Synthesis of α-LiAlO₂ Powders with a Controlled Granulometric Composition for a Carbonate-Melt-Based Matrix Electrolyte

Abstract—Three methods of synthesizing α-LiAlO₂ powders for the manufacture of a matrix electrolyte for a molten carbonate fuel cell are considered. A submicron fraction with a specific surface area of 79 m²/g is fabricated by spray pyrolysis from an aqueous solution, and coarse rod-shaped fractions with a particle length of up to 19 μm are synthesized from a halide melt and an aqueous solution. Ceramic matrices prepared by belt casting are tested in a single fuel cell filled with the 53Li₂CO₃–47Na₂CO₃ melt as an electrolyte. The matrices showed good gas tightness: the nitrogen flow into an anode through the matrix does not exceed 0.6% during life tests for 1100 h, which included 15 thermal cycles with cooling of the fuel cell until the melt freezes.