Which mixing and granulation solutions with a ring-layer granulator are common for battery materials such as cathode and anode powders?
In battery production, plants are used for the manufacture of cathode and anode powders that make a high homogeneity, defined particle properties and controlled process management possible. Depending on the material system and the process route, different mixing and granulating solutions are used.
In practice, several plant concepts are common.
Ring-layer mixers
Ring-layer mixers are continuously operating high-performance machines. A rapidly rotating tool creates a thin, highly dynamic ring layer in the cylindrical trough. In this layer, powders are intensively dispersed, wetted and granulated.
Typical features are high circumferential speeds, short residence times and a high specific energy input. Ring-layer mixers are particularly suitable for large throughputs and for process lines with high demands on uniformity.
Intensive mixers or high-performance batch mixers
These plants work batchwise and produce intensive blending. They are frequently used for the premixing of active materials, conductive additives and binders. They often serve as a preliminary stage ahead of a granulating or slurry step.
Ploughshare mixers and paddle mixers
These mixers are suitable for homogenisation tasks with moderate shear loading. They are used where the particle structure is to be treated as gently as possible. Depending on the design, they can be operated as batch or as continuous mixers.
Planetary and vacuum mixers
These systems are used above all for slurries. They homogenise active material, conductive additives, binders and solvents into a uniform electrode mass. Vacuum operation helps to avoid gas inclusions.
Inclined intensive mixers
Inclined intensive mixers produce a very high de-agglomeration performance and are frequently suitable for slurry preparation. They are also used in the dry mixing process, however.
These amixon® mixing solutions are used for battery materials
In the preparation of cathode and anode powders, dispersive mixing is the priority. The aim is to achieve a very uniform distribution of active material, conductive additives and binders. At the same time, metallic abrasion must be prevented from entering the product. For these applications, batchwise mixers with a ceramic-armoured mixing chamber and ceramic-coated mixing tools are therefore frequently used.
Suitable plants must meet two requirements simultaneously. They must achieve a high mixing quality and de-agglomerate the material completely. This is particularly important with cathode materials, since even slight ferritic contamination can impair product quality.
In practice, vertical batch mixers from amixon® GmbH with an intensive but controlled dispersing action are also used for this. A design that can be inerted is important here.
With the Gyraton® mixing silo (ceramic-lined), amixon® can homogenise large powder masses of up to 100 m³ ideally. This is an important contribution to ensuring constant quality over long periods.