Optimization of La2O3-containing diopside based glass-ceramic sealants for fuel cell applications
Artikel i vetenskaplig tidskrift, 2009

We report on the optimization of La2O3-containing diopside based glass-ceramics (GCs) for sealant applications in solid oxide fuel cells (SOFC). Seven glass compositions were prepared by modifying the parent glass composition, Ca0.8Ba0.1MgAl0.1La0.1Si1.9O6. First five glasses were prepared by the addition of different amounts of B2O3 in a systematic manner (i.e. 2, 5, 10, 15, 20 wt.%) to the parent glass composition while the remaining two glasses were derived by substituting SrO for BaO in the glasses containing 2 wt.% and 5 wt.% B2O3. Structural and thermal behavior of the glasses was investigated by infrared spectroscopy (FTIR), density measurements, dilatometry and differential thermal analysis (DTA). Liquid-liquid amorphous phase separation was observed in B2O3-containing glasses. Sintering and crystallization behavior, microstructure, and properties of the GCs were investigated under different heat treatment conditions (800 and 850 degrees C: 1-300 h). The GCs with >5 wt.% B2O3 showed an abnormal thermal expansion behavior above 600 degrees C. The chemical interaction behavior of the glasses with SOFC electrolyte and metallic interconnects, has been investigated in air atmosphere at SOFC operating temperature. Thermal shock resistance and gas-tightness of GC sealants in contact with 8YSZ was evaluated in air and water. The total electrical resistance of a model cell comprising Crofer 22 APU and 8YSZ plates joined by a CC sealant has been examined by the impedance spectroscopy. Good matching of thermal expansion coefficients (CTE) and strong, but not reactive, adhesion to electrolyte and interconnect, in conjunction with a low level of electrical conductivity, indicate that the investigated GCs are suitable candidates for further experimentation as SOFC sealants. (C) 2009 Elsevier B.V. All rights reserved.

sofc

barium

Coefficient of

Glass-ceramic sealant

thermal expansion (CTE)

Interaction

Solid oxide fuel cell (SOFC)

Interconnect

crystallization

Författare

Ashutosh Goel

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Dilshat U. Tulyaganov

Centro de Investigacao em Materiais Ceramicos e Compositos

State Committee of Geology and Mineral Resources

V. V. Kharton

Centro de Investigacao em Materiais Ceramicos e Compositos

A. A. Yaremchenko

Centro de Investigacao em Materiais Ceramicos e Compositos

Sten Eriksson

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

José M.F. Ferreira

Centro de Investigacao em Materiais Ceramicos e Compositos

Journal of Power Sources

0378-7753 (ISSN)

Vol. 189 2 1032-1043

Ämneskategorier

Oorganisk kemi

DOI

10.1016/j.jpowsour.2009.01.013