Grid-scale Corrosion-free Zn/Br Flow Batteries Enabled by Multi-electron Transfer Reaction

Aqueous flow batteries are one of the most competitive technologies for storing electricity from intermittent renewable energy sources, which are intrinsically safe and scalable. Zinc/bromine flow batteries (Zn/Br FB) are popular due to the high theoretical energy densities (>500 Wh L-1) and inexpensive (600 cycles vs. <30 cycles) at 40 mA cm-2. Using this new bromine reaction, we built a large-scale battery system (5kW/6.6 kWh, EE 78%).