Oxygen transport and surface exchange properties of Sr0.5Sm0.5CoO3 − δ

Oxygen tracer diffusion (D⁎) and chemical diffusion (D˜) were measured in dense Sr0.5Sm0.5CoO3 − δ (SSC) ceramics by Isotope Exchange Depth Profiling/Secondary Ion Mass Spectrometry (IEDP/SIMS) and electrical conductivity relaxation (ECR) over the temperature ranges of ~ 100–200 °C and 400–600 °C, respectively. In addition, the surface exchange coefficients were determined over the same temperature ranges. The transport properties and exchange kinetics of SSC are comparable to or better than those of other solid oxide fuel cell cathode candidates in the literature. The ionic conductivity of SSC was calculated using the Nernst-Einstein equation, and is comparable to that of leading solid oxide electrolytes at intermediate temperatures.

► Oxygen D* and k* were measured on SSC using IEDP/SIMS.
► Oxygen D(chem) and k(chem) were measured using electrical conductivity relaxation.
► D and k values were compared to similar SOFC cathodes materials.
► Ionic conductivity and transference number were calculated.