Investigations of new horizons on H2/O2 proton exchange membrane fuel cells

Yazaydın, Ahmet Özgür
Proton exchange membrane fuel cells are electrochemical devices which convert the chemical energy of hydrogen into electrical energy with a high efficiency. They are compact and produce a powerful electric current relative to their size. Different from the batteries they do not need to be recharged. They operate as long as the fuel is supplied. Fuel cells, therefore, are considered as one of the most promising options to replace the conventional power generating systems in the future. In this study five PEMFCs; namely EAE1, AOY001, AOY002, AOY003 and AOY004 were manufactured with different methods and in different structures. A test station was built to make the performance tests. Performances of the PEMFCs were compared by comparing the voltage-current (V-i) diagrams obtained during the initial tests at 25 ð C of fuel cell and gas humidification temperatures. AOY001 showed the best performance among all PEMFCs with a current density of 77.5 mA/cm2 at 0.5 V and it was chosen for further parametric studies where the effect of different flow rates of H2 and O2 gases, gas humidification and fuel cell temperatures on the performance were investigated. It was found that increasing fuel cell and gas humidification temperatures increased the performance. Excess flow rate of reactant gases had an adverse effect on the performance. On the other hand increasing the ratio of flow rate of oxygen to hydrogen had a positive but limited effect. AOY001 delivered a maximum current density of 183 mA/cm2 at 0.5 V. The highest power obtained was 4.75 W


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Erkan, Serdar; Eroğlu, İnci; Department of Chemical Engineering (2011)
Fuel cells are electricity generators which convert chemical energy of hydrogen directly to electricity by means of electrochemical oxidation and reduction reactions. A single proton exchange membrane (PEM) fuel cell can only generate electricity with a potential between 0.5V and 1V. The useful potential can be achieved by stacking cells in series to form a PEM fuel cell stack. There is a potential to utilize 100W class fuel cells. Fuelling is the major problem of the portable fuel cells. The aim of this th...
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Microbial Fuel Cells (MFCs) are biological fuel cells based on the oxidation of fuels by electrogenic bacteria to generate an electric current in electrochemical cells. There are several methods that can be employed to improve their performance. In this study, the effects of gold surface modification with different thiol molecules were investigated for their implementation as anode electrodes in micro-scale MFCs (mu MFCs). Several double-chamber mu MFCs with 10.4 mu L anode and cathode chambers were fabrica...
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Pinecone-derived activated carbon (AC) and bimetallic transition metal phosphide (TMP) composites were produced and utilized as electrochemical capacitor (EC) electrodes and oxygen evolution reaction (OER) catalysts in this study. The base transition metal (TM) was Ni for all samples, and the secondary TM was one of Fe, Mn and Co. AC serves as a porous structure for double layer formation and active sites for OER catalysis. Bimetallic TMP is utilized due to redox reactions in EC and catalytic activity in OE...
Numerical Investigation of thermal management of Solid Oxide Fuel Cells by flow arrangement
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Electrochemical capacitors are the energy storage devices based mainly on electrical double layer formation. Their power densities are exceptionally high; however, their energy densities are characteristically low to compete various types of batteries in market. Therefore, there have been great amount of studies to enhance electrochemical capacitors’ energy density. Utilization of inorganic materials such as transition metal oxides and/or phosphides is one of the most common strategies to increase energy de...
Citation Formats
A. Ö. Yazaydın, “Investigations of new horizons on H2/O2 proton exchange membrane fuel cells,” M.S. - Master of Science, Middle East Technical University, 2003.