Increase of the throughput speed in the electrode production by an innovative drying management (Epic)

According to the current state of the art, battery electrodes are coated as a water- or solvent-based slurry onto a current collector foil and convectively dried in a continuous impingement jet dryer. The drying process limits the production speed, as a too high drying rate deteriorates the electrode properties. Following the drying process, the electrodes are first calendered and then post-dried in a separate process step, transferred to a drying room and assembled to battery cells. The residual moisture, which is important for the cell properties, depends on the boundary conditions in the drying room and the history of the electrodes along the process chain from drying to cell assembly in the drying room. Currently, the individual process steps are considered separately from each other without taking interactions into account, thus saving potentials and process simplifications remain unused. The goal of the project EPIC is to reduce the production costs of battery electrodes by increasing the drying speed by at least 50% and reducing the energy costs for drying by at least 20% compared to the current state of the art. This will be achieved by using innovative drying technologies and a knowledge-based design of the process control during drying, an energetically and qualitatively optimized post-drying and a moisture management adapted to the specific material system along the process chain from drying to cell assembly. As a starting point for achieving the project objective, the process control of purely convective drying is to be optimized energetically and ecologically on the basis of a systematic approach. In addition, alternative drying methods are to be researched and transferred into an industrially scalable process. The best possible design of drying, post-drying and moisture management is based on the findings from previous projects by means of an evaluative comparison of different process routes, taking into account quality aspects and process-structure-property relationships that meet the requirements. Furthermore, it is considered how a significant minimisation of costs and environmental impact can be achieved by minimising the energy consumption of the drying room. For this purpose, individual process cost models for the single process steps and the overall moisture management are developed and evaluated comparatively.