AQUEOUS REDOX FLOW BATTERIES COMPRISING METAL LIGAND COORDINATION COMPOUNDS

• US 20140028260A1
• Filed: 07/23/2013
• Published: 01/30/2014
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Sun Catalytix Corporation (Martin Marietta Corporation)
• Inventors: GOELTZ, JOHN, AMADEO, DESIREE, ESSWEIN, ARTHUR J., JARVI, THOMAS D., KING, EVAN R., REECE, STEVEN Y., TYAGI, NITIN
• Granted Patent: US 9,768,463 B2
• Time in Patent Office: Days
• US Class Current: 320/127
• CPC Class Codes: H01M 8/08 Fuel cells with aqueous electrolytes
• CPC Class Codes: H01M 8/188 by recharging of redox couples containing fluids; Redox flow type batteries
• CPC Class Codes: H01M 8/20 Indirect fuel cells, e.g. fuel cells with redox couple being irreversible H01M8/18 takes precedence
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

This invention is directed to aqueous redox flow batteries comprising redox-active metal ligand coordination compounds. The compounds and configurations described herein enable flow batteries with performance and cost parameters that represent a significant improvement over that previous known in the art.

Claims

1. A flow battery comprising:

a first aqueous electrolyte comprising a first redox active material;

a second aqueous electrolyte comprising a second redox active material;

a first electrode in contact with said first aqueous electrolyte;

a second electrode in contact with said second aqueous electrolyte; and

a separator disposed between said first aqueous electrolyte and said second aqueous electrolyte;

wherein;

(a) each of the first and second redox active materials comprises a metal-ligand coordination compound that independently exhibits substantially reversible electrochemical kinetics;

or

(b) the first, second, or both redox active materials comprise a metal ligand coordination compound in concentrations of at least 0.75 M;

or

(c) the first, second, or both first and second redox active materials comprise a metal ligand coordination compound and said flow battery is capable of operating with a current density of at least 100 mA/cm² and a round trip voltage efficiency or at least 70%;

or

(d) the first, second, or both redox active materials comprise a metal ligand coordination compound and the separator has a thickness of 100 micron or less;

or

(e) the first, second, or both redox active materials comprise a metal ligand coordination compound and wherein the energy density of the electrolytes is at least 30 Wh/L;

or

(f) the flow battery comprises any combination of (a) through (e).

7. The flow battery of claim 1 or 2, wherein the first, the second, or both of the redox-active metal ligand coordination compounds comprises at least one ligand having a structure according to Formula IA, IB, or IC:

8. The flow battery of claim 7, wherein

X₁ and X₂ are both OH or an anion thereof;

R₁ is independently H, C_1-3 alkoxy, C_1-3 alkyl, a boric acid or a salt thereof, carboxy acid or a salt thereof, C_2-6 carboxylate, cyano, halo, hydroxyl, nitro, sulfonate, sulfonic acid or a salt thereof, phosphonate, phosphonic acid or a salt thereof, or a polyglycol; and

n is 1.

9. The flow battery of claim 1 or 2, where the first metal-ligand coordination compound comprises at least one ascorbate, a catecholate, citrate, a glycolate or polyol, gluconate, glycinate, α

-hydroxyalkanoate, β

-hydroxyalkanoate, γ

-hydroxyalkanoate, malate, maleate, phthalate, sarcosinate, salicylate, or lactate ligand.

10. The flow battery of claim 1 or 2, where the second metal-ligand coordination compound comprises at least one ascorbate, a catecholate, citrate, a glycolate or polyol, gluconate, glycinate, α

-hydroxyalkanoate, β

-hydroxyalkanoate, γ

-hydroxyalkanoate, malate, maleate, phthalate, sarcosinate, salicylate, or lactate ligand.

11. The flow battery of claim 1 or 2, where the first metal-ligand coordination compound comprises at least one ligand of Formula I, IA, IB, or IC.

12. The flow battery of claim 1 or 2, where the second metal-ligand coordination compound comprises at least one ligand of Formula I, IA, IB, or IC.

13. The flow battery of claim 1 or 2, wherein either the first or the second or both the first and second metal-ligand coordination compound comprises Al, Ca, Ce, Co, Cr, Fe, Mg, Mn, Mo, Si, Sn, Ti, W, Zn, or Zr.

