Method of forming catalyst layer by single step infiltration

Patent metadata

Field	Value
Publication number	US-9960428-B1
Application number	US-201615208912-A
Country	US
Kind code	B1
Filing date	Jul 13, 2016
Priority date	Jul 13, 2015
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

Provided herein is a method for electrocatalyst infiltration of a porous substrate, of particular use for preparation of a cathode for a solid oxide fuel cell. The method generally comprises preparing an electrocatalyst infiltrate solution comprising an electrocatalyst, surfactant, chelating agent, and a solvent; pretreating a porous mixed ionic-electric conductive substrate; and applying the electrocatalyst infiltration solution to the porous mixed ionic-electric conductive substrate.

First claim

We claim:

1. A method of electrocatalyst infiltration of a porous substrate comprising
preparing an electrocatalyst infiltration solution, where the electrocatalyst infiltration solution comprises:
a solvent,
an electrocatalyst, where the electrocatalyst is present in the concentration from about 0.2 M to about 1.0 M,
a chelating agent, where the chelating agent is present in a concentration from about 1:0.2 to about 1:1 mol fraction electrocatalyst to chelating agent, and
a surfactant, where the surfactant is present in a concentration from about 30% CMC to about 100% CMC;

pretreating a porous substrate, where the temperature of the porous substrate is from about 10° C. to about 40° C.; and,
applying the electrocatalyst infiltration solution to a porous substrate, where the porous substrate is mixed ionic-electronic conductive substrate, thereby forming a cathode.

2. The method of claim 1 where the cathode is a solid oxide fuel cell cathode.

3. The method of claim 1 where the cathode has an electrocatalyst threshold of from about 2 wt % to about 10 wt %.

4. The method of claim 1 where solid oxide fuel cell cathode has an electrocatalyst threshold of from about 6 wt % to about 10 wt %.

5. The method of claim 1 , where the porous substrate comprises an LSCF.

6. The method of claim 1 , where the porous substrate is an LSCF-SDC.

7. The method of claim 1 , where the temperature of the porous substrate is from about 15° C. to about 35° C.

8. The method of claim 1 , where the temperature of the porous substrate is from about 15° C. to about 30° C.

9. The method of claim 1 , where the electrocatalyst is a metal oxide or noble metal.

10. The method of claim 1 , where the electrocatalyst is a metal salt.

11. The method of claim 1 , where the electrocatalyst is LSCo.

12. The method of claim 1 , where the electrocatalyst is in a concentration from about 0.2 M to about 1.0M.

13. The method of claim 1 , where the electrocatalyst is present in a concentration from about 0.5 M to about 1.0M.

14. The method of claim 1 , where the electrocatalyst is present in a concentration from about 0.8 M to about 1.0M.

15. The method of claim 1 , where the surfactant is a nonionic surfactant.

16. The method of claim 1 , where the surfactant is Triton X-100.

17. The method of claim 1 , where the surfactant is present in a concentration from about 50% CMC to about 100% CMC.

18. The method of claim 1 , where the surfactant is present in a concentration from about 80% CMC to about 100% CMC.

19. The method of claim 1 , where the chelating agent is citric acid.

20. The method of claim 1 , where the chelating agent is present in a concentration from about 1:0.2 to about 1:0.5 mol fraction electrocatalyst to chelating agent.

21. The method of claim 1 , where the chelating agent is present in a concentration from about 1:0.25 to about 1:0.35 mol fraction electrocatalyst to chelating agent.

22. The method of claim 1 , where the electrocatalyst infiltration solution is applied by ultrasonic atomization.

23. The method of claim 1 , where the applying is by ultrasonic atomization and where the droplet size is in a range from about 10 microns to about 30 microns.

24. A method of electrocatalyst infiltration of a porous substrate comprising:
preparing an electrocatalyst infiltration solution, where the electrocatalyst infiltration solution comprises:
a solvent,
an electrocatalyst, where the electrocatalyst is a metal salt in the concentration from about 0.8 M to about 1.0 M,
a chelating agent, where the chelating agent is present in a concentration from about 1:0.25 to about 1:0.35 mol fraction electrocatalyst to chelating agent, and
a surfactant, where the surfactant is present in a concentration from about 80% CMC to about 100% CMC;

pretreating a porous substrate, where the temperature of the porous substrate is from about 15° C. to about 30° C.; and,
applying the electrocatalyst infiltration solution by ultrasonic atomization where the droplet size is in a range from about 10 microns to 30 microns, to a porous substrate, where the porous substrate is mixed ionic-electronic conductive substrate, thereby forming a solid oxide fuel cell cathode.

Assignees

• Us Energy
• Us Dept Energy

Inventors

• Gerdes Kirk
• Lee Shiwoo
• Dowd Regis

Classifications

• H01M8/12

  operating at high temperature, e.g. with stabilised ZrO2 electrolyte · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2250/10

  Fuel cells in stationary systems, e.g. emergency power source in plant · CPC title

• H01M4/8605 Primary

  Porous electrodes · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title