Synthesis and characterization of nanocrystalline ScSZ electrolyte for SOFCs

Sc2O3 stabilized zirconia (ScSZ) was processed by combustion synthesis. X-ray diffraction was carried for analyzing the phase and crystallinity of the processed powder. The results indicate the effectiveness of the combustion synthesis process to produce nanocrystalline ScSZ from the precursor salts without any intermediate calcination step. Comparison with the X-ray diffraction pattern of a commercial 8YSZ sample showed that the process is also effective in producing the desired cubic fluorite phase. The powder was compacted and sintered to produce a dense electrolyte pellet. The sintering temperature was found to be considerably lower compared to conventional microcrystalline zirconia ceramics. The electrical conductivity of the ScSZ electrolyte was found to be higher compared to 8YSZ processed under same conditions. The Arrhenius plot of conductivity yielded two activation energies corresponding to low and high temperature regions. The activation energy of the 10ScSz electrolyte was found to be considerably lower than the 8YSZ sample.

► Nanocrystalline 10ScSZ electrolyte was processed successfully. ► The sintering temperature was lower compared to microcrystalline zirconia. ► Conductivity of the 10ScSZ was higher than 8YSZ processed under same conditions. ► Two activation energies corresponding to low and high temperature regions were found. ► The activation energy of the 10ScSz was lower than 8YSZ and other zirconia electrolytes.