Novel K2NiF4-Type Materials for Solid Oxide Fuel Cells: Compatibility with Electrolytes in the Intermediate Temperature Range

Many new materials have been identified as being of potential interest to solid oxide fuel cell developers. Recent work has suggested that materials of the La2NiO4 composition possess sufficient activity to act as an effective cathode. Whilst there have been many studies of the transport properties of materials of this family the reactivity with electrolyte compositions has received relatively little attention. In this work we have investigated the compatibility of La2NiO4 + d (LNO) with LSGM and ceria gadolinium oxide (CGO) electrolytes. It is clear that under an air atmosphere LNO reacts readily with CGO electrodes with the formation of a higher order Ruddlesden-Popper (La-n + 1NinO3n + 1) phase as one of the reaction products. In contrast, there is no evidence of secondary phase formation with LSGM electrolytes from the obtained diffraction data over a period of 72 h at temperatures up to 1,273 K.