Preparation and characterization of lithium aluminate

The synthesis of LiAlO 2 by reaction of alumina with mixtures of alkali carbonates or with alkali hydroxides was studied. At 600–700°C, α-LiAlO 2 was the major allotropic phase produced by the reaction of γ-Al 2O 3 with mixtures of Li 2CO 3 and K 2CO 3. Reaction of LiOH (or mixtures of LiOH and KOH) with γ-Al 2O 3 at 450°C produced only β-LiAlO 2 while reaction of LiOH with α-Al 2O 3 at 450°C produced mainly γ-LiAlO 2. The major product of the reaction with LiOH at 600°C was γ-LiAlO 2, regardless of the Al 2O 3 allotrope used. The α- and β- LiAlO 2 powders were observed by scanning electron microscopy to have three distinguishable particle morphologies, which were classified as clumps, platelets and rods. Both α-LiAlO 2 and β-LiAlO 2 particles were produced in the form of clumps and platelets while β-LiAlO 2 particles were also produced in the form of rods.