The Fraunhofer Institute for Surface Engineering and Thin Films IST is collaborating with the Fraunhofer USA Center Midwest on the LIMAC project, which stands for “Amorphous Carbon Interlayers for Reliable Lithium Metal Battery Cells.” The project has been in operation since September 2025 and is expected to continue until August 2028.
As part of LIMAC, researchers are exploring new approaches to further improve batteries, with a focus on lithium-metal anodes. The team sees untapped potential here to develop more durable battery cells, particularly when it comes to the interface between the lithium-metal anode and the (solid) electrolyte. According to the researchers, the stability of this interface is essential to achieve more reliable and long-lasting battery cells.
To stabilize this interface, Fraunhofer experts introduce thin layers of amorphous carbon. In the first step, these layers are deposited on copper current collectors using an innovative Laser-Arc PVD process. “The coated materials will then be tested on battery cells and compared with reference cells,” the researchers explain. The goal is to determine which properties of the interlayers are critical to achieving the most stable interface within the battery cell. It is clear that the stabilizer is intended to allow the lithium contained in the cell to serve as an active anode material.
In addition to the technical results, the project also examines the ecological perspective and future transferability to larger cell formats. “On the one hand, a life cycle assessment (LCA) will be used to examine the relevant material and energy flows as well as the environmental impacts of the approach; on the other hand, a concept to scale the technology to larger pouch cells will be simultaneously developed,” the team explains. In this way, the project combines materials development and cellular research with ecological evaluation and initial considerations for future scale.
The potential added value for manufacturers is clear: more powerful and longer-lasting lithium-metal batteries could reduce the weight of electric vehicles while maintaining high energy densities. However, LIMAC is still in the basic research stage.
ist.fraunhofer.de
