Conductivity Evaluation of Rutile-Type Ti_(1-x)Nb_xO_2 as Interconnect Material for Low Temperature Solid Oxide Fuel Cells

摘要

Rutile-type Ti_(0.93)Nb_(0.07)O_2 was characterized and evaluated as a potential interconnect material for low temperature solid oxide fuel cells. It was revealed that Ti_(0.93)Nb_(0.07)O_2 shows the conductivity of ca. 50 S/cm in reducing atmospheres over a wide temperature range of 400 ～ 1000 ℃. 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_(0.93)Nb_(0.07)O_2 is effective in improving the initial conductivity and reducing the rate of conductivity degradation upon aging in air.