(103a) The Influence of Electrode Microstructure on the Performance of Non-Aqueous Redox Flow Batteries
To this end, we systematically compare the operando performance of RFBs containing selected carbon paper, felt, and cloth electrodes using the single-electrolyte cell configuration  and a model organic redox couple (TEMPO/TEMPO+) . Using polarization and electrochemical impedance spectroscopy, we quantify the impact of electrode microstructure on battery performance. We find that, depending on the electrode choice and flow conditions, current densities as high as 450 mA cm-2 can be achieved at an overpotential of 0.3 V with a cell area specific resistance as low as 0.7 Î© cm2. This result suggests that, through appropriate cell engineering and materials selection, high power performance may be realized in nonaqueous flow batteries. Finally, a simple convection-diffusion mass transport model is developed to explain the observed experimental behavior and provide guidance for the bottom-up design of next generation RFB electrodes.
We gratefully acknowledge the financial support of the Swiss National Science Foundation (P2EZP2_172183) and the Joint Center for Energy Storage Research (JCESR), an Energy Innovation Hub funded by the United States Department of Energy.
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