(28b) Optical Techniques to Illuminate Improvements in Aqueous Organic Redox Flow Batteries

The global increase in renewable energy generation penetration has spurred research in emerging redox flow batteries (RFBs) technologies to address variability in electricity supply. Novel chemistries for aqueous organic RFBs are being explored as potentially inexpensive, long-lifetime electrolytes. However, both electrolyte and hardware engineering challenges remain for RFBs, which limit their feasibility for grid-scale operation. In this study we use optical techniques including absorption spectroscopy and fluorescence microscopy, coupled with electrochemistry, to illuminate molecular degradation, active species crossover, intermolecular interactions, and heterogeneous mass transport within operating RFBs. Through each of these, we develop electrolyte and hardware engineering solutions to significantly improve aqueous organic RFB performance. These optical techniques provide unique insight that is applicable to a variety of RFB chemistries and architectures, pushing the envelope toward a clean energy future.