Preparation and Characterization of Pr_(2-x)Sr_xCoO_(4+δ) Cathode Materials for IT-SOFC

The samples of Pr2-xSrxCoO4+δ(x=0.8,1.0,1.2) as cathode material for intermediate-temperature solid oxide fuel cell(IT-SOFC) were synthesized by solid-state reaction.Crystal structure,thermal expansion,electrical conductivity and electrochemical properties were investigated by XRD,SEM,dilatometry,DC four-probe method,AC impedance and cyclic voltammetry(CV) techniques,respectively.The XRD results showed all the samples obtained as a single K2NiF4-structural phase,there were no chemical reaction occurred between the Pr0.8Sr1.2CoO4+δ electrode and the Sm0.2Ce0.8O1.9(SDC) electrolyte at 1100℃ in air.The thermal expansion coefficients(TECs) increased with Sr content increasing.The electrical conductivity of the specimens was over 100S/cm at 800℃.The polarization resistance decreased with the increasing of Sr content.Pr0.8Sr1.2O4+δ had the optimum value of 0.29Ω·cm2 at 700℃ in air.