Fraunhofer ISE Thick-Electrode Design Lifts Battery Energy Density by Up to 15%
Fraunhofer ISE built lithium, sodium and zinc-ion battery cells with thicker electrodes, raising energy density up to 15% without added weight.
Photo by Castorly Stock on Pexels
The Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) announced on September 9, 2026 that it has built battery cells with thicker electrodes that raise energy density by 10 to 15% at the same weight, by increasing electrode coating thickness from the conventional 100 to 200 micrometers up to 800 micrometers. The German institute demonstrated the approach in lithium-ion, sodium-ion and zinc-ion cells and produced lithium-ion pouch-cell prototypes on a semi-automated line in its Battery Materials and Cell Production Lab.
Thicker electrode coatings reduce the number of thin metal current collectors needed inside a cell, freeing up space and weight for the active material that actually stores energy, according to Dr. Oliver Fitz, group leader for battery cell technology at Fraunhofer ISE, who is credited with the core technical explanation in the institute’s release. The manufacturing process is PFAS-free and solvent-free, which Fraunhofer ISE said lowers process complexity compared with conventional wet-coating systems and could reduce capital and operating costs at scale.
Three battery chemistries, three funded projects
The work draws on three German government-funded research projects. “VORAN,” focused on sodium-ion battery storage for stationary and mobile use, runs through June 2027. “InFAB,” on manufacturing and assembly of zinc-ion batteries for stationary storage, and “WinZIB2,” on a globally deployable zinc-ion battery system, have both been completed. The Federal Ministry for Economic Affairs and Energy funded VORAN and InFAB, while the Federal Ministry of Education and Research funded WinZIB2, according to Dr.-Ing. Daniel Biro, head of Fraunhofer ISE’s Electrical Energy Storage Department, who credited the funding bodies in the institute’s announcement. Fraunhofer ISE worked with equipment developer acp systems AG, manufacturing partner Helmut Hechinger GmbH & Co. KG, the University of Stuttgart’s Institute for Photovoltaics and the Karlsruhe Institute of Technology’s Helmholtz Institute Ulm.
Institute director Prof. Dr. Andreas Bett linked the research to the broader role of stationary storage in a climate-neutral power grid. Markus Duffner, CEO of manufacturing partner Helmut Hechinger, said the company sees potential to industrialize the process in Baden-Württemberg, though no commercialization timeline or cost figures for mass production have been published.
| Metric | Value |
|---|---|
| Energy density gain | Up to 15% (range 10-15%) |
| Conventional electrode coating thickness | 100-200 micrometers |
| New electrode coating thickness | Up to 800 micrometers |
| Chemistries demonstrated | Lithium-ion, sodium-ion, zinc-ion |
| Prototype form factor | Lithium-ion pouch cells |
| Manufacturing status | Lab-scale validation, not yet series production |
Part of a broader push on domestic battery storage capacity
The announcement comes as battery manufacturers and financiers separately expand storage manufacturing capacity. In the United States, US energy storage installations reached a record 20.2 GWh in the second quarter of 2026, and the Department of Energy selected seven critical mineral and battery projects for $500 million in funding. Fraunhofer ISE’s approach targets a different link in the supply chain: improving how much energy a given cell can store, rather than expanding how many cells get built. For background on how battery chemistry and duration choices affect grid storage generally, see Winss’ explainer on grid-scale battery storage.
About Fraunhofer ISE
The Fraunhofer Institute for Solar Energy Systems, based in Freiburg, Germany, is part of the Fraunhofer-Gesellschaft, Europe’s largest applied-research organization. Fraunhofer ISE researches solar power generation, hydrogen technologies, and electrical and thermal energy storage, and operates a Battery Materials and Cell Production Lab used to prototype new cell designs before industry partners scale them. The institute has previously worked on sodium-ion and zinc-ion storage chemistries through publicly funded projects including VORAN, InFAB and WinZIB2, the same projects underpinning the thick-electrode design announced in September 2026. Fraunhofer ISE said the next step is further scale-up and validation work with industry partners such as Helmut Hechinger GmbH & Co. KG before the design could move toward mass production.
Sources: Fraunhofer ISE; pv magazine; electrive.com
Featured image: photo by Castorly Stock on Pexels (free Pexels license).
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I specialize in sustainability education, curriculum co-creation, and early-stage project strategy. At WINSS, I craft articles on sustainability, transformative AI, and related topics. When I’m not writing, you’ll find me chasing the perfect sushi roll, exploring cities around the globe, or unwinding with my dog Puffy — the world’s most loyal sidekick.
