Materials for high-performance aqueous organic redox flow batteries

Abstract

Quinones and related compounds for use in flow batteries are provided. Many of these compounds are found to mitigate the effects of crossover in a flow battery. Other structure for improving battery performance is provided.

1 - 14 . (canceled) 
     
     
         15 . A flow battery comprising:
 a positive electrode;   a positive electrode electrolyte including water and a first redox couple, the positive electrode electrolyte flowing over and contacting the positive electrode, the first redox couple including an organic compound having formula II and a reduction product of the organic compound, the organic compound having formula II being reduced during discharge;   a negative electrode; and   a negative electrode electrolyte including water and a second redox couple, the negative electrode electrolyte flowing over and contacting the positive electrode, the second redox couple also including an organic compound having formula II, a reduction product of the organic compound having formula I being oxidized to the organic compound during discharge:
   A-X—B  II
 
   
       wherein: 
       A is a substituted or unsubstituted flavins with substituents, quinoxaline with and without substituents, substituted anthraquinones, and substituted naphthaquinones; and 
       B is a substituted quinone. 
     
     
         16 . The flow battery of  claim 15  further comprising an ion exchange membrane interposed between the positive electrode and the negative electrode. 
     
     
         17 . The flow battery of  claim 16  wherein the ion exchange membrane has an equivalent weight greater than 1000 with respect to protogenic groups. 
     
     
         18 . The flow battery of  claim 15  wherein the positive electrode and/or the negative electrode include multi-walled carbon nanotubes. 
     
     
         19 . The flow battery of  claim 15  wherein the positive electrode and the negative electrode each independently includes water-soluble materials. 
     
     
         20 . The flow battery of  claim 19  wherein the water-soluble materials include carbon and a binder material. 
     
     
         21 . The flow battery of  claim 15  wherein the positive electrode electrolyte and the negative electrode electrolyte each independently include a molecule with different redox properties in various ranges of potentials. 
     
     
         22 . A flow battery comprising:
 a positive electrode;   a positive electrode electrolyte including water and a first redox couple, the positive electrode electrolyte flowing over and contacting the positive electrode, the first redox couple including a first organic compound and a reduction product of the first organic compound, the first organic compound being reduced during discharge:   a negative electrode; and   a negative electrode electrolyte including water and a second redox couple, the negative electrode electrolyte flowing over and contacting the positive electrode, the second redox couple also including a second organic compound, a reduction product of the second organic compound being oxidized to the second organic compound during discharge, one or both of the first organic compound and the second organic compound including a compound selected from the group consisting of:   
       
         
           
           
               
               
           
         
       
       and combinations thereof 
       wherein R 4 , R 5 , R 6 , and R 7  are each independently H, 
       
         
           
           
               
               
           
         
       
       —SO 3 H, —SO 3 Na, —SO 3 K, —CO 2 H, —CO 2 Na, —CO 2 K, —OH, —OMe, alkyl, (CH 2 CH 2 O) n OMe, NH 2 , NMe 2 , I, Cl, Br, F, —CF 3 , —CF 2 H, —NO 2 , —N(R) 3   + X 1   − , CCl 3 , —CN, —PO 3 H 2 , —COOH, —O − M +   2 , —SO 3   −1 M + , —PO 3   2− M +   2 , —COO − M + , —COOR, —CHO, or —COR where R is H or C 1-10  alkyl, M +  is a positively charged counter-ion, and X 1   −  is a negatively charge counter-ion. 
     
     
         23 . A flow battery comprising:
 a positive electrode;   a positive electrode electrolyte including water and a first redox couple, the positive electrode electrolyte flowing over and contacting the positive electrode, the first redox couple including a first organic compound and a reduction product of the first organic compound, the first organic compound being reduced during discharge:   a negative electrode; and   a negative electrode electrolyte including water and a second redox couple, the negative electrode electrolyte flowing over and contacting the positive electrode, the second redox couple also including a second organic compound, a reduction product of the second organic compound being oxidized to the second organic compound during discharge, one or both of the first organic compound and the second organic compound including a compound selected from the group consisting of:   
       
         
           
           
               
               
           
         
       
       and combinations thereof. 
     
     
         24 . The flow battery of  claim 23  further comprising an ion exchange membrane interposed between the positive electrode and the negative electrode. 
     
     
         25 . The flow battery of  claim 24  wherein the ion exchange membrane has an equivalent weight greater than 1000 with respect to protogenic groups. 
     
     
         26 . The flow battery of  claim 23  wherein the positive electrode and/or the negative electrode include multi-walled carbon nanotubes.