Microstructural variations and their influence on the performance of solid oxide fuel cells based on yttrium-substituted strontium titanate ceramic anodes

Donor-substituted strontium titanates have been widely recognised as alternative anode materials to the state-of-the-art Ni/YSZ cermets in solid oxide fuel cells (SOFCs). Electrolyte-supported SOFCs based on Y sub(0.07)Sr sub(0.895)TiO sub(3) ceramic anodes with different microstructural designs were prepared. Ni or Ni with Ce sub(0.8)Gd sub(0.2)O sub(1.9) (CGO) was infiltrated onto the pore walls within the ceramic anode framework as an electrocatalyst for anode reactions. Performances and electrochemical impedance spectroscopy measurements of the cells were analysed in detail to observe the influence of low ionic conductivity of Y sub(0.07)Sr sub(0.895)TiO sub(3) to cell performance, to understand how to control the degradation of the cells, and to obtain a possible mechanism for the anode processes. The anode design containing both functional and current collecting layers with sufficient Ni-CGO infiltration is favourable for high power output and low performance degradation.