Manufacturing of battery cells remains a cost and resource intensive endeavor. Rising prices for energy and materials are further challenging for the manufacturers. In particularly the coating and drying of the electrodes is a crucial step, which possess high potential for cost reduction.

In the state-of-the-art tape-casting process for electrode production, materials need to be suspended in solvents before they can be further processed. In turn, at the end of the electrode production, these solvents need to be removed again. Fraunhofer ISIT has developed a dry coating process, which works completely without solvents and bears several advantages over wet processing. On one hand, the drying of the coated electrode slurry is an energy intensive process. It also requires a large space because of the long drying sections needed for an optimal process result. These factors lead to high production costs. On the other hand, working with solvents entails handling of chemicals and requires additional recovery systems, increasing the costs even further. With the dry coating process developed by Fraunhofer ISIT, the use of solvents becomes obsolete. Furthermore, higher loadings even exceeding the range of conventional electrodes are possible. This allows a significant cost reduction along with enhanced environmental sustainability of the manufacturing process.

However, changing the production process form wet to dry coating bears opportunities and challenges at the same time. Polyvinylidene fluoride (PVDF) and carboxyl methyl cellulose with styrene butadiene rubber (CMC/SBR) are the commonly used binder systems for conventional wet processing. Since the dry coating process of Fraunhofer ISIT is based on brush coating with subsequent hot pressing, binder systems featuring different properties are required. This opens the opportunity of the application of a broad spectrum of thermoplastic binders but involves the challenge of identifying the most promising candidates and optimizing their application.

In the current work various binder materials were tested and analyzed for their possible application in a dry coating process for electrode production. Furthermore, selected materials were used in the established dry mixing and dry coating process of Fraunhofer ISIT. The relationship between the material properties and the quality of the resulting electrodes was intensively studied, since better understanding of this relationship may not only lead to improvement of the product quality but also to a further development of the process itself.