Evaluation of nickel-titanium oxide-niobium pentoxide metal ceramic composite as interconnect for solid oxide fuel cell

With increasing importance for clean energy, fuel cells have gained great significance in recent decades. Solid oxide fuel cells are easy to transport due to presence of solid electrolyte and also have requisite electrical properties,but have been obstructed by their limitation to be used at only temperatures greater than 6000C and less than 8000C. To construct a stack of cells, materials that are good electrical conductors and having necessary mechanical strengths at that temperatures are being considered as interconnects between the cells. Evaluation of Nickel-Titanium dioxide-Niobium pentoxide (NTN) as interconnect and comparison to Stainless Steel 441 alloy has been made in this research. The criteria for evaluation are the resistance, long-term stability and the power density characteristics of the cell for each interconnect. Electrical measurements by impedance spectroscopy techniques were conducted at variousworking temperatures using a gas mixture of 10 % hydrogen and 90% nitrogen to evaluate both interconnect materials in the working range of fuel cells. Scanning Electron Microscopy images of Lanthanum Strontium Manganite paste before and after the fuel cell measurements are shown.The results showed that both NTN and Stainless Steel 441 interconnects exhibit similar electrical properties under operating conditions of the fuel cell. Since theNTN interconnect is less prone to corrosion and does not have the effect of chromium poisoning, it can be considered as a viable interconnect material for solid oxide fuel cells.