WO2025131310A1

WO2025131310A1 - Method of controlling a powder feeding process for electrode manufacturing, method for electrode manufacturing, powder feeding apparatus and electrode manufacturing system

Info

Publication number: WO2025131310A1
Application number: PCT/EP2023/087695
Authority: WO
Inventors: Minglong He; Gabriel SCHULER; Anna Andersson; Alexander Fach; Staffan SODERGARD
Original assignee: ABB Schweiz AG
Current assignee: ABB Schweiz AG
Priority date: 2023-12-22
Filing date: 2023-12-22
Publication date: 2025-06-26
Anticipated expiration: 2026-06-22

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 powder feeding apparatus and a method of controlling an electrode manufacturing system are provided. A closed-loop control method of the powder feeding 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

METHOD OF CONTROLLING A POWDER FEEDING PROCESS FOR ELECTRODE MANUFACTURING, METHOD FOR ELECTRODE MANUFACTURING, POWDER FEEDING APPARATUS AND ELECTRODE MANUFACTURING SYSTEM

TECHNICAL FIELD

Embodiments of the present disclosure relate to methods for electrode manufacturing, including controlling a powder feeding process and controlling an electrode manufacturing process. In particular, methods for closed-loop control of a powder feeding 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.

BACKGROUND

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-life (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.

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.

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.

SUMMARY

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.

According to a first aspect of the present disclosure, a method of controlling a powder feeding process for electrode manufacturing for an electrochemical energy storage device is provided. The method includes providing a powder material to a material feed conveyor, conveying the powder material to an inline sieve, sieving the powder material with the inline sieve, and loading the sieved powder material into a subsequent process, wherein the providing and sieving are controlled by at least one powder feeding process parameter. The method further includes acquiring at least one powder quality parameter of the powder material, preferably wherein the at least one powder quality parameter is acquired in-situ, and adjusting the at least one powder feeding process parameter based on the at least one powder quality parameter according to a predetermined powder feeding 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 according to the first aspect, feeding at least one liquid material in a liquid feeding process, the feeding being controlled based on at least one liquid feeding process parameter, mixing a slurry including the at least one powder material and the at least one liquid material in a slurry mixing process, the mixing being controlled based on at least one slurry mixing process parameter, and coating the slurry onto an electrode substrate in a coating process to produce the electrode, the coating being controlled 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.

According to a third aspect of the present disclosure, a powder feeding apparatus for feeding powder material for an electrode manufacturing system is provided. The powder feeding apparatus includes a material input for receiving a powder material, a material feed conveyor configured for conveying the powder material, at least one sensor being configured for acquiring at least one powder quality parameter of the powder material, preferably wherein the at least one sensor is configured for in-situ acquisition, an inline sieve having a predetermined mesh size, a material output for loading sieved powder material into a subsequent process apparatus, and a controller configured for controlling the powder feeding apparatus by implementing the method according to the first aspect.

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 according to the third aspect, the 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 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 second aspect.

Aspects of the present disclosure provide improved control of the powder feeding process, so that the desired quality parameters can be obtained. The quality parameters which are influenced by the powder feeding process, such as quality parameters of the mixed slurry, quality parameters of the slurry deposition, and quality parameters of the resulting electrode, can be reached in less time and with improved consistency and repeatability. Further, the powder feeding process and/or the overarching electrode manufacturing process can be adapted to varying raw material properties, the amount of scrap material generated from defects or quality deficiencies is reduced, and the improved control system allows for scrap material to be reprocessed, improving the efficiency of the electrode manufacturing system.

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

BRIEF DESCRIPTION OF THE DRAWINGS

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: Fig. 1 illustrates a flow chart of an electrode manufacturing process;

Fig. 2 illustrates a schematic view of a powder feeding apparatus according to embodiments of the present disclosure;

Fig. 3 illustrates a flow chart of a method of controlling a powder feeding apparatus according to embodiments of the present disclosure; and

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

DETAILED DESCRIPTION

Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with any other embodiment to yield yet a further embodiment. It is intended that the present disclosure includes such modifications and variations.

Within the following description of the drawings, the same reference numbers refer to the same or to similar components. Generally, only the differences with respect to the individual embodiments are described. Unless specified otherwise, the description of a part or aspect in one embodiment applies to a corresponding part or aspect in another embodiment as well.

