Reinvestigations of the Li2O–Al2O3 system. Part I: LiAlO2 and Li3AlO3

Abstract Reinvestigations of the Li 2 O–Al 2 O 3 system focused on the synthesis and properties of LiAlO 2 and Li 3 AlO 3 phases have been performed with the help of XRD and IR measuring techniques and Li 2 CO 3 , LiOH·H 2 O, Al 2 O 3 -sl., α-Al 2 O 3 , Al(NO 3 ) 3 ·9H 2 O and boehmite as reactants. Results of investigations have shown the formation of α-, β-, and γ- polymorphs of LiAlO 2 . It was found that only the use of LiOH·H 2 O as a reactant yields to β-LiAlO 2 as a reaction product. On the other hand, it was proved that Li 3 AlO 3 does not form in the Li 2 O–Al 2 O 3 system. A new method for the synthesis of α-LiAlO 2 was developed, consisting in grinding the mixture of Li 2 CO 3 and Al(NO 3 ) 3 ·9H 2 O and heating the obtained paste at the temperature range of 400–600 °C. The IR spectroscopy was used to characterize obtained phases.