Lithium bromide

Purified G3 (Nippon Nyukazai), triethylene glycol butyl methyl ether (G3Bu, Wako), LiTFSA (battery-grade, Solvay Chemicals), lithium bromide (>99.0%, Tokyo Chemical Industry), lithium chloride (Ishizu Seiyaku), iron(iii) bromide (99%, Wako), and iron(iii) chloride (99%, Kojundo Chemical Laboratory) were used as received. All SILs were prepared in an Ar-filled glove box ([H₂O] < 3.5 ppm). LiBr and G3 were mixed at a 1 : 1 molar ratio and heated at 120 °C for at least 12 h to obtain [Li(G3)]Br. [Li(G3Bu)]Br was prepared by mixing LiBr and G3Bu at a 1 : 1 molar ratio and heating at 100 °C for at least 12 h. [Li(G3)][FeBr₄] and [Li(G3)][FeCl₃Br] were prepared by mixing [Li(G3)]Br and FeBr₃ or FeCl₃, respectively, at a 1 : 1 molar ratio, and heating at 100 °C for at least 12 h. [Li(G3Bu)][FeBr₄] and [Li(G3Bu)][FeCl₃Br] were prepared in the same way, using [Li(G3Bu)]Br rather than [Li(G3)]Br. [Li(G3)][FeCl₄] and [Li(G3Bu)][FeCl₄] were prepared by mixing LiFeCl₄ and G3 or G3Bu, at 100 °C or room temperature, respectively, for at least 12 h. The LiFeCl₄ used here was obtained by grinding LiCl and FeCl₃ powders in a mortar at a 1 : 1 molar ratio. [Li(G3)][TFSA] and [Li(G3Bu)][TFSA] were prepared according to a procedure described elsewhere.^{28 (link)}