Membrane

Patent metadata

Field	Value
Publication number	US-10777833-B2
Application number	US-201515329850-A
Country	US
Kind code	B2
Filing date	Aug 4, 2015
Priority date	Aug 4, 2014
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

An electrolyte membrane including (i) a porous mat of nanofibres, wherein the nanofibres are composed of a non-ionically conducting heterocyclic-based polymer, the heterocyclic-based polymer comprising basic functional groups and being soluble in organic solvent; and (ii) an ion-conducting polymer which is a partially- or fully-fluorinated sulphonic acid polymer. The porous mat is essentially fully impregnated with ion-conducting polymer, and the thickness of the porous mat in the electrolyte membrane is distributed across at least 80% of the thickness of the electrolyte membrane. Such a membrane is of use in a proton exchange membrane fuel cell or an electrolyser.

First claim

The invention claimed is:

1. An electrolyte membrane comprising:
(i) a porous mat of entangled nanofibres, wherein the nanofibres are electrospun, and wherein the nanofibres are composed of a non-ionically conducting heterocyclic-based polymer, wherein the heterocyclic-based polymer is selected from the group consisting of polybenzimidazoles, poly(pyridine), poly(pyrimidine), polybenzthiazoles, polyoxadiazoles, polyquinolines, polyquinoxalines, polythiadiazoles, polytriazoles, polyoxazoles and polythiazoles and derivatives thereof, and the heterocyclic-based polymer comprising basic functional groups and being soluble in organic solvent, wherein the organic solvent is N-methylpyrrolidone, dimethylformamide, dimethylacetamide, or dimethyl sulphoxide; and
(ii) an ion-conducting polymer which is a partially- or fully-fluorinated sulphonic acid polymer;

wherein the porous mat is essentially fully impregnated with ion-conducting polymer, and wherein the thickness of the porous mat in the electrolyte membrane is distributed across at least 80% of the thickness of the electrolyte membrane.

2. The electrolyte membrane according to claim 1 , wherein the heterocyclic-based polymer is a polyazole or a derivative thereof.

3. The electrolyte membrane according to claim 2 , wherein the polyazole is selected from the group consisting of polybenzimidazole, polytriazole, polythiazole and polydithiazole and their derivatives.

4. The electrolyte membrane according to claim 1 , wherein the nanofibres have an average diameter of 100-400 nm.

5. The electrolyte membrane according to claim 1 , wherein the porous mat has a porosity in the range of 70-98%.

6. The electrolyte membrane according to claim 1 , wherein the porous mat has an average basis weight in the range 1.0 g/m2 to 7 g/m2.

7. The electrolyte membrane according to claim 1 , wherein the ratio of ion-conducting polymer:nanofibres in the electrolyte membrane is greater than 70:30.

8. A catalysed membrane comprising an electrolyte membrane according to claim 1 and a catalyst layer on a first and/or second face of the electrolyte membrane.

9. A membrane electrode assembly comprising an electrolyte membrane according to claim 1 and a gas diffusion electrode on a first and/or second face of the electrolyte membrane.

10. A membrane electrode assembly comprising a catalysed membrane according to claim 8 and a gas diffusion layer on the catalyst layer.

11. A proton exchange membrane fuel cell comprising an electrolyte membrane according claim 1 .

12. An electrolyser comprising an electrolyte membrane according to claim 1 .

13. A proton exchange membrane fuel cell comprising a catalysed membrane according to claim 8 .

14. A proton exchange membrane fuel cell comprising a membrane electrode assembly according to claim 9 .

15. A proton exchange membrane fuel cell comprising a membrane electrode assembly according to claim 10 .

Assignees

• Johnson Matthey Fuel Cells Ltd
• Centre Nat Rech Scient
• Univ Montpellier

Inventors

• Jones Deborah
• Roziere Jacques
• Cavaliere Sara
• Subianto Surya
• Burton Sarah

Classifications

• B01D69/1214

  Chemically bonded layers, e.g. cross-linking · CPC title

• H01M8/1032

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

• H01M8/103

  having nitrogen, e.g. sulfonated polybenzimidazoles [S-PBI], polybenzimidazoles with phosphoric acid, sulfonated polyamides [S-PA] or sulfonated polyphosphazenes [S-PPh] · CPC title

• H01M8/1023 Primary

  having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes · CPC title

• H01M8/0289

  Means for holding the electrolyte (solid polymer electrolytes H01M8/1018) · CPC title