Preparation and characterization of high purity Zn-doped (La 0.8 Sr 0.2 )AlO 2.9 electrolyte for intermediate temperature solid oxide fuel cells

Abstract

Abstract Ionic conductivity of perovskite oxides La0.8Sr0.2AlO2.9 with different size of B-site ions were measured. In addition, the behavior of lattice parameter with dopant content was investigated in terms of the size of the B-site ions and the tolerance factor of the perovskite structure; the ionic conductivity of La0.8Sr0.2Al1−xZnxO3−δ (LSAZ) was measured at various operating temperatures, from 500 to 800 °C in air. Ionic conductivity was found to be significantly increased by adding small amount of Zn doping. The La0.8Sr0.2Al0.8Zn0.2O2.8 specimen showed ionic conductivities at 0.0304 S cm−1 at 800 °C in air. The average thermal expansion coefficient (TEC) of La0.8Sr0.2Al0.8Zn0.2O2.8 was 10.07 × 10−6 K−1 in the temperature range from 40 to 800 °C in air. As a result, the La0.8Sr0.2Al0.8Zn0.2O2.8 is a prospective candidate as electrolyte material for solid oxide fuel cells in intermediate temperatures.