Evaluation and improvement of the flow in vanadium redox-flow batteries
Vanadium redox-flow batteries (VFB) are a promising stationary energy storage technology, which allows a power input and output in the kW to MW range. The flow of electrolyte, which moves between the tanks and through the cells respectively the stack, is one important characteristic of redox-flow batteries (RFB). The efficient operation of VFB is only possible if the electrolyte is transported sufficiently. The mass transport towards the porous carbon electrodes is affected among others by the electrode structure, the implemented flow fields, and the operation conditions of the VFB. In principle, flow fields are well-known from fuel cells. Moreover, the effect of the flow field type and geometry on the RFB performance has already been discussed in literature.
The motivation of this project is the improvement of the VFB by adjustment of an existing flow field design. For this purpose, the flow in VFB is experimentally investigated, described and evaluated. In this context different experiments, such as optical measuerements and cell tests, as well as multidimensional models, for example CFD-simulations, are used. The final aim of this project is the improvement of cell performance and efficiency of VFB by an optimised flow field design with a simulationeous cost reduction.