Performance of Differently Cross‐Linked, Partially Fluorinated Proton Exchange Membranes in Polymer Electrolyte Fuel Cells

1995 ◽  
Vol 142 (9) ◽  
pp. 3044-3048 ◽  
Author(s):  
Felix N. Büchi ◽  
Bhuvanesh Gupta ◽  
Otto Haas ◽  
Günther G. Scherer
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Proton Exchange Membranes ◽  
Polymer Electrolyte Fuel Cells ◽  
Proton Exchange

scholarly journals Computational Chemistry in Proton Exchange Membrane for Polymer Electrolyte Fuel Cells

MEMBRANE ◽  
2007 ◽  
Vol 32 (2) ◽  
pp. 89-94
Author(s):  
Michihisa Koyama ◽  
Kenji Sasaki ◽  
Hideyuki Tsuoi ◽  
Nozomu Hatakeyama ◽  
Akira Endou ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Computational Chemistry ◽  
Polymer Electrolyte ◽  
Proton Exchange Membrane ◽  
Polymer Electrolyte Fuel Cells ◽  
Proton Exchange ◽  
Exchange Membrane

Plasma Surface Modification of Carbon Electrodes for Polymer Electrolyte Fuel Cells (EFC 2005-86319)

2006 ◽  
Vol 3 (3) ◽  
pp. 322-326 ◽  
Author(s):  
K.-F. Chiu ◽  
M. Y. Hsieh
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Inductively Coupled Plasma ◽  
Proton Exchange Membrane ◽  
Polymer Electrolyte Fuel Cells ◽  
Proton Exchange ◽  
Cell Performance ◽  
Carbon Surface ◽  
Carbon Electrodes ◽  
Plasma Treatments

Carbon electrodes are one of the key materials in polymer electrolyte fuel cells (PEFC), or proton exchange membrane fuel cells (PEMFC). The electrodes should allow water or water vapor, which is produced by the redox reactions, to flow out of the cells efficiently. In the meantime, the catalysis reactions are not interfered. In this study, the carbon electrodes for PEMFC have been modified in terms of the hydrophobic and hydrophilic properties by plasma irradiation. The process utilized inductively coupled plasma (ICP) driven by applying radio frequency (rf) power on an induction coil. A pure Ar, O2, and Ar∕O2 gas mixture were used as the plasma gas. Only one side of the sample has been treated. The material properties of the plasma treated and untreated carbon electrodes were investigated by Raman spectroscopy, Fourier transformed infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). FTIR results show the plasma treatments effectively modified the functional groups on the carbon surface, and therefore the hydrophilic and hydrophobic properties of the surface. SEM and Raman spectra data suggested that the ion bombardment during plasma treatments alters the surface morphology and carbon bonding structures of the samples, which also result in a hydrophilic surface. The treated carbon electrodes were used as cathodes and have been packed with commercial carbon anodes and catalyst coated membrane to form 5cm×5cm fuel cells. The current-voltage polarization curves of these fuel cells were measured and compared. The test results show the feasibility of improving the cell performance by plasma treated electrodes. The feasibility of altering the hydrophobic and hydrophilic properties by plasma treatment has been demonstrated. The capillary effect due to the unbalanced hydrophilicity between the treated and untreated electrode surfaces may be responsible for the improved cell performance.

New Conceptual Gas Distributor With Mass Transfer Enhancing Function in Polymer Electrolyte Fuel Cells

2004 ◽  
Author(s):  
P. W. Li ◽  
S. P. Chen ◽  
M. K. Chyu
Keyword(s):  
Mass Transfer ◽  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Gas Flow ◽  
Flow Fields ◽  
Pem Fuel Cells ◽  
Polymer Electrolyte Fuel Cells ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Sharp Drop

A new conceptual structure of the gas distributors in polymer electrolyte fuel cells (PEFC) or proton exchange membrane (PEM) fuel cells is developed in this work. Basically, instead of partitioned channels and non-interrupted walls, the proposed new gas distributors make use of discretized elements as the current collector in the flow fields, which can help to enhance the mass transfer in the gas flow fields while maintaining the function of transmitting current out of the fuel cell. Experimental operation without external humidification of the reactant gases for single PEM fuel cells and cell stacks using conventional and the currently presented gas distributors were conducted for comparison and verification. It was found that the maximum operational cell current, beyond which there is a sharp drop of the cell voltage, could be significantly improved when using the currently proposed gas distributors and the same membrane-electrode-assembly (MEA) sheets. Correspondingly, the output electrical power can have at least 11 percent increment for the operation with free-convective airflow and around 50 percent increment for the operation with forced convective airflow.

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