High-performance PrBaCo2O5+δ–Ce0.8Sm0.2O1.9 composite cathodes for intermediate temperature solid oxide fuel cell

Abstract PrBaCo 2 O 5+ δ –Ce 0.8 Sm 0.2 O 1.9 (PBCO–SDC) composite material are prepared and characterized as cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). The powder X-ray diffraction result proves that there are no obvious reaction between the PBCO and SDC after calcination at 1100 °C for 3 h. AC impedance spectra based on SDC electrolyte measured at intermediate temperatures shows that the addition of SDC to PBCO improved remarkably the electrochemical performance of a PBCO cathode, and that a PBCO–30SDC cathode exhibits the best electrochemical performance in the PBCO– x SDC system. The total interfacial resistances R p is the smallest when the content of SDC is 30 wt%, where the value is 0.035 Ω cm 2 at 750 °C, 0.072 Ω cm 2 at 700 °C, and 0.148 Ω cm 2 at 650 °C, much lower than the corresponding interfacial resistance for pure PBCO. The maximum power density of an anode-supported single cell with PBCO–30SDC cathode, Ni–SDC anode, and dense thin SDC/LSGM (La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3− δ )/SDC tri-layer electrolyte are 364, 521 and 741 mW cm −2 at 700, 750 and 800 °C, respectively.