Evaluation of simple, easily sintered La0.7Ca0.3Cr0.97 O3-δ perovskite oxide as novel interconnect material for solid oxide fuel cells

Abstract

Simple, easily sintered perovskite oxide as a novel interconnect material for solid oxide fuel cells (SOFCs) was evaluated at a SOFC co-firing temperature (1400 °C). Chemical compatibility, sintering character, electrical conductivity and thermal expansion were investigated to characterize the compatibilities of La0.7Ca0.3Cr0.97O3-δ (LCC97) with Y0.16Zr0.84O2-δ (YSZ), NiO, Sm0.2Ce0.8O2-δ (SDC), La0.8Sr0.2MnO3-δ (LSM), and BaZr0.1Ce0.7Y0.2O3-δ (BZCY), respectively. The XRD analysis indicates LCC97 chemically incompatible with BZCY. The mixtures of LCC97/SDC and LCC97/NiO, respectively, exhibit high relative densities of 97.6% and 96.2% after sintering at 1400 °C for 5 h in air. However, the samples of LCC97/YSZ and LCC97/LSM only have poor sintering abilities. The samples of LCC97 mixed with LSM, SDC, NiO and YSZ, respectively, have a decreasing electrical conductivity of 24.0 S cm-1, 12.2 S cm-1, 7.8 S cm-1 and 0.17 S cm-1 at 850 °C in air, which are all much lower than that of the LCC97 sample (62.0 S cm-1). Different mixing slightly increases the TEC value of LCC97. Results indicate that, under SOFC co-firing conditions, the novel interconnect material LCC97 has desired compatibilities with SDC and NiO, while it displays poor compatibilities with YSZ and LSM. © 2009 Elsevier B.V. All rights reserved.