Polyarene mediators for mediated redox flow battery

Abstract

The fundamental charge storage mechanisms in a number of currently studied high energy redox couples are based on intercalation, conversion, or displacement reactions. With exception to certain metal-air chemistries, most often the active redox materials are stored physically in the electrochemical cell stack thereby lowering the practical gravimetric and volumetric energy density as a tradeoff to achieve reasonable power density. In a general embodiment, a mediated redox flow battery includes a series of secondary organic molecules that form highly reduced anionic radicals as reaction mediator pairs for the reduction and oxidation of primary high capacity redox species ex situ from the electrochemical cell stack. Arenes are reduced to stable anionic radicals that in turn reduce a primary anode to the charged state. The primary anode is then discharged using a second lower potential (more positive) arene. Compatible separators and solvents are also disclosed herein.

What is claimed is: 
     
         1 . A battery comprising:
 an anode including an anode chamber coupled to an anode current collector electrode;   a cathode including a cathode chamber coupled to a cathode current collector electrode; and   a separator disposed between the anode and cathode, the separator comprising polyethylene oxide.   
     
     
         2 . The battery of  claim 1 , wherein the battery is a redox flow battery. 
     
     
         3 . The battery of  claim 2 , wherein the anode chamber comprises a redox mediator dissolved in a solvent, the solvent selected from the group consisting of: tetrahydrofuran, dimethoxyethane, diglyme, triglyme, tetraethyleneglycol dimethylether, and mixtures thereof. 
     
     
         4 . The battery of  claim 1 , wherein the separator is a gel comprising the polyethylene oxide and tetraethyleneglycol dimethylether. 
     
     
         5 . The battery of  claim 3 , wherein the redox mediator comprises biphenyl.