Method for providing dry electrode material

Abstract

This document describes a method for providing dry electrode material containing active material and a fibrillated thermoplastic binder. The method is carried out in the following steps: - Providing dry active material in bulk, - Dispersing and homogenizing the active material with the multi-shaft vertical mixer 1 in a first operating mode with high energy input into the active material to introduce high shear forces, - Cooling the dispersed active material to a temperature below the softening temperature of a subsequently introduced binder, in a second operating mode, - Introducing dry thermoplastic binder as bulk material into the cooled active material and homogenizing the binder with the active material in a third operating mode, - Fibrillation of the binder dispersed in the active material during an operating mode in which high shear forces are introduced into the mixture and the temperature in the mixture is above the softening temperature of the binder but below its melting temperature, and - Cooling the electrode material and dispensing it as bulk material from the mixing container 3.

Description

[0001] The invention relates to a method for providing dry electrode material containing active material and fibrillated thermoplastic binder for application to a carrier substrate for the production of electrochemical storage cells.

[0002] To manufacture electrochemical storage cells (battery cells), such as lithium-ion batteries, electrode material is required, which is located on an electrode as a support substrate. The electrode material itself consists of an active material and a thermoplastic binder. Depending on the desired design of the electrochemical storage cell, the active material includes at least one metal oxide component, for example, a lithium metal oxide such as lithium cobaltate, lithium manganate, or the like, as well as graphite and / or carbon black. The electrode material may also contain other substances, such as electrically conductive additives.

[0003] In the past, electrode material had to be powdered and applied as a suspension or paste to a film-like substrate (electrode foil) using a solvent, and then dried. More recently, dry coating processes for applying electrode material to such a substrate have been developed. This eliminates the need for solvents. Furthermore, the energy-intensive drying process is no longer required. In such a dry coating process, a thermoplastic polymer is used as an adhesion promoter. This polymer should be homogeneously distributed within the remaining electrode material in the form of thread-like or hair-like structures.According to a previously known method, the active material and binder, prepared by mixing in an industrial mixer, are introduced into the calender gap of two counter-rotating calender rollers to exert sufficient shear force on the binder so that it forms the desired fibers. This is achieved with the application of heat, such that the softened binder holds the active material together and a continuous electrode material film is produced. This film is then transferred to the electrode foil.

[0004] Industrial mixing machines are used to mix the components of the electrode material. For the necessary mixing of the active material components—their dispersion and homogenization—a correspondingly high energy, and thus shear force, must be introduced into the mixture. This is possible with high-intensity mixers whose mixing tools are driven at a correspondingly high speed and therefore exhibit a corresponding peripheral speed of the mixing tool blades. Since the mixing of the active material is to be carried out not on a laboratory scale, but on an industrial scale with particularly larger filling volumes of the mixing vessel, especially more than 1,200 liters as a usable volume, there are limits to the rotational speed of the mixing tools due to design constraints and motor power limitations.Furthermore, it would be desirable if dry electrode material with fibrillated binder distributed within it could be provided without the step of calendering the electrode material required by the prior art.

[0005] From AT 310 426, a machine for mixing and processing powdery, granular, or small-sized plastic particles is known. This previously known mixer is designed as a multi-shaft vertical mixer. This multi-shaft vertical mixer has a mixing vessel with mutually overlapping mixing sectors. A drive shaft with impeller tools is arranged in each mixing sector. This mixer is intended for mixing larger usable volumes, for which the design and mechanical effort required to mix larger usable volumes with a single-shaft vertical mixer would otherwise not be justified.

[0006] Based on this discussed prior art, the invention therefore aims to propose a method for providing dry active material and electrode material containing fibrillated thermoplastic binder, which is simplified compared to the method described above.

