TuRoX

The use of energy from renewable sources is strongly linked to fluctuating environmental influences. The simultaneous development of suitable energy storage systems is therefore a key element of the energy transition, as a temporary surplus of valuable energy remains usable. Redox flow batteries (RFB) are a flexible option for energy conversion and storage with rapidly growing research and development activities. By separating the capacity of the electrolyte stored in external tanks from the power resulting from the number and performance of the cells electrically connected to form "stacks", variably scalable storage systems in the range from kW/kWh to MW/MWh can be realized. In addition to the established vanadium electrolyte (VRFB), which has a high market penetration, alternative and in some cases organic electrolytes have recently reached market maturity.

Regardless of the electrolyte used, commercial systems share the planar design of the cells. However, their geometry poses a number of challenges, such as high production costs in relation to the cell output, long sealing lengths or ionic leakage currents in the series connections of the stacks.

These problems could be solved by using tubular cells produced by extrusion and corresponding systems. The BMWK joint project StaTuR of HAW Hamburg with external partners successfully demonstrated their feasibility. The X-Energy sub-project TuRoX builds on the partnership and further develops tubular redox flow cells and stacks with the aim of achieving a higher degree of technological maturity. Using a model-based design, supplier components from the partners and external contractors are to be aggregated into redox flow stacks for the vanadium electrolyte that are closer to the market and the transferability of the approach described above is to be evaluated using the example of an alternative, organic electrolyte.