Prediction of Pourbaix diagrams of quinones for redox flow battery by COSMO-RS

Redox-flow batteries are relevant to store energy from intermittent sources such as solar panels or wind turbines, thereby smoothing their supply. Up now, most redox-flow based on vanadium. Vanadium is a rare and expensive material, thus recent research has focused organic compounds and, in particular, anthraquinones electroactive materials. However, the tunability of chemistry poses needle-in-haystack challenge structures exhibiting desirable electrochemical properties may be hard pinpoint. Moreover, low water solubility readily available hinder use battery electrolytes. To aid endeavor, theoretical approach proposed predict Pourbaix diagrams redox-active compounds, allowing silico anticipation behavior entire pH range. DFT/COSMO-RS predicted pKa reduction potentials good agreement with experimental data, resulting calculated also 4 ones literature, proving reliability method. Finally, effect nature position some functional groups anthraquinone backbone discussed, illustrating power method both understand quantify activity redox active