Wetting of Porous α-LiAlO2 by Molten Carbonate

Cracking of α-LiAlO2 matrices in molten carbonate fuel cells (MCFC) leads to reduction in the performance. It was demonstrated in this work that the mechanical strength of α-LiAlO2 matrices is improved by heat-treating at 800°C under ambient gas atmosphere. The mechanical strength (2.91MPa) of the h...

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Bibliographic Details
Published in:Journal of the Electrochemical Society 2018-01, Vol.165 (5), p.F324-F333
Main Authors: Gao, Liangjuan, Selman, J. Robert, Nash, Philip
Format: Article
Language:English
Online Access:Get full text
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Summary:Cracking of α-LiAlO2 matrices in molten carbonate fuel cells (MCFC) leads to reduction in the performance. It was demonstrated in this work that the mechanical strength of α-LiAlO2 matrices is improved by heat-treating at 800°C under ambient gas atmosphere. The mechanical strength (2.91MPa) of the heat-treated matrix was enhanced more than 5 fold compared to the non-heat-treated matrix (0.58MPa). The porosity and crystal structure of the α-LiAlO2 matrices were not changed after the heat-treatment. The wetting behavior and distribution of carbonate in the heat-treated and the non-heat-treated matrix were investigated and compared. Both non-heat-treated and heat-treated α-LiAlO2 matrices were completely wetted by molten carbonate. The molten carbonate distribution was concentrated right underneath the circular region formed by the molten carbonate drop in the matrix. Non-heat-treated α-LiAlO2 samples cracked as a result of the complete absorption of molten carbonate, however, the heat-treated α-LiAlO2 matrices did not crack, presumably due to their enhanced mechanical strength.
ISSN:1945-7111
DOI:10.1149/2.0771805jes