Continuous production system and method for producing electrode compositions, binder metering system and metering method for same

Abstract

The invention relates to a binder metering system (10) for continuously metering a fibrillatable binder (20) for producing electrode compositions and to a metering method for same. The invention further relates to a continuous production system (84) for producing electrode compositions, comprising the binder metering system (10) and a continuous mixer (86) coupled to the binder metering system, and to a continuous production method for electrode compositions.

Description

[0001] Continuous production system and process for the manufacture of electrode compounds as well as binder dosing system and dosing method therefor

[0002] The invention relates to a continuous production system and a method for producing electrode masses, as well as a binder dosing system and a method for continuously dosing a fibrilliable binder for the production of electrode masses using the binder dosing system.

[0003] Electrochemical energy storage devices are of great importance in many technical fields. The electrodes for such energy storage devices are typically manufactured using a wet process, in which electrode materials dispersed in a carrier solvent, so-called "slurries," are applied to a current collector, for example, a metallic collector foil, and further processed into the electrode. The electrodes can be combined with a separator to form a cell for an energy storage device.

[0004] Electrode compounds contain various powdered starting materials that are mixed together in a wet process using a carrier solvent. These starting materials include an electrochemical active material, a binder, and additives such as electrical conductivity enhancers. However, wet processes require an additional drying step to remove the carrier solvent. This results in high costs, as removing the carrier solvent from the electrode compound is a technically and energetically demanding process.

[0005] Therefore, solvent-free processes for the production of electrode compounds have already been proposed in so-called "dry processes," in which the powdered starting materials are mixed together without the addition of a solvent. For this purpose, the powdered starting materials are mixed and granulated batchwise, for example, in a jet mill. In addition to such pure batch processes, semi-continuous processes are also known, in which the powdered starting materials are mixed in a batch process and further processed into electrode compounds in a continuous mixer, such as an extruder.

[0006] Methods for producing electrode masses in a dry process are known, for example, from EP 1 512 185 B1 and US 2014 / 0210 129 A1.

[0007] However, the production of dry electrode materials using batch processes has the disadvantage that high throughputs can only be achieved with several mixing systems connected in parallel. Furthermore, semi-continuous production processes are difficult to scale, as the processing time in the mixer per batch can increase significantly and requires more cooling and heating. Using a jet mill to mix the powdered raw materials also generates a high airflow, which subsequently needs to be cleaned to remove solids. This further increases the production costs of the electrode materials. Finally, jet mills or other batch-based mixing systems are only suitable for producing the pure, granular electrode material. Additional, independent equipment is required for post-processing or comminution of the granular electrode material.

[0008] One challenge in electrode manufacturing is therefore the provision of a fully continuous dry process for manufacturing electrode compounds, as well as a production system to execute this process. Using a fully continuous manufacturing process increases production capacity and ensures consistent quality of the resulting electrode compounds. In this respect, fully continuous manufacturing processes offer several advantages over batch processes in which electrode compounds are produced.

[0009] Electrode compounds produced using a dry process also utilize shear-sensitive, fibrilliant binders such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer (FEP), because these form fibrils during mixing, creating a composite structure with the other starting materials. This improves the mechanical integrity of the resulting electrode compounds. Although the binder is present in only a low proportion of 1–2 wt% in the electrode compound, it has a significant influence on its properties. A challenge in the continuous production of electrode compounds using a dry process therefore lies in the dosing of the powdered starting materials, and especially in the precise continuous dosing of the poorly flowing, fibrilliant binder.

[0010] WO 2023 / 220 025 A1 already proposes a method for handling polytetrafluoroethylene (PTFE) powder, in which the PTFE powder is conveyed by applying a pressure difference.

[0011] The invention is therefore based on the objective of avoiding the disadvantages of the prior art in the production of electrode masses in the dry process and in particular of providing a binder dosing system with which the fibrilliable binder can be dosed continuously and precisely in a simple manner into a mixer suitable for the continuous production of electrode masses.

[0012] The object is solved according to the invention by a binder dosing system for the continuous dosing of a fibrilliant binder for the production of electrode masses according to claim 1, a method for the continuous dosing of a fibrilliant binder according to claim 5, a production system for the production of electrode masses according to claim 12 and a method for the continuous production of electrode masses according to claim 16.

[0013] According to the invention, a binder dosing system for the continuous dosing of a fibrilliant binder for the production of electrode compounds is provided, comprising a first dosing device, a second dosing device, and a refilling device that connects the first and second dosing devices in the conveying direction. The first dosing device is configured to volumetrically dose the fibrilliant binder into the refilling device. The refilling device includes a separation unit that provides a particle fraction of the fibrilliant binder consisting of particles with a predetermined particle size. Furthermore, the refilling device is configured to replenish the particle fraction of the fibrilliant binder, consisting of particles with a predetermined particle size, into the second dosing device.The second dosing device is designed to continuously dose the fibrilliant binder gravimetrically into a continuous mixer. The binder dosing system includes a cooling device for cooling the fibrilliant binder.

[0014] The inventive method for continuously dosing a fibrilliant binder for the production of electrode compounds can be carried out using the binder dosing system described above and comprises the following steps: a) providing a fibrilliant binder in a first dosing device; b) volumetrically dosing the fibrilliant binder from the first dosing device into a refilling device; c) refilling the fibrilliant binder from the refilling device into a second dosing device, wherein the refilling device comprises a separation unit that provides a particle fraction of the fibrilliant binder consisting of particles with a predetermined particle size, wherein the refilling device only refills the particle fraction with the predetermined particle size into the second dosing device;d) gravimetric, continuous dosing of the fibrillable binder from the second dosing device into a continuous mixer, wherein steps b) and / or c) are controlled and / or carried out at defined time intervals and wherein one or more of steps a) to d) are carried out under cooling.;

[0015] A refilling device is arranged in the conveying direction between the first dosing unit, which performs a volumetric coarse dosing of the binder, and the second dosing unit, which performs a continuous gravimetric fine dosing of the binder. The refilling device serves as a buffer or storage for binder from the first dosing unit and enables controlled and constant refilling of the second dosing unit. This allows for simple, precise, and continuous dosing of the fibrilliable binder with high dosing accuracy.

[0016] Due to the combination of volumetric and gravimetric dosing devices with an intermediate refilling unit, the dosing accuracy of the second dosing device can be kept constant throughout the entire dosing process. Furthermore, the throughput of binders can be increased compared to batch processes or semi-continuous manufacturing processes for electrode compounds. In addition, the binder dosing system requires less maintenance, as no manual intervention is necessary to refill the second dosing device.

[0017] Due to its high temperature and shear sensitivity, the powdered fibrillatable binder tends to adhere to surfaces and form agglomerates or clumps, which can no longer be dosed with the required accuracy. Even the binder's own weight in the dosing devices can cause agglomerate formation. The inventors recognized that the binder must be supplied to the second dosing device in a defined powdered form, and the fill level of fibrillatable binder in the second dosing device must be kept as low as possible to prevent agglomerate formation and ensure highly precise dosing of the binder into a continuous mixer.By interposing a refilling step, the fill level of the shear-sensitive binder in the second dosing device can be kept so low that compaction of the binder in the second dosing device due to its own weight is prevented and gravimetric fine dosing to the other components of the electrode mass becomes possible.

[0018] Cooling the poorly flowing, fibrilliant binder ensures that it can be metered continuously, consistently, and precisely into the process zone of a continuous mixer. Shear forces and temperatures above 18 °C can cause phase changes in the binder molecules, leading to fibrillation, softening, and / or melting, which significantly affects the flow properties of the powdered binder. Cooling prevents clumping and adhesion of the binder powder, thus ensuring the continuity, consistency, and precision of the binder metering.

[0019] With the binder dosing system according to the invention, a dosing accuracy of the second, gravimetric dosing device in step d) can therefore be achieved with a target value deviation of < 3%, preferably < 2%, most preferably < 1%. The standard deviation of the dosing accuracy is preferably < 3%, more preferably < 2%, most preferably < 1%. The dosing accuracy is determined using the NAMUR NA 040 method, wherein the dosing accuracy was determined with 30 successive samples of PTFE as the binder at intervals of 60 s.

[0020] The term "volumetric dosing" refers to volume-controlled dosing of the fibrilliant binder, where the material output is determined by a predetermined and constant dosing parameter used to operate the second dosing device. In other words, with a constant dosing parameter, the same amount of binder is dispensed per unit of time.

[0021] "Gravimetric" dosing refers to weight-controlled dosing of the fibrilliant binder from the second dosing device into a continuous mixer. In contrast to volumetric dosing, one or more dosing parameters are used, which are continuously adjusted or readjusted during the process.

[0022] A fibrilliant binder is understood to be a material that forms fibrils under the influence of shear force, whereby a higher number of fibrils and / or fibrils with a greater length tend to be generated with increasing shear force, increasing temperature and increasing duration of the effect of the shear force on the fibrilliant binder.

[0023] Fibrilliant binders are known, for example, from US 10 741 843 B2 and US 11 545666 B2.

[0024] According to one embodiment, the first metering device preferably comprises a volumetric vibrating trough or vibrating trough that volumetrically meters the fibrilliant binder from a container into the refilling device in step b) while avoiding shear forces. In this case, the metering parameter for the volumetric metering can be a vibration intensity or vibration frequency. As an alternative to a vibrating trough, a belt conveyor can be used, which also enables low-shear metering. The predetermined metering parameter can be pre-calibrated and adjusted to the subsequent process steps c) and d).

[0025] The second dosing device preferably comprises a gravimetric vibrating feeder or vibrating trough that gravimetrically doses the fibrilliant binder from a container into a continuous mixer via the vibrating feeder, avoiding shear forces as described in step d). A scale is used to measure the weight loss within the container per unit of time. This time-dependent weight loss is compensated for by the gravimetric vibrating feeder by adjusting the dosing parameter, such as the vibration intensity or frequency, thus ensuring a constant material output of binder and therefore high dosing accuracy. A so-called loss-in-weight feeder can preferably be used as the second dosing device. A belt conveyor can also be used in the second dosing device instead of the vibrating feeder.

