Conductivity Evaluation of Rutile-Type Ti_1-xNb_xO₂ as Interconnect Material for Low Temperature Solid Oxide Fuel Cells

Abstract

Rutile-type Ti_0.93Nb_0.07O₂ was characterized and evaluated as a potential interconnect material for low temperature solid oxide fuel cells. It was revealed that Ti_0.93Nb_0.07O₂ shows the conductivity of ca. 50 S/cm in reducing atmospheres over a wide temperature range of 400∼1000°C. Also, the effect of Cr-doping on conductivity and the segregation of niobium on grain boundaries was investigated. It was found that Cr-doping to rutile-type Ti_0.93Nb_0.07O₂ is effective in improving the initial conductivity and reducing the rate of conductivity degradation upon aging in air.