High Voltage Redox-Meditated Flow Batteries with Prussian Blue Solid Booster

This work presents Prussian blue solid boosters for use in high voltage redox-mediated flow batteries (RMFB) based on non-aqueous electrolytes. The system consisted of sodium iodide as a redox mediator in an acetonitrile catholyte containing solid Prussian blue powder. The combination enabled the solid booster utilization in the proposed systems to reach as high as 66 mAh g−1 for hydrated Prussian blue and 110 mAh g−1 for anhydrous rhombohedral Prussian blue in cells with an average potential of about 3 V (vs. Na+/Na). Though the boosted system suffers from capacity fading, it opens up possibilities to develop non-aqueous RMFB with low-cost materials.