Gradient Ni/SDC anodes for solid oxide fuel cells by tape casting

NiO/samaria doped ceria (NiO/SDC) anodes with gradient Ni composition distribution were prepared by a process based on tape casting and laminating. Sintering behaviors, microstructure and thermal properties of the gradient anodes were investigated, and compared with those of two NiO/SDC anodes with single NiO composition (75 and 55% NiO). It was shown that the gradient NiO/SDC anode has fine pore and grain structure and steady thermal expansion coefficients (TEC) than each anode with homogeneous Ni composition distribution. Owing to the better microstructure and properties, SOFCs based on the gradient anode with a SDC electrolyte film of about 100 mum in thickness and a LSCF cathode showed a maximum power density of 80 MW/cm(2) at 600degreesC.