Performance and stability of SOFC anode fabricated from NiO-YSZ composite particles

Ni-YSZ cermet anodes for solid oxide fuel cells (SOFCs) were fabricated at various sintering temperatures from NiO-YSZ composite particles made by spray pyrolysis (SP) technique. NiO particles covered with fine YSZ (Y2O3 stabilized ZrO2) particles were used as the composite particles, and the initial ratio of Ni and YSZ was set at 75:25 (mol%). As a result, the cermet anode sintered at 1350 degreesC showed the morphology in which fine YSZ grains were uniformly dispersed on the surface of Ni grain network. Electrical performance such as electrochemical activity and internal resistance of a Ni-YSZ cermet anode changed with sintering temperature. The anode fabricated at 1350 degreesC showed the highest electrical performance. Especially, a single cell voltage with the Ni-YSZ cermet anode kept very stable for 8000 h at 1000 degreesC in the SOFC operation condition of H-2-3% H2O and air. The cermet anode after a long-term test had its initial morphology. It indicates that the Ni-YSZ cermet anode fabricated from NiO-YSZ composite particles is a very promising material for its practical use as SOFCs. (C) 2002 Elsevier Science B.V. All rights reserved.