TiN-Ni Cermets with High Oxidation Resistance and Electrical Conductivity as Candidates for Intermediate-Temperature Solid Oxide Fuel Cell Interconnects

摘要

Novel TiN-Ni cermets with high oxidation resistance and excellent electrical conductivity were developed and evaluated as intermediate-temperature solid oxide fuel cells (IT-SOFCs) interconnects. Three TiN-Ni cermets with 30?vol.%, 50?vol.% and 70?vol.% Ni were prepared by optimizing hot-pressed sintering parameters. Their oxidation kinetics was systematically investigated in air at 600–800°C. Relative density, oxidation rate constant and electrical conductivity can be readily optimized by adjusting the Ni content in the cermets, and their corresponding maximum values reached 99.6%, 2.56?×?10?11?g2?cm?4?s?1 (at 800°C) and 1.5?×?104?S?cm?1 (500?h oxidation reaction at 800°C). Coefficient of thermal expansion could be adjusted as well in the 9.7?×?10?6?k?1 to 13.2?×?10?6?k?1 range to match with the IT-SOFCs components. The electrical conductivity of all samples studied in this work was above 1.0?×?104?S?cm?1, which is much higher than that of all other cermets reported in the literature. We demonstrated that TiN-Ni cermets are promising material as candidates for IT-SOFCs interconnects.