The aim of this project was to develop materials and the manufacturing process for new types of large-area bipolar plates for vanadium redox flow batteries (VFB). Plate sizes of 2 m² to 3 m² were aimed for. The technical objective was to develop a bipolar plate which, despite this special size, has sufficient mechanical stability and impermeability as well as sufficient electrical conductivity.

During the course of the project, the ICVT carried out the material tests using various in-situ and ex-situ methods. For example, the new bipolar plate materials were examined for their uniformity using conductivity mapping and their resistance in the electrolyte was ensured. The direct use of the bipolar plates in VFB was also investigated in parallelized full-cell tests.

In addition to the experimental work, the properties of large cells and large electrodes/plates were investigated using models. Since the actual scale-up of a VFB, i.e. the increase in the active cell area, leads to an increased pressure loss during the flow, the use of flow fields was investigated here, which should be extrudable in the best case.

Following the successful completion of the project described above, the follow-up joint project Re³dOx was launched on 01.09.2019.

Further information: Novel large-area bipolar plates in the extrusion process for redox flow batteries - "Extrusion plate": Final report