Browsing by Author "Peng, R. G."

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A novel scrape-applied method for the manufacture of the membrane-electrode assembly of the fuel-cell system
(2009-12-01)
Wu, S. D.
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Chou, C. P.
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Peng, R. G.
;
Lee, C. H.
;
Wang, Y. Z.
This study investigates the transfer of the scrape-applied method from the electrodes of a lithium battery to the membrane-electrode assembly of fuel cells, including Proton Exchange Membrane Fuel Cells and Direct Methanol Fuel Cell. Three methods are commonly used to manufacture lithium battery electrodes: the roller-applied method, the spraying-applied method, and the scrape-applied method. This study develops novel scrape-applied equipment for lithium battery electrodes. This method is novel and suitable for producing fuel cell, better than other traditional methods. In this study, the stability of coating process was tested by measuring the weight and thickness of a dry electrode. The stability and reproducibility of electrode fabrication were examined by systematic data analysis. Finally, the study used a specially designed single cell composed of 16 conductive segments, which are insulated locally. The current passing through each segment was measured using Hall Effect sensors connected to the segment compartments. Based on the measured distribution of the local current in a segmented single cell, the influence of flooding and stoichiometry variation of feed gas was discussed in terms of electrochemical reaction rate. The experimental results serve as an important basis for future research in this field, which hold potential benefits to the academia and the industry.
Experimental and numerical studies of local current mapping on a PEM fuel cell
(2008-10-01)
Hwnag, J. J.
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Chang, W. R.
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Peng, R. G.
;
Chen, P. Y.
;
Su, A.
Local current distribution on a PEM fuel cell has been mapped experimentally by using a special-designed single cell fixture. it is composed of a composite cathodic flow-field plate, a membrane electrode assembly (MEA) and a stainless-steel anodic flow-field plate. An array of 16 individual conductive segments was distributed on the composite plate. A self-made MEA is in direct contact with the segmented current collectors. Regional-averaged current through each segment is determined by using the Hall-effect sensor. To ensure the data reliability, a comparison of polarization curves was made between the composite flow-field plate and the conventional flow-field plate. Then, the effects of flow-field patterns, dew points of the cathodic feedings and cathodic stoichiometrics on the local current distribution were examined. The transient variation of the local current distribution on the cathode under supersaturated conditions was further visualized to illustrate the flooding phenomena in different flow patterns. This technique developed by the present work has contributed to knowledge and understanding the local current distributions in a PEM fuel cell that is helpful in designing the fuel-cell components. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.