Electrochemical Energy Storage Systems and Methods Featuring High Open Circuit Potential

• US 20140080035A1
• Filed: 07/24/2013
• Published: 03/20/2014
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Lockheed Martin Energy LLC (Martin Marietta Corporation)
• Original Assignee: Sun Catalytix Corporation (Martin Marietta Corporation)
• Inventors: ESSWEIN, ARTHUR J., REECE, STEVEN Y., GOELTZ, JOHN, KING, EVAN R., AMADEO, DESIREE, TYAGI, NITIN, JARVI, THOMAS D.
• Granted Patent: US 9,899,694 B2
• Time in Patent Office: Days
• US Class Current: 429/499
• 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: Y02E 60/50 Fuel cells

Abstract

The invention concerns flow batteries 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 the first aqueous electrolyte; a second electrode in contact with the second aqueous electrolyte and a separator disposed between the first aqueous electrolyte and the second aqueous electrolyte; the flow battery having an open circuit potential of at least 1.4 V, and is capable of operating or is operating at a current density at least about 50 mA/cm², wherein both of the first and second redox active materials remain soluble in both the charged and discharged states. In certain embodiments, the redox active materials are metal ligand coordination compounds. The disclosure also describes systems comprising these flow batteries and methods of them.

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;

said flow battery having an open circuit potential of at least about 1.4 V and being capable of operating or are operating at a current density of at least 50 mA/cm²; and

wherein both of the first and second redox active materials remain soluble in both the charged and discharged states.

2. The flow battery of claim 1, wherein at least one of said first electrode and said second electrodes is a carbon electrode.

3. The flow battery of claim 1 or 2, wherein the flow battery is adapted such that said first and second carbon electrodes remain substantially metal-free during operation of said flow battery.

4. The flow battery of claim 1, wherein at least one of said redox active materials is an organic compound substantially devoid of metal.

5. The flow battery of claim 1, wherein said redox active material comprises an aromatic compound.

6. The flow battery of claim 1, wherein at least one of said redox active materials is a metal ligand coordination compound.

7. The flow battery of claim 1 or 6 having an energy density of at least 30 watt hour/liter (Wh/L).

8. The flow battery of claim 1 or 6, wherein at least one of said first electrolyte or said second electrolyte is an aqueous electrolyte having a pH in a range of from about 1 to about 13.

9. The flow battery of claim 1 or 6, wherein said first electrolyte, said second electrolyte, or both first and second electrolyte is an aqueous electrolyte having a pH in a range of from about 8 to about 13.

10. The flow battery of claim 9, wherein the pH is in a range of from about 10 to about 12.

11. The flow battery of claim 10, wherein the pH is in a range of from about 10.5 to about 11.5.

12. The flow battery of claim 1 or 6, wherein the flow battery is capable of operating with a voltage efficiency of at least about 70%.

13. The flow battery of claim 1 or 6, wherein said separator comprises an ionomer.

14. The flow battery of claim 1 or 6, further comprising a second-electrolyte tank in fluidic communication with the second chamber and a first-electrolyte tank in fluidic communication with the first chamber.

15. The flow battery of claim 1 or 6, further comprising a pump of transporting a fluid between the second-electrolyte tank and the second chamber, between the first-electrolyte tank and the first chamber, or both.

16. A method of operating a flow battery of claim 1 or 6, said method comprising charging said battery by the input of electrical energy or discharging said battery by the removal of electrical energy.

17. A method of operating a flow battery of claim 1 or 6, said method comprising applying a potential difference across the first and second electrode, with an associated flow of electrons, so as to:

(a) reduce the first redox active material while oxidizing the second redox active material;

or

(b) oxidize the first redox active material while reducing the second redox active material.

18. A method of charging a flow battery of claim 1 or 6, with an associated flow of electrons, said method comprising applying a potential difference across the negative and positive electrode, so as to:

(a) reduce the first redox active material;

or

(b) oxidize the second redox active material;

or

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

19. A method of discharging the flow battery of claim 1 or 6, with an associated flow of electrons, said method comprising applying a electrical load across the negative and positive electrode so as to:

(a) oxidize the first redox active material;

or

(b) reduce the second redox active material;

or

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

20. A system comprising a flow battery of claim 1 or 6, 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 with 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) a power conditioning unit.

21. The system of claim 20, 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.

22. The system of claim 20, the system configured to provide stable power for remote camps, forward operating bases, off-grid telecommunications, or remote sensors.