Li3InCl6 was synthesized via a water-mediated synthesis route 8 . Stoichiometric amounts of anhydrous LiCl (Thermo Fisher Scientific, 98+ %) and anhydrous InCl3 (Thermo Scientific, 99.99 %) were weighed inside an Ar-filled glovebox. Distilled H2O in a ratio of 1 mL per 1 g was added and stirred for 15 minutes. The water was evaporated under continuous stirring inside an oil bath heated at 100 °C for 3 hours, leading to a powder containing crystal water.