Synthesis and properties of nano-structured SOFC anode deposits

Nanostructured YSZ+Ni cermet anode functional layers for SOFC were developed by plasma spraying. Spray processing was optimized by controlling plasma enthalpy and velocity in order to obtain well distributed finely porous nanostructured deposits exhibiting high gas permeability, suitable high temperature electronic conductivity, enhanced triple phase boundaries and catalytic activity. The results were compared with conventional NiO+YSZ and Ni-C+YSZ anodes. YSZ electrolyte layer was deposited onto the anodes for electrochemical testing at 800 degrees C in static conditions. Impedance spectroscopy measurements were performed to collect data on polarization resistance and catalytic behavior of anode layers. It was established that enlarged reaction zone, provided by high specific surface area of nanostructured anodes, and finely porous microstructure, led to lower activation and concentration polarizations and enhanced cell performance by more than 60% compared to conventional cells.