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.

In present powder feeding systems for feeding powder materials into the next sub-process, it was identified that online data relating to properties of the powder material being fed 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 subprocesses.

The powder feeding 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 powder feed, such as an iron impurity content, may cause reduced cycle life and cell performance.

Further, the powder feeding process may be susceptible to variations in properties of the incoming raw materials. For example, the incoming powder material introduced in the powder feeding process may be of unexpected quality, sourced from a different supplier, or sourced from a batch which has varying properties. Variations in powder 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.

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

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 powder feeding to supply different amounts of powder material for other needs such as the reprocessing of scrap slurry.

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.

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.

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.

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.

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.

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.

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.

The apparatuses and methods of the present disclosure are related to the manufacturing of electrodes for electrochemical energy storage devices. Particularly, the electrochemical energy storage device is a battery cell, more particularly a lithium-ion battery cell. Accordingly, the materials involved with the various processes and sub-processes described herein are materials typical to the manufacture of battery cell electrodes depending on the cell chemistry. For example, the at least one powder material being fed by one or more powder feeding processes may be an active cathode material, e.g. lithium nickel manganese cobalt oxide (Li-NMC), lithium iron phosphate (LiFePO₄) or lithium cobalt oxide (LiCoO₂), an active anode material, e.g. graphite or lithium titanate (Li4Ti₅O₁₂), or additives such as binders, e.g. polyvinylidene fluoride, or carbon black. Further, the at least one liquid material being fed by one or more liquid feeding processes may be a solvent, e.g. N-methyl-2-pyrrolidone, or water. Further, mixtures of said powders and/or liquids may be provided. However, the present disclosure is not limited thereto, and any powder and/or liquid materials in the state of the art which are suitable for the manufacture of cell electrodes, including mixtures thereof, may be used in the apparatuses and methods of the present disclosure. The present invention has a particular focus on the powder feeding process 120. Particularly, aspects of the present invention relate to methods of controlling a powder feeding process so that accurate and reliable feeding of the appropriate amounts of powder material into a subsequent process can be achieved. By providing methods of control according to aspects and embodiments described herein, the targeted quality parameters as measured in the powder feeding process 120, and the quality parameters as measured in subsequent processes such as slurry mixing and coating 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.

Reference will now be made to Fig. 2, which shows a schematic block diagram of a powder feeding apparatus 200 according to aspects and embodiments described herein. The powder feeding apparatus 200 is configured for feeding a powder material M from an input hopper 210 to an output hopper 240 and into a subsequent process through control of a feed conveyor 220. The feed conveyor 220 is provided with a feed conveyor drive motor 221 which can be controlled to precisely transport powder material M. The feed conveyor 220 is exemplarily shown as including an auger-type screw conveyor mechanism. However, the present disclosure is not limited thereto, and the feed conveyor 220 may include any type of conveyor suitable for transporting powder materials.

The powder feeding apparatus 200 is provided with at least one sensor for acquiring at least one quality parameter of the powder material M being fed. Preferably, the at least one sensor is configured for acquiring the at least one quality parameter in-situ.

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. 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.

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.

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.

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.

The at least one sensor may be provided at any point in the powder feeding apparatus 200, but may preferably be provided at a position along the feed conveyor 220 as in-line sensors 223a, 223b. Further, multiple sensors of the same type may be installed in different positions along the feed conveyor 220, or may be positioned before or after the in-line sieve 230.

The at least one sensor may include a particle size sensor configured for acquiring a measurement of an average particle size or a measurement of a particle size range of the powder material M. The particle size sensor may include, for example, a laser diffraction particle analyser or an image-based particle size sensor. The particle size sensor may be provided at a position in-line in the process line by measuring the powder material directly, or may be provided at a position on-line in a sampling line parallel to or split off from the process line by measuring a sample or diverted stream of the powder material.

The at least one sensor may include a tapped density sensor 222 configured for acquiring a bulk density of the powder material. A tapped density sensor 222 includes a measuring column and a vibration generator, and may be configured to measure a height of a column of powder material both before and after vibrating the column of powder material and comparing the difference in height and/or volume to calculate the bulk density of the powder material. The tapped density sensor 222 may be provided at a position in-line in the process line by measuring the powder material directly, or may be provided at a position on-line in a sampling line parallel to or split off from the process line by measuring a sample or diverted stream of the powder material.

