File Name : fig.s1.tif Caption : fig. s1. xrd patterns and lattice parameters of pba before and after drying under vacuum File Name : fig.s2.tif Caption : fig. s2. nyquist plots of the k|k cells with kfsi-5m (a) and ktfsi-5m (b) before cycling and after 10 cycles of plating/stripping at 0.025 µa.cm-2 File Name : fig.s3.tif Caption : fig. s3. photographs of the separators after cycling at 0.025 ma.cm-2 (a) and 1 ma.cm-2 (b) with kfsi-5m (left) or ktfsi-5m (right) File Name : fig.s4.tif Caption : fig. s4. galvanostatic profiles of pba with kfsi (1m) + dme (a) and ktfsi (1m) + dme (b) recorded at 25 ma/g between 3.0 and 4.3 v File Name : fig.s5.tif Caption : fig. s5. evolution of the capacity of pba during galvanostatic cycling with kfsi (1m) + dme (a) and ktfsi (1m) + dme (b)