one sensor 203a, 203b, 203c is configured for in-situ acquisition, a material output 240 for loading the mixed slurry S into a subsequent process apparatus, and a controller 250 configured for controlling the slurry mixing apparatus 200 by implementing the method according to the first aspect. Further embodiments according to features, aspects and modifications of the slurry mixing apparatus 200 as described earlier in the present disclosure are possible. In particular, according to an embodiment which may be combined with other embodiments described herein, the at least one sensor 203a, 203b, 203c may include a refractometer configured for measuring a solid content of the mixed slurry, an in-line viscometer configured for measuring a viscosity of the mixed slurry, a hydrometer or densitometer for measuring a density of the mixed slurry, a pH sensor for measuring a pH level of the mixed slurry, an inline grindometer for measuring a level of coarseness of the mixed slurry, an in-line voltage or current sensor for measuring a volume resistivity of the mixed slurry and an optical, magnetic field or hall effect sensor for estimating a content of magnetic impurities in the mixed slurry. However, the sensor types discussed above are only examples of possible sensors which may be included in the slurry mixing apparatus 200. The present disclosure is not limited thereto, however, and any slurry quality sensor which is known in the state of the art may be incorporated into the slurry mixing apparatus 200 either as an in-line sensor or as an on-line sensor.

[0116] Further, the slurry mixing apparatus 200 may be provided with additional sensors, particularly additional in-line sensors, so that accurate control of the slurry mixing apparatus 200 based on the desired process parameters may be carried out. For example, the powder material input 210 and / or the liquid material input 220 may be provided with a load cell configured for measuring a mass of the powder material P and / or the liquid material L, respectively, being fed into the slurry mixing apparatus 200. Alternatively, the slurry output 240 may be provided with a load cell configured for measuring a mass of the mixed slurry S being fed out of the slurry mixing apparatus 200. Further, the mixer 230 may be provided with a load cell or torque sensor configured for measuring a mixing torque, which may indicate a viscosity of the mixed slurry while the mixing is carried out.

[0117] The controller of the slurry mixing apparatus 200, i.e. the mixing controller 250, may be a microprocessor, a programmable logic controller (PLC), or a digital signal processor (DSP). Particularly, the mixing controller 250 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 mixing controller 250 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 mixing controller 250 to a data network, in particular a global data network.

[0118] 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 P and at least one liquid feeding apparatus configured for feeding at least one liquid material L. The system further includes a slurry mixing apparatus 200 according to the third aspect, the slurry mixing apparatus 200 being configured to mix a slurry of the at least one powder material P and the at least one liquid material L. The system further includes a coating apparatus 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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. Reference numbers

[0124] 100 Method of manufacturing an

[0125] 165 End-of-line (EOL) testing electrochemical energy storage sensor device

[0126] 166 End-of-line (EOL) testing

[0127] 110 Liquid material feeding process controller

[0128] 115 Liquid quality parameter

[0129] 200 Slurry mixing apparatus

[0130] 116 Liquid feeding controller

[0131] 201 Mixing container

[0132] 120-122 Powder material feeding 202 Lid process 203 a-c Slurry quality sensor

[0133] 210 Powder material input

[0134] 125 Powder quality sensor

[0135] 220 Liquid material input

[0136] 126 Powder feeding controller

[0137] 230 Mixer

[0138] 130 Slurry mixing process

[0139] 231 Mixer motor

[0140] 131 Slurry storage process

[0141] 232 Mixer blade

[0142] 135 Mixing quality sensor

[0143] 240 Slurry output

[0144] 136 Mixing controller

[0145] 140 Coating process 250 Mixing controller

[0146] 141 Deposition process

[0147] 260 Magnetic filter

[0148] 142 Drying process

[0149] 300 Slurry mixing method

[0150] 143 Calendering process

[0151] 310 Slurry mixing input

[0152] 144 Slitting process

[0153] 320 Mixing process parameters

[0154] 145 Coating quality sensor

[0155] 330 Mixing control algorithm

[0156] 146 Deposition controller

[0157] 340 Slurry mixing apparatus

[0158] 147 Drying controller

[0159] 148 Calendering controller 350 Slurry quality sensor

[0160] 150 Further manufacturing 360 Slurry mixing model processes

[0161] 370 Process parameter adjustment

[0162] 160 End-of-line (EOL) testing

[0163] 400 Previous process process

[0164] 450 Previous process sensor 460 Previous process model y Quality parameter from subsequent process

