Fuel cell limiting co poisoning and poisoning diagnostic process

Patent metadata

Field	Value
Publication number	US-12230807-B2
Application number	US-202318100264-A
Country	US
Kind code	B2
Filing date	Jan 23, 2023
Priority date	May 30, 2018
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

A unit cell of a fuel cell may include: a membrane-electrode assembly including a proton exchange membrane, an anode electrode fastened to a first face of the proton exchange membrane, a first flow guide plate positioned facing the anode electrode and including at least one flow channel having a fuel inlet zone, a median flow zone and a fuel outlet zone. The anode electrode may have, at the fuel outlet zone, a tolerance to carbon monoxide pollution greater than its average tolerance to carbon monoxide pollution at the median flow zone and at the fuel inlet zone.

First claim

The invention claimed is:

1. A cell configured for a fuel cell, comprising:
a membrane-electrode assembly, comprising a proton exchange membrane, an anode electrode fixed to a first face of the proton exchange membrane, and a first flow guide plate arranged opposite the anode electrode, the first flow guide comprising a first flow channel having a fuel inlet zone, a first middle flow zone, and a fuel outlet zone; wherein
at the fuel outlet zone, the anode electrode has a carbon monoxide pollution tolerance greater than its average carbon monoxide pollution tolerance at the middle flow zone and at the fuel inlet zone,
the membrane-electrode assembly further comprises a cathode electrode fixed to a second face of the proton exchange membrane,
the cell further comprises a second flow guide plate arranged opposite the cathode electrode comprising a second flow channel,
the second flow channel comprises an oxidizer inlet zone, a second middle flow zone, and an oxidizer outlet zone,
the cathode electrode comprises a PtX alloy catalyst, X being a metal and a proportion of the metal X in the catalyst in the oxidizer outlet zone is lower than an average proportion of the metal X in the catalyst outside the oxidizer outlet zone, and
the metal X is cobalt.

2. The cell of claim 1 , wherein the cathode electrode comprises a zone having a catalyst loading greater than its average catalyst loading outside this zone.

3. The cell of claim 2 ,
wherein the zone of the cathode electrode having a greater catalyst loading is positioned at the oxidizer outlet zone.

4. The cell of claim 2 , wherein the oxidizer outlet zone of the cathode electrode is positioned vertically to the fuel inlet zone.

5. The cell of claim 2 , wherein the oxidizer inlet zone of the cathode electrode is positioned vertically to the fuel outlet zone, and
wherein the oxidizer inlet zone of the cathode electrode has a catalyst loading lower than its average catalyst loading outside this zone.

6. The cell of claim 1 , wherein the proportion of the metal X in the oxidizer outlet zone is at least two times lower than the average proportion of the metal X of the catalyst outside the oxidizer outlet zone.

7. The cell of claim 1 , wherein the anode electrode has, at the fuel outlet zone, a carbon monoxide tolerance at least 30% greater than its average carbon monoxide tolerance at the middle flow zone and at the fuel inlet zone.

8. The cell of claim 1 , wherein the anode electrode comprises PtRu at its outlet zone.

9. The cell of claim 1 , wherein the anode electrode has, at its outlet zone, a catalyst loading greater than its average loading outside the outlet zone.

10. The cell of claim 9 , wherein the anode electrode has, at its outlet zone, a catalyst loading at least 30% greater than its average loading outside the outlet zone.

11. A membrane-electrode assembly configured for implementing the fuel cell of claim 1 , the assembly comprising:
a proton exchange membrane; and
an anode electrode fixed to a first face of the proton exchange membrane, the anode electrode having, at a zone configured to be arranged at a fuel outlet, a carbon monoxide pollution tolerance greater than its average carbon monoxide pollution tolerance at a zone configured to be arranged at a middle flow zone and at a zone intended to be arranged at a fuel inlet.

12. A method for producing an optimized membrane/electrode assembly for a fuel cell, comprising:
simulating aging of a membrane/electrode assembly;
applying to a two-dimensional model of the fuel cell, a first dimension corresponding to a flow direction of a reagent, a second dimension corresponding to a thickness of the cell, cathode flow being modeled by a single flow channel, anode flow being modeled by a single flow channel, the two-dimensional model being configured to determine anode poisoning based on an amount of carbon monoxide in fuel;
using the two-dimensional model by applying it to a flow of fuel comprising carbon monoxide, so as to determine poisoning of the anode by carbon monoxide based on a position in the first dimension;
determining an optimized composition of catalyst layers at an anode and a cathode of the membrane/electrode assembly based upon results of the simulating and the applying and using the two-dimensional model; and
producing a membrane/electrode assembly with said optimized composition of catalyst layers at the anode and cathode.

Assignees

• Commissariat Energie Atomique

Inventors

• Escribano Sylvie
• Chandesris Marion
• Guetaz Laure
• Schott Pascal
• Scohy Marion

Classifications

• H01M8/1004

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

• H01M4/926

  on carbon or graphite · CPC title

• H01M4/921

  Alloys or mixtures with metallic elements · CPC title

• H01M4/8642 Primary

  Gradient in composition · CPC title

• Y02E60/50

  Fuel cells · CPC title