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Standardized methods for the recycling of batteries will be needed for the large scale implementation of storage systems.


Due to the worldwide expansion of renewable energies, the demand for energy storage systems is on the rise. In addition to mobile phones and laptops, lithium-ion batteries are also used these days for electric mobility or for storing energy in private households. The advantage of this technology is its high-storage density. However, since lithium is considered a rare resource, prices are still correspondingly high.

Large-scale industrial plants, energy suppliers and operators of transmission networks (DSOs/TSOs), often rely on redox flow technology. This offers the advantage of low-cost scalability, even though these batteries use more resources than lithium batteries due to their relatively low storage density. A further advantage of the redox flow technology is that there are no significant losses even when stored for a relatively long period of time. In Baden-Württemberg near Karlsruhe, the Fraunhofer Institute for Chemical Technology operates a large-scale redox flow plant that stores locally generated wind power. In order to store up to 20 MWh, various tanks with a total capacity of nearly 700 m³ are required.

A German consortium of industry and science has now joined forces in the Re3dOx project to further reduce the costs of the system and the amount of material used in this technology and to give the technology a larger market share. The aim is to increase resource efficiency by improving reusability. To do this, all energy-intensive core components such as membranes, bipolar plates and electrolytes will be individually analysed and concepts developed to save material . In the laboratory, the components will be aged artificially as part of a life cycle assessment in order to gain new insights into the overall service life and reusability. For the reusable components, new production and reprocessing processes will also be developed.

The Federal Ministry for Economic Affairs and Energy supports the research between 2019-2022. At the end of the project, new products and knowledge about processes surely will find their way into this price sensitive market.