14. The flow battery of claim 1 or 2, wherein the first metal-ligand coordination compound comprises Al³⁺, Ca²⁺, Ce⁴⁺, Co³⁺, Cr³⁺, Fe³⁺, Mg²⁺, Mn³⁺, Mo⁶⁺, Si⁴⁺, Sn⁴⁺, Ti⁴⁺, W⁶⁺, Zn²⁺, or Zr⁴⁺.

15. The flow battery of claim 1 or 2, wherein the second metal-ligand coordination compound comprises Al³⁺, Ca²⁺, Ce⁴⁺, Co³⁺, Cr³⁺, Fe³⁺, Mg²⁺, Mn³⁺, Mo⁶⁺, Si⁴⁺, Sn⁴⁺, Ti⁴⁺, W⁶⁺, Zn²⁺, or Zr⁴⁺.

16. The flow battery of claim 1 or 2, wherein the first metal-ligand coordination compound comprises Cr, Ti, or Fe.

17. The flow battery of claim 1 or 2, wherein the second metal-ligand coordination compound comprises Cr, Ti, or Fe.

18. The flow battery of claim 1 or 2, wherein the second metal-ligand coordination compound comprises an iron hexacyanide compound.

19. The flow battery of claim 1 or 2, wherein either the first or the second or both the first and second metal-ligand coordination compounds is characterized as having a hydrodynamic diameter and the separator is characterized as having a mean pore size, wherein the hydrodynamic diameter of the coordination compound is larger than the mean pore size of the separator.

20. The flow battery of claim 1 or 2, wherein either or both of the first or the second metal-ligand coordination compound are present in the first or second electrolyte, respectively, at a concentration of at least 0.75 M.

27. The flow battery of claim 1,

wherein the first, second, or first and second redox active material comprises a metal ligand coordination complex having a formula comprising M(L1)_X(L2)_y(L3)_z^m, where x, y, and z are independently 0, 1, 2, or 3, and 1≦

x+y+z≦

3; and

where M is Al, Ca, Ce, Co, Cr, Fe, Mg, Mn, Mo, S, Sn, Ti, W, Zn, or Zr;

L1, L2, and L3 are each independently ascorbate, a catecholate, citrate, a glycolate or polyol, gluconate, glycinate, α

-hydroxyalkanoate, β

-hydroxyalkanoate, γ

-hydroxyalkanoate, malate, maleate, phthalate, sarcosinate, salicylate, lactate or a compound having structure according to Formula I, or an oxidized or reduced form thereof;

28. The flow battery of claim 27, where (a) x=3, y=z=0;

(b) x=2, y=1, z=0;

(c) x=1, y=1, z=1;

(d) x=2, y=1, z=0;

(e) x=2, y=z=0;

or (f) x=1, y=z=0.

29. The flow battery of claim 1, wherein either the first or the second or both the first and second metal-ligand coordination compound comprises at least one ligand having a structure according to Formula I.

30. The flow battery of claim 28, wherein either or both of the redox-active metal ligand coordination compounds comprises at least one ligand having a structure according to Formula IA, IB, or IC:

31. The flow battery of claim 30, wherein

X₁ and X₂ are both OH or an anion thereof;

R₁ is independently H, C_1-3 alkoxy, C_1-3 alkyl, a boric acid or a salt thereof, carboxy acid or a salt thereof, C_2-6 carboxylate, cyano, halo, hydroxyl, nitro, sulfonate, sulfonic acid or a salt thereof, phosphonate, phosphonic acid or a salt thereof, or a polyglycol; and

n is 1.

32. The flow battery of claim 1 or 2, where the second metal-ligand coordination compound comprises at least one catechol or pyrogallol ligand.

33. The flow battery of any claim 1 or 2, wherein the second metal-ligand coordination compound is an iron hexacyanide compound.

34. The flow battery of claim 1 or 2, wherein either the first or the second or both the first and second metal-ligand coordination compounds is characterized as having a hydrodynamic diameter and the separator is characterized as having a mean pore size, wherein the hydrodynamic diameter of the coordination compound is larger than the mean pore size of the separator.

