Abstract: Ni8-Fe2-LSGMC5 composite anodes doped with various amounts of La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 -δ (LSGMC5) were prepared by using the impregnation method. The electrochemical properties of the anodes and the power generation characteristics of corresponding cells were studied by alternating current (AC) impedance spectrometry and direct current (DC) polarization using hydrogen and dimethyl ether as fuels, respectively. The results showed that the introduction of LSGMC5 powders into the Ni-Fe anodes improved the structure of the anodes and the anode/electrolyte interfaces significantly, which decreased the Ohmic resistance of the cell and the polarization resistance of the anodes. The LSGMC5 powders in the composite anodes showed different effects on the electro-catalytic oxidation of hydrogen and dimethyl ether (DME). The polarization resistance of the anode decreased with increasing concentration of LSGMC5, and the anode containing 30% LSGMC5 powder showed the best electrochemical properties when using DME as a fuel. The maximum power densities of the cell in DME based on the anode containing 30% LSGMC5 powder reached 1.00, 0.61, and 0.40W·cm-2 at 1073, 1023, and 973 K, respectively. The anode doped with 20% LSGMC5 powder had the best electrochemical properties when using H2 as a fuel, with the further increase in the amount of LSGMC5 powder the polarization resistance increased quickly.

Key words: Solid oxide fuel cell, Ni-Fe composite anode, AC impedance, Polarization, Dimethyl ether