Performance and stability of large planar solid oxide fuel cells using phosphine contaminated hydrogen fuel
Article
Ross, TBA, Zondlo, JW, Sabolsky, EM et al. (2018). Performance and stability of large planar solid oxide fuel cells using phosphine contaminated hydrogen fuel
. JOURNAL OF POWER SOURCES, 395 185-194. 10.1016/j.jpowsour.2018.04.105
Ross, TBA, Zondlo, JW, Sabolsky, EM et al. (2018). Performance and stability of large planar solid oxide fuel cells using phosphine contaminated hydrogen fuel
. JOURNAL OF POWER SOURCES, 395 185-194. 10.1016/j.jpowsour.2018.04.105
Coal syngas, a potential fuel for SOFCs, contains impurities like PH3, which rapidly degrade Ni-based SOFC anodes. Past research showed significant reconstruction of Ni anodes in button cells with degradation rates of ∼0.5 mV∙h−1. It is not evident that these rates correspond to actual stack applications due to major differences in fuel utilization and delivery. Herein, a single planar repeat unit with an active area of 32.64 cm2 is constructed using a Haynes® 242 manifold. The cell operates at 800 °C using dry H2 with and without 10 ppm PH3. The cell employs a co-flow configuration with a fuel utilization of 12.5%. The performance of the cell is evaluated over 440 h by voltage-current measurements and electrochemical impedance spectroscopy. The post-run analysis of the contaminated cell is conducted via XRD, XPS and SEM. The degradation rate for the cell is found to be 3×10−3 mV∙h−1, which is far lower than that reported previously. The cell shows low evidence of significant PH3 poisoning and there is no reconstruction of the Ni-anode microstructure, as seen in button cell testing. Some basic electrochemical and thermodynamic modeling, and microstructural/chemical characterization are presented and related to the cell's relatively stable performance observed in this work.
