Stable positive side material for all-organic flow battery
A quinone derivative with a high redox potential that does not undergo Michael addition or proto-desulfonation. This molecule addresses the key issues faced with the positive side material of an aqueous all-organic flow battery. This new molecule is 2,5-dihydroxy-4,6-dimethylbenzene-1,3-disulfonic acid (or the disulfonate salt thereof). This quinone derivative offers good solubility, electrochemical reversibility, and robustness to charge/discharge cycling. Quinones with reduced crossover are also provided.
1. A flow battery comprising:
a positive electrode;
a positive electrode electrolyte including water and a first redox couple that includes a first organic compound, the first organic compound being a fully substituted sulfonated quinone, the positive electrode electrolyte flowing over and contacting the positive electrode;
a negative electrode;
a negative electrode electrolyte including water and a second redox couple, the negative electrode electrolyte flowing over and contacting the negative electrode; and
a polymer electrolyte membrane interposed between the positive electrode and the negative electrode, wherein the first organic compound is selected from the group consisting of compounds having formulae 1 and 2 with a reduction product H 2 Q 1 selected from compounds having formulae 1′ and 2′, respectively:
wherein R 1 , R 2 can be electron withdrawing groups or electron donating groups depending on a predetermined electrode potential.
2. The flow battery of claim 1 wherein R 1 , R 2 are each independently selected from the group consisting of —NO 2 , —N(R 3 ) 3 + X − , —CF 3 , CCl 3 , —CN, —SO 3 H, —PO 3 H 2 , —COOH, —OH, —O − M + , —SO 3 − M + , —PO 3 2− M + 2 , —COO − M + , —COOR 3 , F, Cl, and Br, where R 3 is H or C 1-10 alkyl, M + is a positively charged counter-ion.
3. The flow battery of claim 1 wherein R 1 , R 2 are each independently selected from the group consisting of C 1-10 alkyl, NH 2 , —NHR 2 , —N(R 2 ) 2 , —NHCOR 2 , —OR 2 , —CH 3 , —C 2 H 5 , and phenyl where R 2 is H or C 1-10 alkyl and M + is a positively charged counter-ion.
4. The flow battery of claim 1 wherein the first organic compound is selected from the group consisting of compounds having formulae 3 and a reduction product H 2 Q 1 is selected from compounds having formulae 3′:
wherein R 1 can be an electron withdrawing group or electron donating group depending on a predetermined electrode potential.
5. The flow battery of claim 4 wherein R 1 is —NO 2 , —N(R 3 ) 3 + X − , —CF 3 , CCl 3 , —CN, —SO 3 H, —PO 3 H 2 , —COOH, —OH, −O − M + , —SO 3 − M + , —PO 3 2− M + 2 , —COO − M + , —COOR 3 , F, Cl, Br, —CHO, or —COR 3 where R 3 is H or C 1-10 alkyl, M + is a positively charged counter-ion.
6. The flow battery of claim 4 wherein R 1 is C 1-10 alkyl, NH 2 , —NHR 2 , —N(R 2 ) 2 , —O − M + , —NHCOR 2 , —OR 2 , —CH 3 , —C 2 H 5 , or phenyl where R 2 is H or C 1-10 alkyl and M + is a positively charged counter-ion.
7. The flow battery of claim 1 wherein the first organic compound is selected from the group consisting of compounds having formulae 4 and a reduction product H 2 Q 1 is selected from compounds having formulae 4′:
wherein R 1 , R 2 can be electron withdrawing groups or electron donating groups depending on a predetermined electrode potential.
8. The flow battery of claim 7 wherein R 1 , R 2 are each independently selected from the group consisting of —NO 2 , —N(R 3 ) 3 + X − , —CF 3 , CCl 3 , —CN, —SO 3 H, —PO 3 H 2 , —COOH, —OH, —O − M + , —SO 3 − M + , —PO 3 2− M + 2 , —COO − M + , —COOR 3 , F, Cl, Br, —CHO, —COR 3 where R 3 is H or C 1-10 alkyl, M + is a positively charged counter-ion.
9. The flow battery of claim 4 wherein R 1 , R 2 are each independently selected C 1-10 alkyl, NH 2 , —NHR 2 , —N(R 2 ) 2 , —O − M + , —NHCOR 2 , —OR 2 , —CH 3 , —C 2 H 5 , or phenyl where R 2 is H or C 1-10 alkyl and M + is a positively charged counter-ion.
10. The flow battery of claim 1 wherein the second redox couple includes a sulfonated anthraquinone.
11. The flow battery of claim 1 wherein the second redox couple includes anthraquinones having formulae 5, 6, and 7 with H 2 Q 2 being reduced compounds thereof:
12. The flow battery of claim 1 wherein R 1 , R 2 are each C 1-10 alkyl.
13. The flow battery of claim 1 wherein R 1 , R 2 are each methyl, ethyl, propyl, or isopropyl.
14. The flow battery of claim 1 wherein first organic compound has the following formula:
15. The flow battery of claim 1 wherein first organic compound has the following formula: