Solid State Ionics, Vol.179, No.35-36, 2042-2046, 2008
Morphological control of electroless plated Ni anodes: Influence on fuel cell performance
The suitability of nickel electroless plating for anode deposition on electrolyte-supported solid oxide fuel cells (SOFCs) based on yttrium-stabilised zirconia (YSZ) has been studied. A deposition technique was developed and characterisation is presented with respect to microstructure, strength and performance of the resultant anode. The study was carried out on YSZ disk-shaped pellets sintered at different temperatures ranging from 1000 degrees C to 1400 degrees C with analysis of the influence of sintering temperature on the Ni-YSZ interface microstructure and fuel cell performance. Lower pre-sintering temperature resulted in higher Ni penetration into the YSZ matrix, forming a graded anode and improving the anode-electrolyte interfacial strength. The optimised electrode showed good mechanical stability under redox cycling which resulted in an enhancement of electrode porosity. Complete fuel cells were tested at 800 degrees C with 5% H-2 and air after a porous La0.2Sr0.8Co0.8Fe0.2O3-delta (LSCF) cathode layer had been deposited by slurry coating. The higher Ni penetration on YSZ substrates pre-sintered at low temperature resulted in an improvement of one order of magnitude of power output compared to a cell in which a metal Ni anode was coated over a fully dense (i.e. high pre-sintering temperature) electrolyte surface. (C) 2008 Elsevier B.V. All rights reserved.