Characterization of solid oxide fuel cell device having a three-layer film structure grown by RF magnetron sputtering

Solid oxide fuel cell (SOFC) having a three-layer film of Ni/YSZ/Ni structure was prepared on NiO and Al2O3 substrates by the RF magnetron sputtering growth. The constitutional YSZ electrolyte and Ni electrode films were characterized based on dependence on the RF power and annealing treatment. A thin YSZ electrolyte film grown on NiO substrate at a lower RF power of 200 W indicated a columnar structure with longitudinal pinholes in the film. By annealing treatment at 1600degreesC, YSZ film was improved as a denser film having a bulk electrolyte structure without pinholes. Ni electrode grown at 300 W showed a low resistivity of 3.6 Omega cm at 1000degreesC, because the contact resistance at grain boundary in the film decreased with increasing RF power. YSZ film grown on Al2O3 substrate at a higher RF power of 600 W was reformed to denser electrolyte film by annealing treatment. An SOFC using the annealed YSZ film exhibited a reproducible power generation property having 0.9 V of the nearly theoretical voltage at 1000degreesC. (C) 2002 Elsevier Science Ltd. All rights reserved.