Redox flow batteries (RFBs) are rechargeable electrochemical systems in which two redox-active species, operating at disparate potentials, are dissolved or suspended in liquid electrolytes, stored in inexpensive tanks, and pumped through a power-converting electrochemical stack (reactor) where they are oxidized and reduced to charge and discharge the battery. We work on the science and engineering of the new generation of sustainable RFBs for long-duration energy storage, combining expertise in inorganic synthesis, solid-state chemistry, materials characterization, electrochemistry, electrochemical engineering, mechanical design and techno-economic modeling.