Abstract
For PEMFC operation, water management is very important to provide both sufficient proton conductivity and mass transport. Therefore, in this study, the effect of the relative humidity (38-87%) on cell performance is examined for PEMFC MEAs with various Nafion® ionomer contents. The MEAs were fabricated using a CCM (catalyst-coated membrane) spraying method. As the relative humidity of the cathodes (RHC) increases, the cell voltages at 0.4 and 1.2 A/cm2 increased for a MEA with 20 wt% ionomer. This can be explained in terms of the expansion of active sites with enhanced ionic conductivity (activation overpotential). In contrast, with a higher RHC value, the cell voltages for 35 wt% ionomer (more hydrophilic) gradually decreased as a result of slower gas transport (concentration overpotential). For MEAs with intermediate ionomer contents, 25 and 30 wt%, the cell voltages at 0.4 A/cm 2 showed maximum values at a RHC of 67%, at which point the mass transport begins to be the more dominant factor. The highest unit cell performance was observed in a MEA with an ionomer content of 25 wt% at a RHC of 59% and in a MEA at 20 wt% ionomer content at a higher humidity of 87%.
Original language | English |
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Pages (from-to) | 13104-13110 |
Number of pages | 7 |
Journal | International Journal of Hydrogen Energy |
Volume | 35 |
Issue number | 23 |
DOIs | |
Publication status | Published - 2010 Dec |
Keywords
- CCM (catalyst-coated membrane) spraying method
- MEA (membrane-electrode assembly)
- Nafion ionomer
- PEMFC (polymer electrolyte membrane fuel cell)
- Relative humidity
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology