La(Ni,Fe)O_3 Stability in the Presence of Cr Species - Solid State Reactivity Study

摘要

The solid-state reactivity between La(Ni_(0.6)Fe_(0.4))O)3 (LNF) andCr_2O_3 in the IT-SOFC operating temperature range of 600-800°Chas been investigated using XRD analysis. Because LNF materialcan be used as a cathode, as a current collecting layer and/or aninterconnect coating, a thorough investigation of its chemicalstability is of importance for SOFC systems utilizing ferriticstainless steel interconnects. This study demonstrates the intrinsicinstability of LNF when exposed to direct contact with Cr_2O_3 at800°C. It has been observed that Cr enters the perovskite phase,replacing first Ni and then Fe already after 200 h. The rate of theCr reaction with LNF depends on temperature and exposure time.After 1000 h at 600°C no reaction products could be detected withXRD. Although this is a promising result, long-term testing underfuel cell operating conditions is needed to prove LNF as a viableIT-SOFC cathode material.