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

Further, the powder feeding apparatus 200 may be provided with additional sensors, particularly additional in-line sensors, so that accurate control of the powder feeding apparatus 200 based on the desired process parameters may be carried out. For example, the input hopper 210 may be provided with a load cell 211 configured for measuring a mass of the powder material M being fed into the powder feeding apparatus 200. Alternatively, the output hopper 240 may be provided with a load cell 241 configured for measuring a mass of the powder material M being fed out of the powder feeding apparatus 200. Said load cells 211, 241 allow for more accurate determination of the rate of powder material being fed to the subsequent process, and allow for more accurate control of the powder feeding apparatus 200 in response to quality parameters.

The feed conveyor 220 transports the powder material to an in-line sieve 230. The powder material is fed through the in-line sieve 230 so that the particle size range of the powder material can be controlled. The in-line sieve 230 is configured to have a predetermined mesh size corresponding to the maximum particle size which is allowed to pass therethrough. In some arrangements, the in-line sieve 230 may be configured to have a fixed mesh size and may be configured to be manually changed by an operator during initial configuration of the powder feeding apparatus 200. Preferably, the in-line sieve 230 may be configured to have an automatic sieve changing mechanism which allows for the in-line sieve 230 to be automatically changed so that the mesh size may be automatically controlled. Further, the in-line sieve 230 may include a single sieve through which the powder material is fed, or may include a plurality of cascading sieves with decreasing mesh size. When referring to a controlling of the in-line sieve 230, the mesh size and/or a vibration rate may be adjusted.

The feed 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 powder material feed. 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 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 provided with a load cell. The 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 powder material, and a corresponding quality parameter of the powder material may be estimated. The magnetic filter 260 is exemplarily shown as being provided after the in-line sieve 230, however the present disclosure is not limited thereto, and the magnetic filter 260 may be provided at other positions in the powder feeding apparatus 200, such as at the positions of in-line sensors 223a, 223b.

Further, the powder feeding apparatus 200 includes a powder feeding controller 250 which is configured to control the powder feeding apparatus 200 according to the control methods described in the present disclosure. The powder feeding controller 250 is in communication with the at least one sensor, particularly a tapped density sensor 222 and in-line sensors 223a, 223b, so that at least one quality parameter acquired by said sensors can be input into the controller 250. Further, the powder feeding controller 250 is in communication with one or more actuators for controlling the powder feeding apparatus 200, particularly a feed conveyor drive motor 221, so that the powder feeding controller 250 may instruct a feeding of powder material. The powder feeding controller 250 may further be in communication with other sensors, such as load cells 211, 241 for more accurate control of a powder material feed rate.

The powder feeding controller 250 may be a microprocessor, a programmable logic controller (PLC), or a digital signal processor (DSP). Particularly, the powder feeding 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 powder feeding 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.

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

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

According to the first aspect of the present invention, a method of controlling a powder feeding process for electrode manufacturing for an electrochemical energy storage device is provided. The method 300 includes providing a powder material to a material feed conveyor, conveying the powder material to an in-line sieve, sieving the powder material with the in-line sieve, and loading the sieved powder material into a subsequent process. The providing of the powder material and the sieving of the powder material, and more particularly the transport of the powder material via the material feed conveyor, are controlled by at least one powder feeding process parameter P_P. The method 300 further includes acquiring 350 at least one powder quality parameter Q_P of the powder material, preferably wherein the at least one powder quality parameter Q_P is acquired in-situ, and adjusting 370 the at least one powder feeding process parameter P_P based on the at least one powder quality parameter Q_P according to a predetermined powder feeding model 360.

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

The powder feeding apparatus is continuously monitored by at least one powder feeding sensor 350 of the powder feeding apparatus, and said sensor(s) acquire at least one quality parameter Q_P of the powder material output from or being transported through the powder feeding apparatus. The at least one quality parameter Q_P is provided to the powder feeding model 360 which includes a plurality of correlations between quality parameters Q_P and process parameters P_P. Using the powder feeding model 360, at least one adjusted powder feeding process parameter AP_P is generated in the process parameter adjustment 370 based on the quality parameter Q_P. The at least one adjusted powder feeding process parameter AP_P is then used to update the set of powder feeding process parameters 320 so that the control algorithm 330 is automatically adjusted in a closed-loop fashion.

