Low temperature sintering ability and electrical conductivity of SOFC interconnect material La0.7Ca0.3Cr0.97O3

Abstract

Relatively low temperature (1150-1300 °C) sintering characteristics and electric conductivities of La0.7Ca0.3Cr0.97O3 with a slight Cr deficiency of 0.03, prepared by an auto-ignition process, have been discussed. The material could reach 94.3% relative density at 1200 °C for 5 h in air, which is about 200 °C lower than that of with no Cr deficiency. XRD results indicated that pure perovskite phase was formed after sintered at the temperature range of 1150-1300 °C. The sample sintered at 1250 °C had the maximum conductivity of 62.0 S cm-1 at 850 °C in air, which is about 2.6 times as high as that of La0.7Ca0.3CrO3 with no Cr deficiency. In pure H2, it got the maximum electrical conductivity of 3.3 S cm-1 at 850 °C as sintered at 1200 °C. The TEC of the material was about 11.4 × 10-6 K-1, which is very compatible to that of other common used SOFC components. Therefore, it is a simple and cost-effective interconnect material for SOFCs. © 2008 Elsevier B.V. All rights reserved.