Kickoff for EU Project STELLAR

New Roll-To-Roll Test Facility for Efficient Next-Generation Lithium Metal Anodes

Press Release / October 29, 2025

Efficient battery technology is a key component in achieving national and European climate targets. Lithium-ion batteries have dominated the market to date, but are increasingly reaching their physical and technological limits. Lithium metal battery systems are considered a promising successor technology. In the EU project STELLAR, the Fraunhofer Institute for Industrial Mathematics ITWM is working with 16 European partners to develop a cost-efficient test facility for the safe and sustainable production of lithium metal anode foils.

In June 2025, the European Union-funded research project »STELLAR« – short for »Safe, sustainable, and high-throughput production of reliable lithium metal anodes for gen 4b/4c/5 batteries« – officially kicked off. The aim of the four-year project is to develop a roll-to-roll test facility for the production of lithium metal anode foils. A roll-to-roll facility is a production plant that continuously unwinds the foils from one roll, processes them, and then rewinds them onto another roll. This technology is particularly efficient for the manufacture of large-area, flexible products such as batteries. The new plant is expected to achieve an industrial production capacity of around 60 kilometers of anode foil per year, ensuring a precise lithium layer thickness in the range of 5 to 15 micrometers.

© Fraunhofer ITWM
Project manager at Fraunhofer ITWM Stefan Duran presents the STELLAR project process – from copper foil to inline inspection of the anode sheets.

Lithium Metal Batteries as the Technology of the Future

Lithium metal batteries are considered a key technology for the next generation of energy storage devices. Compared to conventional lithium-ion batteries, they offer significantly higher energy density. This means that lithium metal batteries can store more energy for the same weight. In addition, the higher energy density can lead to longer operating times – major advantages, especially for electric mobility and portable electronics.

However, the challenge lies in the safe and reproducible manufacture of the sensitive lithium metal anodes, which are highly reactive. For this reason, the very thin lithium layer is applied to wafer-thin copper foils in a vacuum chamber.

Inline quality control under vacuum conditions

The research work focuses in particular on inline monitoring of film properties during the production process under these complex vacuum conditions. Only through continuous quality control can durable and resource-efficient batteries be produced that meet the requirements of future applications.

Our researchers contribute their expertise in the field of optical metrology to this endeavor. The project investigates the feasibility and performance of a wide variety of approaches for inline monitoring of key parameters such as layer thickness, surface roughness, electrical conductivity, and cut edge quality. »With our broad portfolio of measurement technology, we can individually adapt the most suitable methods to the very specific requirements«, explains Dr. Stefan Duran, project manager at Fraunhofer ITWM.

Project Funding

The project is being coordinated by the Belgian company Avesta Holding, a developer and manufacturer of lithium batteries, where the pilot plant will be demonstrated. The European Commission is providing a total of €7.9 million in funding for the four-year project period from June 1, 2025, to May 31, 2029. Fraunhofer ITWM is receiving approximately €757.000 in funding for the development of the optical measurement technology.

© Fraunhofer ITWM
Process for manufacturing lithium metal anode foils

Press Release

Kickoff for EU Project STELLAR

New Roll-To-Roll Test Facility for Efficient Next-Generation Lithium Metal Anodes

More Information

Lithium Metal Batteries as the Technology of the Future

Inline quality control under vacuum conditions

Project Funding

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Dr. Stefan Duran

Contact Press / Media

M.A. Swenja Broschart