PH-gradient-enabled microscale bipolar interfaces for direct liquid-fuel/oxidant fuel cells

Patent metadata

Field	Value
Publication number	US-11949136-B2
Application number	US-202017081174-A
Country	US
Kind code	B2
Filing date	Oct 27, 2020
Priority date	Apr 9, 2018
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

Described herein are direct liquid fuel cells with an alkaline anodic fuel stream including a solution of liquid fuel such as alcohols, ethers, glycols or compounds of hydrazine, and an acidic cathode oxidant stream including a solution of a suitable oxidant such as hydrogen peroxide or a gas steam with 1% to 100% O2. These cells are used as primary stationary and/or mobile power sources and also function in a secondary role as range extenders when coupled with a primary power source.

First claim

What is claimed is:

1. A method of electrochemical conversion from combining a solution of oxidant and a fuel source comprising a liquid fuel, the method comprising:
introducing either a solution of oxidant or a fuel source comprising a liquid fuel to a first electrode comprising a first catalyst coated by a first ion exchange ionomer; or
introducing either a solution of oxidant or a fuel source comprising a liquid fuel to a second electrode comprising a second catalyst coated by a second ion exchange ionomer;
wherein the first electrode and the second electrode are separated by an ion exchange membrane;
wherein the solution of oxidant or the fuel source is fed contacted with the electrodes in a single-pass mode or in a recycle mode; and
wherein the solution of oxidant and the fuel source comprising a liquid fuel are introduced in a fuel to oxidant flow rate ratio that is less than or equal to 33% of a stoichiometric fuel to oxidant flow rate ratio.

2. The method of claim 1 , wherein the first ion exchange ionomer and the second ion exchange ionomer are each independently selected from the group consisting of anion exchange ionomers and cation exchange ionomers.

3. The method of claim 2 , wherein the cation exchange ionomer comprises a material selected from the group consisting of sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene tri-block copolymer, sulfonated tetrafluoroethylene based-copolymer solution, sulfonated poly (phenylene oxide), sulfonated polysulfone, sulfonated poly (arylene ether ketone), sulfonated poly( 4 -phenoxybenzoyl-1,4-phenylene), and combinations thereof.

4. The method of claim 1 , wherein the ion exchange membrane is selected from the group consisting of cation exchange membranes, anion exchange membranes, microscale bipolar interfaces, and combinations thereof.

5. The method of claim 4 , wherein the first ion exchange ionomer and the second ion exchange ionomer are each independently selected from the group consisting of anion exchange ionomers and cation exchange ionomers, and wherein the anion exchange membrane or anion exchange ionomer comprises a material selected from the group consisting of a polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene tri-block copolymer-based backbone, poly (phenylene oxide)-based backbone, polysulfone-based backbone, poly(N,N-diallylazacycloalkane)-based backbone, bromoalkyl-tethered poly(biphenyl alkylene)-based backbone, multiblock copoly(arylene ether)-based backbone, poly (vinylbenzyl chloride)-based backbone, cardo-polyetherketone-based backbone, and combinations thereof.

6. The method of claim 4 , wherein the first ion exchange ionomer and the second ion exchange ionomer are each independently selected from the group consisting of anion exchange ionomers and cation exchange ionomers, and wherein the anion exchange membrane or anion exchange ionomer comprises a functional group selected from the group consisting of benzyl-trimethylammonium, benzyl-imidazolium, guanidium, benzyl-tris (2, 4, 6-trimethoxyphenyl) phosphonium, permethyl cobaltocenium, 1,4-dimethylpiperazinium, benzyl-trimethylphosphonium, and combinations thereof.

7. The method of claim 1 , wherein a reaction with a reduced or oxidized species from the first electrode and an oxidized or reduced species from the second electrode occurs at the ion exchange membrane.

8. The method of claim 7 , wherein the reaction results in splitting water, forming water, forming a compound produced by a half-cell reaction occurring at the first electrode and the second electrode, or forming a compound produced by an overall full cell reaction.

