Electrolytic reduction in LiCl-Li2O of titania microspheres synthesized via vibrational droplet coagulation: Effect of feed morphology

Abstract

In this work, an electrolytic reduction route of TiO₂ microspheres with a well-defined morphology is reported. The TiO₂ microspheres are synthesized via a vibrational droplet coagulation method and are electrochemically reduced in LiCl-Li₂O molten salt. The reduction process of the spheres of different size and morphology is investigated. The electrolytic reduction kinetics, the product chemistry and morphological parameters such as outer diameter, total surface area and pore size are investigated and benchmarked to a conventional TiO₂ powder feed. Moreover, the reduced TiO₂ spheres were investigated by X-ray diffraction, scanning electron microscope and BET method. A core–shell structure was observed in the spheres as an intermediate form during electrolysis when charges below 100 % of the theoretical charge were applied. Raman spectroscopy was performed to identify the composition of the core and the shell to further elucidate the reduction pathway of these TiO₂ spheres throughout the electrolysis process. After full electrolytic conversion of the feed material, LiTiO₂ microspheres were obtained. The presented reduction route provides a novel pathway to synthesize high purity LiTiO₂ for practical applications.