Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7718326 | International Journal of Hydrogen Energy | 2014 | 11 Pages |
Abstract
The electrochemical performance and dimensional stability of Ni-YSZ cermets, conventionally used as solid oxide fuel cell anodes, depend strongly on their microstructure and therefore fabrication conditions. This work was focused on the assessment of a less common two-step firing procedure for fabrication of Ni-YSZ cermets with comparatively low nickel fraction of 30Â vol.%. The impact of different firing parameters including peak temperature (1623-1723Â K), heating/cooling rate (4-10Â K/min), and isothermal treatment temperature (1473-1573Â K) and time (2-8Â h), on the porosity and electrical conductivity of cermets was assessed employing Taguchi experimental planning. The applied procedure yielded Ni-YSZ composites with porosity 26-35% and electrical conductivity ranging from 170 to 420Â S/cm at 873-1173Â K in 10%H2-N2 atmosphere. Microstructural studies indicated that the conductivity is determined mainly by Ni particle size distribution. Analysis of results suggests that, for the studied range of sintering parameters, a higher peak temperature and ramp rate are favorable for the improvement of conductivity, whereas isothermal dwell temperature and time have a rather minor effect on the conductivity level.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
A. Davarpanah, A.A. Yaremchenko, D.P. Fagg, J.R. Frade,