Oxygen diffusion in Sr0.75Y0.25CoO2.62

Oxygen tracer diffusion in polycrystalline samples of Sr0.75Y0.25CoO2.62 (SYC) was studied by Isotope Exchange Depth Profile and Secondary Ion Mass Spectrometry (IEDP/SIMS). The values of the tracer diffusion coefficient, D*, and the surface exchange coefficient, k*, were measured as a function of temperature (500–900 °C). We observed an Arrhenius behavior, A = A0 exp(− EA/kT), with the activation energies of EAD = 1.58 ± 0.05 eV and EAk = 1.79 ± 0.27 eV for D* and k*, respectively. Electrochemical performance of symmetrical cells with Ce0.9Gd0.1O1.95 (CGO) as electrolyte (SYC/CGO/SYC) in the temperature range 620–770 °C has been evaluated. An area-specific resistance (ASR) of 0.17 Ω cm2 was measured at 720 °C.

► Sr0.75Y0.25CoO2.62 considered as cathode material for IT-SOFC.
► Sr–Y cobaltite has high values of D* and k* in the range 500–900 °C.
► Low values of ASR were measured within the range 620–770 °C in air.