Iron flow batteries

Patent metadata

Field	Value
Publication number	US-9559375-B2
Application number	US-201214122885-A
Country	US
Kind code	B2
Filing date	Jun 1, 2012
Priority date	Jun 1, 2011
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

An iron based redox flow cell. The redox flow cell comprises a first half-cell comprising a first electrolyte providing a source of Fe 2+ ions and an electrode disposed within the first half-cell; a second half-cell comprising a second electrolyte providing a source of Fe 2+ and Fe 3+ ions and an electrode disposed within the second half-cell; and a separator between the first and second half-cells, where (a) the second electrolyte comprises a Fe 3+ stabilizing agent; (b) the first electrolyte comprises a hydrogen evolution suppressing agent; or (c) the first electrolyte comprises a hydrogen evolution suppressing agent, and the second electrolyte comprises a Fe 3+ stabilizing agent.

First claim

What is claimed is:

1. An iron flow redox cell comprising:
a first half-cell comprising a first electrolyte providing a source of Fe 2+ ions and an electrode disposed within the first half-cell;
a second half-cell comprising a second electrolyte providing a source of Fe 2+ and Fe 3+ ions and an electrode disposed within the second half-cell;
a separator between the first and second half-cells;
a first storage tank external to the first half-cell for circulating the first electrolyte to and from the first half-cell;
a second storage tank external to the second half-cell for circulating the second electrolyte to and from the second half-cell;
wherein the first and second half-cells conduct an oxidation reduction reaction to charge and discharge the iron flow redox cell, wherein (a) the second electrolyte comprises a Fe 3+ stabilizing agent; (b) the first electrolyte comprises a hydrogen evolution suppressing agent; or (c) the first electrolyte comprises a hydrogen evolution suppressing agent, and the second electrolyte comprises a Fe 3+ stabilizing agent; and
wherein the electrode in the first half-cell comprises an aqueous slurry comprising electrically conductive particles, iron particles, iron coated particles, or a combination thereof.

2. The iron flow redox cell of claim 1 , comprising a Fe 3+ stabilizing agent chosen from cyanide, sucrose, glycerol, ethylene glycol, DMSO, acetate, oxalate, citrate, acetyl acetonate, fluoride, an amino acid, tartrate, malic acid, malonic acid, succinic acid, or a combination of two or more thereof.

3. The iron flow redox cell of claim 2 , wherein the Fe 3+ stabilizing agent comprises an amino acid chosen from glutamate, glycine, or a combination thereof.

4. The iron flow redox cell of claim 1 , wherein the concentration of Fe 3+ stabilizing agent is from about 0.01 M to about 10 M.

5. The iron flow redox cell of claim 1 wherein the concentration of Fe 3+ stabilizing agent is from about 0.1 M to about 5 M.

6. The iron flow redox cell of claim 1 , wherein the concentration of Fe 3+ stabilizing agent is from about 1 M to about 5 M.

7. The iron flow redox cell of claim 1 , further comprising a hydrogen evolution suppressing agent chosen from boric acid, a heavy metal, or a combination thereof.

8. The iron flow redox cell of claim 1 , wherein the hydrogen evolution suppressing agent is chosen from Pb, Bi, Mn, W, Cd, As, Sb, Sn, or a combination of two or more thereof.

9. The iron flow redox cell of claim 7 , comprising boric acid in a concentration of from about 0.1 M to about 5 M.

10. The iron flow redox cell of claim 7 , comprising a heavy metal in a concentration of from about 0.0001 M to about 0.1 M.

11. The iron flow redox cell of claim 1 , wherein the first electrolyte is an anolyte and the pH of the anolyte is from about 1 to about 6.

12. The iron flow redox cell of claim 1 , wherein the first electrolyte is an anolyte and the pH of the anolyte is from about 1 to about 1.8.

13. The iron flow redox cell of claim 1 , wherein the second electrolyte is a catholyte and the catholyte comprises a Fe 3+ stabilizing agent, and the pH of the anolyte is greater than 2.

14. The iron flow redox cell of claim 1 , wherein the electrically conductive particles are chosen from graphite particles.

15. The iron flow redox cell of claim 1 , wherein the electrode in the first half-cell comprises iron coated particles chosen from graphite, copper, titanium, or a combination of two or more thereof.

16. The iron flow redox cell of claim 1 , wherein the electrically conductive particles have a particle size of from about 1 micron to about 1500 mircons.

17. The iron flow redox cell of claim 1 having an energy to power ratio of from about 1:1 to about 10:1.

18. The iron flow redox cell of claim 1 having an energy to power ratio of from about 1:1 to about 5:1.

19. The iron flow redox cell of claim 1 having an energy to power ratio of from about 1:1 to about 3:1.

20. The iron flow redox cell of claim 1 having a plating capacity of from about 150 mAh/cm 2 to about 400 mAh/cm 2 .

21. The iron flow redox cell of claim 1 having a plating capacity of from about 150 mAh/cm 2 to about 200 mAh/cm 2 .

22. The iron flow redox cell of claim 1 having a plating efficiency of from about 60% to about 99%.

23. The iron flow redox cell of claim 1 having a watt-hour efficiency of about 40% to about 85%.

24. The iron flow redox cell of claim 20 , wherein the temperature of at least one of the first electrolyte and the second electrolyte is from about 20° C. to about 80° C. during operation of the cell.

25. A battery comprising one or more of the redox flow cells of claim 1 .

26. The iron flow redox cell of claim 1 , wherein slurry comprises a sufficient volume of particles to maintain electrical conductivity within the first half-cell.

27. The iron flow redox cell of claim 1 , wherein the electrically conductive particles have a particle size less than 1000 microns.

28. The iron flow redox cell of claim 1 , wherein the electrically conductive particles have an average particle size of about 100 microns.

Assignees

• Savinell Robert F
• Wainright Jesse S
• Univ Case Western Reserve

Inventors

• Savinell Robert F
• Wainright Jesse S

Classifications

• H01M8/04186

  of liquid-charged or electrolyte-charged reactants · CPC title

• H01M8/20

  Indirect fuel cells, e.g. fuel cells with redox couple being irreversible (H01M8/18 takes precedence) · CPC title

• H01M10/38

  Construction or manufacture · CPC title

• H01M8/188 Primary

  by recharging of redox couples containing fluids; Redox flow type batteries · CPC title

• Y02E60/528

  Cross-Sectional Technologies · mapped topic