[0026] The fibrilliant binder can be selected from the group consisting of polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and high-molecular-weight polyethylene (PE), as well as combinations thereof. Polytetrafluoroethylene is particularly preferred as a fibrilliant binder.

[0027] The separation unit separates a coarse fraction of the binder from a particle fraction consisting of particles with a predetermined particle size. The refilling device then replenishes only the particle fraction of the binder with the predetermined particle size into the second dosing device. The coarse fraction comprises, in particular, unwanted binder agglomerates that are already present in the binder used as starting material or that have formed during steps a) and / or b). By separating the coarse fraction from the remaining particles of the binder, the particle fraction with the predetermined particle size is provided in the refilling device. In other words, the particle fraction freed from the coarse fraction represents a binder powder with defined properties and thus improved dosing characteristics.

[0028] The separation unit can, in particular, comprise a vibrating screen or a shaking screen. The particle fraction with the predetermined particle size can be defined by a mesh size of 1 to 4 mm. In accordance with DIN 4783-1, the mesh size here and in the following refers to the clear width of the screen holes, defined as the clear distance between two adjacent warp or weft wires measured at the center of the mesh.

[0029] The predetermined particle size can be determined based on the electrode mass specifications.

[0030] Process steps b) and / or c) are carried out in a controlled manner and / or at defined time intervals. Actively controlling steps b) and / or c) offers the advantage that a refill cycle consisting of these two steps is only performed when needed, specifically when the second dosing device requires a supply of fibrilliant binder. It is understood that steps b) and c) should be performed before the second dosing device runs dry to ensure the continuous operation of the dosing system and the downstream continuous mixing process. Alternatively and / or additionally, process steps b) and / or c) can also be performed periodically at defined time intervals. The terms "time span" and "time interval" are used synonymously below. This advantageously eliminates the need for a control system, which is typically complex and costly.The defined time intervals can be implemented, for example, in the form of a predefined dosing cycle for the first and second dosing devices as well as the refilling device.

[0031] According to one aspect of the invention, the refilling device further comprises a binder dispenser in which the particle fraction of the binder with the predetermined particle size is collected before the particle fraction is refilled from the binder dispenser into the second dosing device. The binder dispenser separates the first volumetric dosing device from the second gravimetric dosing device and allows the particle fraction of the binder with the predetermined particle size to be dispensed in a controlled manner into the second dosing device.

[0032] Another aspect of the method according to the invention provides that step c) is only carried out if a predetermined quantity of the particle fraction has been collected in the binder dispenser. In other words, a threshold value in the form of a weight value can be specified for the binder dispenser, above which the fibrilliable binder is refilled into the second dosing device. The weight value can be calculated from the dosing parameters of the first dosing device. This enables automated refilling of the second dosing device.

[0033] The binder dispenser comprises, in particular, a metering element coupled to the second metering device in the conveying direction. The metering element is preferably a metering flap, a metering shovel, a metering slide, or a metering wheel. Preferably, the metering element is a metering flap.

[0034] According to a further aspect of the method according to the invention, the binder dispenser refills a discrete quantity of the particle fraction into the second metering device by means of the metering element. In particular, the metering element is designed such that the refilling of the binder takes place while avoiding shear forces that can occur in the mechanism of the metering element or from the binder spreading on the walls of the binder dispenser.

[0035] The repeated refilling of a discrete quantity of the particle fraction with a predetermined particle size allows for a simple way to keep the fill level in the second dosing unit as low as possible, thus preventing unwanted compaction of the binder. Furthermore, the dosing element minimizes the refill time for the second dosing unit by emptying the binder dispenser abruptly when it opens. The dosing element also prevents the collected binder from falling or trickling uncontrollably into the second dosing unit, thereby preventing interference with the weighing signal of the second dosing unit. During the refilling process, the second dosing unit switches from gravimetric to volumetric dosing.In particular, the dosing parameter of the gravimetric vibrating feeder set before the refilling process is maintained. As soon as the refilling process is complete, the binder has been dispensed from the binder dispenser into the second dosing device, and the dosing element of the binder dispenser has closed again, the second dosing device is recalibrated and gravimetric operation resumes. This ensures the continuous operation of the dosing system and prevents adhesion or agglomeration in the second dosing device. Simultaneously, this allows the second dosing device to operate with the high dosing accuracy required for a continuous electrode compound manufacturing process. In particular, a dosing accuracy with a setpoint deviation of < 3% can be achieved.

[0036] Regardless, steps b) and / or c) can advantageously be designed and / or carried out such that the same quantity of fibrilliable binder is always added to the second dosing device during a refill cycle, which further increases the dosing accuracy of the second dosing device.

[0037] Another aspect of the method according to the invention provides that during step d) a weighing step is carried out in which a weight value of the fibrilliable binder in the second dosing device is continuously determined, wherein if a weight value is detected that is lower than a predetermined target value, a control signal is output from the second dosing device to the refilling device and / or the first dosing device, thereby carrying out step c) and / or step b).

[0038] The second dosing device, due to its gravimetric dosing method, already determines the weight of fibrilliant binder, so the fill level of fibrilliant binder in the second dosing device can also be monitored via this weight value. This allows a refill cycle, consisting of steps b) and c), to be requested from the second dosing device as needed, ensuring that a sufficient quantity of fibrilliant binder is always present in the second dosing device. As a result, the dosing method according to the invention functions fully automatically, without the need for manual intervention.

[0039] Alternatively, steps b), c) and d) can be specified by a dosing cycle. In particular, the temporal sequence of steps b), c) and d) can be specified by the dosing cycle.

[0040] The binder dosing system according to the invention can further comprise a transfer unit arranged downstream of the second dosing device and coupled to the second dosing device. The transfer unit comprises at least one collecting hopper and a vibration unit coupled to the collecting hopper. The transfer unit receives the binder dosed from the second dosing unit and transfers it to a continuous mixer. The vibration unit can vibrate the collecting hopper, thereby preventing the binder from undesirably adhering to the inner walls of the pipe element and / or the collecting hopper. Preferably, the vibration unit comprises an ultrasonic probe.

[0041] The transfer unit can have at least one pipe element coupled to the second dosing device, which projects centrally, in particular to about half its length, into the collecting hopper.

[0042] According to a further aspect of the invention, at least one additional metering device for a further electrode material feeds into the collecting funnel. In particular, several additional metering devices for further electrode materials feed into the collecting funnel.

[0043] According to a further aspect of the invention, the collecting funnel is closed with a lid which has individual openings for metering devices, wherein the collecting funnel is furthermore fluidly connected to an aspiration unit which is designed to extract exhaust air from the collecting funnel.

[0044] According to the invention, the binder dosing system further comprises a cooling device for cooling the fibrillatable binder. The cooling device allows one or more of steps a) - d) to be carried out under cooling, particularly at an ambient temperature of 1-18°C, preferably 5-15°C, and most preferably 4-10°C. Preferably, all steps of the dosing process are carried out under cooling, in particular all steps from the provision of the binder and transfer to the first dosing unit to the continuous dosing and transfer of the binder to the continuous mixer.

[0045] The term "ambient temperature" refers to the temperature of the periphery that directly surrounds the devices used in process steps a) - d). It goes without saying that the ambient temperature also essentially represents the temperature prevailing inside the devices.

[0046] In other words, the individual devices, in particular the first and second dosing devices as well as the refilling device and optionally the transfer unit, are operated under cooled conditions, thereby reducing the agglomeration tendency of the fibrilliant binder and improving the flow properties.

[0047] To lower the ambient temperature, cooling devices such as cooling towers, cooling chambers, cooling modules and / or cooling units can be used to cool the various devices of the binder dosing system used in the process.

[0048] According to a further preferred embodiment, the binder dosing system can thus have a coolable and / or air-conditioned enclosure. The enclosure can, in particular, be a cooling tower in which the first and second dosing devices, the refilling device, and optionally the transfer unit are arranged.

[0049] According to a further preferred embodiment, the binder dosing system is at least partially, preferably completely, enclosed in the cooling tower, which at least partially, preferably completely, encloses the components of the binder dosing system in a cooling chamber and cools the cooling chamber to a predetermined temperature. Alternatively, the cooling device of the binder dosing system comprises at least one cooling module and / or one cooling unit that cools a section of the binder dosing system to a predetermined temperature.

[0050] Instead of a cooling tower, the enclosure can comprise one or more cooling modules with cooling chambers. The first and second dosing devices, the refilling device, and optionally the transfer unit can each be arranged in their own cooling chamber, or several of these devices can be arranged together in a common cooling chamber.

[0051] The cooling units can include a coolable casing for the aforementioned devices or parts thereof. For example, the pipe element of the transfer unit can be equipped with a cooling jacket.

[0052] Another aspect of the invention provides that one or more of steps a) - d) are carried out at constant humidity, in particular at a dew point below 0°C, preferably below -10°C, and most preferably below -20°C. The dew point can be determined using standard ISO 8573-3. Low humidity within the devices reduces the amount of condensation, which also promotes agglomeration of the fibrilliant binder and impairs the properties of the electrode material.

[0053] The humidity can be adjusted, for example, using a climate control unit. In particular, the climate control unit can be located inside the cooled enclosure.

[0054] The dosing method according to the invention enables the continuous, constant, and precise dosing of the poorly flowing, fibrilliant binder into the process zone of a continuous mixer. The binder is preferably dosed under low-shear, dry, and cooled conditions. Shear forces and temperatures above 18 °C can already lead to a phase transition of the binder molecules and, for example, to fibrillation, softening, and / or melting, which significantly affects the flow properties of the powdered binder. Furthermore, a phase transition of the binder can lead to clumping and adhesion of the powder, thus impairing the continuity, consistency, and precision of the binder dosing.

[0055] According to a particularly preferred embodiment, the dosing process is therefore carried out entirely under cooling at preferably < 10 °C and regulated relative humidity to prevent condensation. For this purpose, the dosing system for the binder can be arranged entirely within a cooling tower.