[0165] 500 Subsequent process

[0166] 550 Subsequent process sensor

[0167] 560 Subsequent process model

[0168] 600 Overall system controller

[0169] 610 Overall system model

[0170] 620 Overall control algorithm

[0171] 630 Defect source tracing

[0172] 640 Scrap repair and / or reuse

[0173] L Liquid material

[0174] P Powder material

[0175] S Slurry

[0176] PMMixing process parameter

[0177] APALL Adjusted system process parameters

[0178] APCAdjusted coating process parameter

[0179] APMAdjusted mixing process parameter

[0180] APp Adjusted powder feeding process parameter

[0181] QALL System quality parameters

[0182] Qc Coating quality parameter

[0183] QEOL EOL testing quality parameter

[0184] Qs Slurry quality parameter

[0185] QP Powder quality parameter

[0186] Qx Quality parameter from previous process

Claims

Claims1. A method of controlling a slurry mixing process for electrode manufacturing for an electrochemical energy storage device, the method comprising: feeding at least one powder material, at least one liquid material, and optionally a previously mixed slurry into a slurry mixing apparatus; mixing the at least one powder material, the at least one liquid material and optionally the previously mixed slurry to produce a mixed slurry, the mixing being controlled by at least one mixing process parameter, wherein the method further comprises: acquiring at least one slurry quality parameter of the mixed slurry, preferably wherein the at least one slurry quality parameter is acquired in-situ; and adjusting the at least one mixing process parameter based on the at least one slurry quality parameter according to a predetermined slurry mixing model.

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

3. The method according to any one of claims 1 to 2, wherein the at least one slurry quality parameter is selected from the group comprising: 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; anda content of magnetic impurities in the mixed slurry.

4. The method according to any one of claims 1 to 3, wherein the at least one mixing process parameter is selected from the group comprising: 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 mixing apparatus.

5. The method according to any one of claims 1 to 4, further comprising: providing the at least one slurry quality parameter of the slurry mixing 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 slurry quality parameter; and / or providing the at least one slurry quality parameter of the slurry mixing 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 slurry 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 mixing process parameter based on the at least one external parameter according to the slurry mixing model.

7. The method according to claim 6, wherein the at least one external parameter of the electrode manufacturing is selected from the group comprising: a storage time corresponding to an amount of time the previously mixed slurry has been in storage; a storage temperature at which the previously mixed slurry was stored; and a storage humidity at which the previously mixed slurry was stored.

8. The method according to any one of claims 1 to 7, wherein the at least one powder material comprises at least one of an active cathode material, an active anode material, polymer binder and carbon black, or any pre-prepared mixture thereof; and the at least one liquid material comprises at least one of a solvent and water.

9. The method according to any one of claims 1 to 8, the method further comprising at least one of the following: acquiring a content of magnetic components in the mixed slurry and, if the content of magnetic components exceeds a predetermined threshold, filtering the mixed slurry using a magnetic filter; acquiring a content of impurities in the mixed slurry and, if the content of impurities exceeds a predetermined threshold, filtering the mixed slurry using an impurity filter; and / or acquiring a level of aeration of the mixed slurry and, if the level of aeration exceeds a predetermined threshold, subjecting the mixed slurry to a de-aeration process.

10. 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 according to the method of any one of claims 1 to 9; and coating the mixed slurry onto an electrode substrate in a coating process to produce the electrode, the coating being controlled based on at least one coating process parameter, wherein the coating comprises: 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.

11. The method according to claim 10, further comprising at least one of: storing the slurry after the slurry mixing 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.

12. The method according to any one of claims 10 to 11, 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, the slurry model and a coating model.

13. The method according to claim 12, 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.

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

15. The method according to any one of claim 10 to 14, wherein the at least one powder feeding process parameter, the at least one liquid feeding process parameter and / or the at least one coating process parameter is adjusted based on the at least one slurry quality parameter.

16. The method according to any one of claims 10 to 15, wherein the at least one mixing process parameter is adjusted based on at least one external parameter of the powder feeding process, the liquid feeding process and / or the coating process according to the slurry mixing model.

17. The method according to any one of claims 11 to 16, wherein the at least one mixing process parameter is adjusted based on at least one external parameter of the end-of-line testing process according to the slurry mixing model.

18. A slurry mixing apparatus for mixing a slurry for an electrode manufacturing system, the slurry mixing apparatus comprising: a material input for receiving at least one powder material; a liquid input for receiving at least one liquid material; a mixer configured for mixing the at least one powder material and the at least one liquid material to produce a mixed slurry;at least one sensor being configured for acquiring at least one slurry quality parameter of the mixed slurry, preferably wherein the at least one sensor is configured for in-situ acquisition; a material output for loading the mixed slurry into a subsequent process apparatus; and a controller configured for controlling the slurry mixing apparatus by implementing the method according to any one of claims 1 to 9.

19. 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 according to claim 18, the slurry mixing apparatus being configured to mix a slurry of the at least one powder material and the at least one liquid material; a coating apparatus 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 10 to 17.

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