Synthesis and characterization of 10%Gd doped ceria (GDC) deposited on NiO-GDC anode-grade-ceramic substrate as half cell for IT-SOFC

In the present research work spray pyrolysis technique (SPT) is employed to synthesize GDC (10%Gd doped ceria) thin films on anode-grade-ceramic substrate (porous NiO-GDC). The film/substrate structure was characterized for their micro-structural and electrical properties along with their interfacial-quality. By optimization of preparative parameters of SPT and modification of surface of anode-grade ceramic substrate, we were able to prepare the GDC films having thickness of the order of 13 μm on NiO-GDC substrate. Further to improve the interfacial quality and densification of film, annealing of structure at 1000 °C for 8 h was carried out which leads to fully dense (>96%) GDC films, forming a gas-tight interface with substrate. Impedance measurements revealed that grain interior conductivity for GDC/NiO-GDC half-cell was of the order of 0.1S/cm at 500 °C which is the desired conductivity for successful operation of IT-SOFC. The activation energy for grain interior and grain-boundary conduction estimated for GDC/NiO-GDC was 1.07 eV and 0.93 eV, respectively.