Development of an advanced core-shell ceramic pebble with Li4TiO4 pure phase core and Li2TiO3 nanostructured shell by a physical coating method

An advanced core-shell ceramic pebble with Li₄TiO₄ pure phase core and Li₂TiO₃ nanostructured shell was prepared by a physical coating method. The phase compositions, morphology and microstructure of Li₄TiO₄-Li₂TiO₃ core-shell ceramic pebbles were investigated. We discovered that using chitosan solution to assist rolling coating helps to improve the coating uniformity of core-shell green pebbles. In addition, the results show that the obtained Li₄TiO₄-Li₂TiO₃ core-shell ceramic pebbles have a diameter of ∼1.1 mm, the shell thickness of ∼13 μm and density of 2.31 ± 0.03 g/cm³. It is also noted that the Li₂TiO₃ shell still maintains the nanostructure (∼80 nm) after sintering. This study provides a feasible method for preparing Li₄TiO₄-Li₂TiO₃ core-shell ceramic pebbles which have a great potential application for the test blanket module (TBM) of International Thermonuclear Experimental Reactor (ITER).