Synthesis of La0.9Sr0.1Ga0.8Mg0.2O3-δ powder for solid oxide fuel cell by a nitrate-citrate combustion route

A nitrate-citrate combustion route to synthesize La0.9Sr0.1Ga0.8Mg0.2O3-delta powder for solid oxide fuel cell application was presented. This route is based on the gelling of nitrate solutions by the addition of citric acid and ammonium hydroxide, followed by an intense combustion process due to an exothermic redox reaction between nitrate and citrate ions. The optimum technical parameters are that the pH value is 5, and the molar ratio of citric acid to the total metallic ion is 1.5:1. X-ray diffraction characterization of calcined gel shows that pure phase was synthesized after calcination at 1400degreesC for 10 h, and the TEM result shows the calcined powder with average particle size is about 150 nm. The grain resistance contributes to the total resistance of sintered pellet below 500degreesC. The conductivity of the sintered pellet at 800degreesC was 0.07 S(-1.)cm(-1) higher than the conductivity of YSZ (0.05 S(-1.)cm(-1) at 800degreesC).