The effects of relative humidity on the performances of PEMFC MEAs with various Nafion® ionomer contents

Kun Ho Kim, Kwan Young Lee, Sang Yeop Lee, Eunae Cho, Tae Hoon Lim, Hyoung Juhn Kim, Sung Pil Yoon, Sae Hoon Kim, Tae Won Lim, Jong Hyun Jang

Research output: Contribution to journalArticlepeer-review

71 Citations (Scopus)


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 languageEnglish
Pages (from-to)13104-13110
Number of pages7
JournalInternational Journal of Hydrogen Energy
Issue number23
Publication statusPublished - 2010 Dec


  • 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


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