Influence of aluminum salt addition on in situ sintering of electrolyte matrices for molten carbonate fuel cells

Three aluminum salts are investigated as a sintering aid for the in situ sintering of electrolyte matrices for molten carbonate fuel cells (MCFCs). Only aluminum acetylacetonate shows a potential. At or above 420°C, aluminum acetylacetonate changes to Al 2O 3 and reacts with Li 2CO 3 in the electrolyte to produce γ-LiAlO 2. This reaction product forms necks between matrix particles. Necks grow with increasing sintering time and correspondingly, the mechanical strength of the electrolyte matrix shows an abrupt increase, starting at a sintering time of about 100 h until it levels off at about 250 h. The porosity of the matrices fabricated with aluminum acetylacetonate is in the range acceptable for use in MCFCs.