[0056] Preferably, the binder used as the starting material is already stored in the cooling tower to ensure a material temperature of < 10 °C before the binder is fed into the dosing system. The pre-cooled binder can be fed either via a container emptying station or by means of a pressure differential, for example using a vacuum conveying station or a carrier gas.

[0057] The binder can then be transferred from the container, avoiding shear forces, into a vibrating trough or belt conveyor of the first dosing unit. A precisely defined quantity of the binder material is conveyed volumetrically by the vibrating trough or belt conveyor and discharged batchwise via a chute onto a vibrating or shaking screen of the refilling device. The screen continuously separates binder agglomerates, providing a particle fraction of the binder with a predetermined particle size defined by the screen opening. The entire batch of screened binder is collected below the screen in the binder dispenser.Once the sieving process of the batch is complete, the particle fraction of the binder with the predetermined particle size is dropped via a metering flap or other metering element of the binder dispenser into the collection hopper of a second vibrating trough or belt conveyor of the second metering device.

[0058] The sieved binder is gravimetrically dosed into the continuous mixer using the second dosing device. In particular, the invention enables continuous operation of the second dosing device with high dosing accuracy. From the second dosing device, the binder is dosed centrally into a collection hopper of the transfer unit via a cooled pipe element, especially a downpipe. The transfer unit can be coupled to a suitable continuous mixer. The downpipe of the binder dosing system can be arranged to project into the collection hopper of the transfer unit to ensure a central discharge of the binder into the mixer. This prevents the binder from adhering to and building up on the walls of the collection hopper.

[0059] To prevent the binder from adhering to the surfaces of the binder dosing system, additional measures can be taken. These include an adhesion-reducing coating or a mirror-polished finish on the surfaces that may come into contact with the fibrilliant binder, and / or blowing dry air or nitrogen through fine pores in the surface to create an air cushion. Furthermore, individual components of the binder dosing system can be vibrated or moved, for example, using an ultrasonic probe.

[0060] The binder dosing system according to the invention can be coupled to any continuous mixer suitable for the continuous production of electrode compounds.

[0061] The invention therefore also relates to a continuous production system comprising the binder dosing system according to the invention and a continuous mixer. Furthermore, the invention relates to a method for the continuous production of electrode compounds using the production system.

[0062] The production system for manufacturing electrode masses includes, in particular, the binder dosing system described above and a continuous mixer coupled to the second dosing device of the binder dosing system in the conveying direction.

[0063] For example, the continuous mixer can be a kneader, extruder, planetary roller extruder, or multi-shaft extruder, preferably a co-rotating twin-shaft extruder. The production system described here offers the advantage of fully automatic and continuous production of electrode compounds with consistent quality. Preferably, the continuous mixer is an extruder comprising a housing with a front section A, to which, downstream in the conveying direction, a middle section B and a rear section C are successively connected, wherein the front and / or middle section has at least one inlet for a fibrilliant binder and / or other components.

[0064] Electrode components and an outlet with an ejection opening is provided in the rear section.

[0065] The front section A serves in particular to receive and mix the fibrilliable binder and the other components of the electrode mass.

[0066] The extruder can have at least one extruder shaft extending through the housing in the conveying direction and designed to homogenize and knead the electrode mass in the middle section and to fibrillate the binder under the influence of shear forces and heat.

[0067] In the rear section, the housing may have an outlet through which the electrode mass can be discharged from the extruder.

[0068] Regardless of the type of binder dosing system connected to the continuous mixer, the continuous mixer can also have the features described below, which can further improve the continuous production of electrode compounds. Preferably, however, the production system includes a binder dosing system according to one of the aspects described above.

[0069] The invention therefore also relates to a continuous production system for the manufacture of electrode masses with a continuous mixer, which includes at least one of the properties described below.

[0070] According to one aspect of the continuous mixer, the mixer comprises at least one mixing tool, preferably at least one extruder shaft with several mixing and / or conveying elements, which is at least partially or completely made of a plastic or comprises a plastic sheath encasing a metallic core, particularly wherein the plastic is PEEK. The electrode mass conveyed in the continuous mixer exhibits abrasive properties, which can cause excessive wear on mixing tools, especially the mixing and / or conveying elements of the extruder shaft, made of metallic materials. Furthermore, metal chips or particles worn away from the metallic mixing tools can enter the electrode mass and affect its properties.These disadvantages can be easily prevented by using mixing tools, especially mixing and / or conveying elements, made of non-conductive or only slightly conductive plastic.

[0071] Preferably, the continuous mixer is an extruder, and the mixing elements and / or conveying elements, which are at least partially made entirely of a plastic or comprise a plastic jacket, are arranged in the middle section B of the extruder, since the strongest interaction with the electrode masses takes place in this section.

[0072] According to another aspect, the continuous mixer is an extruder, with the outlet in the rear section C formed as a discharge opening designed so that the granular electrode mass can flow away without further compaction.

[0073] Preferably, the discharge opening is thus essentially limited by the inner wall of the bore of the screw cylinder in which the at least one extruder shaft is arranged.

[0074] In simpler terms, the discharge opening represents an open outlet without the usual nozzle plate at the extruder outlet, from which the electrode mass can be ejected in a flaky, granular form.

[0075] This allows the electrode material to exit the extruder without further compression from external forces. Furthermore, the discharge opening defined above prevents a nozzle effect at the extruder outlet. A nozzle effect at the extruder outlet would lead to compression of the electrode material in the rear section C and, due to the abrasive properties of the electrode material, to excessive wear of the mixer. Another aspect of the continuous mixer is the placement of a discharge chute downstream of the discharge opening. This represents a simple and cost-effective technical solution for removing the electrode material and collecting it for further processing.

[0076] According to another aspect of the continuous mixer, particularly the extruder, a counter bearing is provided downstream of the discharge opening, in which at least one extruder shaft is supported. By arranging the counter bearing downstream of the extruder shaft, contact with the abrasive electrode material is prevented. Furthermore, vibrations of the extruder shaft and other mechanical stresses are avoided. Consequently, this arrangement reduces wear on the extruder shaft.

[0077] According to another aspect of the continuous mixer, particularly the extruder, at least one extruder shaft extends to the discharge opening. In other words, the extruder shaft is essentially flush with the discharge opening. This eliminates the need for a counter bearing.

[0078] According to another aspect of the continuous mixer, particularly the extruder, a section of the at least one extruder shaft in the area of ​​the discharge opening has no conveying or mixing elements. As a result, the electrode mass is no longer conveyed and does not come into contact with a counter bearing, but simply exits the mixer through the discharge opening.

[0079] According to another aspect of the continuous mixer, particularly the extruder, at least one of the sections A, B, and C is assigned a temperature module configured to maintain the respective section at a predetermined temperature. Preferably, each section has a temperature module that can be controlled independently of the temperature modules of the other sections. This allows different temperature curves to be operated within the continuous mixer.

[0080] The method for producing electrode masses using the continuous production system comprises in particular the above-described process steps a) to d) of the dosing method according to the invention, as well as the following additional process steps: e) mixing the fibrillable binder with further components of the electrode mass in the continuous mixer to form a mixed electrode mass; and f) processing the mixed electrode mass by fibrillating the fibrillable binder to obtain a granular electrode mass with fibrillated binder.

[0081] This process enables the production of electrode compounds with consistent, high quality because the addition of fibrillable binders is continuous and highly accurate due to process steps a) - d). These dosing steps protect the fibrillable binder from shear forces until it is introduced into the mixer, thus preventing agglomeration and ensuring the binder is dosed into the mixer in a powdered state with a defined particle size and in a constant quantity. During mixing and processing in steps e) and f), the binder then forms fibrils, resulting in a granular electrode compound with fibrillated binder at the end of the process.Such electrode masses are characterized by high mechanical stability, as the fibrillated binder forms a composite structure around the other electrode components and holds them together.

[0082] The other components of the electrode mass include, in particular, an electrode active material and other additives such as conductivity additives.

[0083] The electrode active material can be either a cathode active material or an anode active material. Preferred cathode active materials for the electrode masses include lithium cobalt oxide (LCO), lithium nickel oxide (LNO), lithium nickel cobalt aluminum oxide (NCA), lithium nickel manganese cobalt oxide (NMC), lithium manganese oxide (LMO), lithium iron phosphate (LFP), lithium nickel manganese oxide (LMR), lithium nickel manganese oxide spinel (LNMO), Prussian blue analogues, Prussian welding analogues, in particular (Na₂Fe[Fe(CN)e]), polyanionic compounds, in particular Na₃V₂(PO₄)F₃, and sodium-containing layered oxides, in particular Naₓ[CuyFe₂]₂. z Mn(iyz)]O2 and combinations thereof.

[0084] The anode active material can be selected from the group consisting of carbon-containing materials, soft carbon, hard carbon, natural graphite, synthetic graphite, silicon, silicon suboxide, silicon alloys, lithium, lithium alloys, aluminum alloys, indium, indium alloys, tin, tin alloys, cobalt alloys, niobium pentoxide, titanium dioxide, titanates, for example lithium titanates (Li4Ti50i2 or Li2Ti3O?), tin dioxide, analogous sodium alloys and mixtures thereof.

[0085] Other components of the electrode material include electrical conductivity additives, such as conductive carbon black, conductive graphite, so-called "carbon nanotubes" (CNTs), carbon fibers, and / or graphene. All other commonly used compounds and materials known in the prior art can be employed as further components and additives.

[0086] In the case of solid-state energy storage devices, solid electrolytes can be added to the electrode mass, for example, ceramic, glass-ceramic, polymer-based, or gel-based solid electrolytes, or mixtures thereof. Sulfide and oxide solid electrolytes are particularly commonly used as ceramic solid electrolytes.

[0087] For fully continuous production of the electrode masses, the powdered components can be fed precisely and continuously, independently or together, at various positions in the front section of the extruder. These components can be metered continuously into the extruder either as a premixed powder mixture or as pure powder components. The metering of the powdered components can occur simultaneously at several points in the front section.

