Solid polymer electrolyte fuel cell with improved voltage reversal tolerance

Patent metadata

Field	Value
Publication number	US-2017309924-A1
Application number	US-201715649150-A
Country	US
Kind code	A1
Filing date	Jul 13, 2017
Priority date	Jul 18, 2011
Publication date	Oct 26, 2017
Grant date	—

Abstract

In solid polymer electrolyte fuel cells, an oxygen evolution reaction (OER) catalyst may be incorporated at the anode along with the primary hydrogen oxidation catalyst for purposes of tolerance to voltage reversal. Incorporating this OER catalyst in a layer at the interface between the anode's primary hydrogen oxidation anode catalyst and its gas diffusion layer can provide greatly improved tolerance to voltage reversal for a given amount of OER catalyst. Further, this improvement can be gained without sacrificing cell performance.

First claim

What is claimed is:

1 . A solid polymer electrolyte fuel cell comprising a cathode, a solid polymer electrolyte, an anode, a cathode gas diffusion layer, and an anode gas diffusion layer, the anode comprising a primary catalyst composition for hydrogen oxidation and a secondary catalyst composition for oxygen evolution reaction, wherein: the primary catalyst composition is incorporated as a layer located adjacent the solid polymer electrolyte; the secondary catalyst composition is incorporated as a layer located between the primary catalyst composition and the anode gas diffusion layer; and the loading of the secondary catalyst composition is in the range from 1 to 90 micrograms/cm 2 .

2 . The fuel cell of claim 1 wherein the loading of the secondary catalyst composition is less than or about 40 micrograms/cm 2 .

3 . The fuel cell of claim 2 wherein the loading of the secondary catalyst composition is less than or about 20 micrograms/cm 2 .

4 . The fuel cell of claim 1 wherein the anode consists essentially of the primary catalyst composition layer and the secondary catalyst composition layer.

5 . The fuel cell of claim 1 wherein the anode gas diffusion layer comprises a microporous layer adjacent the secondary catalyst composition layer.

6 . The fuel cell of claim 1 wherein the primary catalyst composition is selected from the group consisting of Pt, Pd, and alloys thereof.

7 . The fuel cell of claim 6 wherein the primary catalyst composition is supported on a support selected from the group consisting of carbon, tungsten, perylene, and metal oxides.

8 . The fuel cell of claim 1 wherein the secondary catalyst composition is selected from the group consisting of RuIrO 2 , other ruthenium-iridium oxides with varied ratios of Ru to Ir, RuO 2 , IrO 2 , Ru, Ir, and solid solutions thereof.

9 . The fuel cell of claim 8 wherein the secondary catalyst composition is RuIrO 2 .

10 . A solid polymer electrolyte fuel cell comprising a cathode, a solid polymer electrolyte, an anode, a cathode gas diffusion layer, and an anode gas diffusion layer, the anode comprising a primary catalyst composition for hydrogen oxidation and a secondary catalyst composition for oxygen evolution reaction, wherein: the primary catalyst composition is incorporated as a layer located adjacent the solid polymer electrolyte; the secondary catalyst composition is incorporated as a layer located between the primary catalyst composition and the anode gas diffusion layer; and the loading of the secondary catalyst composition is in the range from 1 to 90 micrograms/cm 2 , wherein the secondary catalyst composition layer comprises less than 20 micrograms/cm 2 of carbon powder additive.

11 . The fuel cell of claim 1 wherein the secondary catalyst composition layer comprises perfluorosulfonic acid type polymer additive wherein the ratio of polymer additive to secondary catalyst composition is less than or about 0.1.

12 . A method of preparing the fuel cell of claim 1 comprising incorporating the primary catalyst composition on assembly as a layer located adjacent the solid polymer electrolyte; and incorporating the secondary catalyst composition on assembly as a layer located between the primary catalyst composition and the anode gas diffusion layer.

13 . A method of preparing the fuel cell of claim 12 comprising:
preparing a solid-liquid dispersion comprising the secondary catalyst composition and a carrier liquid; applying a coating of the dispersion to the primary catalyst composition layer or the anode gas diffusion layer; and removing the carrier liquid.

14 . The method of claim 13 comprising applying the coating of the dispersion to the anode gas diffusion layer.

15 . A method for improving durability while maintaining reversal tolerance of a solid polymer electrolyte fuel cell, the solid polymer electrolyte fuel cell comprising a cathode, a solid polymer electrolyte, an anode, a cathode gas diffusion layer, and an anode gas diffusion layer, the anode comprising a primary catalyst composition for hydrogen oxidation and a secondary catalyst composition for oxygen evolution reaction, and the method comprising:
incorporating the primary catalyst composition as a layer located adjacent the solid polymer electrolyte; incorporating the secondary catalyst composition as a layer located between the primary catalyst composition and the anode gas diffusion layer wherein the secondary catalyst composition layer is characterized by a loading of the secondary catalyst composition; and reducing the loading of the secondary catalyst composition to a value in the range from 1 to 90 micrograms/cm 2 .

16 . The fuel cell of claim 10 wherein the carbon powder additive is carbon black.

17 . A solid polymer electrolyte fuel cell comprising a cathode, a solid polymer electrolyte, an anode, a cathode gas diffusion layer, and an anode gas diffusion layer, the anode comprising a primary catalyst composition for hydrogen oxidation and a secondary catalyst composition for oxygen evolution reaction, wherein:
the primary catalyst composition is incorporated as a layer located adjacent the solid polymer electrolyte; the secondary catalyst composition is RuIrO 2 incorporated as a layer located between the primary catalyst composition and the anode gas diffusion layer; and the loading of the secondary catalyst composition is 20 micrograms/cm 2 .

Assignees

• Daimler Ag
• Ford Motor Co

Inventors

• Kundu Sumit
• Mcdermid Scott
• Yang Amy Shun-Wen
• Catoiu Liviu
• Susac Darija

Classifications

• H01M4/8828

  Coating with slurry or ink · CPC title

• H01M4/926 Primary

  on carbon or graphite · CPC title

• H01M4/925

  supported on carriers, e.g. powder carriers · CPC title

• H01M4/923

  Compounds thereof with non-metallic elements · CPC title

• H01M4/92

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title