Screen-printing paste and screen-printing method of fabricating a gas diffusion electrode

US6645660B2 · kind B2 · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Armin Datz · Baiersdorf, DE
• Barbara Schricker · Erlangen, DE
• Manfred Waidhas · Koblenzer Straße, DE
• Winfried Schaffrath · Dresden, DE
• Peter Otschik · Rabenau, DE

Key dates

• Filing date: Feb 26, 2001
• Grant date: Nov 11, 2003
• Expiry date: Feb 26, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A screen-printing paste as a starting material for fabricating a gas diffusion electrode through screen-printing includes at least one polymer, at least one metallic catalyst, and a high-boiling solvent. The polymer is a binder including poly(butyl acrylate)-polymethacrylate copolymer, a poly(vinyl alcohol), and a poly(ethylene oxide). The polymer can be two polymers, a first being used for hydrophobicization and present in an amount of between 0 to 10% by weight based on a content of the metallic-catalyst, and a second being a binder. A screen-printing method of fabricating the electrode for a fuel cell includes forming a screen-printing layer having a thickness between 3 and 40 &mgr;m by applying the screen-printing paste to a base. The solvent and the polymer serve as a screen-printing medium. The screen-printing layer is baked to allow only residues of the solvent and the polymer to remain, which do not interfere with using the electrode in a fuel cell. The method uses a polybutylacrylate-polymethacrylate copolymer as a binder in the screen-printing paste.