[0088] The fibrilliant binder can be dosed into the continuous mixer together with or separately from the other components of the electrode compound. Preferably, the fibrilliant binder is dosed separately and downstream of the other components, and particularly preferably downstream of the conductivity additives, into the continuous mixer. The transfer unit of the binder dosing system described above can be used to dose the binder into the continuous mixer, with the collection hopper of the transfer unit being coupled to the continuous mixer.

[0089] The fibrilliant binder and the other components of the electrode mass added to the front section A are premixed using the extruder shafts, and the premixed electrode mass is conveyed into the middle section B of the extruder.

[0090] In the process zone in the middle section B of the extruder, the individual starting materials are distributed and dispersed together. The electrode active material is embedded in the structure of the electrically conductive additive, creating a kind of coating of the conductive additive around the electrode active material.

[0091] Through the input of mechanical and thermal energy via shear forces and increased process temperature, a phase transformation of the binder molecules is achieved, resulting in the formation of fibrils. This transformation of the binder creates a composite structure with the remaining components of the electrode mass, in which the fibrillated binder finely encapsulates the other components. The degree of fibrillation of the binder can be controlled by the temperature profile in the central section and / or by the type, number, and arrangement of the extruder screw elements. In particular, the screw elements are designed to achieve strong particle-particle interactions in the central section. These interactions exert a high shear force on the fibrillatable binder, leading to accelerated fibril formation.

[0092] In the rear section C of the extruder, the composite structure is processed under cooled conditions into a powdery to granular and flaky electrode dry mass and discharged from the process zone in the rear section C via the discharge opening described above.

[0093] In a subsequent step, the granular electrode mass can be pressed into a layer using a roller calender under pressure and heating, and laminated onto a current collector, for example an aluminum foil or copper foil.

[0094] According to a further aspect of the invention, the method for producing electrode masses according to step f) comprises a quality control procedure with the following process steps g) - i): g) Determining at least one quality-relevant parameter in the obtained electrode mass; h) Comparing the quality-relevant parameter with a predetermined range of values ​​for the quality-relevant parameter, within which properly defined quality-relevant parameters fall; and i) If the comparison shows that the parameter is outside the range of values: Issuing a warning signal; Creating and sending a report in which the parameter lying outside the range of values ​​is highlighted;Adjusting a production-relevant parameter so that the quality-relevant parameter falls within the predefined value range and / or changing a product flow so that the resulting electrode mass is disposed of, whereby, if the comparison shows that the parameter is within the value range: releasing the resulting electrode mass for further processing steps.

[0095] The process steps described here (g) to (i) enable fully automated and continuous monitoring of the electrode material. In the event of anomalies in quality-relevant parameters, the production process can be automatically adjusted. Furthermore, electrode materials with irreparable defects can be automatically disposed of. This saves time and personnel costs.

[0096] The term "quality-relevant parameter" refers to a parameter that represents at least one chemical and / or physical property of the electrode material. Specifically, the quality-relevant parameter is selected from the following group: raw material data; temperature of the electrode material immediately after step f); properties of the electrode material immediately after step f), such as dimensions, shape, color, surface gloss, surface roughness, and / or hardness / softness.

[0097] A "production-relevant parameter" is understood to be a parameter that controls at least one process step in the production of the electrode mass. Preferably, the production-relevant parameter is selected from the group consisting of process parameters of the continuous mixer, such as motor power, torque, and process temperature; process parameters of subsequent steps, in particular the calendering process, such as torque, motor power, contact pressure; and the appearance, thickness, and density of the electrode mass on a current collector.

[0098] The invention is described in more detail below with reference to preferred embodiments and the accompanying drawings, which, however, should not be understood in a limiting sense. The drawings show:

[0099] Figure 1 shows a schematic representation of a binder dosing system according to the invention in a first embodiment;

[0100] Figure 2 shows a schematic representation of the binder dosing system from Figure 1 with a refill control according to a second embodiment;

[0101] Figure 3 shows a schematic representation of the binder dosing system from Figure 1 with a cooling tower according to a third embodiment;

[0102] Figure 4 shows a schematic representation of the binder dosing system from Figure 1 with a cooling tower and a storage room according to a fourth embodiment;

[0103] Figure 5 shows a schematic representation of the binder dosing system from Figure 1 with a container emptying station;

[0104] Figure 6 shows a schematic representation of the binder dosing system from Figure 1 with cooling modules; Figure 7 shows a schematic representation of the binder dosing system from Figure 1 with cooling units;

[0105] Figures 8A to 8E are each schematic representations of a binder dispenser from Figures 1 to 7;

[0106] Figure 9 shows a schematic representation of a production system according to the invention for producing electrode masses with the binder dosing system from Figure 1;

[0107] Figure 10A in a schematic representation of the production system for manufacturing electrode masses from Figure 9 with a cooling tower and a cooling unit according to Figures 3 and 7, Figure 10B in a schematic representation of the production system for manufacturing electrode masses from Figure 9 with a cooling tower and a cooling unit according to Figures 3 and 7, wherein the cooling tower extends to the mixer, and Figure 10C in a schematic representation of the production system for manufacturing electrode masses from Figure 9 with a cooling tower and a cooling unit according to Figures 3 and 7 as well as additional metering devices for the further components of the electrode mass into the continuous mixer;

[0108] Figure 11 shows a schematic representation of a continuous mixer for a production system according to Figures 9 and 10, as well as a temperature-position diagram for the continuous mixer;

[0109] Figure 12 shows a front view of a rear section C of the mixer from Fig. 11, with a sectioning plane AA;

[0110] Figure 13 in a sectional view along the section plane AA from Figure 12;

[0111] Figure 14 shows in perspective the rear section C of the mixer from Figure 12;

[0112] Figure 15 shows a perspective view of the rear section C of the mixer from Figure 12 according to an alternative embodiment, with a section plane BB; Figure 16 shows a sectional view along the section plane BB from Figure 15;

[0113] Figure 17 shows a schematic flowchart of the process steps for a process according to the invention for the continuous dosing of a fibrilliant binder for the production of electrode compounds;

[0114] Figure 18A shows a schematic flowchart of the process steps for a continuous dosing process according to Figure 12 with a refill cycle, and Figures 18B and 18C show a dosing cycle for the first dosing device, the second dosing device and the refill device;

[0115] Figure 19 shows a schematic flowchart of the process steps for a process according to the invention for producing electrode masses; and

[0116] Figure 20A and Figure 20B are electron micrographs of a mixed electrode mass with fibrillated binder on a current collector.

[0117] Figure 1 shows a binder dosing system 10 for the continuous dosing of a fibrilliant binder for the production of electrode compounds.

[0118] The binder dosing system 10 comprises a first dosing device 12, a second dosing device 14 and a refilling device 16, which connects the first and second dosing devices 12, 14 in the conveying direction 18.

[0119] The first metering device 12 is configured to volumetrically meter a powdered fibrilliant binder 20 into the refilling device 16. For this purpose, the first metering device 12 comprises a first storage container 22 which can be filled with fibrilliant binder 20.

[0120] The first storage container 22 can, for example, be designed as a funnel-shaped collection container. In particular, the first storage container 22 is designed to hold a volume of 50 to 100 liters, where this volume corresponds to approximately 10 to 25 kg of a fibrillable binder with a density of 0.3 to 0.6 kg / l. Consequently, the first storage container 22 serves as a material storage unit for a complete container of fibrillable binder. The first storage container 22 can also be equipped with a vibration unit (not shown here), for example, an ultrasonic probe, which can cause the first storage container 22 to vibrate.

[0121] Below the first storage container 22, a vibrating trough 24 is arranged, which can volumetrically meter the fibrilliant binder 20 from the first storage container 22 into the refilling device 16 by means of vibration or oscillation, while avoiding shear forces. In this respect, the first metering device 12 is designed as a volumetric metering unit. Alternatively, a belt metering unit can be used instead of the vibrating trough 24.

[0122] The refilling device 16 is provided below the first metering device 12 or downstream in the direction of flow, wherein the refilling device 16 is designed to refill fibrilliable binder 20 from the refilling device 16 into the second metering device 14.

[0123] The refilling device 16 comprises a separating unit 26 and a binder dispenser 28, wherein the separating unit 26 is arranged between the first dosing device 12 and the binder dispenser 28. Consequently, the binder dispenser 28 is arranged below the separating unit 26 and above the second dosing device 14.

[0124] The separation unit 26 is configured to remove a coarse fraction containing binder agglomerates from the binder stream and to provide a particle fraction of the binder 20 consisting of particles with a predetermined particle size, so that the refilling device 16 refills only the particle fraction with the predetermined particle size into the second metering device 14. Furthermore, a binder residue container (not shown) can be provided to collect the coarse fraction of the binder discharged by the separation unit 26.

[0125] For this purpose, the separation unit 26 has a motor 32 coupled to a separation element 30, which is designed to vibrate the separation element 30 so that binder 20 falling onto the separation element 30 from the first metering device 12 can be separated according to the particle fraction with the predetermined particle size.

[0126] Preferably, the separating element 30 is a vibrating screen or shaking screen with a mesh size of 1 to 4 mm. The binder dispenser 28 is configured to collect the particle fraction with the predetermined particle size before the particle fraction is refilled from the binder dispenser 28 into the second metering device 14.

[0127] As can be seen in Figure 1, the binder dispenser 28 comprises a collection container 34 and a metering element 36, which together with the collection container 34 defines a common collection chamber 38 for the particle fraction to be collected with the predetermined particle size.

[0128] Exemplary embodiments of the binder dispenser 28 are shown in Figures 8A to 8E.

[0129] In the embodiments according to Figures 8A and 8B, the collection container 34 forms a receptacle for the binding agent 20 to be collected, wherein a lower side of the collection container 34 can be closed by the metering element 36 in the form of a metering flap.

