Patterned cathodes of calcium-doped lanthanum manganite (LCM) were fabricated on polycrystalline yttria-stabilized zirconia (YSZ) substrates by RF magnetron sputtering and photolithographic techniques. Samples were generated with a constant electrode/electrolyte contact area but different three phase boundary (TPB) lengths (lTPB’s). Electrochemical impedance spectroscopy (EIS) was performed in the oxygen partial pressure (pO2) and temperature range of 10-3 atm to 1.00 atm and 600-800°C respectively. The area specific polarization resistance, Rp, was found to scale linearly with the inverse of lTPB, suggesting that the TPB is the active region for oxygen reduction. The resistivity decreased with increased temperature and pO2 and showed an activation energy of 1.17 +/- 0.03 eV.
Revised: March 29, 2012 |
Published: April 25, 2010
Citation
Miara L.J., K.J. Yoon, S. Topping, L.V. Saraf, U.B. Pal, and S. Gopalan. 2010.Polarization Resistance of La0.85Ca0.15MnO3 Cathodes for Solid Oxide Fuel Cells (SOFCs) Measured Using Patterned Electrodes.ECS Transactions 28, no. 23:137-146.PNNL-SA-75222.doi:10.1149/1.3502345