Effect of Cl− on the properties of Li2TiO3 ceramic powders synthesized by in-situ hydrolysis

Li2TiO3 powders were obtained by in-situ hydrolysis route along with water washing process, in which TiCl4 and LiOH·H2O were used as raw materials. The removal of soluble chloride salt in the as-prepared Li2TiO3 samples by water-washing process and the effect of Cl− upon the morphology and the sintering behavior of the Li2TiO3 powders have been studied. The results indicated that more than 90% of Cl− can be easily removed from the heat treated Li2TiO3 powders by water-washing. The samples after water-washing are in cube-like shape with uniform particle size distribution, while the original powders are cohered together with irregular morphology. Compared with the originally unwashed Li2TiO3 powders, the washed samples show better sinterability. The density and thermal shrinkage rate of the sintered Li2TiO3 pellets increase with a decrease of the Cl− content in the sample. Sintered body with the relative density of 90.9% T.D. (theoretical density based on the Li2TiO3 single crystal density of 3.43 g/cm3) and the thermal shrinkage rate of 13.1% was obtained from the water washed Li2TiO3 powders, whereas the T.D. and the thermal shrinkage rate were only 72.7% and 10.3% in the sintered body of unwashed sample, respectively. The results illustrated that Cl− had a significant effect on the properties of the Li2TiO3 samples, including purity, morphology and sintering behavior. The removal of Cl− from the Li2TiO3 samples obtained by in-situ hydrolysis is necessary for producing high-quality Li2TiO3 pellets.