Development of Sr2FeMoO6-delta perovskite for solid oxide fuel cell

Abstract

Double perovskites, Sr2FeMoO6 (SFMO), Sr2FeMo1-xCoxO6, Sr2FeMo1-xNixO6, Sr2Fe1-xCoxMoO6, Sr2Fe1-xNixMoO6, Sr2-xLaxFeMo0.5Co0.5O6, Sr2-xPrxFeMo0.5Co0.5O6, Sr2-xLaxFeMo0.5Ni0.5O6 and Sr2-xPrxFeMo0.5Ni0.5O6, have been investigated as anode materials for intermediate-temperature solid oxide fuel cell (IT-SOFC, 600-800ºC). All materials synthesized in air by a conventional solid-state reaction with calcination and sintering temperatures of 1000ºC and 1300ºC for 12 hours, respectively, showed the double-perovskite structure as a major phase and SrMoO4 as a minor phase impurity. The incorporation of Co and Ni into the Mo-site of SFMO structure resulted in the increasing of electrical conductivity of SFMCox and SFMNix. Among the various oxides examined, SFMCo0.5 and SFMNi0.5 showed the highest electrical conductivity of 32.93 and 50.11 S·cm-1 at 800ºC and 600ºC, respectively. Moreover, a trace amount of Co and Ni inserted in the Fe-site led to the increase in the electrical conductivity of SFCoxM and SFNixM as x = 0.1 and became decreasing when x = 0.2. The configuration of single fuel cells of Co-, Ni-doped SFMO/ La0.9Sr0.1Ga0.8Mg0.2O3/ Sr0.5Sm0.5CoO3 was fabricated and the highest power density of 802, 723, 823 and 834 mW·cm-2 at 800ºC was achieved from the cells using SFMCo0.2, SFMNi0.1, SFCo0.1M and SFNi0.1M as anodes, respectively. On the contrary, the conducting properties of SFMCo0.5 and SFMNi0.5 were not achieved by the introduction of La and Pr at Sr-site.