Fuel cell with segregated electrolyte distribution and method for making the same

Patent metadata

Field	Value
Publication number	US-2018331368-A1
Application number	US-201715593383-A
Country	US
Kind code	A1
Filing date	May 12, 2017
Priority date	May 12, 2017
Publication date	Nov 15, 2018
Grant date	—

Abstract

A method of making a fuel cell including the following steps: comprising: (a) mixing carbon nanotubes (CNT) with an initial dispersion, wherein the initial dispersion includes an ionomer; (b) heating and stirring the initial dispersion to form a CNT-ionomer composite suspension; (c) after forming the CNT-ionomer composite suspension, mixing the CNT-ionomer composite suspension with an electrode catalyst solution to form an electrode ink, wherein the electrode catalyst solution includes a carbon black powder and a catalyst supported by the carbon black powder; and (d) coating a proton exchange membrane with the electrode ink to form the fuel cell electrode.

First claim

What is claimed is:

1 . A method of making a fuel cell electrode, comprising:
mixing carbon nanotubes (CNT) with an initial dispersion, wherein the initial dispersion includes an ionomer; heating and stirring the initial dispersion to form a CNT-ionomer composite suspension; after forming the CNT-ionomer composite suspension, mixing the CNT-ionomer composite suspension with an electrode catalyst solution to form an electrode ink, wherein the electrode catalyst solution includes a carbon black powder and a catalyst supported by the carbon black powder; and coating a proton exchange membrane with the electrode ink to form the fuel cell electrode.

2 . The method of claim 1 , wherein the ionomer is included in an ionomer dispersion, and the method further includes mixing water, n-propanol, and the ionomer dispersion to form the initial dispersion.

3 . The method of claim 2 , wherein:
mixing the water, the n-propanol, and the ionomer dispersion includes stirring the water, n-propanol, and the ionomer dispersion; mixing the carbon nanotubes with the initial dispersion includes adding the carbon nanotubes to the initial dispersion while stirring the initial dispersion; and the carbon nanotubes are graphitized carbon nanotubes.

4 . The method of claim 3 , wherein the initial dispersion includes 80 grams of the water, 8 grams of the n-propanol, and 1.8 grams of the graphitized carbon nanotubes.

5 . The method of claim 4 , wherein the carbon nanotubes are multi-wall carbon nanotubes having a diameter ranging between 10 nanometers and 20 nanometers.

6 . The method of claim 5 , wherein heating and stirring the initial dispersion includes stirring the initial dispersion with a magnetic stirrer rotating at 350 revolutions per minute.

7 . The method of claim 6 , wherein heating and stirring the initial dispersion includes heating the initial dispersion to a temperature ranging between 50 degrees Celsius and 100 degrees Celsius.

8 . The method of claim 7 , wherein heating and stirring the initial dispersion includes simultaneously heating and stirring the initial dispersion for 2.5 hours.

9 . The method of claim 8 , further comprising, after simultaneously heating and stirring the initial dispersion for 2.5 hours, continuing stirring the initial dispersion for 16 hours without heating the initial dispersion.

10 . The method of claim 9 , further comprising allowing the initial dispersion to cool through natural convection.

11 . The method of claim 10 , wherein allowing the initial dispersion to cool through natural convection and continuing stirring the initial dispersion for 16 hours without heating the initial dispersion occur simultaneously.

12 . The method of claim 11 , wherein the catalyst includes a plurality of platinum nanoparticles, and the plurality of platinum nanoparticles are deposited on the carbon black powder to form a catalyst-loaded carbon black powder.

13 . The method of claim 12 , wherein mixing the CNT-ionomer composite suspension with the electrode catalyst solution includes mixing the catalyst-loaded carbon black powder with water, n-propanol, and the CNT-ionomer composite suspension to form a segregated ionomer electrode coating.

14 . The method of claim 13 , wherein the segregated ionomer electrode coating includes 3.81 grams of the catalyst-loaded carbon black powder, 8.3 grams of n-propanol, 32.73 grams of water, and 56 grams of the CNT-ionomer composite suspension.

15 . The method of claim 14 , further comprising mixing the segregated ionomer electrode coating in a polymeric bottle containing ZrO 2 beads to form the electrode ink, wherein mixing the segregated ionomer electrode coating includes rolling the polymeric bottle, and the each of the ZrO 2 beads has a diameter of 5 millimeters.

16 . The method of claim 15 , wherein the coating the proton exchange membrane with the electrode ink while the electrode ink is still wet, and letting the electrode ink dry to form the fuel cell electrode.

17 . A fuel cell, comprising:
a proton-conductive polymer electrolyte membrane; an electrode disposed on the proton-conductive polymer electrolyte membrane, wherein the electrode includes:
a CNT-ionomer composite including carbon nanotubes and an ionomer coupled to the carbon nanotubes;
a carbon black powder coupled to the CNT-ionomer composite; and
a plurality of platinum nanoparticles supported by the carbon black powder, wherein the CNT-ionomer composite is coupled to the carbon black powder.

18 . The fuel cell of claim 17 , wherein each of the carbon nanotubes has a diameter ranging between 10 and 20 nanometers.

19 . The fuel cell of claim 17 , wherein the CNT-ionomer composite includes a sulfonated tetrafluoroethylene based fluoropolymer-copolymer.

20 . The fuel cell of claim 17 , wherein the proton-conductive polymer electrolyte membrane includes a sulfonated tetrafluoroethylene based fluoropolymer-copolymer.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Kongkanand Anusorn
• Carpenter Michael K

Classifications

• H01M8/1032

  having sulfur, e.g. sulfonated-polyethersulfones [S-PES] · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• B01J47/12

  characterised by the use of ion-exchange material in the form of ribbons, filaments, fibres or sheets, e.g. membranes (electrodialysis or electro-osmosis B01D61/42) · CPC title

• C08J5/225

  containing fluorine · CPC title

• B01J39/20

  obtained by reactions only involving unsaturated carbon-to-carbon bonds · CPC title