[0007] This problem is solved by a generic method mentioned at the outset, in which the method with a multi-shaft vertical mixer, in which at least one blade tool having at least two blades is located on each drive shaft, wherein the blade tools of the two drive shafts are arranged in a mixing container having two spatially connected, overlapping mixing sectors, offset from each other in height and with respect to the paths of rotation of their blades such that the paths of rotation of at least one blade tool of each drive shaft overlap in their projection into a common plane in certain areas, is carried out in the following steps: - Providing dry active material in bulk, - Dispersing and homogenizing the active material with the multi-shaft vertical mixer in a first operating mode of the multi-shaft vertical mixer with high energy input into the active material to introduce high shear forces acting on the active material, - Cooling the dispersed active material to a temperature below the softening temperature of a subsequently introduced binder, in a second operating mode, - Introducing dry thermoplastic binder as bulk material into the cooled active material and homogenizing the binder with the active material in a third operating mode, which operating mode is carried out so that the temperature in the mixture remains below the softening temperature of the binder, - Fibrillation of the binder dispersed in the active material during an operating mode in which high shear forces are introduced into the mixture and the temperature in the mixture is above the softening temperature of the binder but below its melting temperature, and - Cooling the electrode material and dispensing it as bulk material from the mixing container.

[0008] In this process, the electrode material is mixed and the binder fibrillated in a dry process, with all steps taking place in the same mixing vessel of a high-intensity mixer. After completion of the process, the electrode material can be removed from the high-intensity mixer as bulk material and then applied, for example, to an electrode foil as a support substrate. Heat is then applied to soften or partially melt the thermoplastic binder. The internal cohesion of the individual components of the electrode material, as well as its adhesion to the electrode foil, is achieved by softening or partially melting the binder, which then permeates the electrode material in a network-like pattern and also forms the adhesive bond with the support substrate.A key feature is that the individual process steps are carried out in a multi-shaft vertical mixer, specifically a twin-shaft vertical mixer. The special effect of such a high-intensity mixer is that the rotational paths of the blades used as mixing tools, driven by two adjacent rotary shafts, overlap when projected onto a common plane. Therefore, the mixing tools of adjacent drive shafts are arranged at different heights. This allows the high-intensity mixer to operate in such a way that the blades of the two adjacent drive shafts can be moved through the area of ​​overlapping rotational paths – into the overlapping mixing zone – in a physical overlap arrangement.If adjacent drive shafts are driven in the same direction, the relative speed of the blades of the blade tools moving in opposite directions within the overlap of their rotational paths corresponds to the sum of the blades' circumferential speeds. If adjacent drive shafts are driven at the same rotational speed, the relative speed at which the blades of the blade tools of the two drive shafts move relative to each other in the overlap area corresponds to twice the circumferential speed of one blade tool.This is particularly advantageous for the desired energy input required to introduce high shear forces into the active material, as the dispersion and homogenization process, which typically includes deagglomeration, is possible not only in a shorter time but also with a correspondingly higher energy input, without requiring a higher rotational speed of the impeller tools than in conventional single-shaft high-intensity mixers. Furthermore, depending on the desired result of the mixing process, the drive shafts can rotate significantly slower compared to conventional single-shaft vertical high-intensity mixers to achieve the same mixing result. This is advantageous with regard to the design and construction, as well as the wear and tear of the high-intensity mixer and its individual components, and also with regard to the electric motor drive.

[0009] Furthermore, such a multi-shaft vertical mixer also allows a mixing mode in which adjacent drive shafts are driven in opposite directions, thus ensuring that the blades of the blade tools are guided through the overlap mixing zone in the same direction of movement. This allows such a high-intensity mixer to be operated in a mode in which the previously described effect of the blade circumferential speeds adding up in the overlap mixing zone does not occur.

[0010] Further variability regarding the operating mode in a mixing process can be achieved by driving the drive shafts supporting the mixing tools at different rotational speeds. Furthermore, it is possible to implement an intermittent drive mode, for example, when high energy but low temperature is required to be introduced into the mixture. This high-intensity mixer can thus be operated with an extremely wide range of energy input into the mixture in its mixing vessel, and consequently, the shear forces and temperature introduced into the mixture.This proves to be very advantageous for the production of electrode material, as the same mixer can be used to introduce high shear forces into the mixture, while in another operating mode, the mixture in the mixing vessel can be moved without a large or only a very short-term energy input. A high energy input is desirable for the dispersion and homogenization step, as this process step is intended to compact the graphite, the active material component, due to the high energy input. This is beneficial for the performance of the electrochemical storage cells produced with the electrode material.

