La(Ni,Fe)O3 Stability in the Presence of Chromia—A Solid-State Reactivity Study

The perovskite $La(Ni_{0.6}Fe_{0.4})O_3$ (LNF) is a candidate material for the electrochemically active cathode layer, the cathode current collecting layer, and/or the interconnect protective coating in intermediate temperature solid oxide fuel cells (IT-SOFCs) operated at . Since these operating temperatures enable the use of relatively cheap interconnect materials such as chromia-forming ferritic stainless steel, investigation of the chemical stability of LNF in the presence of chromium species is of importance. This study demonstrates that LNF is chemically unstable at when it is in direct contact with $Cr_2O_3$. It has been observed that Cr enters the perovskite phase, replacing first Ni and then Fe, already after 200h. At 600°C, however, only minor reaction products were detected after 1000h exposure to $Cr_2O_3$. Although this is a promising result, long-term testing under fuel cell operating conditions at 600°C is needed to prove that LNF is a viable IT-SOFC material.