[0130] As can be clearly seen in Figures 8A and 8B, the metering flap 36 forms the bottom of the collection chamber 38 when the binder dispenser 28 is closed. Opposite the bottom, an opening is provided through which the particle fraction with the predetermined particle size can fall from the separation unit 26 into the binder dispenser 28. When the binder dispenser 28 is closed, the metering element 36 therefore forms a physical barrier between the first metering device 12 and the second metering device 14.

[0131] The two embodiments of the binder dispenser 28 in Figures 8A and 8B differ only in the suspension of the metering element 36. In Figure 8A, the metering flap 36 rotates about an axis 40, which is formed laterally as a component of the side wall of the collection container 34, whereas in Figure 8B, the metering flap 36 rotates about an axis 40 that runs centrally through the collection chamber 38.

[0132] The metering element 36 can also be designed as a metering scoop. This is shown schematically in Figure 8C. Specifically, two metering scoops form a cup-shaped receptacle for the binder to be collected. To release the binder, the metering scoops are moved laterally or folded away, creating an opening through which the binder can fall into the second metering device 14.

[0133] It is also conceivable, as shown in Figure 8D, that the metering element 36 is designed as a metering slide. The metering slide can be plate-shaped, for example in the form of a disc, and form a flat collecting surface for the binder. The binder can be released by sliding the metering slide laterally.

[0134] According to Figure 8E, the metering element 36 can also be designed as a metering flap similar to that in Figure 8A, but with the difference that a wall section of the collection container 34 is extended downwards towards the second metering device 14. A downwardly tapered collecting chamber 38 is therefore formed between the metering flap and the extended wall section.

[0135] The binder dispenser 28 can also be equipped with a vibration unit (not shown here), for example an ultrasound probe that can vibrate the binder dispenser 28.

[0136] As further shown in Fig. 1, the second metering device 14 is provided below the refilling device 16, in particular below the binder dispenser 28, and is designed to continuously, gravimetrically meter the fibrilliable binder 20 into a continuous mixer (not shown here).

[0137] The second dosing device 14 comprises a second storage container 42, into which the fibrilliant binder 20 is refilled from the binder dispenser 28. Preferably, the second storage container 42 is designed to hold a volume of 1 to 20 L, corresponding to a quantity of 0.25 to 5 kg of binder. In principle, the dimensions of the second storage container are adapted to the overall throughput of the production system.

[0138] The second storage container 42 can further be equipped with a vibration unit (not shown here), for example, an ultrasonic probe, which can vibrate the second storage container 42. A gravimetric vibrating trough 44 is provided below the second storage container 42, which is configured to gravimetrically and continuously dose the fibrilliant binder 20 from the second storage container 42 into a continuous mixer (not shown here) while avoiding shear forces. Preferably, the gravimetric vibrating trough 44 is configured to enable a throughput of 0.5 to 100 kg per hour of fibrilliant binder 20. A belt conveyor can be used instead of the vibrating trough 44.

[0139] Furthermore, the gravimetric vibrating trough 44 is equipped with a scale 46, which can be used to record the weight loss per unit of time of fibrillable binder 20 in the second storage container 42. The scale 46 is configured to record the total quantity of binder 20 in the second storage container 42.

[0140] The scale 46 is connected to a gravimetric dosing controller 48 for information exchange. The controller is configured to continuously adjust a dosing parameter of the vibrating feeder 44 to ensure a constant material discharge from the vibrating feeder 44. For this purpose, the gravimetric dosing controller 48 receives the weight loss per unit of time as an actual value from the scale 46. The gravimetric dosing controller 48 compares the received actual value with a stored target value. If there is a deviation between the actual and target values, the gravimetric dosing controller 48 modifies a dosing parameter of the vibrating feeder 44 so that the actual value approaches the stored target value. Target and actual ranges can also be used instead of fixed values.

[0141] The vibration intensity or frequency of the gravimetric vibrating trough 44 can be used as a dosing parameter, for example. In this respect, the gravimetric dosing control 48 is designed as a closed-loop control unit.

[0142] The binder dosing system 10 according to the invention additionally comprises a cooling device, which is not shown in Figure 1 for the sake of clarity. The cooling device is explained further below with reference to Figures 3 to 7. Figure 2 shows the binder dosing system 10 from Figure 1, with the difference that a refill control unit 50 is also provided, which is connected to the first dosing device 12, the second dosing device 14 and the refill device 16 for information exchange.

[0143] In particular, the refill control 50 is connected to the gravimetric dosing control 48 of the second dosing device 14 via an information exchange mechanism, enabling it to receive a control signal from the gravimetric dosing control 48. The refill control 50 can then control the first dosing device 12 and the refill device 16 to initiate a refill cycle, thereby supplying the second dosing device 14 with fibrillable binder 20. The refill cycle is described in detail below.

[0144] To improve the flow properties of the fibrilliant binder 20 and thus the dosing accuracy of the binder dosing system 10, it is advantageous to cool the aforementioned devices 12, 14, 16 and to provide an ambient climate with low humidity, as shown in the following description of the embodiments according to Figures 3 to 7. A combination of the individual embodiments is also within the scope of the invention.

[0145] Figure 3 shows the binder dosing system from Figure 1 with a cooling device 51, wherein the binder dosing system is completely enclosed in a cooling tower 52.

[0146] The cooling tower 52 comprises a cooling housing 54, which completely surrounds the binder dosing system 10 and thus encapsulates it from the environment. Within the cooling housing 54 is a cooling chamber 56, which directly surrounds the binder dosing system 10 and is in temperature and climatic contact with it. The cooling chamber 56 has an ambient temperature of 1–18°C, preferably 5–15°C, and most preferably 4–10°C.

[0147] For cooling, a temperature control unit 58 is provided on the cooling housing 54, which is configured to regulate the ambient temperature within the cooling chamber 56. Furthermore, an air conditioning unit 60 can be provided in addition to or as an alternative to the temperature control unit 58. This air conditioning unit is also arranged on the cooling housing 54 and is configured to regulate the ambient climate within the cooling chamber 56, in particular the humidity. It is also conceivable that the temperature control unit 58 and the air conditioning unit 60 are combined into a single unit.

[0148] Particularly preferably, the humidity inside the cooling chamber 56 has a dew point below 0°C, particularly preferably -10°C, most preferably -20°C.

[0149] Since the devices 12, 14, 16 are not hermetically sealed off from the cooling chamber 56, the ambient temperature and climate inside the cooling chamber 56 also correspond to the temperature and climatic conditions inside the aforementioned devices.

[0150] Figure 4 also shows the binder dosing system from Figure 1, which, as in Figure 3, is enclosed in a cooling tower 52. In contrast to Figure 3, Figure 4 additionally shows a storage chamber 62, which forms part of the cooling chamber 56 and is therefore also surrounded by the cooling housing 54.

[0151] Storage space 62 contains only the first dosing device 12 and several containers 64 with fibrilliant binder 20. The refilling device 16 and the second dosing device 14 are arranged in a side arm of the cooling housing 54, which extends downwards from storage space 62 and in the conveying direction 18.

[0152] Advantageously, container 64 containing fibrilliant binder 20 stored in storage room 62 can be tempered to a predetermined temperature before being fed into the binder dosing system 10.

[0153] The container 64, stored in storage room 62, can be fed into the first dosing device 12 via a conveying station 66. The conveying station 66 can be a simple hatch that can be manually filled with the container 64 using a transport cart 68 that moves within the storage room. The conveying station 66 can also be fully automatic, for example, as a container emptying station 70 or a vacuum conveying station (not shown here). In the first case, the emptying of the containers 64 can be carried out via a container emptying station 70 designed as a belt feeder 72. This embodiment is shown in Figure 5.

[0154] Figure 6 also shows the binder dosing system 10 from Figure 1, wherein the cooling device 51 comprises several cooling modules 74 instead of a single cooling tower 52. In principle, each cooling module 74 has the same structure as the cooling tower 52 from Figure 3. In this respect, reference is made to the preceding description.

[0155] Unlike cooling tower 52, the individual cooling modules 74 do not surround the entire binder dosing system 10, but rather each surrounds the various devices 12, 14, 16 individually. Only the connections between the individual devices are left untouched by the cooling modules 74. This offers the advantage that each device of the binder dosing system can be cooled separately from the others. Furthermore, the climatic conditions can be regulated independently of one another.

[0156] Another cooling device 51 is shown in Figure 7, in which the individual devices 12, 14, 16 are each provided with a cooling unit 75.

[0157] Each cooling unit 75 comprises a cooling jacket 76 equipped with a coolant inlet 78 and a coolant outlet 80. The cooling units 75 can each be connected to a common cooling circuit (not shown here), from which a coolant can flow through the various cooling units and thus temper them to a predetermined temperature. Alternatively, the cooling units 75 can each be connected to separate cooling circuits in order to cool and / or air-condition the respective cooling units 75 independently of one another and optionally under different conditions. For example, the cooling units 75 can each be assigned to the first storage tank 22, the second storage tank 42, the collection tank 34, and the separation unit 26.

[0158] Furthermore, the cooling units 75 can also be assigned to the pipe elements 82, which each connect the first metering device 12 with the refilling device 16 and the refilling device 16 with the second metering device 14. A pipe element 82 downstream of the second metering device 14 can also be equipped with a cooling unit 75, whereby the binder 20, metered gravimetrically from the second metering device 14, is also cooled before it enters a continuous mixer.

[0159] Suitable cooling units 75 include, for example, cooling sleeves which can enclose the aforementioned components at least partially, preferably completely.

[0160] Figure 9 shows a production system 84 for manufacturing electrode compounds, with the binder dosing system 10 from Figure 1 and a continuous mixer 86. The continuous mixer 86 is coupled to the second dosing device 14 in the conveying direction 18, which continuously supplies the mixer 86 with binder 20. The cooling device 51 is not shown here for the sake of clarity.

[0161] The continuous mixer 86 shown in Figure 9 is an extruder. Preferably, the continuous mixer 86 is a co-rotating twin-shaft extruder. The construction of the mixer 86 is described below.

[0162] A transfer unit 88 is provided between the second metering device 14 and the continuous mixer 86, which includes at least one collecting hopper 90 and a vibration unit 92 coupled to the collecting hopper 90.

