Fraunhofer ISE Develops PFAS-Free Dry-Coating Technology to Cut Battery Production Costs by 15%

Fraunhofer Institute for Solar Energy Systems ISE, in collaboration with German equipment manufacturer IKA, has developed a new dry-coating process for sodium-ion battery electrodes that eliminates the need for solvents and PFAS-based chemicals. The innovation, developed under the LAENDLE research project, aims to reduce battery manufacturing costs, energy consumption and environmental impact while creating opportunities for domestic and European battery production.

The newly developed process offers an alternative to conventional wet-coating technology, which is widely used in battery electrode manufacturing. Traditional wet coating requires solvents, followed by drying and compaction processes. These additional steps increase equipment investment, operating expenses and energy consumption. The dry-coating technology developed by Fraunhofer ISE removes several of these requirements, making battery production more resource-efficient.

The research team has taken the technology further by eliminating PFAS-containing binders and adhesion promoters, commonly associated with persistent environmental chemicals. In collaboration with IKA, a specialist in mixing and kneading equipment based in Staufen, Germany, Fraunhofer ISE developed a continuous kneading process to produce electrode materials. The technology builds on mixing and kneading methods previously used in industrial applications, including silicone production.

During the project, researchers identified two classes of polymer binders that can be used without PFAS-based chemicals. Several PFAS-free binder materials were successfully tested and implemented in the dry-coating process.

At the Fraunhofer ISE Center for Electrical Energy Storage, the team successfully produced a freestanding electrode film that can be laminated directly onto a current-collecting foil. The electrode layer thickness can be adjusted between 80 and 180 micrometers, with the possibility of producing thicker or thinner layers depending on technical requirements.

An important feature of the process is that it does not require an additional bonding agent on the current-collecting foil. This eliminates another manufacturing step and reduces material consumption, production costs and energy requirements. The technology can also be integrated into existing dry-coating production lines without requiring changes to subsequent manufacturing processes.

According to Fraunhofer ISE, the new method can reduce capital expenditure (CAPEX) per production line by at least 15 percent, with the potential for further savings. Operating expenditure (OPEX) could be approximately 10 to 20 percent lower compared with conventional wet-coating production lines. By eliminating drying, calendering and the application of bonding agents, the process could also reduce energy consumption and carbon dioxide emissions by up to 50 percent.

The next phase of the LAENDLE project will focus on scaling up the technology to pouch-cell production using the assembly line at the Fraunhofer ISE Center for Electrical Energy Storage. Researchers also plan to further reduce the binder content to levels commonly used in the battery industry.

Dr. Oliver Fitz, project manager at Fraunhofer ISE, said simplifying the process and equipment requirements makes the technology more cost-effective and accessible to small and medium-sized enterprises. This could support local battery manufacturing and strengthen European supply chains.

The project is funded by the Baden-Württemberg Ministry of Economic Affairs, Labor and Tourism and is scheduled to continue until June 2027.