Volumetric and gravimetric energy density are decisive for the success of mobile energy storage systems. On the one hand, high-capacity active materials are being developed to increase them and on the other hand significant increases can be achieved through high proportions of active materials and mass loads. The decisive influence on the resulting volumetric energy density has the process of compaction: the so-called calendering. In addition to the significant reduction of the layer volume, compaction leads to a significant increase in electrical conductivity on the cathode side. Furthermore, mechanical properties such as adhesive strength and elasticity can be improved. However, the significant reduction in porosity reduces the transport channels required for ion diffusion.
An important goal of calendering is the optimization of the pore structure. Consequently, the understanding of the process is decisive in order to be able to adjust the optimal pore and particle structure and favourable mechanical properties in a targeted manner. This is where the ProKal project comes in. Within the scope of the project, the understanding of the process-structure-property relationship of calendering of high-energy, continuously and in particular also batch-coated cathodes and anodes with high basis weights and high-capacitive active materials is to be further developed on the basis of iPAT’s knowledge. Anodes and cathodes with the most promising structure will be integrated into battery cells and electrochemically investigated, especially at the MEET impedance spectroscopy, in order to evaluate the electrodes and the battery cell with regard to the achieved energy density and the electrochemical performance.
Based on iwb’s many years of experience in optimizing the dynamic behavior of machine tools, the interaction between machine dynamics, process parameters and material properties will be investigated in addition to the process-structure-property relationships considered at iPAT and meet. As a result of the project, results should be available that will support battery cell production in Germany in the future.