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. Large-scale application of redox flow batteries is limited by its single profit model. Here, authors report an open loop flow battery with profitable potential, coupling energy storage with chemicals manufacturing in a single device.