In June 2025, the European Union launched the STELLAR research initiative to advance the production of next-generation lithium metal anodes. Led by the Fraunhofer Institute for Industrial Mathematics ITWM alongside 16 European partners, the four-year project aims to design and build a roll-to-roll test facility capable of safely and sustainably manufacturing lithium metal anode foils.
Roll-to-roll processing involves continuously unwinding copper foils, applying a thin lithium layer in a vacuum environment, and rewinding the finished material onto a new roll. The STELLAR pilot line is expected to produce around 60 kilometers of anode foil annually, with lithium layer thickness precisely controlled between 5 and 15 micrometers. This continuous manufacturing method supports the scalable, cost-effective fabrication of flexible, large-area battery components.
Lithium metal anodes offer substantially higher energy density than conventional lithium-ion cells, promising longer driving ranges for electric vehicles and extended runtimes in portable electronics. However, the reactivity of metallic lithium requires strict process control. STELLAR emphasizes inline quality monitoring under vacuum conditions, ensuring consistent film properties throughout production. Researchers at Fraunhofer ITWM will apply optical metrology techniques to assess key parameters—layer thickness, surface roughness, electrical conductivity, and edge quality—in real time. “Our broad measurement portfolio lets us tailor methods to the specific challenges of lithium metal film inspection,” says project manager Dr. Stefan Duran.
Coordinated by Belgian battery specialist Avesta Holding, the project will demonstrate the pilot facility at Avesta’s site. The European Commission is providing €7.9 million in funding for the period from June 1, 2025, to May 31, 2029. Fraunhofer ITWM’s share—approximately €757,000—will support the development and integration of advanced optical quality-control systems. By combining scalable roll-to-roll manufacturing with robust inline inspection, STELLAR aims to accelerate the commercialization of Generation 4b/4c/5 lithium metal batteries, contributing to Europe’s climate and mobility goals.
Source: Fraunhofer ITWM Press Releases
