Simple Infiltrated Microstructure Polarization Loss Estimation (SIMPLE) Model Predictions of Today and Tomorrow's Nano-Composite SOFC Cathodes

Abstract

The Simple Infiltrated Polarization Loss Estimation (SIMPLE) model was used to predict the performance of a variety of mixed ionic electron conductor (MIEC) - ion conductor (IC) Solid Oxide Fuel Cell (SOFC) nano-composite cathodes. These predictions agree with the reported values to within 70% or better (without the use of fitting parameters) at all temperatures. Systematic SIMPLE model variation of typical nano-composite cathode geometrical parameters reveals little change in cathode performance with cathode thickness and/or porosity above a critical cathode thickness. Further, SIMPLE modeling suggests that conventionally structured nano-composite cathodes with MIEC surface resistances 10 times lower than Sm0.5Sr0.5CoO3-x (SSC) and ionic conductivities 10 times higher than Ce0.9Gd0.1O1.95 (GDC) could achieve polarization resistances of 0.1 Ωcm2 at ~450oC. Likewise, conventionally structured cathodes with 100 times and 1000 times better materials than SSC and GDC could achieve polarization resistances of 0.1 Ωcm2 at ~375oC, and ~300oC, respectively.