Abstract
The chemical stabilities of modified NiO cathodes doped with 1.5 mol% CoO and 1.5 mol% LiCoO2 fabricated by a conventional tape casting method were evaluated through the real MCFC single cell operation. The heat-treated samples before oxidation had proper porosities and microstructures for a MCFC cathode. At 150 mAcm-2 in current density, the MCFC single cell using a CoO-doped NiO cathode showed stable cell voltages in the range of 0.833-0.843 V for 1000 h. In contrast, the cell using a LiCoO2-doped NiO cathode with a maximum of 0.836 V at 500 h degraded to 0.826 V at 1000 h due to a wet seal breakdown at the cathode side. The amounts of nickel precipitated in the electrolytes of the cells using modified NiO cathodes doped with CoO and LiCoO2 after the operation for 1000 h were 1.2 and 1.4 wt.%, respectively, which were about 60% lower than that of the standard cells using pure NiO cathodes. The enhanced chemical stability of modified NiO cathodes seems to be attributed to the fact that the presence of cobalt increases the lithium content in the cathodes by converting Ni2+ to Ni 3+, resulting in stabilizing the layered crystal structure.
Original language | English |
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Pages (from-to) | 3081-3089 |
Number of pages | 9 |
Journal | Electrochimica Acta |
Volume | 49 |
Issue number | 19 |
DOIs | |
Publication status | Published - 2004 Aug 15 |
Bibliographical note
Funding Information:Financial support by the R&D Management Center for Energy and Resources, which is supported by the Ministry of Trade, Industry and Energy, is gratefully acknowledged.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
Keywords
- Cathode dissolution
- Cathode stability
- Li-Co-Ni oxides
- Molten carbonate fuel cell
- Single cell performance
ASJC Scopus subject areas
- General Chemical Engineering
- Electrochemistry