Fraunhofer ISE’s New Electrode Design Delivers Up to 15% More Energy at the Same Battery Weight

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE, working with industry and research partners, have developed a new battery electrode architecture that could enable cells to store 10–15% more energy at the same weight. The approach has been demonstrated across lithium-ion, sodium-ion and zinc-ion battery chemistries.

The innovation focuses on increasing the thickness of the electrode coating while reducing the number of current collectors required inside the battery cell. Conventional anodes and cathodes typically consist of multiple alternating layers of electrode coating and current collectors. Fraunhofer ISE researchers increased the coating thickness from the conventional range of around 100–200 micrometers to as much as 800 micrometers.

By using fewer current collectors, more space within the cell becomes available for active material. According to the researchers, this can improve energy density by approximately 10–15%, depending on the battery chemistry and cell design.

From Laboratory Research to Pouch Cells

The team initially validated the electrode architecture using small laboratory cells based on zinc-ion, sodium-ion and lithium-ion chemistries. For lithium-ion technology, researchers went a step further by producing prototype pouch cells using industry-standard processes on Fraunhofer ISE’s semi-automated production line.

Importantly, the concept is not limited to one battery chemistry and could potentially be adapted to other cell technologies.

Cleaner and Potentially Lower-Cost Manufacturing

The electrodes developed under the research are PFAS-free and manufactured without toxic solvents. The architecture has also been designed with future industrial-scale production in mind.

Compared with conventional wet-coating production, a potential manufacturing line using the new approach could involve lower process complexity. Fraunhofer ISE says this could translate into lower capital expenditure as well as reduced operating costs, supported by lower space and energy requirements.

The researchers see this simplified manufacturing approach as potentially making battery-cell production more accessible to small and medium-sized companies.

Potential for Stationary Energy Storage

Beyond improving cell-level energy density, the technology could have relevance for the rapidly expanding stationary storage sector. Industry partner Helmut Hechinger GmbH & Co. KG sees potential for battery manufacturing focused particularly on stationary storage, subject to successful further scaling and validation.

With solar and wind penetration increasing, stationary batteries are becoming increasingly important for shifting renewable electricity and meeting demand during morning and evening peaks.

The research was advanced through the VORAN, INFAB and WinZIB2 projects, involving Fraunhofer ISE and partners including acp systems AG, Helmut Hechinger, the University of Stuttgart’s Institute for Photovoltaics and the Karlsruhe Institute of Technology/Helmholtz Institute Ulm.