Electrochemical cells with improved fluid flow design

Patent metadata

Field	Value
Publication number	US-11476471-B2
Application number	US-201916249932-A
Country	US
Kind code	B2
Filing date	Jan 17, 2019
Priority date	Jan 17, 2018
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

An electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells include a membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer. The electrochemical cells also include an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer. The electrochemical cells further include a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure.

First claim

What is claimed is:

1. An electrochemical cell stack, comprising:
a plurality of electrochemical cells stacked along a longitudinal axis, each electrochemical cell comprising:
a membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer;
an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer;
a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure;
a first manifold section that includes an anode feed manifold and a second manifold section that includes an anode discharge manifold;
a first anode distribution channel positioned between the first manifold section and the anode flow field configured to distribute fuel supplied from the anode feed manifold to the anode flow field;
a second anode distribution channel positioned between the second manifold section and the anode flow field configured to collect fuel from the anode flow field and direct the fuel to the anode discharge manifold;
an anode inlet port fluidly connecting the first anode distribution channel with the anode feed manifold via an anode inlet passage, the anode inlet port being formed in a side wall of a support feature that protrudes from the surface of the anode plate into the first anode distribution channel toward the membrane electrode assembly; and
an anode outlet port fluidly connecting the second anode distribution channel with the anode discharge manifold via an anode outlet passage.

2. The electrochemical cell stack of claim 1 , wherein the anode inlet passage and anode outlet passage are positioned between the anode plate and the cathode plate of adjacent electrochemical cells.

3. The electrochemical cell stack of claim 1 , wherein the anode inlet port is configured to direct the anode reactant flow into the first anode distribution channel in a direction generally parallel to the anode plate.

4. The electrochemical cell stack of claim 3 , wherein the support feature is a generally rounded rectangular shape.

5. The electrochemical cell stack of claim 3 , wherein the support feature includes a plurality of anode inlet ports evenly distributed along a length of the side wall.

6. The electrochemical cell stack of claim 1 , wherein the anode outlet port is formed in a side wall of a support feature that protrudes from the surface of the anode plate into the first anode distribution channel toward the membrane electrode assembly.

7. The electrochemical cell stack of claim 6 , wherein the anode outlet port is configured to receive the anode reactant flow from the second anode distribution channel in a direction generally parallel to the anode plate.

8. The electrochemical cell stack of claim 6 , wherein the support feature includes a plurality of anode inlet ports evenly distributed along a length of the side wall.

9. An electrochemical cell stack, comprising:
a plurality of electrochemical cells stacked along a longitudinal axis, each electrochemical cell comprising:
a membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer;
an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer;
a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure;
a first manifold section that includes a cathode discharge manifold and a second manifold section that includes a cathode feed manifold;
a plurality of cathode inlet ports fluidly connecting the cathode flow field with the cathode feed manifold via a cathode inlet passage; and
a plurality of cathode outlet ports fluidly connecting the cathode flow field with the cathode discharge manifold via a cathode outlet passage;
wherein a total inlet area of the plurality of cathode inlet ports is greater than a total outlet area of the cathode outlet ports.

10. The electrochemical cell stack of claim 9 , wherein the cathode inlet passage and cathode outlet passage are positioned between the anode plate and the cathode plate of adjacent fuel cells.

11. The electrochemical cell stack of claim 9 , wherein the plurality of cathode inlet ports and the plurality of cathode outlet ports are rectangular shaped.

12. The electrochemical cell stack of claim 11 , wherein the plurality of cathode inlet ports includes at least two cathode inlet ports arranged perpendicular to one another and the plurality of cathode outlet ports includes at least two cathode outlet ports arranged perpendicular to one another.

13. The electrochemical cell stack of claim 9 , wherein the plurality of cathode inlet ports includes at least two cathode inlet ports positioned at opposite ends of the cathode inlet passage and the plurality of cathode outlet ports includes at least two cathode outlet ports positioned at opposite ends of the cathode inlet passage.

14. The electrochemical cell stack of claim 9 , wherein the porous structure includes at least nickel and chromium and the cathode plate of each cell is formed of uncoated stainless steel.

15. The electrochemical cell stack of claim 14 , wherein the porous structure includes a nickel concentration of 60% to 80% by mass and a chromium concentration of 20% to 40% by mass and at least one surface of the porous structure includes a chromium concentration of about 3% to about 50% by mass.

16. The electrochemical cell stack of claim 14 , wherein the porous structure includes a chromium concentration of about 3% to about 6%, a tin concentration of about 10% to about 20%, and a nickel concentration of about 74% to about 87%.

17. The electrochemical cell stack of claim 16 , wherein a first surface of the porous structure, which faces the membrane electrode assembly, has a higher chromium concentration than an opposite second surface and the first surface has a chromium concentration ranging from about 3% to about 50% by mass and the second surface has a chromium concentration less than about 3% by mass.

18. An electrochemical cell, comprising:
a membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer;
an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer; and
a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure;
a first manifold section that includes an anode feed manifold and a second manifold section that includes an anode discharge manifold;
a first anode distribution channel positioned between the first manifold section and the anode flow field configured to distribute fuel supplied from the anode feed manifold to the anode flow field;
a second anode distribution channel positioned between the second manifold section and the anode flow field configured to collect fuel from the anode flow field and direct the

Assignees

• Nuvera Fuel Cells Llc

Inventors

• Gambini Filippo

Classifications

• H01M8/0232

  Metals or alloys · CPC title

• H01M8/0258 Primary

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

• Y02E60/50

  Fuel cells · CPC title

• H01M8/1004

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• H01M8/241

  with solid or matrix-supported electrolytes · CPC title