Effect of PTFE content in microporous layer on water management in PEM fuel cells

Abstract The effect of hydrophobic agent (PTFE) concentration in the microporous layer on the PEM fuel cell performance was investigated using mercury porosimetry, water permeation experiment, and electrochemical polarization technique. The mercury porosimetry and water permeation experiments indicated that PTFE increases the resistance of the water flow through the GDL due to a decrease of the MPL porosity and an increase of the volume fraction of hydrophobic pores. When air was used as an oxidant, a maximum fuel cell performance was obtained for a PTFE loading of 20 wt.%. The experimental polarization curves were quantitatively analyzed to determine the polarization resistances resulting from different physical and electrochemical processes in the PEM fuel cell. The polarization analysis indicated that the optimized PTFE content results in an effective water management (i.e., a balancing of water saturations in the catalyst layer and the gas diffusion layer), thereby improving the oxygen diffusion kinetics in the membrane-electrode assembly.

[1]  J. Bear.  Dynamics of Fluids in Porous Media , 1975 .

[2]  David Blackwell,et al.  Water flow in the gas diffusion layer of PEM fuel cells , 2005 .

[3]  Frank P. Incropera,et al.  Fundamentals of Heat and Mass Transfer , 1981 .

[4]  M. Hori,et al.  Novel gas diffusion layer with water management function for PEMFC , 2004 .

[5]  Chao-Yang Wang,et al.  Two-phase transport and the role of micro-porous layer in polymer electrolyte fuel cells , 2004 .

[6]  J. Newman,et al.  Modeling Two-Phase Behavior in PEFCs , 2004 .

[7]  E. Ticianelli,et al.  Effects of the cathode gas diffusion layer characteristics on the performance of polymer electrolyte fuel cells , 2002 .

[8]  Jin Hyun Nam,et al.  Effective diffusivity and water-saturation distribution in single- and two-layer PEMFC diffusion medium , 2003 .

[9]  B. Popov,et al.  Effect of carbon loading in microporous layer on PEM fuel cell performance , 2006 .

[10]  Tae-Hee Lee,et al.  Influence of pore-size distribution of diffusion layer on mass-transport problems of proton exchange membrane fuel cells , 2002 .

[11]  G. Squadrito,et al.  Improvement in the diffusion characteristics of low Pt-loaded electrodes for PEFCs , 1999 .

[12]  James M. Fenton,et al.  Analysis of Polarization Curves to Evaluate Polarization Sources in Hydrogen/Air PEM Fuel Cells , 2005 .

[13]  J. Giner,et al.  The Mechanism of Operation of the Teflon‐Bonded Gas Diffusion Electrode: A Mathematical Model , 1969 .

[14]  E. Ticianelli,et al.  Effects of the carbon powder characteristics in the cathode gas diffusion layer on the performance of polymer electrolyte fuel cells , 2002 .

[15]  B. Tilak,et al.  Polarization Characteristics of Porous Electrode Systems with Adsorbed Intermediates Participating in the Electrode Reaction , 1989 .

[16]  M. Schrader.  Ultrahigh vacuum techniques in the measurement of contact angles. IV. Water on graphite (0001) , 1975 .

[17]  I. Raistrick.  Impedance studies of porous electrodes , 1990 .

[18]  Yu Wei,et al.  Improvement in high temperature proton exchange membrane fuel cells cathode performance with ammonium carbonate , 2005 .

[19]  T. E. Springer,et al.  Electrical Impedance of a Pore Wall for the Flooded‐Agglomerate Model of Porous Gas‐Diffusion Electrodes , 1989 .

[20]  Trung Van Nguyen,et al.  Effect of Thickness and Hydrophobic Polymer Content of the Gas Diffusion Layer on Electrode Flooding Level in a PEMFC , 2005 .

[21]  Chao-Yang Wang,et al.  Two-Phase Transport in Polymer Electrolyte Fuel Cells with Bilayer Cathode Gas Diffusion Media , 2005 .

[22]  James M. Fenton,et al.  Characterization of Gas Diffusion Layers for PEMFC , 2004 .

[23]  G. Squadrito,et al.  Effects of the Diffusion Layer Characteristics on the Performance of Polymer Electrolyte Fuel Cell Electrodes , 2001 .

[24]  Zhigang Qi,et al.  Improvement of water management by a microporous sublayer for PEM fuel cells , 2002 .

[25]  Shimshon Gottesfeld,et al.  Low platinum loading electrodes for polymer electrolyte fuel cells fabricated using thermoplastic ionomers , 1995 .

[26]  Edson A. Ticianelli,et al.  Development and electrochemical studies of gas diffusion electrodes for polymer electrolyte fuel cells , 1996 .

[27]  Adam Z. Weber,et al.  Effects of Microporous Layers in Polymer Electrolyte Fuel Cells , 2005 .

[28]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[29]  Frano Barbir,et al.  PEM Fuel Cells , 2006 .

[30]  Chang-Soo Kim,et al.  Effect of PTFE contents in the gas diffusion media on the performance of PEMFC , 2004 .

[31]  A. Shukla,et al.  Effect of diffusion-layer morphology on the performance of polymer electrolyte fuel cells operating at atmospheric pressure , 2000 .

[32]  E. Passalacqua,et al.  Influence of the PTFE content in the diffusion layer of low-Pt loading electrodes for polymer electrolyte fuel cells , 1998 .

[33]  Göran Lindbergh,et al.  Transient Techniques for Investigating Mass-Transport Limitations in Gas Diffusion Electrodes I. Modeling the PEFC Cathode , 2003 .

[34]  J. Newman,et al.  Mass Transport in Gas‐Diffusion Electrodes: A Diagnostic Tool for Fuel‐Cell Cathodes , 1998 .

[35]  T. Springer,et al.  Modeling and Experimental Diagnostics in Polymer Electrolyte Fuel Cells , 1993 .