Energy‐Enhanced Aqueous Organic Flow Batteries Enabled by Integrated Proton‐Coupled Electron Transfer‐Induced Carbon Capture and Utilization

ABSTRACT Aqueous organic redox flow batteries offer a safe, scalable, and potentially cost‐effective solution for storing massive electricity from intermittent renewables. Meanwhile, operating at ambient temperature and pressure, electrochemically induced carbon capture using aqueous redox sorbents in flow systems has recently emerged as a low‐energy technology for climate change mitigation. Integrating these two technologies within an aqueous organic flow system represents a unified route to achieving decarbonization. Here, employing organic molecules undergoing proton‐coupled electron transfer as redox species, we establish aqueous all‐organic flow battery systems that achieve enhanced energy storage as well as coupled CO 2 capture and utilization. During discharge, CO 2 from simulated flue gas is captured as HCO 3 − by the oxygen‐tolerant positive electrolyte (posolyte). The buffered posolyte prevents negative shifts in its redox potential, elevating a flow cell voltage up to 1.32 V, and enhancing discharge energy by at most 24.3% compared to operations under N 2 . During charge, CO 2 is released with a CO 2 / e molar ratio approaching unity at an energy cost of 30.65 kJ mol −1 CO 2 . As a proof‐of‐concept, our work establishes a new paradigm for integrating enhanced energy storage with carbon capture, utilization, and storage, paving the way for next‐generation multifunctional electrochemical redox flow systems.