Electric mobility is advancing in Germany and Europe. In order to gain further momentum, battery cell production capacities in Germany must be expanded intensively and production processes must become more energy-efficient and significantly cheaper. Scientists at the Fraunhofer Institute for Material and Beam Technology IWS in Dresden say they have developed DRYtraec, a revolutionary process that will enable the cost-efficient and environmentally friendly production of battery electrodes in the future. The research team led by Dr. Benjamin Schumm, Dr. Holger Althues, and Prof. Stefan Kaskel will receive the 2025 Joseph von Fraunhofer Prize at the Fraunhofer Annual Conference for this pioneering technology.

The challenge of battery production and the innovative solution from DRYtraec
Electrodes are a central component of every battery and usually consist of a metal foil coated with a thin layer. The coating contains the active components responsible for energy storage. “The coating process is usually carried out using wet chemistry with so-called slurry approaches,” explains Dr. Benjamin Schumm, Head of the Particle Technology Department at Fraunhofer IWS. “DRYtraec technology allows an electrode layer to be produced directly from a dry mixture consisting of active material, conductive carbon black, and a binder.” Unlike the conventional slurry process, no solvent is used. A special calender device generates shear forces in a roll gap, mechanically anchoring particles of the active material and conductive carbon black through the associated fibrillation of the binder. A completely dry electrode layer is formed on the calender rolls, eliminating the need for energy-intensive and space-consuming drying. In addition, double-sided coating is achieved in a single step by direct transfer from both sides to the current collector foils. According to the researchers, the solvent-free DRYtraec electrodes offer outstanding performance and stability without compromising on slurry-based electrodes.

DRYtraec – patented technology with great future potential
The unique scientific and methodological approach of the roller-based dry film transfer process minimizes production risks and facilitates scaling to larger coating widths and higher process speeds. The world's first prototype plant was constructed in 2013 and the technology has been continuously developed since then. The plant enables continuous process control and the production of high-quality electrodes in a roll-to-roll process. "We have created an R&D platform for DRYtraec that offers industrial customers along the value chain a wide range of services from testing to transfer to commercial use. Licensing the technology to a leading company in the European automotive industry paves the way for further scaling up to mass production," explains Dr. Holger Althues, Head of the Battery Materials Department at Fraunhofer IWS.

Suitable for the important battery technologies of the future
The DRYtraec process is also suitable for the important battery technologies of the future, such as sodium-ion or solid-state batteries. Its “drop-in capability” for electrode production has been demonstrated for these cell systems. Prof. Stefan Kaskel, Head of the Battery Technology Technology Field at Fraunhofer IWS, explains: “We initially implemented the process for electrodes in lithium-ion batteries and have now adapted it for lithium-sulfur and solid-state batteries. These will play an increasingly important role in the future, but the performance of the materials suffers from wet chemical processing. With DRYtraec, we offer a promising approach with a double advantage.”