PEMFC electrode mudcrack mitigation at low Pt loading

Patent metadata

Field	Value
Publication number	US-10381653-B2
Application number	US-201715447667-A
Country	US
Kind code	B2
Filing date	Mar 2, 2017
Priority date	Mar 2, 2017
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

An electrode ink composition that forms a fuel cell catalyst layer with reduced mudcracking is provided. The ink composition includes a solvent, a platinum group metal-containing catalyst composition dispersed in the solvent, a primary polymer dispersed within the solvent, the primary polymer being an ionomer, and a secondary polymer dispersed within the solvent, the secondary polymer interacting with the primary polymer via a non-covalent interaction.

First claim

What is claimed is:

1. An electrode ink composition comprising:
a solvent;
a platinum group metal-containing catalyst composition dispersed in the solvent;
a primary polymer dispersed within the solvent, the primary polymer being an ionomer; and
a secondary polymer dispersed within the solvent, the secondary polymer interacting with the primary polymer via ionic bonding;
wherein the primary polymer is described by formulae I or II:

 in which n is 1 to 10; m is 1, 2, or 3; o is 30 to 800; and p is 1, 2, or 3;
wherein the secondary polymer is a high molecular-weight polyvinyl-2-pyrrolidone having a weight average molecular weight greater than or equal to 400 kDa, and wherein the primary polymer and the secondary polymer are each independently present in an amount ranging from 1 weight percent to 20 weight percent based on a total weight of the electrode ink composition.

2. The electrode ink composition of claim 1 wherein the platinum group metal-containing catalyst composition includes platinum or a platinum alloy disposed on support particles.

3. The electrode ink composition of claim 1 wherein the secondary polymer has an overlap concentration that is from 5 times to 20 times lower than an overlap concentration of the primary polymer.

4. A fuel cell comprising:
an anode catalyst layer;
a cathode catalyst layer;
an ion conducting membrane interposed between anode catalyst layer and cathode catalyst layer;
a first gas diffusion layer is disposed over anode catalyst layer;
a second gas diffusion layer is disposed over the cathode catalyst layer;
an anode flow field plate is disposed over the first gas diffusion layer; and
a cathode flow field plate is disposed over the second gas diffusion layer, wherein at least one of the anode catalyst layer or the cathode catalyst layer include a platinum group metal-containing catalyst composition, a primary polymer that is an ionomer, and a secondary polymer, the secondary polymer interacting with the primary polymer via a non-covalent interaction when the primary polymer and the secondary polymer are dispersed in a solvent;
wherein the primary polymer is described by formulae I or II:

in which n is 1 to 10; m is 1, 2, or 3; o is 30 to 800; and p is 1, 2, or 3; and wherein the secondary polymer has an overlap concentration that is from 5 to 20 times lower than an overlap concentration of the primary polymer.

5. The fuel cell of claim 4 wherein the platinum group metal-containing catalyst composition includes platinum or a platinum alloy disposed on support particles.

6. The fuel cell of claim 4 wherein the secondary polymer is described by formula III:

wherein:
n is 1 to 10; and
m is 1, 2 or 3.

7. The fuel cell of claim 4 wherein the primary polymer is long side-chain polymer having an equivalent weight from 850 to 1050 g/mol and a weight average molecular weight from 250 to 500 kDa and the secondary polymer is a short side chain polymer having an equivalent weight from 500 to 850 g/mol and a weight average molecular weight from 300 to 2000 kDa or a long side chain polymer having an equivalent weight from 550 to 850 g/mol and a weight average molecular weight from 500 to 1500 kDa.

8. The fuel cell of claim 4 wherein the secondary polymer is a high molecular-weight polyvinyl-2-pyrrolidone having a weight average molecular weight greater than or equal to 400 kDa.

9. The fuel cell of claim 4 wherein the secondary polymer is selected from the group consisting of polyamides, polyamides-amines, poly(2-ethyl-2-oxazoline), poly(alkyl- and/or aryl-substituted oxazolines), poly(hydroxyalkyl acrylates), poly(hydroxyalkyl methacrylates), poly(hydroxyalkylethyleneimines), polyacrylamides, poly(dimethylaminoalkyl acrylates), poly(dimethylaminoalkyl methacrylates), poly(diallyldimethyl ammonium chloride), poly(aminophosphazenes), poly(alkylaminophosphazenes), and combinations thereof.

10. The fuel cell set forth in claim 4 , wherein the primary polymer and the secondary polymer are each independently present in an amount ranging from 1 weight percent to 20 weight percent based on a total weight of the platinum group metal-containing catalyst composition.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Koestner Roland J
• Kumaraguru Swaminatha P
• Kozhinova Irina A

Classifications

• H01M4/8803

  Supports for the deposition of the catalytic active composition (H01M4/90 takes precedence) · CPC title

• H01M8/1004

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

• H01M4/921

  Alloys or mixtures with metallic elements · CPC title

• H01M8/1041

  Polymer electrolyte composites, mixtures or blends · CPC title

• H01M8/1039

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