BMIMTf ionic liquid-assisted ionic dissociation of MgTf in P(VdF-HFP)-based solid polymer electrolytes

Solid polymer electrolytes (SPEs) with poly(vinylidene fluoride-hexafluoropropylene) [P(VdF-HFP)] (often used as a polymer host) that have been doped with a constant amount of magnesium trifluoromethanesulfonate (MgTf) and with varying concentrations of 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIMTf) are synthesized via a solution casting method. P(VdF-HFP)/MgTf/BMIMTf-based SPEs exhibit approximately 4×10−3 S cm−1 at room temperature, with 75 parts by weight (pbw) of BMIMTf. This study proposes that the variation of the ionic conductivity is caused by ionic dissociation facilitated by BMIMTf. The XRD and TG/DTG results are congruent with each other and aid in substantiating the proposal. FTIR spectra reveal the possibility that BMIM+ has no direct interaction with P(VdF-HFP), which suggests that the polymer host merely serves as an ionic transportation medium and as mechanical support.