Electrolyte Balancing Strategies For Flow Batteries

Patent metadata

Field	Value
Publication number	US-2024079620-A1
Application number	US-202318505711-A
Country	US
Kind code	A1
Filing date	Nov 9, 2023
Priority date	Sep 25, 2013
Publication date	Mar 7, 2024
Grant date	—

Abstract

The present invention is directed to a redox flow battery comprising at least one electrochemical cell in fluid communication with a balancing cell, said balancing cell comprising: a first and second half-cell chamber, wherein the first half-cell chamber comprises a first electrode in contact with a first aqueous electrolyte of the redox flow battery; and wherein the second half-cell chamber comprises a second electrode comprising a catalyst for the generation of O2; and wherein the second half-cell chamber does not contain an aqueous electrolyte.

First claim

1 . A redox flow battery comprising at least one electrochemical cell in fluid communication with a balancing cell, said balancing cell comprising:
a first and second half-cell chamber separated by a membrane, wherein the first half-cell chamber comprises a first electrode in contact with a first aqueous electrolyte of the redox flow battery; and wherein the second half-cell chamber comprises a second electrode comprising a catalyst for generation of O 2 ; and wherein the second half-cell chamber does not contain an aqueous electrolyte.

2 . The redox flow battery of claim 1 , wherein the membrane on the side of the second half-cell chamber is coated with a metal oxide.

3 . The redox flow battery of claim 2 , wherein the metal oxide comprises IrO x .

4 . The redox flow battery of claim 1 , wherein the membrane is arranged such that water transported from the first half-cell chamber across the membrane is directly oxidized into molecular oxygen and protons.

5 . The redox flow battery of claim 1 , wherein the second half-cell chamber comprises a vent configured for egress of oxygen evolved in the second half-cell chamber.

6 . The redox flow battery of claim 1 , wherein the first aqueous electrolyte has a pH in the range of from about 9 to about 14.

7 . The redox flow battery of claim 1 , wherein the first aqueous electrolyte comprises a negative working electrolyte of the redox flow battery.

8 . The redox flow battery of claim 1 , further comprising a porous medium located proximate or adjacent to the membrane in the first chamber, the porous medium providing enhanced convection in that region, leading to neutralization of protons that are injected into the first half-cell chamber.

9 . The redox flow battery of claim 1 , wherein the membrane comprises a sulfonated perfluorinated polymer or co-polymer.

10 . The redox flow battery of claim 1 , wherein the membrane comprises an ionomer.

11 . A working balancing cell, comprising:
a first and second half-cell chamber separated by a membrane, wherein the first half-cell chamber comprises a first electrode in contact with a first aqueous electrolyte of an electrochemical device; and wherein the second half-cell chamber is free of added aqueous electrolyte.

12 . The working balancing cell of claim 11 , wherein the membrane on the side of the second half-cell chamber is coated with a metal oxide.

13 . The working balancing cell of claim 12 , wherein the metal oxide comprises IrO x .

14 . The working balancing cell of claim 11 , wherein the membrane is arranged such that water transported from the first half-cell chamber across the membrane is directly oxidized into molecular oxygen and protons.

15 . The working balancing cell of claim 11 , wherein the second half-cell chamber comprises a vent configured for egress of oxygen evolved in the second half-cell chamber.

16 . The working balancing cell of claim 11 , wherein the first aqueous electrolyte has a pH in the range of from about 9 to about 14.

17 . The working balancing cell of claim 11 , wherein the first aqueous electrolyte comprises a negative working electrolyte of the electrochemical device.

18 . The working balancing cell of claim 11 , further comprising a porous medium located proximate or adjacent to the membrane in the first chamber, the porous medium providing enhanced convection in that region, leading to neutralization of protons that are injected into the first half-cell chamber.

19 . The working balancing cell of claim 11 , wherein the membrane comprises a sulfonated perfluorinated polymer or co-polymer.

20 . The working balancing cell of claim 11 , wherein the membrane comprises an ionomer.

Assignees

• Lockheed Martin Energy Llc

Inventors

• Reece Steven Y
• Badrinarayanan Paravastu
• Tyagi Nitin
• Grejtak Timothy B

Classifications

• H01M8/0693 Primary

  Treatment of the electrolyte residue, e.g. reconcentrating · CPC title

• H01M4/9016 Primary

  Oxides, hydroxides or oxygenated metallic salts · CPC title

• H01M8/04238

  Depolarisation · CPC title

• H01M8/1023

  having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes · CPC title

• H01M8/1039

  halogenated, e.g. sulfonated polyvinylidene fluorides · CPC title