PFI-AIR-TT: A Non-Aqueous Redox Flow Battery Prototype

The integration of large-scale energy-storage systems with our nation's electrical grid is necessary for increased utilization of fluctuating, renewable energy sources such as solar and wind power to store power during times of low consumption and release it during peak user demand. Redox flow batteries (RFBs) are promising candidates for grid storage, with a few large-scale systems currently in operation. However, due to the high costs of vanadium-based active materials and the low charging voltages of aqueous-based RFBs, current systems have not met the cost requirements needed for widespread implementation. Replacing vanadium-based electro-active materials with organic components may lower the cost of components, and utilizing non-aqueous (aprotic) electrolyte solvents could enable a 2- to 3-fold increase in operating voltage; both features make non-aqueous RFBs candidates for large-scale stationary storage. In this PFI:AIR Technology Transfer project, we will design, create, and cycle a non-aqueous RFB containing organic electro-active materials developed at the University of Kentucky. We will synthesize these materials in kilogram batches, utilizing advice from collaborators at Argonne National Laboratory who specialize in large-scale synthesis. In tandem, we will utilize the expertise of our collaborators at Oak Ridge National Laboratory to design and build a prototype flow battery. Upon assembly of a prototype flow cell, we will perform cycling tests with non-aqueous electrolytes containing our custom-made electro-active species. These experiments will allow for materials analysis in a realistic environment, thus enabling us to determine limiting factors and feasibility of our current materials.