DEVELOPMENT OF LOW-COST ANODE MATERIAL FOR SOLID OXIDE FUEL CELLS

Manufacturing cost remains one of the major issues facing the solid oxide fuel cell (SOFC) industry. In the anode supported SOFC design, the cermet anode constitutes around 90% of the total material required to build a cell, making the technology very sensitive to anode raw material price. A new patent-pending process called "nickel yttria reaction-sintered zirconia (NiYRSZ)" has been developed for manufacturing SOFC anodes at a fraction of the cost. Typically, the solid component of the anode consists of about 50150 volume percent nickel and 8 mole percent yttria stabilized zirconia, the latter being a rather costly material. It was discovered that zirconia and yttria powders sintered in the presence of nickel oxide readily form the cubic phase at moderate temperature. Cells manufactured using this process show excellent microstructures for anode supports: a strong bond between the electrolyte and the anode, and a high porosity without addition of pore formers. The strength of the anode was 100 MPa making the material equivalent or slightly superior to an anode fabricated with the traditional NiO/8YSZ material of similar porosity. The resistivity of the material was measured at 850 degrees C and found to be less than 2 m Omega.cm. Cell performance was also compared to cells manufactured with traditional material. Every indication is that SOFC anodes fabricated with this new method perform as well as anodes made with the conventional material set.