[0163] The vibration unit 92 is configured to vibrate the collecting hopper 90 during the transfer of fibrillatable binder 20 from the second metering device 14 into the continuous mixer 86. A pipe element 82 (not shown here) can also be used instead of a collecting hopper 90. Preferably, the vibration unit 92 includes an ultrasonic probe.

[0164] Figure 10A shows a production system 84 for manufacturing electrode compounds according to a preferred embodiment, wherein the binder dosing system 10 according to the embodiment of Figure 4 has a storage chamber 62 which, together with the rest of the binder dosing system 10, is enclosed in a cooling tower 52. In addition, a cooling unit 75 is provided, which is associated with a pipe element 82 that connects the vibrating trough 44 of the second dosing device 14 in the conveying direction 18 with the collecting hopper 90 of the transfer unit 88 and preferably projects centrally into the collecting hopper 90. In this way, cooling of the fibrillated binder 20 can be ensured all the way into the collecting hopper 90.

[0165] Alternatively, the production system 84 for manufacturing electrode masses can be configured as shown in Figure 10B. In contrast to Figure 10A, the transfer unit 88 with the collecting hopper 90 is also enclosed by the cooling tower 52. The cooling tower 52 therefore extends to the mixer 86.

[0166] The other components for the electrode mass 94 can be added by means of at least one additional metering device 200, which also opens into the collecting funnel 90. This embodiment is shown in Figure 10C.

[0167] For example, the other components can be selected from the group consisting of cathode active material, anode active material and conductivity additives.

[0168] The additional dosing devices 200 can be constructed similarly to the binder dosing system 10. Preferably, these comprise a first and / or a second dosing device as described above for the binder dosing system 10. In this respect, reference is made to the description above. A refilling device and a cooling unit can be omitted for shear-insensitive materials such as cathode active material, anode active material, and conductivity additives. The collection hopper 90 can be closed with a lid 202, which has individual openings 204 for the various dosing devices 10, 200.

[0169] Furthermore, the collection funnel 90 is fluidically connected to a self-cleaning aspiration unit 206, which is designed to extract exhaust air 208 from the collection funnel 90.

[0170] Furthermore, the aspiration unit 206 can be configured to create a negative pressure in the collection hopper 90. This improves the conveyance of binder from the binder dosing system 10 into the collection hopper 90. Preferably, the binder dosing system 10 opens centrally into the collection hopper 90 via a preferably cooled downpipe 82, and the additional dosing devices 200 for the further electrode components 94 are arranged around the downpipe 82. Particularly preferably, the opening of the downpipe 82 is positioned directly above the outlet of the collection hopper 90.

[0171] The additional dosing devices 200 for the further electrode components 94 also lead into the collecting funnel 90 via a downpipe 82.

[0172] The fibrilliant binder 20 can be dosed into the continuous mixer 86 via an inlet 96 after the transfer unit 88 together with the other components 94.

[0173] According to an alternative embodiment, the fibrilliant binder 20 is introduced into the continuous mixer via a separate collecting hopper 90, which is preferably arranged downstream of the collecting hopper 90 for the additional dosing devices 200 associated with the other components 94. Such an embodiment is shown schematically in Fig. 11.

[0174] In the continuous mixer 86, the fibrillable binder 20 is mixed and processed with the other components 94 of the electrode mass, in particular homogenized, kneaded, fibrillated, and granulated, thereby obtaining the granular electrode mass with fibrillated binder 98, which can be discharged from the mixer 86 via an outlet 100. The outlet 100 of the continuous mixer can be coupled to a quality control unit 101, which is configured to check the quality of the electrode mass with fibrillated binder 98 and optionally to influence the dosing and / or manufacturing process. The operation of the quality control unit 101 is described in more detail below.

[0175] Alternatively, the electrode mass with fibrillated binder 98, which has not passed quality control or is generated as a waste product of a subsequent process, can be dosed via an additional dosing device 200 through an inlet 96 into the continuous mixer 86 and processed with the binder 20 and the other components 94 to form a fresh electrode mass with fibrillated binder 98.

[0176] Furthermore, the production system 84 according to Figures 10A to 10C can include additional elements to achieve the most precise possible dosing of the binder 20 into the continuous mixer 86.

[0177] For example, several bellows 102 can be provided, each arranged between the first dosing device 12 and the refilling device 16, and between the refilling device 16 and the second dosing device 14. Furthermore, bellows 102 are located between the separation unit 26 and the binder dispenser 28, and between the second dosing device 14 and the transfer unit 88. The bellows 102 serve to vibratorily decouple the aforementioned components from one another in order to ensure the smoothest possible dosing by means of the first and second dosing devices 12 and 14.

[0178] Furthermore, after the vibrating channels 24, 44 in the conveying direction 18, only vertically running pipe elements 82 extend in order to avoid constrictions and dead spaces for the deposition of binder 20.

[0179] The inner walls of the pipe elements 82 and of the individual aforementioned devices 12, 14, 16 can be at least partially, preferably completely, provided with a coating in order to achieve the best possible flow behavior of the binder 20 within the binder dosing system 10. If, for example, the binder is PTFE, a coating made of or based on PTFE is particularly preferred.

[0180] The product-contacting surfaces of the devices 12, 14, 16 and optionally the transfer unit 88 can be designed as mirror-polished surfaces. Furthermore, the containers and pipe elements of the devices 12, 14, 16 can be equipped with vibration elements such as ultrasonic probes (not shown) to gently and with minimal shearing remove any adhesion of the binding agent.

[0181] Furthermore, the containers and pipe elements of the devices 12, 14, 16 can each have inner walls with a plurality of openings through which a gas flow can be generated along the inner walls. This provides a gas cushion to prevent deposits from forming on the inner walls. The gas can be selected from the group consisting of nitrogen, air, and combinations thereof. The gas is preferably dry.

[0182] Furthermore, a binder residue container 104 can be assigned to the separating element 30, in which coarse-grained binder residues, in particular clumps and agglomerates, are collected that do not correspond to the particle fraction of the binder with a predetermined particle size and have been removed from the binder stream. These can be processed and fed back to the first metering device 12.

[0183] The following section describes in more detail the construction of the continuous mixer 86 with reference to Figure 11, which in the embodiments shown is designed as an extruder.

[0184] As explained above, the fibrilliant binder 20 and the other electrode components 94 are introduced via an inlet 96 on the housing 106 of the mixer 86, which extends in the conveying direction 18 from the inlet 96 to the outlet 100. The housing 106 has a tubular shape and includes at least one extruder shaft 108, preferably two co-rotating extruder shafts 108, which extend parallel to the conveying direction 18 over the entire length of the housing 106. The mixer 86 is preferably modularly constructed from several module housings arranged one behind the other. In particular, the mixer has between 8 and 14 module housings.

[0185] The outlet 100 is also fluidically connected to the quality control unit 101, from which the electrode mass can be conveyed further in conveying direction 18 after passing quality control (Fig. 10A). A further conveying direction branches off to the side, leading into a disposal container 110, into which electrode masses that have not passed the quality control of the quality control unit 101 can be disposed of. Alternatively, the electrode mass with fibrillated binder 98 that has not passed quality control can be added back to the process.

[0186] The inlet 96 is located in a front section A of the continuous mixer 86. Downstream of the front section A of the mixer 86, a middle section B and a rear section C follow successively in the conveying direction 18, with the outlet 100 being located in the rear section C.

[0187] The binder 20 and the other components 94 of the electrode mass can optionally be introduced via an additional inlet 96, which is also provided in the front section A. For example, the binder 20 can be dosed separately, i.e., separately from the other components 94. Alternatively or additionally, the components 94 or the binder 20 can also be added via a separate inlet (not shown here) in the middle section B. This addition can be made, for example, via a separate side feeder with side filling. Return of the electrode mass containing fibrillated binder 98, which has failed quality control or is generated as rejects from downstream process steps, preferably takes place in sections B or C of the continuous mixer 86.

[0188] Particularly preferably, the different sections A, B, and C are independently temperature-controlled, for example by temperature modules (not shown here). This is shown schematically in the lower section of Figure 11, which shows a temperature-process position diagram that essentially represents the temperature profile of the mixer 86 shown in Figure 11.

[0189] Preferably, the temperature Ti in the front section A is between 10 and 250°C. In particular, the temperature Ti is chosen such that the fibrilliant binder 20 has not yet formed a continuous fibril network around the other electrode components 94. In this section, the fibrilliant binder 20 is mixed with the other components 94 of the electrode mass.

[0190] Preferably, the temperature T2 in the central section B is in the range of 50–250°C. In particular, the temperature is selected such that the fibrillable binder 20 forms a fibril network. In this section, the other components 94 of the electrode mass are kneaded with the fibrillable binder 20 to form an electrode mass with fibrillated binder 98. As shown in Figure 11, the temperature in section B is particularly preferably equal to or higher than the temperature in section A, i.e., T2 > T1.

[0191] Preferably, the temperature T3 in the rear section C is lower than the temperature in section B. For example, the temperature in the rear section C can be cooled to a temperature range of -20 to 30°C. In this case, the temperature T3 in section C is lower than the temperature T2 in section B. Most preferably, T3 is also lower than Ti. This allows for a particularly manageable consistency of the mixed electrode mass with fibrillated binder 98, which is suitable for further processing.

[0192] The following section explains in more detail the output 100 in the rear section C of mixer 86.

[0193] Figure 12 shows the front view of the rear section C, which is provided with a counter bearing 118 for holding the extruder shaft 108. A cross-sectional view and a perspective view of the rear section C are also shown in Figures 13 and 14, which are explained below. The housing 106 comprises two interconnected housing bores 119 that extend through the mixer 86 in the conveying direction. Each housing bore 119 receives an extruder shaft 108, which is equipped with a plurality of conveying and mixing elements 120 that convey and process the electrode mass.

