Infrared Studies of PVC-based Electrolytes Incorporated with Lithium Triflate and l-butyl-3-methyl imidazolium trifluoromethanesulfonate as Ionic Liquid

摘要

In this work, l-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIMCF_3SO_3) is employed as ionic liquid in PVC-based polymer electrolyte system with lithium triflate (LiCF_3SO_3) as doping salt. The samples in film form were prepared by quantitatively varying the concentration of BMIMCF_3SO_3 to a fixed ratio of PVC-LiCF_3SO_3 using solution cast technique. The highest room temperature ionic conductivity of 1.120 x 10-~7 Scm-~1 was exhibited by PVC-LiCF_3SO_3-BMIMCF_3SO_3 containing 3 wt. % BMIMCF_3SO_3. FTIR spectra of the polymer electrolytes were examined to study the complexation of the PVC-based polymer electrolytes. Intensity of free ions, ion pairs, and ion aggregates were obtained from FTIR deconvolution in an attempt to correlate with ionic conductivity results. The intensity of free ions was found to be high for sample with 3 wt. % BMIMCF_3SO_3.