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Phase and Microstructural Stability of Electrolyte Matrix Materials for Molten Carbonate Fuel Cells
Author(s) -
Choi H.J.,
Lee J.J.,
Hyun S.H.,
Lim H.C.
Publication year - 2010
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/fuce.200900199
Subject(s) - materials science , molten carbonate fuel cell , particle size , phase (matter) , particle (ecology) , electrolyte , chemical engineering , chemistry , oceanography , organic chemistry , electrode , engineering , geology
LiAlO 2 powder is used as a material for molten‐carbonate fuel cell (MCFC) matrices. The physical and chemical stabilities of LiAlO 2 powder during MCFC operation determine the performance and lifetimes of the cells. Change to the phase and particle size in the allotropic phase of LiAlO 2 was examined with long‐term stability tests on pure α‐LiAlO 2 matrix, Al‐reinforced α‐LiAlO 2 matrix, Al‐reinforced γ‐LiAlO 2 matrix, aqueous γ‐LiAlO 2 matrix and an α‐/β‐LiAlO 2 mixture powder in molten carbonate at 650 °C in air. In the γ‐LiAlO 2 and α‐/β‐LiAlO 2 mixture, the particle growth was continuous from the early stages of heat‐treatment to 20,000 h. Crystalline phase transformation (γ‐LiAlO 2 and β‐LiAlO 2 to α‐LiAlO 2 and γ‐LiAlO 2 , respectively) of these powders and matrices also occurred, and γ‐LiAlO 2 made the third phase like LiAl 5 O 8 . By contrast, the sizes of these particles and the crystalline phase of α‐LiAlO 2 did not change during immersion tests. These results show that, among α‐/β‐ and γ‐LiAlO 2 , α‐LiAlO 2 is the most stable phase in molten carbonate.