In this study, we investigated the role of solid electrolyte interface (SET) films in the cells fabricated with the ionic liquids ([N-2,N-2,N-1(201)][TFSI] and [Li(G4)][TFSI]). The SET was introduced beforehand to the graphite electrode, which facilitated the intercalation of Li-ions into the graphite electrode in [Li(G4)][TFSI]. In addition, the discharge capacity in the case of the cell fabricated with [Li(G4)][TFSI] was almost similar to that observed in the case of the cell fabricated with organic electrolyte. The SET performed the pulling apart combination of glyme and Li-ion. Identification analysis of the SET component having action of extracting Li-ion from [Li(G4)] was carried out. (C) The Author(s) 2018. Published by ECS.