High-temperature PEM Fuel Cell Characterization: an Experimental Study Focused on Potential Degradation due to the Polarization Curve

High-Temperature Proton Exchange Membrane Fuel Cell constant current ageing tests highlighted that the characterizations used to monitor the state of health of single cells could be potentially degrading. An experimental campaign to analyze potential degradation due to polarization curves was carried out. More exactly, four methodologies to generate a polarization curve including Electrochemical Impedance Spectroscopies (EIS) were cycled 30 times. The tested single cells were based on a commercial PBI Membrane Electrodes Assembly (MEA) with an active surface of 45 cm2 (BASF Celtec®-P 1100 type). Before the first cycling test and after the last cycling one, complete characterizations, composed by a voltammetry and a polarization curve including EIS, were performed. The results show that one of the MEA has a voltage which increased for one of the four methods to obtain the polarization curve. This growth is linked to a decrease of ohmic losses: in an unexpected way, it could be considered as a way to improve the break-in period. Similarly, the monitoring of CO2 emission (as corrosion has been suspected to be involved at high voltage, i.e. low current density) confirms the potential degradation of the electrodes during the measurement of the polarization curve.

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Design and Experimental Characterization of a High-Temperature Proton Exchange Membrane Fuel Cell Stack

Journal of Fuel Cell Science and Technology ◽

10.1115/1.4003753 ◽

2011 ◽

Vol 8 (5) ◽

Cited By ~ 11

Author(s):

Robert Radu ◽

Nicola Zuliani ◽

Rodolfo Taccani

Keyword(s):

Fuel Cells ◽

High Temperature ◽

Fuel Cell ◽

Proton Exchange Membrane ◽

Single Cells ◽

Pem Fuel Cells ◽

Proton Exchange ◽

Pure Hydrogen ◽

Exchange Membrane

Proton exchange membrane (PEM) fuel cells based on polybenzimidazole (PBI) polymers and phosphoric acid can be operated at temperature between 120 °C and 180 °C. Reactant humidification is not required and CO content up to 1% in the fuel can be tolerated, only marginally affecting performance. This is what makes high-temperature PEM (HTPEM) fuel cells very attractive, as low quality reformed hydrogen can be used and water management problems are avoided. From an experimental point of view, the major research effort up to now was dedicated to the development and study of high-temperature membranes, especially to development of acid-doped PBI type membranes. Some studies were dedicated to the experimental analysis of single cells and only very few to the development and characterization of high-temperature stacks. This work aims to provide more experimental data regarding high-temperature fuel cell stacks, operated with hydrogen but also with different types of reformates. The main design features and the performance curves obtained with a three-cell air-cooled stack are presented. The stack was tested on a broad temperature range, between 120 and 180 °C, with pure hydrogen and gas mixtures containing up to 2% of CO, simulating the output of a typical methanol reformer. With pure hydrogen, at 180 °C, the considered stack is able to deliver electrical power of 31 W at 1.8 V. With a mixture containing 2% of carbon monoxide, in the same conditions, the performance drops to 24 W. The tests demonstrated that the performance loss caused by operation with reformates, can be partially compensated by a higher stack temperature.

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Performance comparison between high temperature and traditional proton exchange membrane fuel cell stacks using electrochemical impedance spectroscopy

Journal of Power Sources ◽

10.1016/j.jpowsour.2014.01.049 ◽

2014 ◽

Vol 256 ◽

pp. 250-257 ◽

Cited By ~ 16

Author(s):

Ying Zhu ◽

Wenhua H. Zhu ◽

Bruce J. Tatarchuk

Keyword(s):

High Temperature ◽

Electrochemical Impedance Spectroscopy ◽

Fuel Cell ◽

Impedance Spectroscopy ◽

Proton Exchange Membrane ◽

Electrochemical Impedance ◽

Performance Comparison ◽

Proton Exchange ◽

Exchange Membrane

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Fabrication of Micro PEM Fuel Cells Using Pyrolysis and Experimental Testing

ASME 2010 4th International Conference on Energy Sustainability, Volume 1 ◽

10.1115/es2010-90140 ◽

2010 ◽

Author(s):

Yun Wang ◽

Liem Pham ◽

Guilherme Porto Vasconcellos

Keyword(s):

Fuel Cell ◽

Proton Exchange Membrane ◽

Performance Test ◽

Electrochemical Impedance ◽

Experimental Testing ◽

Active Surface ◽

Pem Fuel Cells ◽

Proton Exchange ◽

And Performance ◽

Exchange Membrane

In this paper, we propose a relatively new fabrication technique for micro proton exchange membrane fuel cell (μPEMFC) fabrication. Microgrooves are fabricated on the polymer Circlex plate first which is relatively easy to manufacture comparing with directly patterning on carbon, cheap, and mechanically robust (in contrast to graphite). By carbonizing the machined polymer at high temperature, the bipolar plates are produced for a μPEMFC assembly to distribute the reactants via its micro groove structure. A μPEMFC with 0.64 cm2 active surface is fabricated. A maximum power of ∼70 mW/cm2 is achieved for 1 atm at 25 °C, which is comparable with most of data reported in the literature. The Electrochemical Impedance Spectroscopy (EIS) and performance test are conducted on fuel cell steady-state operation.

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