La2NiO4+δ as cathode for SOFC: Reactivity study with YSZ and CGO electrolytes

In this work was studied the electrochemical response of La 2 NiO 4+ δ compound by impedance spectroscopy measurements. This compound is a potential cathode material to be used in Solid Oxide Fuel Cell (SOFC). The area specific resistances (ASR) of a La 2 NiO 4+ δ /YSZ/ La 2 NiO 4+ δ symmetrical cell were determined between 600 and 800 °C. The ASR values increases with time suggesting a chemical reaction between the cells components. Reactivity studies were carried out between La 2 NiO 4+ δ and both YSZ and CGO electrolytes. The reactivity studies were performed by means of two different tests: La 2 NiO 4+ δ films deposited onto both electrolytes and heated at 900 °C for 72 h (Pellet Test), and intimate mixture of La 2 NiO 4+ δ with either YSZ or CGO powders were heat treated at 900 °C during 2 h (Powders Test). In each case the reaction products were evaluated by XRD. Both studies suggest a high reactivity between the electrode ( La 2 NiO 4+ δ ) and the electrolytes (YSZ, CGO).