Fraunhofer Institute for Solar Energy Systems ISEThe growing demand for stationary battery storage systems for the energy transition calls for safe, sustainable alternatives to lithium-ion batteries. In the collaborative project “ZACK,” GRILLO, Freudenberg, Dr. Hesse, Fraunhofer ISE, the University of Stuttgart, and the DECHEMA Research Institute are developing zinc-ion batteries with water-based electrolytes for stationary energy storage. By using sustainable raw materials available in the EU and innovative approaches from the electroplating industry, the project is creating a high-performance, safe storage solution for home storage, balancing power, and continuous power supply.
Zinc-Ion Batteries with Modified Interfaces Between Electrodes and Electrolyte
ZACK
Initial Situation
Approximately 95% of installed home storage systems are based on lithium-ion batteries. Their rapid spread is accompanied by safety-critical incidents and geopolitical dependencies on suppliers and critical raw materials such as lithium and cobalt, some of which are extracted under problematic conditions. Zinc-ion batteries (ZIB) with water-based electrolytes offer a sustainable alternative but face technical challenges: Corrosion and dendrite growth at the zinc anode, limited cycle stability, and pH-induced degradation shorten the service life. A comprehensive solution strategy has not yet been developed–innovative approaches to stabilizing the electrode-electrolyte interfaces are required.
Reaction mechanism of the underlying battery cell chemistry, which is to be optimized in the project regarding long-term stability.
Objective
"ZACK” is developing a competitive zinc-ion battery as a safe and sustainable alternative to lithium-ion storage systems for stationary applications. The focus is on stabilizing the cell chemistry–specifically the zinc anode, the electrode-electrolyte interface, and the separator–to significantly increase the number of charge-discharge cycles and the battery’s service life. Two complementary cathode platforms address different application areas: manganese dioxide for high capacity and Prussian blue analogs for high cell voltage. The goal is to develop an application-ready prototype (TRL 4–5) with over 10 Ah, more than 65 Wh/kg, and over 500 cycles, as well as material costs below 50 €/kWh–using only raw materials available in the EU.
Approach
The interdisciplinary consortium is addressing the entire chain–from materials to components to cells–in closely integrated iterative loops. GRILLO is developing corrosion-resistant zinc anodes; Dr. Hesse is applying proven principles of electroplating to electrolyte design; Freudenberg is functionalizing separators; and the DECHEMA Research Institute synthesizes high-performance MnO₂ cathode materials. Fraunhofer ISE develops gel and water-in-salt electrolytes as well as PBA cathodes, conducts in-situ cell tests (including pH measurements), and builds the multilayer prototypes, including safety and cost analyses. The University of Stuttgart supports the development with physical modeling for the targeted design of the electrolyte and cell.
Project Partner
- GRILLO Zinc Powder GmbH, Goslar
- Freudenberg Performance Materials GmbH & Co. KG, Weinheim
- Dr. Hesse GmbH & CIE KG, Bielefeld
- Fraunhofer-Institut für Solare Energiesysteme (ISE), Freiburg
- Universität Stuttgart - Institut für Photovoltaik (ipv), Stuttgart
- DECHEMA Forschungsinstitut, Bad Homburg
Associated Partner:
- acp systems AG, Zimmern o.R.
- Helmut Hechinger GmbH & Co. KG, Villingen-Schwenningen
Funding
The “ZACK” project is funded by the Federal Ministry of Economic Affairs and Energy (BMWE).