Through continuous monitoring and closed-loop control of the powder feeding process, particularly based on quality parameters acquired in-situ, the process parameters P_P of the powder feeding process can be specifically tuned to account for variations in material quality. For example, the desired target solid content of a mixed slurry can be assured by optimising the powder material feeding and/or the liquid material feeding. As a further example, the desired target viscosity of the a mixed slurry can be assured by optimising the powder material feeding and/or sieving based on an in-line tapped density measurement or an in-line particle size measurement.

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.

On the other hand, a “quality parameter” refers to a parameter which defines an aspect of a process ingredient, material, intermediate product or final product of a process which is obtained, measured or estimated by some form of analysis. A quality parameter constitutes a value of a property of the process ingredient, material, intermediate product or final product which may be measured, for example, by one or more sensors or one or more analyses. Typically, a quality parameter, particularly of an intermediate product or a final product, is influenced by the process parameters which define the process used to generate said intermediate product or final product. A quality parameter may be compared to a threshold or a target range in order to determine whether a defect or quality deficiency has occurred.

According to embodiments, the at least one powder feeding process parameter P_P may 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. According to further embodiments, the at least one powder quality parameter Q_P may 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 P_P may be any process parameter typical for operating a powder feeding apparatus, and the at least one powder quality parameter Q_P may be any quality parameter for which a suitable sensor is available, which preferably can be acquired in-situ. According to an embodiment, which may be combined with other embodiments described herein, the powder feeding model 360 is based on at least one correlation between the at least one powder feeding process parameter P_P and the at least one powder quality parameter Q_P.

Preferably, the powder feeding 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 powder feeding 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 powder feeding 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 powder feeding model 360 may be replaced with an empirical model. As a further alternative, the powder feeding 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.

The closed-loop control method 300 for controlling the powder feeding process as described implements the closed-loop control based on quality parameters Q_P acquired within the powder feeding 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 Q_P acquired in the powder feeding 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. In the context of the present disclosure, the terms “previous process” and “subsequent process” refer 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.

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 powder quality parameter Q_P of the powder feeding 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 powder quality parameter. For example, the powder feeding process may come before a subsequent process 500 which corresponds to a slurry mixing process in which the powder material being fed from the powder feeding process is mixed into a slurry with a liquid material. The powder feeding process may acquire a quality parameter Q_P, such as an average particle size or a tapped density, and the process parameters of the slurry mixing may be automatically adapted based thereon. If the tapped density, for example, indicates that the powder material being fed has a higher density than expected, the slurry mixing recipe can be adapted to suit so that the desired slurry density or slurry solid content 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 powder feeding quality parameter Q_P based on a model 560 of the subsequent process 500. According to a further embodiment, which may be combined with other embodiments described herein, the method 300 according to the first aspect may further include providing the at least one powder quality parameter of the powder feeding process to a previous process 400 of the electrode manufacturing as a feed-back signal, such that at least one process parameter of the previous process is adjusted based on the at least one powder quality parameter Q_P. For example, the powder feeding process may come after a previous process 400 which corresponds to a powder pre-mixing process in which two or more different powder materials are mixed. The powder feeding process may acquire a quality parameter Q_P, such as an average particle size or a tapped density, and the process parameters of the pre-mixing in the previous process 400 may be automatically adapted to optimise the quality parameter Q_P. Particularly, as shown in the figure by the optional dashed lines, the process parameters of the previous process 400 may be adjusted based on the powder feeding quality parameter Q_P based on a model 460 of the subsequent process 400.

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 Q_x, QY of a previous process 400 or a subsequent process 500 and adjusting the at least one powder feeding process parameter P_P based on the at least one external parameter Q_x, QY according to the powder feeding model 360. As exemplarily shown in the figure by the optional dashed lines, an external quality parameter Q_x which is acquired by the at least one sensor 450 in a previous process 400 may be provided, as an external parameter, to the powder feeding process 300 so that one or more powder feeding process parameters P_P can be adjusted based on the external parameter using the powder feeding model 360. Similarly, an external quality parameter Q_Y which is acquired by the at least one sensor 550 in a subsequent process 500 may be provided, as an external parameter, to the powder feeding process 300 so that one or more powder feeding process parameters P_P can be adjusted based on the external parameter using the powder feeding model 360.

