Nobuyuki Imanishi

Chemical stability between NiO/8YSZ cermet and alkaline-earth metal substituted lanthanum chromite

Abstract The reaction between the separator in solid oxide fuel cells, alkaline-earth substituted lanthanum chromite (LaCr 0.8 Mg 0.2 O 3 ,La 0.8 Ca 0.2 CrO 3 and La 0.8 Sr 0.2 CrO 3 ), and the fuel electrode, NiO8YSZ cernet, was investigated at high temperature. No chemical reaction was observed at the fuel electrode/separator interface of all samples annealed in a temperature range up to 1350°C. In the combination of fuel electrode and La 0.8 Sr 0.2 CrO 3 annealed at 1400°C, no diffusion of specific elements was observed at the interface even for an annealing period of 12 h. In the case of the fuel electrode and La 0.8 Ca 0.2 CrO 3 , which was annealed at 1400°C, a dissolution of Ca into 8YSZ of the NiO/8YSZ cermet was observed at the NiO/8YSZ side of the interface. For the couple of the fuel electrode and LaCr 0.9 Mg 0.1 O 3 treated at 1400°C, the Ni concentration increased and the Mg concentration decreased at the LaCr 0.9 Mg 0.1 O 3 side of the interface. It was expected that a LaCr 1− x Ni x O 3 solid solution was formed by the replacement reaction of Mg by Ni.