Long-Term Chemical Stability of LaNi(Fe)O[sub 3] as a Cathode Material in Solid Oxide Fuel Cells

Chemical reactivity of (LNF) with has been investigated in order to examine the long-term stability of the LNF phase at , which shows a high performance as the cathode of intermediate-temperature solid oxide fuel cells (IT-SOFCs). The chemical stability of LNF was compared with that of (LSM) under the existence of . The LNF powder, a powder mixture of LNF and , and a powder mixture of LSM and were, respectively, heated at , and they are analyzed by X-ray powder diffraction with the Rietveld refinement. We found that the LNF phase maintains the hexagonal crystal system heated in air up to . In the mixture, the LNF phase kept its pristine crystal structure while a new phase, , was detected, which was produced by the reaction between and the residual contained in the starting LNF powder. In the mixture, LSM reacted with and produced a significant amount of . LNF showed a much better chemical stability against than LSM. LNF can serve as a long-life cathode in the IT-SOFC system.