Host‐Guest Interactions Enhance the Performance of Viologen Electrolytes for Aqueous Organic Redox Flow Batteries

Host-guest interactions are an attractive approach to design redox electrolytes, enabling precisely tune the key properties for flow batteries such as half-cell potential, solubility, and stability. Herein we report a host-guest complex of highly water soluble (2-hydroxypropyl)-β-cyclodextrin with 1-decyl-1′-ethyl-4,4′-bipyridinium dibromide anolyte in new aqueous organic battery (AORFB). The supramolecular ensured total RFB voltage increase ≈9 % up 0.97 V provided stable capacity delivery more than 500 cycles fade rate 0.037 %/cycle (2.84 %/day) at high Coulombic (>99.5 %) energy (>62 efficiencies. results highlight promising strategy towards effective storage renewable within AORFBs.