The future development of energy supply systems indicates an increasing reliance on electrical energy. In this context, battery technologies are gaining growing importance across a wide range of applications. In addition to mobile applications, such as electric vehicles, they play a central role as energy storage systems for renewable energy sources. In view of ongoing climate change and the associated need for sustainable energy concepts, renewable energies constitute a key component of future energy systems. However, due to their weather-dependent and therefore fluctuating availability, high-performance energy storage technologies are required to ensure a reliable and stable energy supply. In this regard, all-solid-state batteries (ASSBs) are considered a promising approach for the further development of existing battery technologies (see Figure 1). Compared to conventional lithium-ion batteries, they offer the potential for higher energy density as well as improved safety characteristics.

The aim of this project is to produce tailored functional particle systems in a pilot-scale facility under controlled conditions. These particle systems serve as conductive battery hetero-aggregates and are intended for use as cathode materials in ASSBs (see Figure 2). For application in ASSBs, the cathode material must exhibit both high electronic conductivity and high ionic conductivity. The objective of the project is to control the formation and mixing of hetero-aggregates by optimizing process conditions, thereby improving their aggregate structure and, consequently, the electrochemical properties of the cathode material. Achieving this requires a thorough understanding of the aggregation mechanisms as well as the interparticle forces between the different particles in a multiphase flow.

For the production of the hetero-aggregates, the particles are processed in the dry state using a vibrated fluidized bed technique, in which the particle bed is fluidized by a gas flow (see Figure 3). In addition, a jet layer is applied as a secondary gas stream to enhance homogenization of the particle mixture. Mechanical vibrations are introduced to promote agglomerate breakup and ensure a uniform distribution of the hetero-aggregates. For the characterization of the hetero-aggregates, analytical techniques such as focused ion beam scanning electron microscopy (FIB-SEM), computed tomography (CT), and electrical conductivity measurements are employed. Numerical simulations based on coupled CFD–DEM models are employed for process design, systematic variation of process parameters, and for gaining insight into particle–gas interactions in multiphase flow systems.