Driven electrochemical cell for electrolyte state of charge balance in energy storage devices

Patent metadata

Field	Value
Publication number	US-2016248109-A1
Application number	US-201415027229-A
Country	US
Kind code	A1
Filing date	Oct 28, 2014
Priority date	Nov 1, 2013
Publication date	Aug 25, 2016
Grant date	—

Abstract

The invention concerns redox flow batteries comprising one or more electrochemical cells in fluid contact with an electrochemical balancing cell, the balancing cell comprising: (i) a first electrode comprising a gas diffusion electrode and the first electrode comprising a hydrogen oxidation catalyst, wherein the first electrode being maintained at a potential more positive than the thermodynamic potential for hydrogen evolution; (ii) a second electrode, the second electrode contacting negative electrolyte, and the second electrode being maintained at a potential sufficiently negative to reduce the negative electrolyte; (iii) a membrane dis posed between the positive electrode and the negative electrode, the membrane suitable to allow hydrogen cations to flow from the membrane to the negative electrolyte; and (iv) a means for contacting hydrogen with the first electrode.

First claim

What is claimed:

1 . A redox flow battery comprising one or more electrochemical cells in fluid contact with an electrochemical balancing cell, said electrochemical balancing cell comprising:
a first electrode comprising a gas diffusion electrode and said first electrode comprising a hydrogen oxidation catalyst, said first electrode being maintained at a potential more positive than a thermodynamic potential for hydrogen evolution; a second electrode, said second electrode contacting a negative electrolyte, and said second electrode being maintained at a potential sufficiently negative to reduce the negative electrolyte; a membrane disposed between said first electrode and said second electrode, said membrane suitable to allow hydrogen cations to flow from the membrane to the negative electrolyte; and a means for contacting hydrogen with said first electrode.

2 . The redox flow battery of claim 1 , wherein said hydrogen oxidation catalyst comprises one or more precious metals.

3 . The redox flow battery of claim 2 , wherein said one or more precious metals comprise platinum or platinum containing alloys.

4 . The redox flow battery of claim 1 , wherein said second electrode comprises carbon.

5 . The redox flow battery of claim 4 , wherein said second electrode comprises non-functionalized carbon.

6 . The redox flow battery of claim 1 , wherein said membrane is an ion selective membrane.

7 . The redox flow battery of claim 1 , additionally comprising a power supply to supply energy to said first and second electrodes, said energy being sufficient to drive the balancing cell.

8 . The redox flow battery of claim 1 , wherein the first electrode is maintained at a potential to avoid corrosion of the hydrogen oxidation catalyst in the first electrode.

9 . The redox flow battery of claim 1 , wherein said means for contacting hydrogen with said first electrode utilizes hydrogen from head space gas of said one or more electrochemical cells as at least a portion of said hydrogen.

10 . A method for balancing the state of charge of a flow battery, said method comprising:
obtaining a hydrogen-containing gas, optionally produced as a byproduct of said flow battery; contacting said hydrogen-containing gas with a first electrode, said first electrode comprising carbon functionalized with a hydrogen oxidation catalyst, and said first electrode being maintained at a potential that is more positive than a thermodynamic potential for hydrogen evolution; contacting a negative electrolyte with a second electrode, said second electrode being maintained at a potential sufficiently negative to reduce the negative electrolyte; and applying a voltage to said first and second electrodes in an amount sufficient to drive said balancing;
wherein said first and second electrodes are separated by a membrane disposed between said first electrode and said second electrode, said membrane suitable to allow hydrogen cations to flow from the membrane to the negative electrolyte.

11 . The method of claim 10 , wherein said hydrogen oxidation catalyst comprises one or more precious metals.

12 . The method of claim 11 , wherein said one or more precious metals comprises platinum or platinum alloys.

13 . The method of claim 10 , wherein said second electrode comprises carbon.

14 . The method of claim 13 , wherein said second electrode comprises non-functionalized carbon.

15 . The method of claim 10 , wherein said membrane is an ion selective membrane.

16 . The method of claim 10 , wherein at least a portion of said hydrogen-containing gas is obtained as a byproduct of said flow battery.

Assignees

• Lockheed Martin Advanced Energy Storage Llc

Inventors

• Esswein Arthur J
• Goeltz John

Classifications

• H01M4/92 Primary

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title

• H01M16/00

  Structural combinations of different types of electrochemical generators · CPC title

• H01M8/188 Primary

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

• H01M8/1039

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

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title