[0194] Furthermore, the housing 106 has a discharge opening 122 forming the outlet 100, through which the electrode mass can be discharged from the mixer 86. In the illustrated embodiment, the discharge opening 122 extends in a closed, frame-like manner around the two extruder shafts 108.

[0195] In the area of ​​the discharge opening 122, in particular downstream of the discharge opening 122, the extruder shaft 108 is freed in a section 124 from conveying and mixing elements 120.

[0196] Furthermore, a discharge chute 126 is formed downstream of the discharge opening 122. This chute is fluidically connected to the discharge opening 122 and extends radially away from it. The granular electrode mass can leave the mixer 86 via the discharge chute 126 (indicated by the dashed line) by trickling downwards. The discharged electrode mass can be collected, for example, in a collection container (not shown here).

[0197] At least one extruder shaft 108 has an extruder head 128 at its free end, which is supported by a mandrel 130 in a mandrel holder 132. The mandrel holder 132 is fastened in the counter bearing 118 via bearings 134.

[0198] Alternatively, the counter bearing 118 can be omitted, as shown in Figure 15.

[0199] According to the embodiment shown in Figure 15, the housing 106 of the mixer 86 ends immediately after a conveying section 136, through which the electrode mass is moved through the mixer 86 in the conveying direction. The two extruder shafts 108 are essentially flush with the discharge opening 122, which surrounds the two extruder shafts 108 in an annular manner. Therefore, the conveyed electrode mass can exit the mixer 86 unhindered at the end face via the discharge opening 122. The discharge opening 122 is explained in more detail in Figure 16. Specifically, the discharge opening 122 is designed so that the granular electrode mass can be discharged from the outlet 100 in a flaky, granular form without further compaction. The outlet 100 is thus open, without the otherwise usual die plate at the extruder outlet.

[0200] According to the embodiment shown in Fig. 16, the discharge opening 122 is essentially limited by the inner wall 140 of the housing bore 119, i.e. the bore of the screw cylinder in which the at least one extruder shaft 108 is arranged.

[0201] Next, a method for the continuous dosing of a fibrilliant binder 20 for the production of electrode masses is explained with reference to Figure 17.

[0202] The fibrilliant binder 20 can be selected from the group consisting of polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and high-molecular-weight polyethylene (PE), as well as combinations thereof. The fibrilliant binder polytetrafluoroethylene is particularly preferred.

[0203] In a first step S1, the powdered fibrilliant binder 20 is provided in a first dosing device 12. For example, the fibrilliant binder 20 can be taken from a container 64 and placed into the first dosing device 12. This can be done manually or semi-automatically, or fully automatically using a conveying station 66.

[0204] In a subsequent step S2, the fibrilliant binder 20 is volumetrically metered from the first metering device 12 into the refilling device 16. Preferably, the volumetric metering is carried out by means of the vibrating trough 24, which oscillates with a constant vibration intensity and / or a constant vibration frequency, thereby ensuring a consistent material discharge from the first metering device 12.

[0205] In step S3, the fibrilliant binder 20 is then refilled from the refilling device 16 into a second metering device 14. This step S3 preferably includes the refilling device 16 providing the particle fraction of the binder consisting of particles with a predetermined particle size by means of a separation unit 26, wherein the refilling device 16 only refills the particle fraction with the predetermined particle size into the second metering device 14.

[0206] Furthermore, step S3 can include a collection step that follows the preceding separation step and in which the particle fraction with the predetermined particle size is collected in the binder dispenser 28 before the particle fraction is refilled from the binder dispenser 28 into the second dosing device 14.

[0207] The S3 step is particularly preferably carried out only if a predetermined amount of the particle fraction has been collected in the binder dispenser 28.

[0208] The binder dispenser 28 most preferably refills a discrete amount of the particle fraction into the second metering device 14 by means of the metering element 36, in particular the metering flap.

[0209] After step S3, in step S4 the fibrillable binder 20 is gravimetrically and continuously dosed from the second dosing device 14 into the continuous mixer 86.

[0210] Alternatively, a transfer step can be carried out in step S4, in which the fibrilliable binder 20 is transferred to the continuous mixer 86 by means of the transfer unit 88.

[0211] At least one of the preceding steps S1 to S4 takes place under cooling, in particular at an ambient temperature of 1–18°C, preferably 5–15°C, and most preferably 4–10°C. According to a particularly preferred embodiment, all of the aforementioned steps take place under cooling.

[0212] Particularly preferably, the humidity during steps S1 - S4 has a dew point of less than 0°C, particularly preferably less than -10°C, most preferably less than -20°C.

[0213] Optionally, step S4 can be followed by a refill cycle with steps S5 to S7, which is explained below with reference to Figure 18A. In step S5, a weighing step is carried out by the scale 46, in which a weight value of the fibrilliant binder 20 in the second dosing device 14, in particular in the second storage container 42, is continuously determined.

[0214] Next, in step S6, it is determined whether the measured weight value is lower than a predetermined target value stored in the refill control unit 50. This target value could, for example, be a predefined fill level value of the second dosing device 14. If this value is not reached, step S7 is performed, which involves the output of a control signal from the refill control unit 50 to the refill device 16 and / or the first dosing device 12, thereby triggering steps S2 and / or S3.

[0215] During step S3, after the separation unit 26 has provided the particle fraction of the binder from particles with a predetermined particle size and a predetermined quantity of the particle fraction has been collected in the binder dispenser 28, step S5 is suspended and step S4 continues in volumetric mode for a short period. During this period, the metering element 36 of the binder dispenser 28 is opened and the discrete quantity of the particle fraction collected on the metering element is emptied all at once into the second metering device 14. This prevents interference with the weighing signal of the balance 46. Subsequently, the balance 46 is recalibrated, weighing step S5 is resumed, and the second metering device 14 is operated again in gravimetric mode in step S4.

[0216] These steps ultimately lead to step S4 being carried out continuously with high dosing accuracy.

[0217] Alternatively and / or additionally, the refill cycle can be carried out at regular time intervals.

[0218] According to a further embodiment, steps S2 to S4 can each be executed via a predefined dosing cycle. This cycle can be set in advance. Consequently, it is no longer necessary for the refill cycle to be actively controlled by the refill controller 50 as shown in Figure 18A. Instead, the first and second dosing devices 12, 14 and the refill device 16 can operate independently of each other without requiring adjustment by the refill controller 50.

[0219] Figure 18B shows a dosing cycle 112 for the first dosing device 12, a dosing cycle 114 for the refilling device 16 and a dosing cycle 116 for the second refilling device 14.

[0220] The dosing cycle 112 for the first dosing device 12 alternately comprises step S2, i.e., the dosing of binder into the refilling device 16, and step S2a, in which the first dosing device 12 is switched off or placed in standby mode. Step S2 is performed within a predefined time interval h, and step S2a within a predefined time interval t2. In the example shown, h and t2 are approximately the same length. However, t2 can also be greater than or equal to h, in which case step S2a can be performed over several minutes and step S2 over less than one minute.

[0221] The dosing cycle 114 for the refilling device 16 alternately comprises step S3, i.e., refilling binder into the second dosing device 14, and step S3a, in which the refilling device 16 is switched off or placed in standby mode. Step S3 is carried out within a predefined time interval t4 and step S3a within a predefined time interval t3.

[0222] The time interval t4 is shorter than the time interval t3. Preferably, the time interval t4 lasts no more than 20% of the time interval t2, more preferably no more than 10%, and most preferably no more than 5%. In particular, S3 can be carried out within a few seconds.

[0223] Furthermore, steps S3 are performed between steps S2 and during steps S2a. Preferably, step S3 is performed at approximately the time interval t2 / 2. Therefore, step S3a is performed during step S2.

[0224] The dosing cycle 116 for the second dosing device 14 alternately comprises step S4, i.e., the gravimetric dosing of binder into the mixer 86, and step S4a, in which the refilling device 16 is switched from gravimetric dosing mode to volumetric dosing mode. Step S4 is performed in a predefined time interval ts and step S4a in a predefined time interval te. During the initial commissioning of the second dosing device 14, step S4b is performed once, in which the second dosing device 14 is completely switched off.

[0225] Steps S4 and S4a are essentially complementary to steps S3 and S3a. This means that step S4 is executed in parallel with step S3a. Furthermore, step S4a is only executed if step S3 is also executed in parallel. The time interval t4 is essentially the same as the time interval t3, and the time interval te is essentially the same as the time interval t4. Thus, step S4a can be executed in a few seconds, and step S4 can be executed over several minutes.

[0226] Figure 18C shows an alternative design for the dosing cycles 112, 114 and 116.

[0227] In contrast to the dosing cycle 112 in Figure 18B, the time interval t2 is now longer than the time interval ti. Preferably, the time interval t2 is at least twice as long as the time interval ti.

[0228] The dosing cycle 114 performs step S3 during step S2a of the dosing cycle 112, but no longer at t2 / 2, but approximately at t2 / 4.

[0229] The dosing cycle 116 is no longer complementary to the dosing cycle 114. Instead, step S4a has a time interval t6 that is longer than the time interval t4 of step S3. Furthermore, steps S4a and S3 are coordinated such that step S3 is performed immediately before step S4, i.e., at the end of the time interval te.

[0230] Figure 19 schematically shows the process steps for producing the granular electrode masses with fibrillated binder 98. The first steps S1 to S4 correspond to the preceding steps according to Figure 17, so reference is made to the above description. For the sake of clarity, the refill cycle and the dosing cycle are not shown. However, it is understood that the refill cycle or the dosing cycle can also be carried out here as described above. Step S4 is followed by step S8, in which the fibrillable binder 20 is mixed with further components 94 of the electrode mass in the continuous mixer 86.

[0231] The remaining components 94 comprise an electrode active material as well as further additives such as conductivity enhancers and combinations thereof. Reference is made to the description above in this respect.

[0232] Subsequently, the components 94 mixed with the binder 20 are homogenized in step S9 by means of the extruder shaft 108. A homogenized electrode mass with a fibrilliant binder is obtained. Preferably, steps S8 and S9 take place in the front section A of the mixer or extruder 86. Particularly preferably, steps S8 and S9 are carried out at a temperature Ti of 10–250°C.

