Fuel Cell Electrode Having Increased Oxygen Concentration and Methods of Preparing Electrode

Patent metadata

Field	Value
Publication number	US-2018261852-A1
Application number	US-201715452177-A
Country	US
Kind code	A1
Filing date	Mar 7, 2017
Priority date	Mar 7, 2017
Publication date	Sep 13, 2018
Grant date	—

Abstract

A membrane electrode assembly includes a membrane, a gas diffusion layer and a catalyst layer between the membrane and the gas diffusion layer. The catalyst layer comprises catalyst comprising active catalyst particles supported on support particles, a proton conducting ionomer and a phospholipid containing soluble oxygen. One method of preparation includes preparing a catalyst solution comprising a solvent and catalyst, adding proton conducting ionomer to the catalyst solution to form a catalyst ink, saturating a solution of solvent and a phospholipid with oxygen and mixing the saturated phospholipid with the catalyst ink.

First claim

What is claimed is:

1 . A membrane electrode assembly, comprising:
a membrane; a gas diffusion layer; and a catalyst layer between the membrane and the gas diffusion layer, the catalyst layer comprising:
catalyst comprising active catalyst particles supported on support particles;
a proton conducting ionomer; and
a phospholipid containing soluble oxygen.

2 . The membrane electrode assembly of claim 1 , wherein the phospholipid is a phosphocholine.

3 . The membrane electrode assembly of claim 2 , wherein the phosphocholine is one of 1,2-dilauroyl-sn-glycero-3-phosphocholine, 1,2-dimyristoyl-sn-glycero-3-phosphocholine, 1,2-Dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-Distearoyl-sn-glycero-3-phosphocholine, and 1,2-Dioleoyl-sn-glycero-3-phosphocholine and mixtures thereof.

4 . The membrane electrode assembly of claim 1 , wherein the active catalyst particles are platinum, and a weight ratio of active catalyst particles to the phospholipid is greater than or equal to 0.2 and less than or equal to 0.4.

5 . The membrane electrode assembly of claim 1 , wherein a weight ratio of the proton conducting ionomer with the phospholipid to the support particles is greater than or equal to 0.6 and less than or equal to 1.2.

6 . The membrane electrode assembly of claim 1 , wherein a weight ratio of phospholipid to ionomer is greater than or equal to 0.2 and less than or equal to 0.6.

7 . The membrane electrode assembly of claim 1 , wherein the phospholipid is also a hydrogen conducting phospholipid, a weight ratio of hydrogen conducting phospholipid to ionomer being greater than or equal to 0.5 and less than or equal to 1.0.

8 . The membrane electrode assembly of claim 7 , wherein the hydrogen conducting phospholipid is a polyethylene glycol modified phospholipid.

9 . The membrane electrode assembly of claim 7 , wherein the hydrogen conducting phospholipid is a phospholipid into which a fluorinated aromatic amino acid is incorporated.

10 . The membrane electrode assembly of claim 9 , wherein the fluorinated aromatic amino acid is one of pentafluorophenylalanine and difluorotyrosine.

11 . The membrane electrode assembly of claim 7 , wherein the hydrogen conducting phospholipid is a phospholipid with a fatty acid bound on a polar head of the phospholipid with an ether linkage.

12 . The membrane electrode assembly of claim 11 , wherein the fatty acid is one or more of lauric acid, myristic acid, palmitic acid, oleic acid and phytanic acid.

13 . The membrane electrode assembly of claim 1 , wherein the catalyst layer has an active catalyst particle gradient such that a concentration of active catalyst particles is greatest toward the gas diffusion layer and lowest toward the membrane.

14 . The membrane electrode assembly of claim 13 , wherein the catalyst layer has a phospholipid gradient such that a concentration of the phospholipid is greatest toward the gas diffusion layer and lowest toward the membrane.

15 . A method of preparing a membrane electrode assembly, comprising:
preparing a catalyst solution comprising a solvent and catalyst; adding proton conducting ionomer to the catalyst solution to form a catalyst ink; saturating a solution of solvent and a phospholipid with oxygen; mixing the saturated phospholipid with the catalyst ink.

16 . The method of claim 15 , wherein the saturating comprises bubbling gas containing oxygen through the solution for at least two hours.

17 . The method of claim 15 , further comprising layering the mixed catalyst ink and saturated phospholipid onto one of a membrane and a gas diffusion layer using either electrospinning or electrospraying.

18 . The method of claim 15 , wherein the phospholipid is one of 1,2-dilauroyl-sn-glycero-3-phosphocholine, 1,2-dimyristoyl-sn-glycero-3-phosphocholine, 1,2-Dipalmitoyl-sn-glycero-3-phosphocholine, 1,2-Distearoyl-sn-glycero-3-phosphocholine, and 1,2-Dioleoyl-sn-glycero-3-phosphocholine and mixtures thereof.

19 . The method of claim 15 , wherein the active catalyst particles are platinum, and a weight ratio of active catalyst particles to the phospholipid is greater than or equal to 0.2 and less than or equal to 0.4.

20 . A method of preparing a membrane electrode assembly, comprising:
preparing a catalyst solution comprising a solvent and catalyst; saturating a solution of solvent and a phospholipid with oxygen; mixing proton conducting ionomer to the saturated phospholipid; depositing a catalyst solution comprising the solvent and the catalyst on one of a membrane and a gas diffusion layer; and depositing the mixture of proton conducting ionomer and the saturated phospholipid on the deposited catalyst solution.

Assignees

• Nissan North America Inc

Inventors

• Gumeci Cenk
• Kumar Amod
• Dale Nilesh

Classifications

• H01M4/921

  Alloys or mixtures with metallic elements · CPC title

• H01M4/8663 Primary

  Selection of inactive substances as ingredients for catalytic active masses, e.g. binders, fillers · CPC title

• H01M4/926

  on carbon or graphite · CPC title

• H01M4/8807

  Gas diffusion layers · CPC title

• H01M4/8828

  Coating with slurry or ink · CPC title