Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

Series

2003

Current density

Articles 1 - 3 of 3

Full-Text Articles in Engineering

Full Cell Mathematical Model Of A Mcfc, N. Subramanian, B. S. Haran, Ralph E. White, Branko N. Popov Jan 2003

Full Cell Mathematical Model Of A Mcfc, N. Subramanian, B. S. Haran, Ralph E. White, Branko N. Popov

Faculty Publications

A theoretical model for the molten carbonate fuel cell was developed based on the three-phase homogeneous approach. Using this model, the contribution of different cell components to losses in cell performance has been studied. In general, at low current densities, the electrolyte matrix contributed to the major fraction of potential losses. Mass transfer effects became important at high current densities and were more prominent at the cathode. Electrolyte conductivity and cathode exchange current density seemed to play a limiting role in determining cell performance. Using the model, the maximum power density from a single cell for different cell thicknesses was …


Polyetheretherketone Membranes For Elevated Temperature Pemfcs, Balasubramanian Lakshmanan, Wayne Huang, David Olmeijer, John W. Weidner Jan 2003

Polyetheretherketone Membranes For Elevated Temperature Pemfcs, Balasubramanian Lakshmanan, Wayne Huang, David Olmeijer, John W. Weidner

Faculty Publications

Membrane electrode assemblies ~MEAs! made from polyetheretherketone ~PEEK! showed excellent fuel cell performance and thermal stability in the presence of substantial CO at elevated temperatures ~i.e., 120°C! in proton exchange membrane fuel cells ~PEMFCs!. For example, the current from a MEA made from PEEK membrane at 0.6 V and 120°C was 0.50 A/cm2 when run on pure hydrogen and 0.45 A/cm2 when run on reformate ~50% H2 , 1300 ppm CO, and balance N2). The current density from a MEA made from Nafion at 0.6 V and 120°C was 0.61 A/cm2 when run on pure hydrogen. The main difference between …


Theoretical Analysis For Obtaining Physical Properties Of Composite Electrodes, Parthasarathy M. Gomadam, John W. Weidner, Thomas A. Zawodzinski, Andrew P. Saab Jan 2003

Theoretical Analysis For Obtaining Physical Properties Of Composite Electrodes, Parthasarathy M. Gomadam, John W. Weidner, Thomas A. Zawodzinski, Andrew P. Saab

Faculty Publications

A theoretical analysis is presented that allows in situ measurements of the physical properties of a composite electrode, namely, the electronic conductivity, the ionic conductivity, the exchange-current density, and the double-layer capacitance. Use is made of the current-voltage responses of the composite electrode to dc and ac polarizations under three different experimental configurations. This analysis allows the physical properties to be obtained even when the various resistances in the composite (e.g., ionic, electronic, and charge-transfer) are of comparable values.