New organic redox pairs and their use at flow batteries

Abstract

Redox Flow Batteries (RFBs) are promising electrochemical devices for energy storage generated by renewable sources, which are remarkably intermittent. Among the advantages of RFBs in this application is the low cost of production, flexibility, mobility, fast response, simple design and safety advantages over commercial lithium-ion and lead-acid batteries. Since the 1970s, several efforts have been made to maximize the operation of flow batteries, and the study of new redox pairs is the most relevant. In this context, numerous redox pairs have already been developed for both aqueous and non-aqueous systems, including mainly metal cations, organometallic compounds, and organic molecules. The use of organic redox pairs in nonaqueous systems is interesting because these compounds can be modified structurally, aiming at the optimization of solubility, stability and redox potential, besides the non-aqueous solvents to allow larger potential window compared to water. Considering this context, this work aims to synthesize new organic redox pairs, based on computational studies, to be used in non-aqueous RFBs of organic solvents and ionic liquids, in addition to computationally studying the variables that control the charge and discharge process. (AU)