Current Distribution in a Polymer Electrolyte Membrane Fuel Cell Under Flooding Conditions

Abstract

Non-uniform current distribution in polymer electrolyte membrane fuel cells results in local over-heating, accelerated ageing, and lower power output than expected. This issue is very critical when fuel cell experiences water flooding. In this work, the performance of a PEM fuel cell is investigated under cathode flooding conditions. A partially flooded GDL model is proposed to study local current density distributions along flow fields over a wide range of cell operating conditions. The model results show as cathode inlet humidity and/or cell pressure increase the average current density for the unflooded portions of the cell increases but the system becomes more sensitive to flooding. Operating the cell at higher temperatures would lead to higher average current densities and the chance of system being flooded is reduced. In addition, higher cathode stoichiometries prevent system flooding but the average current density remains almost constant.

Key findings

• ▸Increasing cathode inlet humidity and/or cell pressure increases average current density, but makes the system more sensitive to flooding.
• ▸Operating at higher temperatures increases average current density and reduces the chance of system flooding.
• ▸Higher cathode stoichiometries prevent system flooding, but have little effect on average current density.

Keywords

Identifiers

DOI

10.1115/fuelcell2009-85155

Journal

ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology

Year

2008