35. A system comprising a flow battery of claim 1 or 2, and further comprising:

(a) a first chamber containing the first aqueous electrolyte and a second chamber containing the second aqueous electrolyte;

(b) at least one electrolyte circulation loop in fluidic communication each electrolyte chamber, said at least one electrolyte circulation loop comprising storage tanks and piping for containing and transporting the electrolytes;

(c) control hardware and software; and

(d) an optional power conditioning unit.

36. The system of claim 35, the system connected to an electrical grid configured to provide renewables integration, peak load shifting, grid firming, baseload power generation/consumption, energy arbitrage, transmission and distribution asset deferral, weak grid support, frequency regulation, or a combination thereof.

37. The system of claim 35, the system configured to provide stable power for remote camps, forward operating bases, off-grid telecommunications, or remote sensors.

38. A method of operating a flow battery of claim 1 or 2, said method comprising charging said battery by the input of electrical energy or discharging said battery by the removal of electrical energy.

39. A method of charging a flow battery or system of claim 1 or 2, with an associated flow of electrons, said method comprising applying a potential difference across the first and second electrode, so as to:

(a) reduce the first redox active metal-ligand coordination compound;

or

(b) oxidize the second redox active metal-ligand coordination compound;

or

(c) both (a) and (b).

40. A method of discharging the flow battery or system of claim 1 or 2, with an associated flow of electrons, said method comprising applying a potential difference across the first and second electrode so as to:

(a) oxidize the first redox active metal-ligand coordination compound;

or

(b) reduce the second redox active metal-ligand coordination compound;

or

(c) both (a) and (b).

2. A flow battery comprising:

a first aqueous electrolyte comprising a first redox active material;

a second aqueous electrolyte comprising a second redox active material;

a first electrode in contact with said first aqueous electrolyte;

a second electrode in contact with said second aqueous electrolyte and a separator disposed between said first aqueous electrolyte and said second aqueous electrolyte;

wherein the first or second redox active material, or both the first and second redox active materials comprise a metal ligand coordination compound having a formula comprising M(L1)_x(L2)_y(L3)_z ^m, where M is independently a non-zero valent metal or metalloid of Groups 2-16, including lanthanides and actinides,

wherein x, y, and z are independently 0, 1, 2, or 3, and 1≦

x+y+z≦

3;

m is independently −

5, −

4, −

3, −

2, −

1, 0, 1, 2, 3, 4, or 5; and

L1, L2, and L3 are each independently ascorbate, citrate, a glycolate, gluconate, glycinate, α

-hydroxyalkanoate, β

-hydroxyalkanoate, γ

-hydroxyalkanoate, malate, maleate, phthalate, a polyol, sarcosinate, salicylate, lactate, or a compound having structure according to Formula I, or an oxidized or reduced form thereof;

3. The flow battery of claim 2, wherein the first and second redox active materials comprise a metal ligand coordination compound.

4. The flow battery of claim 2, wherein (a) x=3, y=z=0;

(b) x=2, y=1, z=0;

(c) x=1, y=1, z=1;

(d) x=2, y=1, z=0;

(e) x=2, y=z=0;

or (f) x=1, y=z=0.

5. The flow battery of claim 2, wherein the first aqueous electrolyte comprises a first metal-ligand coordination compound and the second aqueous electrolyte comprises a second metal-ligand coordination compound, wherein the first and second metal-ligand coordination compounds are different.

6. The flow battery of claim 2, wherein the first, the second, or both the first and second metal-ligand coordination compound comprises at least one ligand having a structure according to Formula I.

21. The flow battery of claim 2, wherein the first and second metal-ligand coordination compounds each exhibits substantially reversible electrochemical kinetics.

22. The flow battery of claim 2, wherein the cell exhibits a round trip voltage efficiency of at least 70%, when measured at 200 mA/cm².

23. The flow battery of claim 2, wherein the flow battery is capable of operating, or is operating, with a current density of at least 100 mA/cm² and a round trip voltage efficiency of at least 70%.

24. The flow battery of claim 2, wherein the separator has a thickness of about 100 micron or less.

25. The flow battery of claim 2, wherein the energy density of the electrolytes is at least about 30 Wh/L.

26. The flow battery of claim 2, wherein the cell retains at least 70% round trip voltage efficiency when subjected to 10 charge/discharge cycles.