[0011] An operating mode of the multi-shaft vertical mixer involving the application of significant shear forces is also highly beneficial for the fibrillation process of the binder or binder particles incorporated into the active material. This is because the heat input is primarily a result of the impact of the rotating mixing tool(s) with the material particles in the mixing vessel. Therefore, the mixing tools can be driven at a peripheral speed sufficient to introduce enough heat into the mixture—active material and binder—to soften the binder. When the mixture containing the softened binder is conveyed through the overlapping mixing zone, it experiences a particular shear stress due to the opposing rotational forces of the impeller tools within this zone, which is responsible for the fibrillation of the binder.The process can be carried out in such a way that the shear stress on the softened binder particles is largely confined to the overlap mixing zone. This allows the formation of sufficiently long binder strands without them becoming bonded to the remaining electrode material. Preferably, the process is carried out such that the binder particles, before being conveyed into the overlap mixing zone, are heated by heat input to just below their softening temperature. Due to the significantly higher energy input in the overlap mixing zone, they are then heated above their softening temperature in a short time and, due to the shear forces prevailing there, are drawn into the desired strands. Thus, bonding of the active material particles by the binder does not occur in this process, at least not to any significant extent. The supplied electrode material can be discharged from the mixing vessel as bulk material.

[0012] Preferably, such a high-intensity mixer also has a bottom-clearing tool in each mixing sector. This tool serves to generate the desired mixing swirl in each mixing sector as well as to convey the supplied electrode material out of the mixing vessel, which for this purpose has a discharge nozzle in each mixing sector.

[0013] To cool the active material heated during the dispersion and homogenization process, the multi-shaft vertical mixer, preferably designed as a twin-shaft vertical mixer, can be operated in a mode where the mixture is merely circulated, thus allowing the heat contained within it to be dissipated more quickly. For mixing and dispersing the binder particles in the active material, this high-intensity mixer can be operated in a mode where the binder is distributed but not softened.

[0014] Process steps where little or no heat is to be introduced into the mixture can be performed with intermittent drive of the drive shafts. During the breaks in mixing, the mixture can be circulated if desired. During the operating phases, a high energy input can be introduced into the mixture, which is desirable for the homogenization process. The drive breaks ensure that the temperature input does not exceed the intended temperature threshold.

[0015] To minimize heat input while still providing a sufficient number of blades for the respective mixing process, a preferred embodiment provides for several blade tools, for example two to four, arranged vertically apart on each drive shaft. This results in an impact between the blades and the mixture at different heights, so that the heat introduced into the mixture is coupled more homogeneously at different levels, thus preventing overheating. Preferably, the drive shafts are equipped with blade tools that have two blades diametrically opposed to each other with respect to the axis of rotation. The number and design of the blades depend on the desired mixing result. For example, they can be angled. Numerous possibilities are known to those skilled in the art.

[0016] A further advantage of using wing tools is that the wings can have different geometries on their rotationally oriented sides, depending on the direction of rotation of the respective drive shaft. For example, the narrow side of such a wing pointing in one direction of rotation can have a geometry that results in a higher energy input, and thus also a higher shear force input, into the mixture than the narrow side of the wing pointing in the opposite direction of rotation. In cross-section, such a wing can, for example, be teardrop-shaped, with the rounded wing geometry being the side of the wing that couples more energy into the mixture than the opposite direction of rotation.