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 powder volume rate or a powder mass rate of a different powder material into a different powder feeding process, a liquid volume rate or a liquid mass rate of a liquid material into a liquid feeding process, and a solid content of a mixed slurry acquired from a slurry mixing process.

For example, the powder feeding process 300 may acquire, as an external parameter Q_Y, a quality parameter which corresponds to a solid content of a mixed slurry after the powder material being fed in the powder feeding process 300 has been mixed in the subsequent slurry mixing process. The solid content of the mixed slurry may then be further optimised by generating one or more adjusted powder feeding process parameters AP_P based on the slurry solid content using the powder feeding model 360.

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.

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 according to the first aspect described above. The method further includes 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 P_L, mixing a slurry comprising the at least one powder material and the at least one liquid material in a slurry mixing process 130, the mixing being controlled based on at least one slurry mixing process parameter P_M, and 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 P_c, 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.

In a general sense, the method may define an overall closed-loop control system which encapsulates the closed-loop control methods of each sub-process of the electrode manufacturing process, wherein the overall closed-loop system can adjust process parameters of each sub-process based on quality parameters acquired in other sub-processes.

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

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 P_P. The method of controlling the powder feeding process 120 is according to the first aspect and embodiments described above. At least one powder quality sensor 125 is provided for acquiring at least one powder quality parameter Q_P which, within the closed-loop control system of the powder feeding process 120, is fed back to the powder feeding controller 126. Further to the above-described aspect and embodiments, the at least one powder quality parameter Q_P is further provided to the overall system controller 600.

The at least one powder feeding process parameter P_P may 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 Q_P may 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 P_P may be any process parameter typical for operating a powder feeding apparatus, and the at least one powder quality parameter Q_P may be any quality parameter for which a suitable sensor is available, which preferably can be acquired in-situ.

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 P_L. At least one liquid quality sensor 115 may be provided for acquiring at least one liquid quality parameter Q_L which, 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 Q_L is provided to the overall system controller 600.

The at least one liquid feeding process parameter P_L may 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 Q_L may 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 P_L may be any process parameter typical for operating a powder feeding apparatus, and the at least one powder quality parameter Q_L may 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 P_M. The at least one mixing process parameter P_M may 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 Q_s which, within the closed-loop control system of the mixing process 130, may be fed back to the mixing controller 136. Further, the at least one slurry quality parameter Q_s is provided to the overall system controller 600.

The at least one mixing process parameter P_M may 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 Q_L may 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 P_L may be any process parameter typical for operating a powder feeding apparatus, and the at least one powder quality parameter Q_L may 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 P_c. The at least one coating process parameter P_c may 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 Q_c which, within the closed-loop control system of the coating process 140, may be fed back and/or fed forward to one of the deposition controller 146, the drying controller 147, the calendering controller 148 and, optionally, the slitting controller. Further, the at least one coating quality parameter Q_c is provided to the overall system controller 600.

For process parameters related to the deposition process, the at least one coating process parameter P_c may 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 P_c may 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 P_c may 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 P_c may be any process parameter typical for operating a deposition apparatus, a drying apparatus, a calendering apparatus or an electrode slitting apparatus. The at least one coating quality parameter Q_c may 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 Q_c may be any quality parameter for which a suitable sensor is available, which preferably can be acquired in-situ.

The overall system controller 600 is provided with the quality parameters Q_P, Q_L, Q_s, 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. 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.

The plurality of adjusted process parameters AP LL may include one or more of the group containing an adjusted powder feeding process parameter AP_P, an adjusted liquid feeding process parameter AP_L, an adjusted mixing process parameter AP_M, and an adjusted coating process parameter AP_C. 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.

For example, a slurry quality parameter Q_s which 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 AP_C to correct and/or take account for the slurry density. Similarly, a slurry quality parameter Q_s which 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 AP_L to correct and/or take account for the slurry viscosity. 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 liquid feeding process parameter P_L, the at least one slurry mixing process parameter P_s, and/or the at least one coating process parameter P_c is adjusted based on the at least one powder quality parameter Q_P. In other words, process parameters which are external to the powder feeding process 120 may be adjusted based on a quality parameter which is internal to the powder feeding process 120.

