Abstract
The renewed interest in RF batteries may lead to a promising technology for stationary applications if low-cost chemistries are identified for widespread deployment. For this to happen, systemic research rather than component-specific research is required. In this context, we note the introduction of organic redox couples such as quinones and others, dissolved in an aqueous or non-aqueous electrolyte, which are currently breathing new life into redox flow technology. In addition to their abundance and low cost, these molecules have the advantages of solubility, stability and adequate potential. What's more, the richness of their chemistry makes it possible to obtain a wide range of molecules with adjustable redox potentials. We have therefore defined selection criteria for these molecules, which include i) their weight equivalent for a given capacity, ii) the symmetry of the molecule for solubility reasons, iii) the size of the molecule to minimize their migration across the membrane, and iv) their multi-electron activity. This effort has also extended to polymer chemistry, with the study of aqueous RF batteries based on polymers and materials that are non-corrosive, safe and inexpensive.
