Electrochemical cells having designed flow fields and methods for producing the same

Patent metadata

Field	Value
Publication number	US-10147957-B2
Application number	US-201615093604-A
Country	US
Kind code	B2
Filing date	Apr 7, 2016
Priority date	Apr 7, 2016
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

Electrochemical cells can include flow channels designed to provide an electrolyte solution more efficiently to an electrode or ionically conductive separator. Such electrochemical cells can include an ionically conductive separator disposed between a first half-cell and a second half-cell, a first bipolar plate in the first half-cell, and a second bipolar plate in the second half-cell. At least one of the first bipolar plate and the second bipolar plate are a composite containing a conductive material and a blocking material. The blocking material defines a plurality of flow channels that are spaced apart from one another and extend laterally through the composite with respect to the ionically conductive separator. The plurality of flow channels are also in fluid communication with one another in the composite. Such electrochemical cells can be incorporated in electrochemical stacks and/or be fluidly connected to a fluid inlet manifold and a fluid outlet manifold.

First claim

What is claimed is the following:

1. An electrochemical cell comprising:
an ionically conductive separator disposed between a first half-cell and a second half-cell; and
a first bipolar plate in the first half-cell and a second bipolar plate in the second half-cell, at least one of the first bipolar plate and the second bipolar plate being a porous composite comprising a porous conductive material and a blocking material;
wherein the porous conductive material provides less of an impediment to fluid flow than does the blocking material;
wherein the blocking material comprises a thermoplastic polymer;
wherein the blocking material defines a plurality of flow channels that are spaced apart from one another and extend laterally through the composite with respect to the ionically conductive separator;
wherein the plurality of flow channels are in fluid communication with one another through the porous composite;
wherein at least one of the plurality of flow channels has an inlet but no outlet and at least one of the plurality of flow channels has an outlet but no inlet; and
wherein at least some of the plurality of flow channels optionally contain the porous conductive material.

2. The electrochemical cell of claim 1 , wherein the porous conductive material comprises a non-woven carbon paper, a woven carbon cloth, a carbon felt, or a carbon foam.

3. The electrochemical cell of claim 1 , wherein the plurality of flow channels are substantially parallel to one another in the composite.

4. The electrochemical cell of claim 1 , further comprising:
a first electrode in the first half-cell and a second electrode in the second half-cell, the first electrode intervening between the first bipolar plate and the ionically conductive separator, and the second electrode intervening between the second bipolar plate and the ionically conductive separator.

5. The electrochemical cell of claim 4 , wherein the first bipolar plate is in contact with the first electrode, and the second bipolar plate is in contact with the second electrode.

6. The electrochemical cell of claim 1 , wherein the first bipolar plate and the second bipolar plate are in contact with opposing sides of the ionically conductive separator.

7. The electrochemical cell of claim 1 , wherein the blocking material is impregnated into the porous conductive material.

8. The electrochemical cell of claim 1 , wherein the blocking material comprises a layer upon the porous conductive material.

9. The electrochemical cell of claim 1 , further comprising:
a fluid inlet manifold configured to provide a first electrolyte solution to the first bipolar plate and a second electrolyte solution to the second bipolar plate; and
a fluid outlet manifold configured to withdraw the first electrolyte solution from the first bipolar plate and the second electrolyte solution from the second bipolar plate;
wherein the fluid inlet manifold and the fluid outlet manifold are configured to provide and to withdraw the first electrolyte solution and the second electrolyte solution from alternating flow channels within the composite.

10. The electrochemical cell of claim 9 , wherein the fluid inlet manifold and the fluid outlet manifold are configured to provide and to withdraw the first electrolyte solution and the second electrolyte solution on opposing lateral faces of the first bipolar plate and the second bipolar plate.

11. The electrochemical cell of claim 9 , further comprising:
one or more frame layers configured to hold the first bipolar plate in the first half-cell and to provide a fluidic seal therein, and one or more frame layers configured to hold the second bipolar plate in the second half-cell and to provide a fluidic seal therein;
wherein at least one of the frame layers in the first half-cell is configured to provide the first electrolyte solution to the first bipolar plate, and at least one of the frame layers in the second half-cell is configured to provide the second electrolyte solution to the second bipolar plate.

12. The electrochemical cell of claim 1 , further comprising:
one or more frame layers configured to hold the first bipolar plate in the first half-cell and to provide a fluidic seal therein, and one or more frame layers configured to hold the second bipolar plate in the second half-cell and to provide a fluidic seal therein.

13. An electrochemical stack comprising:
a plurality of the electrochemical cells of claim 1 abutted together with one another.

14. The electrochemical stack of claim 13 , further comprising:
an additional conductive layer disposed between adjacent electrochemical cells.

15. The electrochemical stack of claim 13 , wherein the electrochemical stack is present in a flow battery.

16. The electrochemical stack of claim 13 , further comprising:
a fluid inlet manifold configured to provide a first electrolyte solution to the first bipolar plate and a second electrolyte solution to the second bipolar plate; and
a fluid outlet manifold configured to withdraw the first electrolyte solution from the first bipolar plate and the second electrolyte solution from the second bipolar plate;
wherein the fluid inlet manifold and the fluid outlet manifold are configured to provide and to withdraw the first electrolyte solution and the second electrolyte solution from alternating flow channels within the porous composite.

17. A method comprising:
impregnating a blocking material into a portion of a porous conductive material to form a porous composite; and
fabricating an electrochemical cell comprising a first bipolar plate in a first half-cell and a second bipolar plate in a second half-cell, the first half-cell and the second half-cell being separated by an ionically conductive separator;
wherein the blocking material comprises a thermoplastic polymer;
wherein at least one of the first bipolar plate and the second bipolar plate comprises the porous composite;
wherein the blocking material defines a plurality of flow channels that are spaced apart from one another and extend laterally through the composite with respect to the ionically conductive separator;
wherein the plurality of flow channels are in fluid communication with one another through the porous composite;
wherein at least one of the plurality of flow channels has an inlet but no outlet and at least one of the plurality of flow channels has an outlet but no inlet; and
wherein at least some of the plurality of flow channels optionally contain the porous conductive material.

18. The method of claim 17 , wherein the electrochemical cell is fabricated from rolled source materials in a continuous production line.

19. The method of claim 18 , wherein the composite and the plurality of flow channels therein are also formed in the continuous production line before fabricating the electrochemical cell.

20. The method of claim 17 , wherein impregnating the blocking material comprises thermally impregnating the thermoplastic polymer into the conductive material.

21. The method of claim 17 , further comprising:
abutting a plurality of the electrochemical cells together with one another to form an electrochemical stack.

22. A method comprising:
disposing a blocking material in a layer upon a porous conductive material to form a porous composite;
removing a portion of the blocking material from the layer to define a plurality of flow channels that are spaced apart from one another; and
fabricating an electrochemical cell comprising a

Assignees

• Lockheed Martin Energy Llc

Inventors

• Madden Thomas H
• Badrinarayanan Paravastu
• Warrington Curtis
• Puranam Srivatsava

Classifications

• H01M8/2483

  characterised by internal manifolds · CPC title

• H01M8/188

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

• H01M8/0239

  Organic resins; Organic polymers · CPC title

• H01M8/0258 Primary

  characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant · CPC title

• H01M8/0241

  Composites · CPC title