Particularly, the at least one liquid feeding process parameter P_L may be adjusted based on the at least one powder quality parameter Q_P using a liquid feeding model. For example, in the case where the at least one powder quality parameter Q_P includes an in-line tapped density measurement, the value of the tapped density of the at least one powder material being fed into the slurry mixing process 130 may require an increased 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 tapped density of the powder material (quality parameter) and a solvent volume (process parameter), the liquid feeding process parameter P_L corresponding to the volume of solvent being fed may be automatically adjusted to suit.

Further, the at least one slurry mixing process parameter P_M may be adjusted based on the at least one powder quality parameter Q_P using a slurry mixing model. For example, in the case where the at least one powder quality parameter Q_P includes an in-line average particle size measurement, the value of the average particle size of the at least one powder material being fed into the slurry mixing process 130 may require that the slurry mixing is performed with an increased mixing time so that the desired slurry quality targets are achieved, and said process parameter may be automatically adjusted.

Further still, the at least one coating process parameter P_c may be adjusted based on the at least one powder quality parameter Q_P using a coating model. For example, in the case where the at least one powder quality parameter Q_P includes an in-line particle size range measurement, the particle size range of the at least one powder material being fed into the slurry mixing process 130 may require that the drying is performed with an increased drying temperature so that the desired quality targets of the deposited layer are achieved, and said process parameter may be automatically adjusted.

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 P_P is adjusted based on at least one external parameter of the liquid feeding process 110, the slurry mixing process 130 and/or the coating process 140 according to the powder feeding model. In other words, process parameters which are internal to the powder feeding process 120 may be adjusted based on a quality parameter which is external to the powder feeding process 120. Said external parameter may be at least one liquid quality parameter Q_L, at least one slurry quality parameter Q_s, and/or at least one coating quality parameter Q_c.

Particularly, at least one powder feeding process parameter P_P may be adjusted based on the at least one liquid quality parameter Q_L using the powder feeding model. For example, in the case where the at least one liquid quality parameter Q_L includes an in-line pH measurement of water being fed by the liquid feeding, the size of the in-line sieve in the powder feeding apparatus may need to be decreased so that the desired slurry quality targets are achieved, and said process parameter may be automatically adjusted and the in-line sieve may be automatically swapped.

Further, at least one powder feeding process parameter P_P may be adjusted based on the at least one slurry quality parameter Q_s using the powder feeding model. For example, in the case where the at least one slurry quality parameter Q_s includes an in-line solid content measurement of the slurry, the mass of powder material being fed by the powder feeding apparatus may need to be adjusted so that the desired slurry quality targets are achieved. Further still, at least one powder feeding process parameter P_P may be adjusted based on the at least one coating quality parameter Q_c using the powder feeding model. For example, in the case where the at least one coating quality parameter Q_c includes an in-line density measurement of the deposited slurry layer, the loading weight of an additive in the powder feeding apparatus may need to be adjusted so that the desired coating density targets are achieved.

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.

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 P_c, 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.

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 P_c to generate, based on the overall system model 610, an adjusted coating process parameter AP_C so 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 P_L and at least one mixing process parameter P_M to generate, based on the overall system model 610, an adjusted liquid feeding process parameter AP_L and an adjusted mixing process parameter AP_M so that the stored slurry can be re-mixed and the desired slurry quality parameters can be achieved.

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 P_P is adjusted based on at least one external parameter of the EOL testing process 160 according to the powder feeding model. For example, if the EOL testing 160 indicates that the final cell weight is insufficient, this may indicate that the mass of powder material being fed by the powder feeding apparatus is required to be increased so that the desired cell capacity is achieved. For the next batch of electrode manufacturing, the powder feeding may be adjusted to suit.

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.

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.

In the above embodiment, which will be referred to as the defect source tracing, the one or more models included in the control method may include a plurality of correlations which indicate the effects of specific process parameters on the probability of generating a defect. For example, in the slurry mixing process 130, a slurry mixing process parameter P_M may, 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 Q_c which indicates the specific defect, identify with a level of probability that the specific defect was caused by the specific value of the slurry mixing process parameter P_M. 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.

