Three-chamber electrochemical balancing cells for simultaneous modification of state of charge and acidity within a flow battery

Patent metadata

Field	Value
Publication number	US-2017317363-A1
Application number	US-201615143344-A
Country	US
Kind code	A1
Filing date	Apr 29, 2016
Priority date	Apr 29, 2016
Publication date	Nov 2, 2017
Grant date	—

Abstract

Parasitic reactions, such as evolution of hydrogen at the negative electrode, 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 adjustment 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, a cation-selective membrane forming a first interface between the first chamber and the third chamber, and a bipolar membrane, a cation-selective membrane, or a membrane electrode assembly forming a second interface between the second chamber and the third chamber.

First claim

What is claimed is the following:

1 . 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; a first cation-selective membrane forming a first interface between the first chamber and the third chamber; and a bipolar membrane, a second cation-selective membrane, or a membrane electrode assembly forming a second interface between the second chamber and the third chamber.

2 . The electrochemical balancing cell of claim 1 , wherein a membrane electrode assembly forms the second interface;
wherein the membrane electrode assembly comprises a cation-selective membrane and an oxygen-formation catalyst.

3 . The electrochemical balancing cell of claim 2 , wherein the oxygen-formation catalyst comprises an iridium oxide catalyst.

4 . The electrochemical balancing cell of claim 1 , wherein a second cation-selective membrane forms the second interface.

5 . The electrochemical balancing cell of claim 4 , further comprising:
an oxygen-formation catalyst disposed in the second chamber.

6 . The electrochemical balancing cell of claim 1 , wherein a bipolar membrane forms the second interface.

7 . The electrochemical balancing cell of claim 6 , further comprising:
an oxygen-formation catalyst disposed in the second chamber.

8 . The electrochemical balancing cell of claim 7 , wherein the oxygen-formation catalyst comprises a nickel catalyst or a nickel-based catalyst.

9 . The electrochemical balancing cell of claim 1 , wherein at least one of the first cation-selective membrane and the second cation-selective membrane comprises a sulfonated, perfluorinated polymer or a sulfonated hydrocarbon.

10 . The electrochemical balancing cell of claim 1 , wherein the first electrode is a negative electrode and the second electrode is a positive electrode.

11 . 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;
a first cation-selective membrane forming a first interface between the first chamber and the third chamber; and
a bipolar membrane, a second cation-selective membrane, or a membrane electrode assembly forming a second interface between the second chamber and the third chamber;
wherein the first half-cell is in fluid communication with the first chamber and the second half-cell is in fluid communication with the third chamber.

12 . The flow battery system of claim 11 , wherein the first electrolyte solution is a positive electrolyte solution and the second electrolyte solution is a negative electrolyte solution.

13 . The flow battery system of claim 11 , wherein a membrane electrode assembly forms the second interface;
wherein the membrane electrode assembly comprises a cation-selective membrane and an oxygen-formation catalyst.

14 . The flow battery system of claim 13 , wherein the second chamber contains water or an acidic aqueous solution.

15 . The flow battery system of claim 11 , wherein a bipolar membrane or a second cation-selective membrane forms the second interface and the electrochemical balancing cell further comprises an oxygen-formation catalyst in the second chamber.

16 . The flow battery system of claim 15 , wherein the second chamber contains an alkaline aqueous solution when a bipolar membrane forms the second interface.

17 . The flow battery system of claim 15 , wherein the second chamber contains water or an acidic aqueous solution when a second cation-selective membrane forms the second interface.

18 . The flow battery system of claim 11 , wherein the first electrode is a negative electrode and the second electrode is a positive electrode.

19 . The flow battery system of claim 11 , wherein the first electrolyte solution and the second electrolyte solution each comprise an aqueous electrolyte solution.

20 . The flow battery system of claim 11 , wherein at least one of the first electrolyte solution and the second electrolyte solution comprises a coordination complex as an active material.

21 . 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;
a first cation-selective membrane forming a first interface between the first chamber and the third chamber; and
a membrane electrode assembly or a second cation-selective membrane forming a second interface between the second chamber and the third chamber;
wherein the membrane electrode assembly comprises a cation-selective membrane and an oxygen-formation catalyst, or an oxygen-formation catalyst is disposed in the second chamber when a second cation-selective membrane forms the second interface;

introducing a first electrolyte solution comprising a first active material into the first chamber; introducing a second electrolyte solution comprising a second active material into the third chamber; introducing water or an acidic aqueous solution into 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; and converting water into oxygen and protons in the second chamber and reducing the first active material in the first chamber under the potential;
wherein the protons migrate into the second electrolyte solution in the third chamber.

22 . The method of claim 21 , further comprising:
placing the electrochemical balancing cell in fluid communication with a first half-cell and a second half-cell of a flow battery;
wherein the first half-cell is a positive half-cell in fluid communication with the first chamber of the electrochemical balancing cell, and the second half-cell is a negative half-cell in fluid communication with the third chamber of the electrochemical balancing cell; and
transferring the first electrolyte solution and the second electrolyte solution between the electrochemical balancing cell and the flow battery.

23 . The method of claim 21 , wherein the first electrolyte solution and the second electrolyte solution each comprise an aqueous electrolyte solution.

24 . The method of claim 21 , wherein at least one of the first electrolyte solution and the second electrolyte solution comprises a coordination complex as an active material.

25 . 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;
a cation-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 an oxygen-formation catalyst is present in the second ch

Assignees

• Lockheed Martin Advanced Energy Storage Llc

Inventors

• Pijpers Joseph Johannes Henricus

Classifications

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/04276

  Arrangements for managing the electrolyte stream, e.g. heat exchange · CPC title

• H01M2300/0014

  Alkaline electrolytes · CPC title

• H01M8/188 Primary

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

• H01M8/04186 Primary

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