Flow battery balancing cells having a bipolar membrane for simultaneous modification of a negative electrolyte solution and a positive electrolyte solution

Patent metadata

Field	Value
Publication number	US-2016308234-A1
Application number	US-201615098273-A
Country	US
Kind code	A1
Filing date	Apr 13, 2016
Priority date	Apr 14, 2015
Publication date	Oct 20, 2016
Grant date	—

Abstract

Parasitic reactions, such as production of hydrogen and oxidation by oxygen, can occur under the operating conditions of flow batteries and other electrochemical systems. Such parasitic reactions can undesirably impact operating performance by altering the pH and/or state of charge of one or both electrolyte solutions in a flow battery. Electrochemical balancing cells can allow rebalancing of electrolyte solutions to take place. Electrochemical balancing cells suitable for placement in fluid communication with both electrolyte solutions of a flow battery can include: a first chamber containing a first electrode, a second chamber containing a second electrode, a third chamber disposed between the first chamber and the second chamber, an ion-selective membrane forming a first interface between the first chamber and the third chamber, and a bipolar membrane forming a second interface between the second chamber and the third chamber.

First claim

What is claimed is the following:

1 . A flow battery system comprising:
a first half-cell containing a first electrolyte solution; and a second half-cell containing a second electrolyte solution;
wherein both the first half-cell and the second half-cell are in fluid communication with an electrochemical balancing cell comprising:
a first chamber containing a first electrode;
a second chamber containing a second electrode;
a third chamber disposed between the first chamber and the second chamber:
an ion-selective membrane forming a first interface between the first chamber and the third chamber; and
a bipolar membrane forming a second interface between the second chamber and the third chamber;

wherein at least one of the first electrolyte solution and the second electrolyte solution comprises an aqueous electrolyte solution.

2 . The flow battery system of claim 1 , wherein the ion-selective membrane comprises a cation-exchange material.

3 . The flow battery system of claim 2 , wherein the cation-exchange material comprises a sulfonated, perfluorinated polymer.

4 . The flow battery system of claim 1 , wherein the first electrolyte solution is a negative electrolyte solution, and the second electrolyte solution is a positive electrolyte solution.

5 . The flow battery system of claim 4 , wherein the first half-cell is in fluid communication with the first chamber and the second chamber, and the second half-cell is in fluid communication with the third chamber.

6 . The flow battery system of claim 4 , wherein the first half-cell is in fluid communication with the third chamber, and the second half-cell is in fluid communication with the first chamber and the second chamber.

7 . The flow battery system of claim 1 , wherein the first electrode is a negative electrode and the second electrode is a positive electrode.

8 . The flow battery system of claim 1 , wherein the first electrolyte solution and the second electrolyte solution each comprise an aqueous electrolyte solution.

9 . The flow battery system of claim 1 , wherein at least one of the firs electrolyte solution and the second electrolyte solution comprises a coordination complex as an active material.

10 . A method comprising:
providing an electrochemical balancing cell comprising:
a first chamber containing a first electrode;
a second chamber containing a second electrode;
a third chamber disposed between the first chamber and the second chamber;
an ion-selective membrane forming a first interface between the first chamber and the third chamber; and
a bipolar membrane forming a second interface between the second chamber and the third chamber;
introducing a first electrolyte solution comprising a first active material into the third chamber; introducing a second electrolyte solution comprising a second active material into the first chamber and the second chamber;
wherein at least one of the first electrolyte solution and the second electrolyte solution comprises an aqueous electrolyte solution;
applying a potential across the electrochemical balancing cell so as to induce a current therein, such that the second electrode is a positive electrode and the first electrode is a negative electrode; and converting water into protons and hydroxide ions at the bipolar membrane;
wherein the protons migrate into the first electrolyte solution in the third chamber and the hydroxide ions migrate into the second electrolyte solution in the second chamber.

11 . The method of claim 10 , further comprising:
placing the electrochemical balancing cell in fluid communication with a first half-cell and a second half-cell of a flow battery; and transferring the first electrolyte solution and the second electrolyte solution between the electrochemical balancing cell and the flow battery.

12 . The method of claim 11 , wherein the first electrolyte solution is transferred to a negative half-cell of the flow battery and the second electrolyte solution is transferred to a positive half-cell of the flow battery.

13 . The method of claim 11 , wherein the first electrolyte solution is transferred to a positive half-cell of the flow battery and the second electrolyte solution is transferred to a negative half-cell of the flow battery.

14 . The method of claim 10 , wherein the first electrolyte solution and the second electrolyte solution each comprise an aqueous electrolyte solution.

15 . The method of claim 10 , wherein at least one of the first electrolyte solution and the second electrolyte solution comprises a coordination complex as an active material.

16 . A method comprising:
providing an electrochemical balancing cell comprising:
a first chamber containing a first electrode;
a second chamber containing a second electrode;
a third chamber disposed between the first chamber and the second chamber;
an ion-selective membrane forming a first interface between the first chamber and the third chamber; and
a bipolar membrane forming a second interface between the second chamber and the third chamber;
introducing a first electrolyte solution comprising a first active material into e third chamber; introducing a second electrolyte solution comprising a second active material into the first chamber and the second chamber;
wherein at least one of the first electrolyte solution and the second electrolyte solution comprises an aqueous electrolyte solution;
providing hydrogen peroxide to the second chamber; applying a potential across the electrochemical balancing cell so as to induce a current therein, such that the second electrode is a positive electrode and the first electrode is a negative electrode; converting the hydrogen peroxide into protons and oxygen in the second chamber; and converting water into protons and hydroxide ions at the bipolar membrane;
wherein the protons formed at the bipolar membrane migrate into the first electrolyte solution in the third chamber and the hydroxide ions formed at the bipolar membrane migrate into the second electrolyte solution in the second chamber.

17 . The method of claim 16 , further comprising:
placing the electrochemical balancing cell in fluid communication with a first half-cell and a second half-cell of a flow battery; and transferring the first electrolyte solution and the second electrolyte solution between the electrochemical balancing cell and the flow battery.

18 . The method of claim 17 , wherein the first electrolyte solution is transferred to a positive half-cell of the flow battery and the second electrolyte solution is transferred to a negative half-cell of the flow battery.

19 . The method of claim 17 , wherein the first electrolyte solution is transferred to a negative half-cell of the flow battery and the second electrolyte solution is transferred to a positive half-cell of the flow battery.

20 . The method of claim 19 , wherein the second active material comprises an iron hexacyanide complex.

21 . The method of claim 7 , wherein the hydrogen peroxide is added to the second chamber.

22 . The method of claim 17 , wherein the hydrogen peroxide is added to a portion of the second electrolyte solution after being transferred from the flow battery but before entering the second chamber.

23 . The method of claim 16 , wherein the first electrolyte solution and the second electrolyte solution each comprise an aqueous electrolyte solution.

24 . The method

Assignees

• Lockheed Martin Advanced Energy Storage Llc

Inventors

• Reece Steven Y
• Goeltz John
• Pijpers Joseph Johannes Henricus
• Badrinarayanan Paravastu

Classifications

• H01M8/1023

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

• H01M8/1039

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

• H01M8/04186

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

• H01M8/0202

  Collectors; Separators, e.g. bipolar separators; Interconnectors · CPC title

• H01M8/188 Primary

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