Fraunhofer is conducting research on longer-lasting batteries

October 26, 2026

Source: E & M powernews

Thin carbon layers are expected to make lithium-metal batteries last longer. Two Fraunhofer institutes are investigating this approach through August 2028.

Lithium-metal batteries could enable higher energy densities in the future, thereby producing more powerful energy storage systems. However, it remains challenging to operate the battery cells reliably over extended periods. Against this backdrop, the Fraunhofer Institute for Thin Film and Surface Technology (IST) in Braunschweig, in collaboration with the Fraunhofer USA Center Midwest (CMW), is investigating how the service life of such batteries can be improved through special coatings.

The joint research project is titled “LIMAC – Amorphous Carbon Interlayers for Reliable Lithium-Metal Battery Cells.” As announced by Fraunhofer IST in a press release, the project began in September of this year and will run through August 2028. Funding is provided through the internal Fraunhofer program “PACT” (Program for Affiliate Cooperation and Knowledge Transfer). The program aims to strengthen collaboration as well as the transfer of knowledge and technology between Fraunhofer institutes.

Thin layers are intended to stabilize the interface

Lithium-metal batteries are considered a potential approach for future energy storage systems with high energy density. Unlike conventional lithium-ion batteries with graphite anodes, metallic lithium itself serves as the active material in the negative electrode, the anode. According to the researchers, batteries using lithium as the anode material could store more energy than conventional lithium-ion batteries while weighing the same.

However, according to the Fraunhofer IST, a major challenge lies in maintaining a permanently stable connection between the lithium-metal anode and the electrolyte. The electrolyte ensures that lithium ions can move within the battery cell. If the contact surface with the anode changes, this can impair the battery’s performance and shorten its lifespan.

In the “LIMAC” research project, scientists are investigating whether thin interlayers made of amorphous carbon can stabilize the contact surface between the anode and the electrolyte. In amorphous carbon, the atoms are not arranged in a regular pattern.

To this end, the researchers are first developing thin carbon layers, which they apply to copper using a special process. They then test the coated materials in battery cells and compare their properties with those of reference cells. In this way, they aim to determine which properties of the coating are crucial for achieving the most stable contact surface possible.

Environmental Impacts Also in Focus

In addition, the researchers intend to investigate the environmental impacts of the coating process. Using a life cycle assessment (LCA), they aim to map the relevant material and energy flows and evaluate the environmental impacts of the process.

Another goal of the project is to adapt the technology for use in larger battery cells. While the researchers are initially conducting their investigations on small, coin-shaped button cells, they also plan to develop a concept for so-called pouch cells. These are larger battery cells whose components are housed in a flat, flexible foil casing.

In the long term, lithium-metal batteries with higher energy density could be used in electric vehicles, aerospace, and stationary energy storage systems, among other applications. The researchers see particular potential for the technology in applications that require high storage capacity with the lowest possible weight.

Author: Davina Spohn