[0017] In the first operating mode of the multi-shaft vertical mixer, and for carrying out the steps of dispersing and homogenizing the active material, as well as for the fibrillation step of the binder distributed in the active material, the peripheral speed of the impeller blades can be 10–45 m / s. This depends on the consistency of the active material and thus also on the energy to be coupled into the mixture. During the fibrillation step, the temperature input is controlled so that the temperature of the mixture is heated to above the softening temperature of the binder, but below its melting temperature. As mentioned above, this can be achieved by intermittently driving the drive shaft. Additional cooling of the mixture will be discussed below. In a second operating mode, the peripheral speed of the impeller blades is 5–10 m / s.In this operating mode, the mixture is cooled to dissipate the heat introduced during the preceding step of dispersing and homogenizing the active material before the thermoplastic binder is introduced as bulk material into the dispersed and homogenized active material. To homogenize the binder within the active material, the impeller blades are driven, for example, at a peripheral speed of 5–30 m / s. This operating mode ensures that the temperature introduced into the mixture does not exceed, or at least not significantly exceed, the softening temperature of the thermoplastic binder.

[0018] It is particularly advantageous for carrying out this process if, at least in the process steps of cooling the dispersed active material, homogenizing the binder in the dispersed active material, and / or fibrillating the binder, the mixture is actively cooled using cooled tools and / or a cooled mixing vessel wall. Such active heat removal allows the temperature of the mixture to be controlled. Therefore, the mixing process with active heat removal can also be carried out at peripheral speeds of the paddle tools that would otherwise result in excessive heat being coupled into the mixture. This applies especially to the process of dispersing the binder in the previously dispersed and homogenized active material and to the process of fibrillating the binder.

[0019] Conventional methods require a considerable amount of time to homogenize the thermoplastic binder in the previously dispersed and homogenized active material due to the limited permissible temperature input into the mixture. This time typically amounts to several hours. The inventive method significantly reduces this time due to the multi-wave characteristics of the high-intensity mixer and the measures described above.

[0020] The invention is described below with reference to an exemplary embodiment and the accompanying figures. These show: Fig. 1: A high-intensity mixer designed as a twin-shaft vertical mixer in a perspective view with the lid removed, Fig. 2: the high-intensity mixer of the Fig. 1 in a top view, Fig. 3: The high-intensity mixer of the preceding figures in a longitudinal section, Fig. 4: a diagram illustrating the various process steps for providing dry electrode material over time in relation to the respective operating mode and the resulting temperature in the mixture and Fig. 5a, Fig. 5b: a top view of the high-intensity mixer corresponding to that of the Fig. 2 to represent the drive direction of the wing tools in a first operating mode ( Fig. 5a) and in a second operating mode ( Fig. 5b).

[0021] A high-intensity mixer 1 serves to provide dry electrode material, which is to be applied to a support substrate, typically an electrode foil, in connection with the production of electrochemical storage cells. The in Fig. The high-intensity mixer 1 shown in Figure 1 is designed as a twin-shaft vertical mixer and therefore has two drive shafts 2, 2.1. The two drive shafts 2, 2.1 are arranged inside a mixing vessel 3, extend through the bottom of the mixing vessel 3, and are driven by a motor. The mixing vessel 3 is double-walled to integrate pathways for a coolant. This allows heat to be dissipated from the mixture via the inner wall of the vessel. The volume enclosed by the vessel wall of the mixing vessel 3 is divided into two mixing sectors 4, 4.1. The two mixing sectors 4, 4.1 merge seamlessly into one another. The inner walls of the mixing sectors 4, 4.1 are cylindrical, with an opening 5 at the transition from one mixing sector 4 or 4.1 to the other. The opening 5 between the two mixing sectors 4, 4.11 represents a narrowing, such that the interior of the mixing container 3 has a figure-eight shape in a top view. The opening 5 is framed by two wear strips 6, 6.1, which in the illustrated embodiment have a triangular cross-section. The wear strips 6, 6.1 are replaceable and can also be replaced by strips with a different cross-sectional geometry or design of their opposing wear edges.

