Sr-doped LaInO3 and its possible application in a single layer SOFC

The effects of dopants on the electrical conductivity of the perovskite-typ e oxide LaInO3 have been investigated. Replacement of La by Sr is the most effective way to enhance the conductivity of LaInO3, whereas Ca substitutio n for In is rather difficult due to the large difference in the ion radii. The optimum composition is La0.9Sr0.1InO3-delta whose maximum conductivity is 7.6 X 10(-3) S cm(-1) at 900 degrees C. The electrical conductivity of L a0.9Sr0.1InO3-delta has been measured over a wide range of oxygen partial p ressure from pO(2) =1 to 10(-25) atm. P-type and n-type behavior at high an d low oxygen partial pressure have been observed, respectively, while at in termediate oxygen partial pressures, the electrical conductivity changes on ly slightly with the oxygen partial pressure. The concept of a single layer solid oxide fuel cell based on a La0.9Sr0.1InO3-delta ceramic pellet has b een tested. A maximum power density of 3 mW cm(-2) at 800 degrees C was ach ieved when dilute H-2 and air were used as fuel and oxidizing agent, respec tively. (C) 2000 Elsevier Science B.V. All rights reserved.