Cathode performance of nanostructured La(1-a) Sr(a) Co (1-b)Fe(b)O(3-x) on a Ce0.8Sm0.2O2 electrolyte prepared by citrate-nitrate auto-combustion

Nanostructured La1-aSraCo1-bFebO3-x a = 0.3-0.5; b = 0-0.2 and Ce0.8Sm0.2O2 powders were successfully prepared by citratenitrate autocombustion synthesis and were characterized by scanning electron microscopy and X-ray diffraction analysis. Electrochemical impedance spectroscopy measurements on symmetric cells were performed to evaluate the applicability of La1-aSraCo1-bFebO3-x as a cathode material for intermediate temperature solid oxide fuel cells based on Sm doped-ceria electrolytes. Our results demonstrated that strontium has a positive effect while iron shows a slightly negative effect on the interfacial resistance. The effect of the electrode sintering temperature was investigated by varying the temperature from 850 to 1250°C, and the best sintering temperature was found to be 900°C. The best characteristics as cathode at intermediate operating temperatures were found for the composition with a = 0.4 and the minimum iron doping, b = 0.05; at 700°C, an area specific resistance of 0.13 cm2 was measured.