Fraunhofer ISE Achieves Higher Energy Density in Battery Cells
Thicker electrodes increase the energy density of lithium-, sodium-, and zinc-ion batteries and open up new possibilities for stationary energy storage.
September 11, 2026
Source: E & M powernews
Researchers at Fraunhofer ISE have developed electrodes with a coating thickness of up to 800 micrometers. This could yield significant cost savings.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE (Fraunhofer ISE), in collaboration with research and industry partners, have developed an electrode architecture designed to store 10 to 15 percent more energy while maintaining the same cell weight. This is achieved through thicker electrode coatings and a reduced number of current collectors. The institute has tested the concept for lithium-ion, sodium-ion, and zinc-ion batteries, according to a recent press release from the institute.
In conventional battery cells, the anode and cathode consist of several thin layers of electrode coating and current collectors. The research team increased the thickness of the electrode coating from the previously standard 100 to 200 micrometers to up to 800 micrometers.
This has two effects: First, fewer current collectors are needed. Second, the space freed up can be used for additional active material. According to Fraunhofer ISE, this increases the energy density by 10 to 15 percent, depending on the battery type and design.
Concept Tested for Three Cell Chemistries
The researchers initially tested the electrode architecture using small laboratory cells based on lithium-ion, sodium-ion, and zinc-ion technology. For lithium-ion cells, the institute also manufactured pouch cell prototypes on a semi-automated production line in the Battery Materials and Cell Production Lab at Fraunhofer ISE. In pouch cells, the active layers are enclosed by a flexible outer foil, typically made of aluminum.
The electrodes are free of per- and polyfluorinated alkyl substances (PFAS). Furthermore, according to Fraunhofer ISE, the manufacturing process does not require any toxic solvents.
According to the institute, the architecture can also be adapted to other cell chemistries.
Simplified Electrode Production
In addition to energy density, the development aims to simplify production. According to the institute, a potential production line for the electrodes is expected to be less complex than today’s wet-coating systems. The reduced space and energy requirements are also expected to lower operating costs.
The research consortium’s industry partner is Helmut Hechinger GmbH & Co. KG. The machinery manufacturer ACP Systems AG is developing equipment for the production of the electrodes.
Hechinger sees a potential application particularly in stationary battery storage systems. “If the next scaling steps and validations show promising prospects in terms of both cost and performance, we could explore industrialization. We see great potential in Baden-Württemberg for battery production focused on stationary storage systems,” says Hechinger CEO Markus Duffner.
Prof. Dr. Andreas Bett, director of the Fraunhofer ISE, also sees great potential in this development: “In a climate-neutral energy system with fluctuating energy sources such as solar and wind, stationary battery storage systems are an integral part of covering morning and evening electricity peaks,” he is quoted as saying. “In California, for example, battery storage systems already supply most of the electricity in the evenings. Germany would do well to build up manufacturing capacity to meet the growing demand for batteries and thereby generate value added within the country.”
Development in Three Research Projects
The cell architecture was developed in the research projects “VORAN,” “INFAB,” and “WinZIB2.” VORAN investigates sodium-ion battery storage for stationary and mobile applications and will run through June 2027. INFAB and WinZIB2 focus on zinc-ion batteries and have already been completed.
In addition to Fraunhofer ISE, Hechinger, and ACP Systems, the University of Stuttgart with its Institute for Photovoltaics and the Karlsruhe Institute of Technology with the Helmholtz Institute Ulm were also involved.
The Federal Ministry for Economic Affairs and Energy (BMWE) funded the VORAN and INFAB projects. The Federal Ministry of Education and Research funded WinZIB2. The Baden-Württemberg Ministry of Economic Affairs also contributed to the research funding.
Author: Katia Meyer-Tien
