authors |
Davarpanah, A; Yaremchenko, AA; Fagg, DP; Frade, JR |
nationality |
International |
journal |
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY |
author keywords |
Ni-YSZ; Composite; Cermet; SOFC anode; Electrical conductivity; Two-step sintering |
keywords |
YTTRIA-STABILIZED ZIRCONIA; NICKEL-OXIDE; ELECTRICAL-PROPERTIES; NI/YSZ CERMETS; TRANSPORT-PROPERTIES; CONDUCTIVITY; COMPOSITES; ELECTROLYTE; CERAMICS; KINETICS |
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 30 vol.%. The impact of different firing parameters including peak temperature (1623-1723 K), heating/cooling rate (4-10 K/min), and isothermal treatment temperature (1473-1573 K) and time (2-8 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 420 S/cm at 873-1173 K in 10%H-2-N-2 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. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. |
publisher |
PERGAMON-ELSEVIER SCIENCE LTD |
issn |
0360-3199 |
year published |
2014 |
volume |
39 |
issue |
27 |
beginning page |
15046 |
ending page |
15056 |
digital object identifier (doi) |
10.1016/j.ijhydene.2014.07.053 |
web of science category |
Chemistry, Physical; Electrochemistry; Energy & Fuels |
subject category |
Chemistry; Electrochemistry; Energy & Fuels |
unique article identifier |
WOS:000341897500059
|