Solid Oxide Fuel Cell (SOFC) systems operate at temperatures 500 – 950oC and have garnered interest in recent years due to their higher conversion efficiencies when compared to heat engines, variable fuel capability, low noise operation and cell design flexibility. While these advantages make SOFCs one of the most sought after technologies, the technical challenges associated with high temperature operation and the issues with the utilization of hydrocarbon fuels currently create economic barriers for widespread implementation. Developing SOFC systems for direct hydrocarbon utilization in intermediate temperature regimes allows immediate use of fossil fuels, eliminates the need for separate fuel reformers and purification systems and allows by-product heat to be recycled back into the cell stack or used in a cogeneration heat and power application. This also improves system stability and reduces degradation offering major cost benefits and promoting an ever increasing interest in SOFC commercialization, solidifying their position in the new energy economy.
In this work, lab scale single cell SOFCs containing doped Ni-ScSZ anodes will be examined to measure their appropriateness for hydrocarbon operation. Likewise, the influence of alloying other elements into the nickel will be studied, for instance iron, vanadium, silver or copper. These systems will be investigated to determine their methane reforming ability, measure their electro-catalytic activity, examine their efficiency to suppress coking and study their tolerance for sulphur impurities. Preliminary work will be carried out on Ni-YSZ/YSZ anode supported button cells to be used as baseline comparisons followed by cells containing doped Ni within a 1mol% Ceria (CeO2) -10 mol% Scandia (Sc2O3) Stabilized Zirconia (10Sc1CeSZ) matrix. The 1mol% CeO2 serves as a mixed conductor and oxidation catalyst for the hydrocarbon fuel. ScSZ will be the electrolyte of choice to lower operating temperature and improve O2- transport to the anode. Characterization of the anode powders will be carried out via X-Ray Diffraction, BET and SEM. Particle size, anode shrinkage, porosity, cell microstructure, substrate roughness, layer-interfacial composition, cell performance and electrode resistance will be examined using a particle size analyzer, dilatometer, Archimedes’ method, cross-sectional SEM, interferometry, EDS, I-V measurements and IS spectra.