Membranes for fuel cells, method for producing said membranes and production of fuel cells using membranes of this type

US7682723B2 · kind B2 · utility

Assignee

• VOLKSWAGEN AKTIENGESELLSCHAFT · DE

Inventors

• Dieter Melzner · Göttingen, DE
• Annette Reiche · Oettingen, DE
• Ulrich Maehr · Berlin, DE
• Suzana Kiel · Göttingen, DE
• Stefan Haufe · Neubiberg, DE

Key dates

• Filing date: Aug 4, 2006
• Grant date: Mar 23, 2010
• Expiry date: Mar 10, 2027

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A membrane for fuel cells, which is characterized by a homogeneous absorption and good retention of doping agents, and which guarantees a high mechanical stability at high temperatures when doped. Such membranes consist of at least one polymer, whose nitrogen atoms are chemically bonded to a central atom of a derivative of a polybasic inorganic oxo acid. The membranes are produced from polymer solutions that are devoid of water and oxo acid derivatives, by heating the solution that has been introduced into a membrane mold until a self-supporting membrane has been formed and then by thermally regulating the latter. Inventive fuel cells having a membrane electrode assembly (MEA) that comprises a membrane of the invention and phosphoric acid as the doping agent have, for example, an impedance of 0.5-1 Ωcm2 at a measuring frequency of 1000 Hz and at an operating temperature of 160° C. and a gas flow for hydrogen of 170 mL/min and for air of 570 mL/min. They can be used as high-temperature polyelectrolyte membrane fuel cells for a working temperature of up to at least 250° C.