Reduction of voltage loss by voltage cycle through the use of specially formed bipolar plates

US7955752B2 · kind B2 · utility

Assignee

• GM GLOBAL TECHNOLOGY OPERATIONS LLC · US

Inventors

• Bernd Krause · Liederbach, DE
• Joerg Roth · Bad Kötzting, DE

Key dates

• Filing date: Jun 1, 2005
• Grant date: Jun 7, 2011
• Expiry date: Apr 5, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E60/50
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A fuel cell that includes specially configured bipolar plates that separate the reactant gas flow field in an active area of the fuel cell into a primary flow channels and a secondary channels. In one embodiment, the primary flow channels are in use over the entire operating range of the fuel cell and the secondary flow channels are only in use at high cell current outputs. At low power demands, the primary channels operate at a voltage below 0.8 volts and provides a gas current density of more than 0.2 A/cm2. The secondary flow channels have no gas supply and operate at mass transport limited conditions. Because of this design, voltage cycling is significantly reduced or eliminated, thus increasing the life of the fuel cell.