A redox flow battery coupling energy storage and chemical manufacturing in a single device.

Redox flow batteries provide a competitive solution for renewable energy integration and grid fluctuations stabilization. However, the profit pattern solely relies on the grid price difference between peak and off-peak period. Herein, we report an open-loop flow battery coupling energy storage and chemical manufacturing in a single device. Specifically, we pair VO2+ reduction with organic compounds oxidation to value-added chemicals during discharging, and VO2+ oxidation with hydrogen evolution during charging. The battery demonstrates versatility across 13 organic substrates and compatibility with most typical posolytes. Taking VO2+/VO2+ pairing with ethylene glycol-to-glycolic acid conversion and H2 production as an example, the battery displays >100% voltage and energy efficiencies, and exhibits cycling stability over 200 cycles. By scaling up and integrating with a photovoltaic panel, the device produces 532.2 g of glycolic acid and 272.9 L of H2 over 10 days with daytime charging and nighttime discharging. Techno-economic analysis suggests that the system is profitable with a levelized cost of electricity of -0.26 $/kWh. This work demonstrates the profit pattern diversification potential of redox flow batteries by co-production of value-added chemicals and fuels.