Fig. 2: Thermal characterization of materials.

a Thermogram for polyethylene oxide (PEO) (black curve) and for a typical statistical copolymer (blue curve). b Crystallinity content versus comonomer content, for statistical copolymers with (orange) and without (black) 18 wt% lithium bis-(trifluoromethanesulfonyl)imide (LiTFSI), where squares are for PEO, circles are for copolymers of ethylene oxide with propylene oxide (PEOPO) and triangles are for copolymers of ethylene oxide with 1,2-butylene oxide (PEOBO).