Membrane electrode assembly and fuel cell comprising core-shell catalyst

Patent metadata

Field	Value
Publication number	US-11145873-B2
Application number	US-201816479881-A
Country	US
Kind code	B2
Filing date	Feb 19, 2018
Priority date	Feb 23, 2017
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

A membrane electrode assembly includes an electrolyte membrane, and a pair of electrodes sandwiching the electrolyte membrane. The pair of electrodes each include a catalyst layer, and a gas diffusion layer disposed on the catalyst layer on an opposite side to the electrolyte membrane. At least one of the catalyst layers contains first catalyst particles, and second catalyst particles. The first catalyst particles are either platinum particles or platinum alloy particles, or both. The second catalyst particles are core-shell particles having a core part and a shell part, the core part formed of at least one selected from transition metals other than platinum, the shell part covering the core part and formed of at least one of platinum and a platinum alloy. In the catalyst layer, the second catalyst particles are present in a smaller percentage in an electrolyte membrane side than they are in a gas diffusion layer side.

First claim

The invention claimed is:

1. A membrane electrode assembly comprising
an electrolyte membrane, and a pair of electrodes sandwiching the electrolyte membrane, wherein
the pair of electrodes each include a catalyst layer, and a gas diffusion layer disposed on the catalyst layer on an opposite side to the electrolyte membrane,
at least one of the catalyst layers of the pair of electrodes contains first catalyst particles, and second catalyst particles,
the first catalyst particles are either platinum particles or platinum alloy particles, or both,
the second catalyst particles are core-shell particles that have a core part and a shell part, the core part comprising at least one selected from the group consisting of transition metals other than platinum, the shell part covering the core part and comprising at least one of platinum and a platinum alloy, and
in the catalyst layer of at least one of the electrodes, the second catalyst particles are present in a smaller percentage in an electrolyte membrane side than they are in a gas diffusion layer side.

2. The membrane electrode assembly of claim 1 , wherein
the catalyst layer of at least one of the electrodes contains a proton-conductive resin, and
in said catalyst layer, the proton-conducive resin is present in a greater percentage in the electrolyte membrane side than it is in the gas diffusion layer side.

3. A membrane electrode assembly comprising
an electrolyte membrane, and a pair of electrodes sandwiching the electrolyte membrane, wherein
the pair of electrodes each include a catalyst layer, and a gas diffusion layer disposed on the catalyst layer on an opposite side to the electrolyte membrane,
at least one of the catalyst layers of the pair of electrodes contains first catalyst particles, and second catalyst particles,
the first catalyst particles are either platinum particles or platinum alloy particles, or both,
the second catalyst particles are core-shell particles that have a core part and a shell part, the core part comprising a transition metal other than platinum, the shell part covering the core part and comprising at least one of platinum and a platinum alloy, and
in the catalyst layer of at least one of the electrodes, the second catalyst particles are present in a smaller percentage in a gas inlet side of said catalyst layer than they are in a gas outlet side of said catalyst layer.

4. The membrane electrode assembly of claim 1 , wherein the transition metal is at least one selected from the group consisting of copper, iron, nickel, cobalt, ruthenium, rhodium, iridium, silver, and gold.

5. The membrane electrode assembly of claim 1 , wherein in the catalyst layer of at least one of the electrodes, the second catalyst particles are present in a smaller percentage than the first catalyst particles.

6. The membrane electrode assembly of claim 1 , wherein the second catalyst particles have a larger average particle size than the first catalyst particles.

7. A fuel cell comprising
the membrane electrode assembly of claim 1 , and
a pair of separators sandwiching the membrane electrode assembly.

8. The membrane electrode assembly of claim 3 , wherein the transition metal is at least one selected from the group consisting of copper, iron, nickel, cobalt, ruthenium, rhodium, iridium, silver, and gold.

9. The membrane electrode assembly of claim 3 , wherein in the catalyst layer of at least one of the electrodes, the second catalyst particles are present in a smaller percentage than the first catalyst particles.

10. The membrane electrode assembly of claim 3 , wherein the second catalyst particles have a larger average particle size than the first catalyst particles.

11. A fuel cell comprising
the membrane electrode assembly of claim 3 , and
a pair of separators sandwiching the membrane electrode assembly.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Yamasaki Kazuya
• Ishimoto Hitoshi
• Sakata Motohiro

Classifications

• H01M4/921 Primary

  Alloys or mixtures with metallic elements · CPC title

• H01M4/926

  on carbon or graphite · CPC title

• H01M8/1004

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

• H01M8/1007

  with both reactants being gaseous or vaporised (H01M8/12 takes precedence) · CPC title

• H01M4/8828

  Coating with slurry or ink · CPC title