9. The method of claim 1 , wherein
the first catalyst is a metallic or a non-metallic particle or a metallic or a non-metallic film comprising a material selected from the group consisting of CoO, a noble metal, a metal alloy thereof, a metal mixture thereof, and a combination thereof; or
the second catalyst is a metallic or a non-metallic particle or a metallic or a non-metallic film comprising a material selected from the group consisting of CoO, a noble metal, a metal alloy thereof, a metal mixture thereof, and a combination thereof.

10. The method of claim 1 , wherein the first ion exchange ionomer or the second ion exchange ionomer comprises a material selected from the group consisting of:
a perfluorinated membrane having a thickness of 0.002 inches and a chemical formula of (C 7 HF 13 O 5 S·C 2 F 4 ) x in the following structural orientation, wherein the value of m/(m+n) is in the range of from about 0.001 to about 1:

a perfluorinated membrane having a thickness of 0.005 inches and a chemical formula of (C 7 HF 13 O 5 S·C 2 F 4 ) x in the following structural orientation, wherein the value of m/(m+n) is in the range of from about 0.001 to about 1:

a perfluorinated membrane having a thickness of 0.007 inches and a chemical formula of (C 7 HF 13 O 5 S·C 2 F 4 ) x in the following structural orientation, wherein the value of m/(m+n) is in the range of from about 0.001 to about 1:

sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene tri-block copolymer, sulfonated poly (phenylene oxide), poly(ethylene-co-tetrafluoroethylene)-graft-poly(styrene sulfonic acid), poly(vinylidene fluoride)-graft-poly(styrene sulfonic acid), sulfonated poly(arylene ether ether ketone), sulfonated poly( 4 -phenoxybenzoyl-1,4-phenylene), sulfonated polysulfone, and combinations thereof.

11. The method of claim 1 , wherein the first ion exchange ionomer coating or the second ion exchange ionomer coating is of a thickness and coverage sufficient to increase a pH gradient across the ion exchange membrane compared to a pH gradient without the first ion exchange ionomer coating or without the second ion exchange ionomer coating.

12. The method of claim 1 , wherein the first ion exchange ionomer coating or the second ion exchange ionomer coating is of a thickness and a coverage sufficient to provide a pH gradient of about 1 pH unit per nm of the ion exchange membrane.

13. The method of claim 1 , wherein the first ion exchange ionomer coating or the second ion exchange ionomer coating is of a thickness and a coverage sufficient to prevent catholyte contact with an anode active site.

14. The method of claim 1 , wherein the solution of oxidant comprises an oxidant selected from the group consisting of hydrogen peroxide, oxygen, and perchlorate.

15. The method of claim 1 , wherein the liquid fuel is selected from the group consisting of an alcohol, an ether, and hydrazine hydrate.

16. The method of claim 15 , wherein the alcohol is selected from the group consisting of glycol, methanol, and ethanol.

17. The method of claim 1 , wherein the concentration of the fuel source is in the range of from about 0.01 M to about 25 M.

18. The method of claim 1 , wherein the concentration of the fuel source is in the range of from about 0.1 M to about 10 M.

19. The method of claim 1 , wherein
the first catalyst is a metallic or a non-metallic particle or a metallic or a non-metallic film comprising a material selected from the group consisting of Ni, Pt, Pd, Ir, Au, Ag, CoO, a metal alloy thereof, a metal mixture thereof, and a combination there

Assignees

• Wang Zhongyang
• Ramani Vijay K
• SANKARASUBRAMANIAN Shrihari
• Washington University St Louis

Inventors

• Wang Zhongyang
• Ramani Vijay K
• SANKARASUBRAMANIAN Shrihari

Classifications

• H01M8/083 Primary

  Alkaline fuel cells · CPC title

• H01M8/1004

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

• H01M2300/0014

  Alkaline electrolytes · CPC title

• H01M2300/0082

  Organic polymers · CPC title

• H01M4/8668 Primary

  Binders · CPC title