Battery Research Germany: Fraunhofer ISE Increases Energy Density of Battery Cells by Up to 15 Percent
Freiburg, Germany – Researchers at the Fraunhofer Institute for Solar Energy Systems ISE, together with partners from research and industry, have developed a new electrode architecture that allows battery cells to store 10 to 15 percent more energy at the same weight. The concept has been experimentally validated for lithium-ion, sodium-ion and zinc-ion batteries and, for lithium-ion cells, has already been transferred to pouch cells manufactured under near-industrial conditions.
Up to 800 Micrometers: Thicker Electrodes Increase Energy Density
At the core of the new cell architecture are significantly thicker electrode coatings. The 100 to 200 micrometers customary until now have been increased to up to 800 micrometers. This reduces the number of current collectors needed and provides more space for active material. Depending on the battery type and design, this increases energy density by 10 to 15 percent.
"We have succeeded in increasing the thickness of the electrode coating from the previously customary 100 to 200 micrometers to up to 800 micrometers, significantly reducing the number of current collectors required," says Dr. Oliver Fitz, group leader for battery cell technology at Fraunhofer ISE.
The architecture was first tested on small lithium-ion, sodium-ion and zinc-ion cells. Fraunhofer ISE additionally manufactured lithium-ion pouch cells on a semi-automated production line. According to the researchers, the concept can also be transferred to other cell chemistries.
Simpler Manufacturing as the Next Step Toward Industrialization
In addition to cell performance, the development also took later production into account. The cells are free of PFAS (per- and polyfluoroalkyl substances), a group of industrial chemicals that are difficult to break down. Toxic solvents are likewise not used in production. According to Fraunhofer ISE, a possible electrode production process would also have lower process complexity than today's wet-coating plants. This is expected to reduce investment costs as well as the space and energy requirements of production.
Further scaling and validation steps are required before industrial production can begin. Industry partners are Helmut Hechinger GmbH & Co. KG and machine manufacturer acp systems AG. Should further tests prove successful, Hechinger has indicated it will examine industrialization and sees particular potential in battery manufacturing for stationary storage.
Research Strength as a Basis for Industrial Battery Production
The research work demonstrates the technological breadth of battery development in Germany – ranging from different cell chemistries to new production processes. What is decisive for industrial value creation, however, is whether such developments can be transferred from research scale into competitive series production.
Fraunhofer ISE Institute Director Prof. Dr. Andreas Bett also sees an industrial policy dimension in this. Germany should build up manufacturing capacity for growing battery demand and thereby retain value creation within the country. For the new electrode architecture, it will now be decisive whether the higher energy density and the manufacturing advantages are confirmed at further scale.
About the Joint Research Project
The development of the new electrode architecture is embedded in several research projects. The VORAN project, running until June 2027, focuses on sodium-ion batteries, while the completed InFAB and WinZIB2 projects deal with zinc-ion batteries.
In addition to Fraunhofer ISE, participants include the University of Stuttgart's Institute for Photovoltaics, the Karlsruhe Institute of Technology (KIT) with the Helmholtz Institute Ulm, and industry partners acp systems AG and Helmut Hechinger GmbH & Co. KG. VORAN and InFAB were funded by the Federal Ministry for Economic Affairs and Energy (BMWE); WinZIB2 was funded by today's Federal Ministry of Research, Technology and Space (BMFTR), formerly the Federal Ministry of Education and Research (BMBF).
Source: IWR Online, 11 Sep 2026
