Anode of Intermediate Temperature Solid Oxide Fuel Cells

Ni-Ce0.8Gd0.2O1.9 (CGO) cermet anodes of intermediate temperature solid oxide fuel cells (IT-SOFCs) were prepared by the iso-static pressing method, which were sintered at 1450℃ and successively reduced at 700℃ with H2 diluted by 80% He. The resulting anodes were characterized by the pore structure measurements, SEM, XRD and EDS as well. The conductivity and the electrical performance in corresponding cells were also measured. The prepared Ni-CGO cermet anodes mainly possess the pores of 1-2μm in diameter and the porosity of up to 30% that increases with the content of NiO. It can be observed by the SEM measurements that the metal phase is well amalgamated with the ceramic phase and that the anode combines with the electrolyte tightly. NiO in the anodes can be reduced to Ni completely by the mixture of 20%H2-80%He at 700℃ without the phase transformation of CGO. The conductivity of the reduced anode increases as the NiO content increases. The threshold value of the NiO content is 40% in weight, over which the remarkable increase in conductivity is not available. The fuel cells composed of Ni-CGO as the anode, CGO as the electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-α(LSCF) as the cathode provide with the power density of up to 0.14W/cm2 at 650℃.