Mixed Valency and Electrostatic Repulsion as Design Principles for Redox Mediators in Heterogeneous Electrochemical Systems

M.R. Anstey, A.M. Greenwood, J. Nicoleau, N.A. Kennedy, J.C. Goodell, K.A. Dean, D.N. Blauch, M.R. Gau, P.J. Carroll, N.C. Tomson
Davidson College,
United States

Keywords: redox mediator, flow battery


Redox flow batteries, metal-air batteries, and many Beyond Lithium technologies are built around redox couples that span all normal phases of matter. Unfortunately, challenges arise in all heterogeneous systems due to the necessity to operate at gas, liquid, and solid interfaces. Due to these kinetic barriers, there is a demand for a catalyst to enable more efficient charge transport, reclaiming lost current and capacity. This work focuses on new redox mediators that can bridge the gap to improve stability, cyclability, and energy density in heterogeneous systems within all the core technologies. This presentation will describe (1) the concept of redox mediation and the ideal molecular features that lead to an enhancement of battery performance, (2) the synthesis and development of our first generation of redox mediators, (3) the measurements of redox activity and a correlation to stability and molecular structure, and (4) the preliminary results showing redox activity in the presence of ambient atmospheric oxygen.