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.

The defect source tracing 630 may further be used to determine whether one or more materials, intermediate products or final products should be removed from the electrode manufacturing process as scrap material. Depending on the type of defect and/or the quality of the scrap material, the scrap material may be disposed of. However, preferably, since the defect source tracing 630 indicates why said scrap material may have been removed from the process, a scrap repair and/or re-use process 640 may be carried out so that the scrap material is reprocessed or repurposed in such a way as to minimise waste. By reprocessing or repurposing scrap material, such as scrap slurry or scrap electrodes which may have been in various stages of coating, drying and calendering, the material efficiency and energy efficiency of the manufacturing process can be significantly improved.

According to an embodiment, which may be combined with other embodiments described herein, the method according to the second aspect may further include, if the identifying indicates that the source of the defect is in the slurry mixing process, removing the mixed slurry as a scrap slurry and optionally removing the electrode as a scrap electrode, and/or if the identifying indicates that the source of the defect is in the coating process, removing the electrode as a scrap electrode. The scrap material, i.e. the scrap slurry and/or the scrap electrode, may be removed from the electrode manufacturing process and optionally stored under prescribed storage conditions.

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.

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.

In particular, the scrap slurry may be reprocessed by adjusting the at least one mixing process parameter P_M based 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 AP_P of 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 P_c based 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 AP_C of 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.

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.

Referring once again to Fig. 2, according to the third aspect of the present disclosure, a powder feeding apparatus 200 for feeding powder material M for an electrode manufacturing system is provided. The powder feeding apparatus 200 includes a material input for receiving a powder material M, a material feed conveyor 220 for conveying the powder material M, at least one sensor 222, 223a, 223b configured for acquiring at least one powder quality parameter Q_P of the powder material M, preferably wherein the at least one sensor 222, 223a, 223b is configured for in-situ acquisition, an in-line sieve 230 having a predetermined mesh size, a material output for loading sieved powder material into a subsequent process apparatus, and a controller 250 configured for controlling the powder feeding apparatus 200 by implementing the method according to the first aspect. Further embodiments according to features, aspects and modifications of the powder feeding 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 may include a particle size sensor configured for acquiring a measurement of an average particle size or a measurement of a particle size range of the powder material M. The particle size sensor may include, for example, a laser diffraction particle analyser or an image-based particle size sensor. Further, the at least one sensor may include a tapped density sensor 222 configured for acquiring a bulk density of the powder material. However, the sensor types discussed above are only examples of possible sensors which may be included in the powder feeding apparatus 200. The present disclosure is not limited thereto, however, and any powder quality sensor which is known in the state of the art may be incorporated into the powder feeding apparatus 200 either as an in-line sensor or as an on-line sensor.

Further, the powder feeding apparatus 200 may be provided with additional sensors, particularly additional in-line sensors, so that accurate control of the powder feeding apparatus 200 based on the desired process parameters may be carried out. For example, the input hopper 210 may be provided with a load cell 211 configured for measuring a mass of the powder material M being fed into the powder feeding apparatus 200. Alternatively, the output hopper 240 may be provided with a load cell 241 configured for measuring a mass of the powder material M being fed out of the powder feeding apparatus 200.

The controller of the powder feeding apparatus 200, i.e. the powder feeding controller 250, may be a microprocessor, a programmable logic controller (PLC), or a digital signal processor (DSP). Particularly, the powder feeding 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 powder feeding controller 250 may further include at least one storage means, which may include random access memory (RAM), readonly 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 powder feeding controller 250 to a data network, in particular a global data network.

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 according to the third aspect, the at least one powder feeding apparatus 200 being configured for feeding at least one powder material M. The system further includes at least one liquid feeding apparatus configured for feeding at least one liquid material, a slurry mixing apparatus configured to mix a slurry of the at least one powder material M 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.

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.

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.

Spatially relative terms such as “under”, “below”, “lower”, “over”, “upper” and the like are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc. and are also not intended to be limiting. Like terms refer to like elements throughout the description.

As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.

With the above range of variations and applications in mind, it should be understood that the present invention is not limited by the foregoing description, nor is it limited by the accompanying drawings. Instead, the present invention is limited only by the following claims and their legal equivalents.

