Cost‐effective Synthesis of α‐LiAlO2 Powders for Molten Carbonate Fuel Cell Matrices

Lithium aluminate (α‐/β‐LiAlO₂) particles were fabricated using three methods. The first method used organic glycerin and triethylene glycol which functioned as a catalyst for fabrication of α‐LiAlO₂ particles with Al(OH)₃ and LiOH·H₂O as the starting materials. As a result of the heat‐treatment of the starting materials, α‐/β‐LiAlO₂ particles could be obtained. The amount of α‐LiAlO₂ particles in α‐/β‐LiAlO₂ increased slightly as more organics were added. Additionally, when synthesised α‐/β‐LiAlO₂ particles were heat‐treated in a CO₂ gas flow, β‐LiAlO₂ was partially transformed to α‐LiAlO₂. In the second method, molten salts (Li₂/Na₂/K₂CO₃) were used as a catalyst to fabricate α‐LiAlO₂ as a major phase, however, this method requires a washing process which can produce unexpected impurities. In the third method, pure α‐LiAlO₂ was obtained by heat‐treatment of cheap sources such as Li₂CO₃ and Al(OH)₃ at 600–800 °C. The mean particle size (604 nm–11.85 μm) and the specific surface area (3.22–11.4 m² g^–1) of α‐LiAlO₂ were suitable for reinforcing the matrix and tape casting. Lastly, this study examined the effect of CO₂ for the synthesising of α‐LiAlO₂ particles.