1. Li-NMR

Li NMR spectra of LiTFSI (0.013 m, 450 ml) (bottom), 1/LiTFSI (0.02 m/0.013 m, 450 ml) (middle) and 1/LiTFSI/PC (0.02 m/0.013 m/ 0.13 m, 450 ml) (top) in CDCl 3 : THF-d 6 (v/v, 6 : 1) solution. LiCl D 2 O solution in a coaxial NMR tube was used as an internal standard and the lithium signal was set at 0 ppm. The dashed line indicates the chemical shift of the lithium ion for the pure LiTFSI solution. All the spectra were recorded at room temperature.