Reference numbers

100 Method of manufacturing an 166 End-of-line (EOL) testing electrochemical energy storage controller device 200 Powder feeding apparatus

110 Liquid material feeding process 210 Input hopper

115 Liquid quality parameter 211 Input load cell

116 Liquid feeding controller 220 Feed conveyor

221 Feed conveyor drive motor

120-122 Powder material feeding

222 Tapped density sensor process

223a, 223b In-line sensor

125 Powder quality sensor

230 In-line sieve

126 Powder feeding controller

240 Output hopper

130 Slurry mixing process

250 Powder feeding controller

131 Slurry storage process

260 Magnetic filter

135 Mixing quality sensor

300 Powder feeding method

136 Mixing controller

140 Coating process 310 Powder feeding input

141 Deposition process

320 Powder feeding process

142 Drying process parameters

143 Calendering process

330 Powder feeding control

144 Slitting process algorithm

145 Coating quality sensor

340 Powder feeding apparatus

146 Deposition controller

350 Powder feeding sensor

147 Drying controller

360 Powder feeding model

148 Calendering controller

370 Process parameter adjustment

150 Further manufacturing processes 400 Previous process

160 End-of-line (EOL) testing 450 Previous process sensor process 460 Previous process model

165 End-of-line (EOL) testing 500 Subsequent process sensor

550 Subsequent process sensor 560 Subsequent process model

600 Overall system controller

610 Overall system model

620 Overall control algorithm

630 Defect source tracing

640 Scrap repair and/or reuse

M Powder material

P_p Powder feeding process parameter

APALL Adjusted system process parameters

AP_C Adjusted coating process parameter

AP_M Adjusted mixing process parameter

AP_P Adjusted powder feeding process parameter

QALL System quality parameters

Qc Coating quality parameter

QEOL EOL testing quality parameter

QP Powder quality parameter

Qs Slurry quality parameter

Qx Quality parameter from previous process

Q_y Quality parameter from subsequent process

Claims

1. A method of controlling a powder feeding process for electrode manufacturing for an electrochemical energy storage device, the method comprising: providing a powder material to a material feed conveyor; conveying the powder material to an inline sieve; sieving the powder material with the inline sieve; and loading the sieved powder material into a subsequent process, wherein the providing and sieving are controlled by at least one powder feeding process parameter, wherein the method further comprises: acquiring at least one powder quality parameter of the powder material, preferably wherein the at least one powder quality parameter is acquired in-situ; and adjusting the at least one powder feeding process parameter based on the at least one powder quality parameter according to a predetermined powder feeding model.

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

3. The method according to any one of claims 1 to 2, wherein the at least one powder quality parameter of the powder material is selected from the group comprising: an average particle size; a range of particle size; a content of magnetic components; a tapped density; and a content of impurities.

4. The method according to any one of claims 1 to 3, wherein the at least one powder feeding process parameter is selected from the group comprising: a powder volume rate of the powder material into the powder feeding process; a powder mass rate of the powder material into the powder feeding process; and a mesh size of the inline mesh.

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

7. The method according to claim 6, wherein the at least one external parameter is selected from the group comprising: a powder volume rate or a powder mass rate of a different powder material into a different powder feeding process; a liquid volume rate or a liquid mass rate of a liquid material into a liquid feeding process; and a solid content of a mixed slurry acquired from a slurry mixing process.

8. The method according to any one of claims 1 to 7, wherein the 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.

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

10. The method according to claim 9, 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 electrochemical energy storage device having the electrode in an end-of-line testing process.

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

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

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

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

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

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

17. A powder feeding apparatus for feeding powder material for an electrode manufacturing system, the powder feeding apparatus comprising: a material input for receiving a powder material; a material feed conveyor configured for conveying the powder material; at least one sensor being configured for acquiring at least one powder quality parameter of the powder material, preferably where the at least one sensor is configured for in-situ acquisition; an inline sieve having a predetermined mesh size; a material output for loading sieved powder material into a subsequent process apparatus; and a controller configured for controlling the powder feeding apparatus by implementing the method according to any one of claims 1 to 8.

18. An electrode manufacturing system for manufacturing electrodes for an electrochemical energy storage device, the system comprising: at least one powder feeding apparatus according to claim 17, the 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 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 9 to 16.