Performance assessment of Pr1-xSrxCo0.8Cu0.2O3- perovskite oxides as cathode material for solid oxide fuel cells with Ce0.8Sm0.2O1.9 electrolyte

In this paper, Pr1-xSrxCo0.8Cu0.2O3- (x=0.2, 0.3, 0.4, 0.5, 0.6) cathode material is investigated for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Pr1-xSrxCo0.8Cu0.2O3- oxides are prepared by the EDTA-citrate complexing method. XRD results show that there is a structural change from orthorhombic (x=0.2 and 0.3) to cubic (x=0.4, 0.5 and 0.6) in Pr1-xSrxCo0.8Cu0.2O3- system. The electrical conductivities of all the samples are all higher than 523S cm(-1) between 500 and 800 degrees C. The semiconductor-to-metal conductivity transition takes place at around x=0.4. In order to further reduce thermal expansion coefficients (TECs) and improve electrochemical performance of the Pr1-xSrxCo0.8Cu0.2O3- cathode, we fabricate Pr0.5Sr0.5Co0.8Cu0.2O3--x wt% Ce0.8Sm0.2O1.9 (PSCC-xSDC, x=20-60) composite cathodes. In PSCC-xSDC electrode, the TEC and polarization resistance (R-p) both decrease with the addition of SDC. The PSCC-50SDC composite cathode has the lowest R-p. The lowest R-p 0.029 cm(2) is obtained at 800 degrees C for PSCC-50SDC electrode. Subsequently, we fabricate SDC (300 mu m thick) electrolyte-supported fuel cell with PSCC-50SDC cathodes. The maximum power densities is 428mWcm(-2) at 800 degrees C. The present results demonstrate that PSCC-50SDC composite is a promising candidate cathode for IT-SOFCs.