Discovery and design of novel electrolytes is crucial for improvement in electrochemical energy storage systems such as redox flow batteries. Microemulsions, thermodynamically stable fluid aggregates consisting of oil, water, and emulsifiers, are being studied as electrolytes due to their unique properties. They allow for the incorporation of water-insoluble, nonpolar redox species in aqueous electrochemical systems, through dispersed oil domains. Microemulsions have nanoscopic heterogeneity, where nonpolar and polar regions are separated at the nanoscale by an amphiphile but are macroscopically homogeneous. Nonpolar redox species partition into the stable but dynamic nonpolar regions of the fluid, while salt dissolved in the aqueous region serves as a supporting electrolyte to maintain solution conductivity. The inherent complexity of these solutions raises fundamental questions about their behavior in electrochemical systems. An understanding of the interrelationship between composition, microstructure, and electrochemical behavior, is needed if these structured fluids are to be utilized as breakthrough electrolytes for energy storage. These relationships are probed through phase diagram behavior studies, spectroscopic analyses, and electroanalytical methods. It has been shown that composition and the related structure greatly influence the resulting electrochemical behavior of these systems. Furthermore, it is demonstrated that microemulsion composition alters electrochemical behavior, regardless of redox couple chemistry. Finally, the first demonstration of oil-soluble redox species used as the primary redox active components in microemulsion redox flow batteries will be presented. Polarization curve analysis, areal specific resistance measurements, and cycling identify key questions that will motivate second generation improvements in this technology.

Microemulsion electrolyte design for edox flow batteries

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.