[0022] Three wing tools F1-F3; F1'-F3' are arranged vertically apart on each drive shaft 2, 2.1. Furthermore, a soil-clearing wing tool 7, 7.1 is mounted on each drive shaft 2, 2.1 (see figure). Fig. 3) Each wing tool F1-F3; F1'-F3' has two wings diametrically opposed to each other with respect to the axis of rotation. Such mixed tools are well known and therefore require no further explanation here. The wing tools F1-F3 of drive shaft 2 are different from the wing tools F1'-F3' of drive shaft 2.1, as shown in Fig. 3. The vertical offset is designed such that between each pair of wings F1, F2; F2, F3, a wing F1', F2' of the drive shaft 2.1 is centrally located. The distance between the drive shafts 2, 2.1 and the span of the wing tools F1-F3; F1'-F3' are coordinated so that their paths of rotation, as shown in Fig. 2 projected onto a plane, they overlap. The same applies to the soil-clearing tools 7, 7.1, which are also arranged at different heights. The overlapping mixing area of ​​the two mixing sectors 4, 4.1 is shown in Fig. 2 is identified by reference numeral 8. The vane tools F1-F3; F1'-F3' and the bottom-clearing tools 7, 7.1 are internally cooled and connected to a coolant circuit not shown in detail in the figures. Cooling the vane tools F1-F3; F1'-F3' not only removes heat from the mixture in the mixing container 3, but also prevents material build-up, particularly of thermoplastic binder. The vane tools F1-F3; F1'-F3' are arranged on the drive shafts 2, 2.1 such that they are, as shown in Fig. Figure 2 shows that when the end sections of their blades engage in the overlap mixing area 8, they also physically overlap with each other. If both drive shafts 2, 2.1 are driven at the same rotational speed, which is likely to be the case, the end sections of the blades of blade tools F1-F3 pass those of blade tools F1'-F3' synchronously.

[0023] In the diagram of Fig. Figure 4 describes the operating mode of the high-intensity mixer 1 over time with respect to the rotational speed of its drive shafts 2, 2.1 and thus its impeller tools F1-F3; F1'-F3', as well as the temperature development in the mixture during the process of providing dry electrode material. In a first step, dry active material – graphite and the desired metal oxide(s) – is filled into the mixing vessel 3 in bulk. For dispersion and homogenization, which may also include deagglomeration, the drive shafts 2, 2.1 of the high-intensity mixer 1 are driven in a first operating mode (Phase 1). This operating mode is designed to introduce a high shear force into the active material. Both drive shafts 2, 2.1 rotate in the same direction (see Figure 4). Fig. 5a) and, in the illustrated embodiment, driven at the same rotational speed. The blade tools F1-F3; F1'-F3' are driven at a peripheral speed of approximately 38 m / s. In the overlap mixing zone 8, this synchronous drive of the drive shafts 2, 2.1 results in the blades of the blade tools F1-F3; F1'-F3' being moved past each other in opposite directions, so that the relative speed of the overlapping blade ends passing each other in the vertical direction is 76 m / s. The overlap mixing zone 8 and the adjacent areas of the two mixing sectors 4, 4.1 can therefore be referred to as a high-intensity mixing zone. As a result of the transition of the two mixing sectors 4, 4.1 into one another and the rotary drive of the drive shafts 2, 2.1 with their blade tools F1-F3; F1'-F3', the conditions are created for the forces acting on the mixture to be applied to the mixing material.The centrifugal forces acting on the mixture particles in the overlapping mixing area 8 allow them to transfer from one mixing sector 4, 4.1 to the other mixing sector 4.1, 4. Due to the selected peripheral speed of the impeller tools F1-F3; F1'-F3', heat is coupled into the material located in the mixing vessel 3. Since the mixing vessel 3 and the mixing tools F1-F3; F1'-F3' are cooled, the heating of the mixture is controlled, as heat is simultaneously dissipated from the mixture via cooling. The high energy introduced into the active material also ensures the desired coating of the metal oxide particles with carbon black or graphite.

