Six strontium substituted lanthanum cobaltite’s (La1-xSrxCoO3-d, x=0, 0.05, 0.15, 0.25, 0.35 and 0.5)were synthesized using the glycine-nitrate process. The cobaltites were characterized with powder XRD,dilatometry, 4-point DC conductivity measurements and electrochemical impedance spectroscopy oncone-shaped electrodes using a Ce1.9Gd0.1O1.95 electrolyte. All the compounds were single phasedbelonging to hexagonal crystal system. The thermal expansion coefficient decreases until a strontiumcontent of 15% where after it increases. The conductivity increased for temperatures below 600 oC withincreasing strontium content. At higher temperatures the conductivity increased until the strontiumcontent reached 15%, where after it began to decrease. It was shown that the activity of the cobaltite’swere strongly dependent on the strontium content. The highest activity, towards the reduction of oxygen,was found for the strontium rich composition, La0.5Sr0.5CoO3-d, with an area specific resistance of 0.92Wcm2at 600oC. It was concluded that the activity of the cobaltites towards the reduction of oxygen isdetermined mainly by the oxide ionic conductivity.
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