Gas diffusion electrodes for polymer electrolyte fuel cells using novel organic/inorganic hybrid electrolytes: effect of carbon black addition in the catalyst layer

2005 ◽  
Vol 50 (13) ◽  
pp. 2719-2723 ◽  
Author(s):  
Osamu Nishikawa ◽  
Kazuo Doyama ◽  
Kenji Miyatake ◽  
Hiroyuki Uchida ◽  
Masahiro Watanabe
Keyword(s):  
Fuel Cells ◽  
Carbon Black ◽  
Polymer Electrolyte ◽  
Catalyst Layer ◽  
Gas Diffusion ◽  
Polymer Electrolyte Fuel Cells ◽  
Gas Diffusion Electrodes ◽  
Inorganic Hybrid

scholarly journals Gas Diffusion Electrodes for Polymer Electrolyte Fuel Cells Using Novel Organic/Inorganic Hybrid Electrolytes

2004 ◽  
Vol 72 (4) ◽  
pp. 232-237 ◽  
Author(s):  
Osamu NISHLKAWA ◽  
Kazuo DOYAMA ◽  
Kenji MIYATAKE ◽  
Hiroyuki UCHIDA ◽  
Masahiro WATANABE
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Gas Diffusion ◽  
Polymer Electrolyte Fuel Cells ◽  
Gas Diffusion Electrodes ◽  
Inorganic Hybrid

Characterization of Gas Diffusion Electrodes for Polymer Electrolyte Fuel Cells

2010 ◽  
Vol 7 (4) ◽  
Author(s):  
A. Pozio ◽  
A. Cemmi ◽  
M. Carewska ◽  
C. Paoletti ◽  
F. Zaza
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Diffusion Layer ◽  
Gas Permeability ◽  
Current Collector ◽  
Gas Diffusion Layer ◽  
Gas Diffusion ◽  
Polymer Electrolyte Fuel Cells ◽  
Metal Catalyst ◽  
Gas Diffusion Electrodes

Gas diffusion electrodes (GDEs), applied in polymer electrolyte fuel cells, are composed of a multilayer structure containing porous carbon materials and noble metal catalyst. Gas diffusion layer (GDL), a GDE component, consists of a thin layer of carbon black mixed with an organic binder, frequently polytetrafluoroethylene, which is coated onto a sheet of macroporous carbon backing cloth or paper. GDL serves as a current collector that allows ready access of fuel and oxidant to the anode and the cathode catalyst surfaces, respectively. In this work, a complete GDL state-of-the-art is first presented. Then, the effects of different fabrication methods and composition of gas diffusion layer are investigated and discussed in the light of gas permeability, thermal analysis, morphology, and electrical resistance. Besides, performances in H2/air fed cell at 50°C in different humidity conditions were discussed, and a comparison with own products and commercial GDLs was carried out. It was found that the different preparation methods influence the GDL properties, allowing the most suitable choice depending on the cell humidity conditions.

scholarly journals Inhomogeneous Distribution of Polytetrafluorethylene in Gas Diffusion Layers of Polymer Electrolyte Fuel Cells

2021 ◽  
Vol 136 (3) ◽  
pp. 843-862
Author(s):  
Dieter Froning ◽  
Uwe Reimer ◽  
Werner Lehnert
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Diffusion Layer ◽  
Liquid Water ◽  
Catalyst Layer ◽  
Gas Diffusion ◽  
Polymer Electrolyte Fuel Cells ◽  
Inhomogeneous Distribution ◽  
Gas Diffusion Layers ◽  
Diffusion Layers

AbstractPolymer electrolyte fuel cells require gas diffusion layers that can efficiently distribute the feeding gases from the channel structure to the catalyst layer on both sides of the membrane. On the cathode side, these layers must also allow the transport of liquid product water in a counter flow direction from the catalyst layer to the air channels where it can be blown away by the air flow. In this study, two-phase transport in the fibrous structures of a gas diffusion layer was simulated using the lattice Boltzmann method. Liquid water transport is affected by the hydrophilic treatment of the fibers. Following the assumption that polytetrafluorethylene is preferably concentrated at the crossings of fibers, the impact of its spatial distribution is analyzed. Both homogeneous and inhomogeneous distribution is investigated. The concentration of polytetrafluorethylene in the upstream region is of advantage for the fast transport of liquid water through the gas diffusion layer. Special attention is given to the topmost fiber layer. Moreover, polytetrafluorethylene covering the fibers leads to large contact angles.

A Catalyst Layer Flooding Model for Polymer Electrolyte Fuel Cells

2008 ◽  
Author(s):  
Partha P. Mukherjee ◽  
Chao-Yang Wang
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Liquid Water ◽  
Crucial Role ◽  
Active Sites ◽  
Catalyst Layer ◽  
Gas Diffusion ◽  
Polymer Electrolyte Fuel Cells ◽  
Limiting Current ◽  
Cathode Side

It is widely recognized that the performance degradation and the limiting current behavior in polymer electrolyte fuel cells (PEFC) are mainly attributed to the excessive build up of liquid water in the cathode side and the resulting flooding phenomena. Liquid water blocks the open pore space in the catalyst layer (CL) and the gas diffusion layer (GDL) leading to hindered oxygen transport and covers the electrochemically active sites in the CL thereby rendering reduced catalytic activity. The CL flooding therefore plays a crucial role in the overall PEFC performance limitation. In order to elucidate the primary mechanisms of liquid water removal out of the CL, the factors affecting CL flooding and to discern the role and contribution of CL flooding on the overall PEFC voltage loss, a CL flooding model has been developed. The flooding model is based on a simplified structure-wettability representation of the PEFC CL and a physical description of water and heat balance along with electrochemical performance analysis. The model shows that the evaporation mechanism, depending upon the cell operating temperature and the GDL thermal conductivity, plays a crucial role in the CL flooding behavior and the cell performance.

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