Synthesis and performance of Ti subchlorides (TiClx, x = 2, 3) as a Ti-ion transport agent in NaCl-CaCl2 molten electrolyte

To manufacture titanium subchlorides (TiClx, x = 2, 3), a combustion synthesis technique based on a displacement reaction between PbCl2 and Ti is devised. During the combustion reaction at 670–940°C, a molten product including TiCl2 (and/or TiCl3) and Pb is formed. The reaction mechanism and high-temperature kinetics are described in addition to temperature-time profiles measured by thermocouples. XRD examination confirms the formation of TiCl2 and TiCl3 phases depending on the PbCl2/Ti ratio. SEM and XPS analysis techniques are also used to characterize Ti subchlorides. The selective dissolution of titanium via the generated titanium subchlorides and subsequent deposition on the cathode at 650°C is achieved by electrorefining Ti-Cu alloy (anode) in NaCl-CaCl2-TiCl2 molten chlorides.