Fuel cell electrode and fuel cell system including a functionalized carbon support

Patent metadata

Field	Value
Publication number	US-12580204-B2
Application number	US-202318188668-A
Country	US
Kind code	B2
Filing date	Mar 23, 2023
Priority date	Mar 23, 2023
Publication date	Mar 17, 2026
Grant date	Mar 17, 2026

Abstract

An electrode for a fuel cell system is provided. The electrode includes a carbon support. The carbon support includes carbon particles each functionalized with one or more sulfur and oxygen-containing moieties. Platinum-based catalyst particles are disposed on the carbon support. Ionomer is disposed on the carbon support. A weight ratio of the ionomer to the carbon support is about 0.4 or less.

First claim

What is claimed is:

1 . An electrode for a fuel cell system, the electrode comprising:
a carbon support comprising:
a first plurality of carbon particles each functionalized with one or more sulfur and oxygen-containing moieties; and
a second plurality of carbon particles that are substantially free of any of the one or more sulfur and oxygen-containing moieties;
platinum-based catalyst particles disposed on the second plurality of carbon particles; wherein the first plurality of carbon particles that are functionalized are substantially free of any of the platinum-based catalyst particles; ionomer disposed on the carbon support, wherein a weight ratio of the ionomer to the carbon support is from about 0.2 to about 0.4; and a micro-porous substrate that is disposed adjacent to and supports a catalyst layer comprising the carbon support, the platinum-based catalyst particles, and the ionomer.

2 . The electrode of claim 1 , wherein the sulfur and oxygen-containing moieties include sulfate moieties and/or derivatives thereof.

3 . The electrode of claim 1 , wherein the sulfur and oxygen-containing moieties are chosen from sulfate moieties, sulfoxide moieties, sulfone moieties, sulfonic acid moieties, or combinations thereof.

4 . The electrode of claim 1 , wherein the first plurality of carbon particles have a degree of functionalization of the sulfur and oxygen-containing moieties of from about 0.2 to about 0.8.

5 . The electrode of claim 1 , wherein the weight ratio of the ionomer to the carbon support is about 0.2.

6 . The electrode of claim 1 , wherein the platinum-based catalyst particles comprise platinum metal or a platinum alloy.

7 . The electrode of claim 1 , wherein the platinum-based catalyst particles are present in the catalyst layer in an amount of from about 30 wt. % to about 50 wt. %, based on a weight of the carbon support.

8 . The electrode of claim 1 , wherein the electrode is a cathode.

9 . The electrode of claim 1 , wherein the electrode is an anode.

10 . The electrode of claim 1 , wherein the one or more sulfur and oxygen-containing moieties comprise sulfoxide, sulfone, or sulfonic acid functionality that exhibits X-ray photoelectron spectroscopy (XPS) absorption intensity peaks at wavenumbers of about 168.4 nm and about 169.8 nm.

11 . The electrode of claim 1 , wherein the electrode exhibits a proton transport resistance at 50% relative humidity that is at least 60% lower than a comparative electrode having non-functionalized carbon particles at the same weight ratio of ionomer to carbon support.

12 . A fuel cell system comprising:
a first electrode; a second electrode comprising:
a carbon support comprising:
a first plurality of carbon particles each functionalized with one or more sulfur and oxygen-containing moieties; and
a second plurality of carbon particles that are substantially free of any of the one or more sulfur and oxygen-containing moieties;

platinum-based catalyst particles disposed on the second plurality of carbon particles;
wherein the first plurality of carbon particles that are functionalized are substantially free of any of the platinum-based catalyst particles;
ionomer disposed on the carbon support, wherein a weight ratio of the ionomer to the carbon support is from about 0.2 about 0.4; and
a micro-porous substrate that is disposed adjacent to and supports a catalyst layer comprising the carbon support, the platinum-based catalyst particles, and the ionomer; and
a fuel cell membrane disposed between the first and second electrodes.

13 . The fuel cell system of claim 12 , wherein the ratio of the ionomer to the carbon support is about 0.2.

14 . The fuel cell system of claim 12 , wherein the one or more sulfur and oxygen-containing moieties comprise sulfoxide, sulfone, or sulfonic acid functionality that exhibits X-ray photoelectron spectroscopy (XPS) absorption intensity peaks at wavenumbers of about 168.4 nm and about 169.8 nm.

15 . The fuel cell system of claim 12 , wherein the second electrode exhibits a proton transport resistance at 50% relative humidity that is at least 60% lower than a comparative electrode having non-functionalized carbon particles at the same weight ratio of ionomer to carbon support.

16 . A method for making an electrode for a fuel cell system, the method comprising:
preparing an ionomer premix comprising an ionomer dispersed within a solvent; preparing a catalyst-functionalized carbon premix dispersed within additional solvent, the catalyst-functionalized carbon premix comprising:
platinum-based catalyst particles;
a first plurality of carbon particles each functionalized with one or more sulfur and oxygen-containing moieties; and
a second plurality of carbon particles that are substantially free of any of the one or more sulfur and oxygen-containing moieties;
wherein the platinum-based catalyst particles are disposed on the second plurality of carbon particles;
wherein the first plurality of carbon particles that are functionalized are substantially free of any of the platinum-based catalyst particles; and
combining the ionomer premix and the catalyst-functionalized carbon premix to form a catalyst ink having a weight ratio of the ionomer to the first plurality and second plurality of carbon particles of from about 0.2 to about 0.4.

17 . The method of claim 16 , further comprising milling the catalyst ink to reduce an average particle size(s) of the platinum-based catalyst particles and/or the first plurality of carbon particles and/or the second plurality of carbon particles.

18 . The method of claim 16 , further comprising:
casting the catalyst ink on a micro-porous substrate; and drying the catalyst ink to form a catalyst layer on the micro-porous substrate; wherein the catalyst layer comprises the platinum-based catalyst particles and the ionomer; wherein the micro-porous substrate is disposed adjacent to and supports the catalyst layer.

19 . The method of claim 16 , wherein preparing the catalyst-functionalized carbon premix comprises combining the additional solvent and the first plurality of carbon particles functionalized with the one or more sulfur and oxygen-containing moieties chosen from sulfate moieties, sulfoxide moieties, sulfone moieties, sulfonic acid moieties, or combinations thereof.

20 . The method of claim 16 , wherein combining comprises forming the catalyst ink having the weight ratio of the ionomer to the first plurality and second plurality of carbon particles of about 0.2.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Ramaswamy Nagappan
• Yarlagadda Venkata Raviteja
• Mellott Nathan
• Kumaraguru Swaminatha P

Classifications

• H01M4/8857 Primary

  Casting, e.g. tape casting, vacuum slip casting · CPC title

• H01M4/8882

  Heat treatment, e.g. drying, baking · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M4/8828

  Coating with slurry or ink · CPC title

• H01M4/926 Primary

  on carbon or graphite · CPC title