[0024] Once the active material is sufficiently dispersed and homogenized, which also involves a compaction process of any graphite it may contain, the active material in the mixing vessel 3 is cooled to a temperature below the softening temperature of a thermoplastic binder to be introduced into the active material (Phase 2). For this purpose, the vane tools F1-F3; F1'-F3' and the bottom-clearing tools 7, 7.1 are driven intermittently at a lower peripheral speed, ultimately solely to circulate the mixture in the mixing vessel 3 in order to remove the heat introduced by the preceding operating mode as quickly as possible, thus keeping the overall process duration short.To keep the cooling process step of the dispersed and homogenized active material short, temperature control in the preceding operating mode through active cooling is useful in order to limit the heat input.

[0025] Once the active material has cooled sufficiently, a thermoplastic binder is introduced as bulk material into the mixture contained in mixing vessel 3. In the discussed embodiment, the binder content of the total electrode material is 2.5%. Polyvinylidene fluoride (PVDF), for example, is suitable as a binder. To homogenize the binder introduced as bulk material, the high-intensity mixer 1 is operated in a third operating mode (phase 3). In this process, a high amount of energy is introduced into the mixture, but only a low temperature, in order to avoid overheating the binder particles. The temperature of the mixture in mixing vessel 3 should not reach the softening temperature of the thermoplastic binder. In this operating mode, the drive shafts 2, 2.1 are driven in opposite directions in the illustrated embodiment (see figure). Fig. 5b), so that the end sections of the blades of the blade tools F1-F3; F1'-F3' are moved in the same direction through the overlap mixing zone 8. The circumferential speed of the blade tools F1-F3; F1'-F3' is lower at 10-30 m / s than in the first operating mode. Due to cooling and intermittent driving of the drive shafts 2, 2.1 in this operating mode, the temperature input is controlled. For this reason, despite the high energy input, the temperature in the mixture remains below the softening temperature of the binder (see also Fig. 4).

[0026] Once the binder particles are sufficiently homogeneously distributed within the active material, the fibrillation phase of the binder particles begins (phase 4). The binder should be arranged in a hair-like or fibrous structure within the active mass, so that it penetrates the electrode material in a network-like pattern. For fibrillation, the high-intensity mixer 1 is again operated in a mode in which high shear forces are introduced into the mixture. This operating mode is characterized by the fact that the heat input is controlled such that the softening temperature of the thermoplastic binder is reached and exceeded, but its melting temperature is not. Preferably, for this purpose, the drive shafts 2, 2.1 with their impeller tools F1-F3; F1'-F3' are driven in the same direction, so that particularly high shear forces occur in the overlapping mixing zone 8.Furthermore, the heat input is limited by active cooling of the mixture, whereby a large cooling surface is provided as a result of the division of the mixing vessel 3 into two mixing sectors 4, 4.1 and by the number of cooled impeller tools F1-F3; F1'-F3' as well as the cooled bottom-clearing tools 7, 7.1. In addition, the high-intensity mixer 1 is also operated intermittently during this phase (in . Fig. (4 to Phase 4 not shown) . Once the binder particles, which have become extremely elongated through this process, are homogeneously distributed in the active material, the mixture in the mixing vessel 3 – the dry electrolyte material – is cooled (phase 5). This cooling takes place in the second operating mode already described above, specifically, in the illustrated embodiment, with intermittent drive of the drive shafts 2, 2.1.

[0027] The supplied electrode material is then discharged from the mixing container 3 in bulk. The bottom-clearing tools 7, 7.1 push the supplied electrode material towards a discharge opening in the side wall of each mixing sector 4, 4.1 and push it through.

[0028] To keep the mixture in the mixing container 3 moving during an intermittent drive operating mode, the impeller tools F1-F3 and F1'-F3' can continue to be driven during phases of reduced peripheral speed, but only at a peripheral speed that introduces significantly less energy and thus less heat into the mixture. When the process is carried out with active cooling, which is preferred, this heat input is less than the heat dissipated by the active cooling.

