COMPLEX ELECTROLYTE MEMBRANE FOR A FUEL CELL, METHOD FOR MANUFACTURING SAME, AND FUEL CELL INCLUDING SAME

• US 20130236798A1
• Filed: 10/05/2010
• Published: 09/12/2013
• Est. Priority Date: 10/05/2010
• Status: Active Grant

• Current Assignee: Industry Academic Cooperation Foundation
• Original Assignee: Industry Academic Cooperation Foundation
• Inventors: Han, Haksoo, Jeong, Minsu, Choi, Seung-Hyuk
• Granted Patent: US 9,368,821 B2
• Time in Patent Office: Days
• US Class Current: 429/408
• CPC Class Codes: C08J 2379/06 Polyhydrazides; Polytriazoles; Polyamino-triazoles; Polyoxadiazoles
• CPC Class Codes: C08J 5/2206 based on organic and/or inorganic macromolecular compounds
• CPC Class Codes: C08J 5/2256 based on macromolecular compounds obtained by reactions other than those involving carbon-to-carbon bonds, e.g. obtained by polycondensation
• CPC Class Codes: H01B 1/127 comprising five-membered aromatic rings in the main chain, e.g. polypyrroles, polythiophenes
• CPC Class Codes: H01B 1/128 comprising six-membered aromatic rings in the main chain, e.g. polyanilines, polyphenylenes
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 8/1018 Polymeric electrolyte materials
• CPC Class Codes: H01M 8/103 having nitrogen, e.g. sulfonated polybenzimidazoles [S-PBI], polybenzimidazoles with phosphoric acid, sulfonated polyamides [S-PA] or sulfonated polyphosphazenes [S-PPh]
• CPC Class Codes: H01M 8/1048 Ion-conducting additives, e.g. ion-conducting particles, heteropolyacids, metal phosphate or polybenzimidazole with phosphoric acid
• CPC Class Codes: H01M 8/1058 characterised by a porous support having no ion-conducting properties
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 20/141 Feedstock
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Disclosed is a composite electrolyte membrane for a fuel cell. The composite electrolyte membrane includes a polybenzimidazole-based polymer and a metal-grafted porous structure. The composite electrolyte membrane is doped with phosphoric acid. The metal-containing porous structure is present in an amount of 0.1 to 30% by weight, based on the weight of the polymer. The presence of the metal-containing porous structure allows the fuel cell electrolyte membrane to have excellent thermal properties and high proton conductivity.

Claims

1. A composite electrolyte membrane for a fuel cell which comprises a polybenzimidazole-based polymer and a metal-grafted porous structure and is doped with phosphoric acid wherein the metal-grafted porous structure is present in an amount of 0.1 to 30% by weight, based on the weight of the polymer.

2. The composite electrolyte membrane according to claim 1, wherein the polybenzimidazole-based polymer is selected from the group consisting of polybenzimidazole (PBI), poly(2,5-benzimidazole) (2,5-PBI), poly(2,6-benzimidazole) (2,6-PBI), and ABPBI.

3. The composite electrolyte membrane according to claim 1, wherein the metal is selected from the group consisting of aluminum, copper, iron, nickel, and combinations thereof.

4. The composite electrolyte membrane according to claim 1, wherein the metal-grafted porous structure is Al-MCM-41.

5. The composite electrolyte membrane according to claim 1, wherein the metal-grafted porous structure has a size of 900 nm or less.

16. A fuel cell employing the composite electrolyte membrane according to any one of claims 1 to 5.

6. A method for producing a composite electrolyte membrane for a fuel cell, comprising

forming a metal-grafted porous structure,

mixing the metal-grafted porous structure with a solution of a polybenzimidazole-based polymer to form a composite membrane, and

doping the composite membrane with phosphoric acid to impart ionic conductivity thereto.

7. The method according to claim 6, wherein the formation of the metal-grafted porous structure comprises:

adding a metal chloride to an aqueous solution of an alkyltrimethylammonium halide;

adding aqueous ammonia to the mixture, followed by stirring;

dropwise adding tetraethyl orthosilicate to the resulting mixture, followed by stirring; and

washing the reaction mixture, followed by drying and calcination to obtain a powder.

8. The method according to claim 7, wherein the alkyltrimethylammonium halide is selected from the group consisting of hexadecyltrimethylammonium bromide, dedecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, cetyltrimethylammonium chloride, myristyltrimethylammonium chloride, decyltrimethylammonium bromide, octyltrimethylammonium bromide, hexyltrimethylammonium bromide, and mixtures thereof.

9. The method according to claim 6, wherein the polybenzimidazole-based polymer is selected from the group consisting of polybenzimidazole (PBI), poly(2,5-benzimidazole) (2,5-PBI), poly(2,6-benzimidazole) (2,6-PBI), and ABPBI.

10. The method according to claim 6, wherein the metal is selected from the group consisting of aluminum, copper, iron, nickel, and combinations thereof.

11. The method according to claim 6, wherein the metal-grafted porous structure is Al-MCM-41.

12. The method according to claim 6, wherein the metal-grafted porous structure has a size of 900 nm or less.

13. The method according to claim 7, wherein the metal chloride is added in an amount such that the metal ions are present at a level of 1 to 30 mole % relative to the total moles of the solution.

14. The method according to claim 6, wherein the metal-grafted porous structure is present in an amount of 0.1 to 30% by weight relative to the weight of the polybenzimidazole-based polymer.

15. The method according to claim 7, wherein the calcination is carried out at a temperature in the range of 300 to 800°

C.