[0233] Subsequently, step S10 is carried out, in which the homogenized electrode mass is kneaded with a fibrillable binder. For this purpose, the extruder shaft 108 in section B can have polygonal elements in addition to shaft elements. Through kneading and the particle-particle interactions that occur during this process, the fibrillable binder forms a continuous fibril network in the electrode mass, and an electrode mass with fibrillated binder 98 is obtained. Preferably, step S10 takes place in the central section B of the mixer 86. Particularly preferably, step S10 takes place at a temperature T2 between 50 and 250°C. Most preferably, the temperature T2 in step S10 is higher than the temperature Ti in steps S8 and / or S9.

[0234] Next, in step S11, the electrode mass is prepared with fibrillated binder 98 for further processing. Step S11 preferably takes place in the rear section C of the mixer 86. Here, the electrode mass with fibrillated binder 98 is granulated by the extruder shaft or processed into a powdery, flaky, or granular electrode mass.

[0235] It is particularly preferred that step S11 is carried out under cooled conditions at a temperature T3 in the range of -20 to 30°C. It is particularly preferred that step S11 is carried out at a lower temperature T3 compared to the temperature T2 in step S10. It is also particularly preferred that step S11 is carried out at a temperature T3 that is lower than the temperature T2 in steps S8 to S10.

[0236] Finally, in step S12, the granular electrode mass with fibrillated binder 98 is discharged from the mixer 86 via the outlet 100.

[0237] Optionally, after step S12, a quality control check can be carried out by the quality control unit 101, encompassing steps S13 to S17.

[0238] In step S13, at least one quality-relevant parameter of the obtained electrode mass 98 is recorded, for example by an optical system, in particular by IR spectroscopy.

[0239] Alternatively, other imaging techniques can be used, such as light microscopy.

[0240] In the next step (S14), the recorded quality-relevant parameter is compared with a predetermined value range for the quality-relevant parameter, within which properly defined quality-relevant parameters fall. This predefined value range can be empirically determined in advance using experimental data.

[0241] In step S15, the comparison is then evaluated. This evaluation can be performed, for example, using a database containing the required parameters. These parameters can be determined beforehand through empirical experiments. If the comparison reveals that the quality-relevant parameter is outside the defined range: a warning signal is issued; a report is generated and sent, highlighting the parameter that is outside the defined range; a production-relevant parameter is adjusted so that the quality-relevant parameter falls within the predefined range; and / or a product flow is modified so that the electrode material is disposed of. If the comparison reveals that the parameter is within the defined range: the electrode material 98 is released for further processing steps.

[0242] Depending on the comparison, either step S16 can be carried out in the first case, in which the electrode mass 98 is directed into a disposal container 110 and removed from the process, or step S17 can follow in the second case, in which the electrode mass with fibrillated binder 98 is released for the further processing steps.

[0243] Figures 20a and 20b show electron micrographs of the granular electrode mass with fibrillated binder 98. The fibrils or fibril network of the binder 20 are visible, extending around the individual components of the electrode in a spiderweb-like fashion and connecting them together.

Claims

Patent claims 1. Binder dosing system (10) for the continuous dosing of a fibrilliant binder (20) for the production of electrode compounds, comprising a first dosing device (12), a second dosing device (14), and a refilling device (16) connecting the first and second dosing devices (12, 14) in the conveying direction (18), wherein the first dosing device (12) is configured to volumetrically dose the fibrilliant binder (20) into the refilling device (16), wherein the refilling device (16) comprises a separation unit (26) that provides a particle fraction of the fibrilliant binder (20) consisting of particles with a predetermined particle size, and wherein the refilling device (16) is configured to refill the particle fraction of the fibrilliant binder (20) consisting of particles with a predetermined particle size into the second dosing device (14), and wherein the second The dosing device (14) is designed toto continuously dose the fibrilliant binder (20) gravimetrically, and wherein the binder dosing system (10) comprises a cooling device (51) for cooling the fibrilliant binder (20).

2. Binder dosing system (10) according to claim 1, characterized in that a transfer unit (88) is arranged downstream of the second dosing device (14), which is coupled to the second dosing device (14) and transfers the fibrilliable binder (20) from the second dosing device (14) into a continuous mixer (86), wherein the transfer unit (88) comprises at least one collecting hopper (90) and a vibration unit (92) coupled to the collecting hopper (90).

3. Binder dosing system (10) according to claim 2, characterized in that the transfer unit (88) has at least one pipe element (82) coupled to the second dosing device (14), which projects centrally, in particular to about half its length, into the collecting hopper (90).

4. Binder dosing system (10) according to one of claims 1 to 3, characterized in that the cooling device (51) comprises a cooling tower (52) which the binder dosing system (10) at least partially, preferably completely, encloses in a cooling chamber (56) and cools the cooling chamber (56) to a predetermined temperature, and / or wherein the cooling device (51) comprises at least one cooling module (74) and / or a cooling unit (75) which cools a section of the binder dosing system (10) to a predetermined temperature.

5. A method for continuously dosing a fibrilliant binder for the production of electrode compounds using the binder dosing system according to any one of claims 1 to 4, wherein the method comprises the following steps: a) providing a fibrilliant binder (20) in a first dosing device (12); b) volumetrically dosing the fibrilliant binder (20) from the first dosing device (12) into a refilling device (16); c) refilling the fibrilliant binder (20) from the refilling device (16) into a second dosing device (14), wherein the refilling device (16) comprises a separation unit (26) which provides a particle fraction of the fibrilliant binder (20) consisting of particles with a predetermined particle size, wherein the refilling device (16) refills only the particle fraction with the predetermined particle size into the second dosing device (14);and d) gravimetric continuous dosing of the fibrilliant binder (20) from the second dosing device (14) into a continuous mixer (86), wherein steps b) and / or c) are controlled and / or carried out at defined time intervals, and wherein one or more of steps a) - d) are carried out under cooling.; 6. Method according to claim 5, characterized in that the refilling device (16) comprises a binder dispenser (28) in which the particle fraction with the predetermined particle size is collected before the particle fraction is refilled from the binder dispenser (28) into the second metering device (14).

7. Method according to claim 6, characterized in that step c) is carried out when a predetermined amount of the particle fraction has been collected in the binder dispenser (28).

8. Method according to claim 6 or 7, characterized in that the binder dispenser (28) refills a discrete amount of the particle fraction into the second metering device (14) by means of a metering element (36), in particular a metering flap, a metering shovel, a metering slide, a metering wheel.

9. Method according to any one of claims 5 to 8, characterized in that during step d) a weighing step is carried out in which a weight value of the fibrilliable binder (20) is continuously determined in the second dosing device (14), wherein if a weight value is detected that is lower than a predetermined target value, a control signal is output from the second dosing device (14) to the refilling device (16) and / or the first dosing device (12), whereby step c) and / or step b) is carried out, or that steps b), c) and d) are predetermined by a dosing cycle (112, 114, 116).

10. Method according to one of claims 5 to 9, characterized in that one or more of steps a) - d) are carried out under cooling at an ambient temperature of 1 - 18 °C, preferably of 5 - 15 °C, most preferably of 4 - 10 °C.

11. Method according to one of claims 5 to 10, characterized in that one or more of steps a) - d) are carried out at a constant humidity, in particular at a dew point less than 0°C, preferably less than -10°C, most preferably of -20°C.

12. Production system (84) for producing electrode masses, comprising a binder dosing system (10) according to one of claims 1 to 4 and a continuous mixer (86) coupled to the second dosing device (14) in the conveying direction (18).

13. Production system (84) according to claim 12, characterized in that the continuous mixer (86) is an extruder comprising a housing (106) with a front section A to which, downstream in the conveying direction (18), a middle section B and a rear section C are successively connected, wherein at least one inlet (96) for a fibrilliant binder and / or further electrode components is provided in the front and / or middle section and an outlet (100) with a discharge opening (122) is provided in the rear section, wherein at least one extruder shaft (108) is received in the housing (106) extending through the housing (106) in the conveying direction (18), wherein the at least one extruder shaft (108) has several mixing elements and / or conveying elements (120) which are at least partially made entirely of a plastic or comprise a plastic sheath enclosing a metallic core,in particular wherein the plastic is PEEK, and / or wherein the discharge opening (122) is designed such that the electrode mass can be discharged unhindered from the outlet (100) in granular form, in particular wherein the discharge opening (122) is substantially limited by an inner wall (140) of a housing bore (119) in which the at least one extruder shaft (108) is arranged.

14. Production system (84) according to claim 13, characterized in that a discharge chute (126) is arranged downstream of the discharge opening (122).

15. Production system (84) according to claim 13 or 14, characterized in that a counter bearing (118) is provided downstream of the discharge opening (122) in which the at least one extruder shaft (108) is mounted.

16. Method for the continuous production of electrode masses, wherein the method comprises steps a) - d) of the method according to any one of claims 5 to 11 and additionally the following steps: e) Mixing the fibrillable binder (20) with other components (94) of the electrode mass in a continuous mixer (86); and f) Processing the fibrillable binder (20) with the other components (94) of the electrode mass by fibrillating the fibrillable binder to obtain a granular electrode mass with fibrillated binder (98).

17. Method for the continuous production of electrode masses according to claim 16, characterized in that, after step f), a quality control is carried out with the following process steps g) - i): g) Determining at least one quality-relevant parameter in the electrode mass with fibrillated binder (98); h) Comparing the quality-relevant parameter with a predetermined range of values ​​for the quality-relevant parameter, within which properly defined quality-relevant parameters fall;i) If the comparison shows that the parameter is outside the range of values: issue a warning signal, create and send a report highlighting the parameter that is outside the range of values, adjust a production-relevant parameter so that the quality-relevant parameter falls within the predefined range of values ​​and / or change a product flow so that the electrode mass is disposed of, whereby if the comparison shows that the parameter is within the range of values: release the electrode mass with fibrillated binder (98) for further processing steps.;

Images