A novel method for preparing anode cermets for solid oxide fuel cells

A new method for fabrication of metal-cermet anodes in solid-oxide fuel cells (SOFCs) has been developed. Highly porous, yttria-stabilized zirconia (YSZ) films were prepared using a mixture of zircon fibers (YSZp, Si-stabilized, and <0.3% Si) and normal YSZ powders (YSZd). The films remained highly porous following calcination up to 1550 degrees C, after which either Cu or Ni could be incorporated by impregnation with the nitrate salts. For Cu cermets, the performance increased with metal loading to at least 40% Cu. At 800 degrees C using H-2 as the fuel and a 230 mu m, YSZ electrolyte, the current-voltage (I-V) curves for either a Cu- or Ni-cermet anode formed using this new method were found to be identical to the I-V curve for a Ni cermet formed using traditional methods. Scanning electron microscopy showed that the anode films remained porous even with addition of Cu, so that additional modification was possible. Tests of this concept through the addition of ceria by impregnation with the Ce(NO3)(3) led to an additional increase in the cell performance. (C) 1999 The Electrochemical Society. S0013-4651(99)04-074-4. All rights reserved.