Properties and performance of La1.6Sr0.4NiO4+δ–Ce0.8Sm0.2O1.9 composite cathodes for intermediate temperature solid oxide fuel cells

La1.6Sr0.4NiO4+δ–Ce0.8Sm0.2O1.9 composite cathodes were prepared successfully using combustion synthesis method for intermediate temperature solid oxide fuel cells. The chemical compatibility, thermal expansion behavior, electrical conductivity and electrode performance were studied. The X-ray diffraction of La1.6Sr0.4NiO4+δ–Ce0.8Sm0.2O1.9 composite result proved a slight reaction between La1.6Sr0.4NiO4+δ and Ce0.8Sm0.2O1.9. Both the thermal expansion coefficient and the electrical conductivity of La1.6Sr0.4NiO4+δ–Ce0.8Sm0.2O1.9 decreased with increasing Ce0.8Sm0.2O1.9 content. AC impedance spectroscopy measurements indicated that the addition of 30 wt% Ce0.8Sm0.2O1.9 to La1.6Sr0.4NiO4+δ exhibited the lowest polarization resistance (0.238 Ωcm2) at 800 °C in air, which was only one fourth of the La1.6Sr0.4NiO4+δ electrode measured at the same temperature.