[0029] The invention has been described with reference to exemplary embodiments. Without departing from the scope of protection described by the applicable claims, numerous further embodiments of the inventive concept would be apparent to a person skilled in the art, without these needing to be explained in more detail within the scope of these explanations. Reference symbol list 1 High-Intensity Mixer 2, 2.1 Drive shaft 3 mixing containers 4, 4.1 Mixed sector 5 Breakthrough 6, 6.1 Wear strip 7, 7.1 Soil clearing tool 8 Overlap mixing area F1 - F3 Wing tool F1' - F3' Wing tool

Claims

A method for providing dry electrode material containing active material and fibrillated thermoplastic binder for application to a carrier substrate for the production of electrochemical storage cells, which method is carried out with a multi-shaft vertical mixer (1) in which at least one vane tool (F1-F3; F1'-F3') having at least two vanes is mounted on each drive shaft (2, 2.1), wherein the vane tools (F1-F3; F1'-F3') of the two drive shafts (2, 2.1) are arranged in a mixing vessel (3) having two spatially connected, intersecting mixing sectors (4, 4.1) offset from each other in height and with respect to the paths of rotation of their vanes such that the paths of rotation of at least one vane tool (F1-F3; F1'-F3') of each drive shaft (2, 2.1) overlap in their projection into a common plane in certain areas, with the following steps: - Providing dry active material as bulk material- Dispersing and homogenizing the active material with the multi-shaft vertical mixer (1) in a first operating mode of the multi-shaft vertical mixer (1) with high energy input into the active material to introduce high shear forces acting on the active material; - Cooling the dispersed active material to a temperature below the softening temperature of a binder to be subsequently introduced in a second operating mode; - Introducing dry thermoplastic binder as bulk material into the cooled active material and homogenizing the binder with the active material in a third operating mode, which operating mode is carried out so that the temperature in the mixture remains below the softening temperature of the binder; - Fibrillating the binder distributed in the active material in an operating mode.in which high shear forces are introduced into the mixture and the temperature in the mixture is above the softening temperature of the binder, but below its melting temperature, and- cooling of the electrode material and dispensing it as bulk material from the mixing container (3). Method according to claim 1, characterized in that in the first operating mode the wing tools (F1-F3; F1'-F3') of the two drive shafts (2, 2.1) are driven in the same direction and preferably at the same rotational speed at high rotational speed. Method according to claim 2, characterized in that in the first operating mode the circumferential speed of the wing tools (F1-F3; F1'-F3') is 10 - 45 m / s. Method according to one of claims 1 to 3, characterized in that in the second operating mode the dispersed active material is circulated by driving the tools (F1-F3; F1'-F3'; 7, 7.1) of the two drive shafts (2, 2.1) in opposite directions at a low rotational speed. Method according to claim 4, characterized in that in the second operating mode the circumferential speed of the wing tools (F1-F3; F1'-F3') is max. 5 - 10 m / s and the drive of the wing tools (F1-F3; F1'-F3') is such that the active material is only circulated. Method according to one of claims 1 to 5, characterized in that in the third operating mode the two drive shafts (2, 2.1) are driven in opposite directions with a mean rotational speed. Method according to claim 6, characterized in that in the third operating mode the peripheral speed of the wing tools (F1-F3; F1'-F3') is 10 - 30 m / s, in which operating mode the energy required for homogenization is introduced into the mixture, wherein the temperature of the mixture does not exceed the softening temperature of the binder. Method according to one of claims 1 to 7, characterized in that the steps of cooling the dispersed active material, mixing the binder in the active material and / or fibrillating the binder are carried out with intermittently driven drive shafts (2, 2.1), wherein both drive shafts (2, 2.1) are driven synchronously intermittently. Method according to one of claims 1 to 8, characterized in that heat is actively extracted from the mixture located in the mixing container (3) during the process steps of cooling the active material, introducing the binder into the active material and fibrilizing the binder. Method according to claim 9, characterized in that heat is extracted from the mixture via the tools (F1-F3, 7; F1'-F3', 7.1) and / or the mixing vessel wall, which are cooled for this purpose and connected to a coolant circuit.

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