Diketopyrrolopyrrole Based Derivative for Non-Aqueous Redox Flow Battery

Abstract

Non-aqueous Redox Flow Batteries (RFBs) exploiting the wider electrochemical potential gap between catholyte and anolyte operate at higher cell voltages and lead to high energy and power densities with compelling energy efficiencies. However, stable anolytes are rare, primarily due to their low stability in presence of oxygen and moisture. The inherent atmospheric reactivity of anolyte puts a formidable demand to judiciously design molecules with high electron affinity and electrochemical stability. In this study, a non-aqueous organic RFB utilizing the redox pair is demonstrated employing commercially available Unisol blue (UB) dye (1,4-bis(isopropylamino) anthraquinone) as catholyte and air stable diketopyrrolopyrrole (DPP)-based derivative as anolyte. Cyclic voltammetry measurements with repeated sweep scans over 200 cycles are performed to find the redox potentials for both materials and electrochemical stability of the redox couple. The electrochemical performance of the RFB is studied by assembling cell with UB and DPP as redox pair. The study opens up a route to design/select molecules for non-aqueous RFBs.