The Effects of Lithium Triflate (LiCF3SO3) on the PMMA-based Solid Polymer Electrolytes

The effects of Lithium triflate salt (LiCF3SO3), on the poly (methyl methacrylate) (PMMA)-based solid polymer electrolytes plasticized with propylene carbonate (PC) solvated in Tetrahydrofuran (THF) have been studied through a.c impedance spectroscopy and infrared spectroscopy. Lithium triflate was incorporated into the predetermined PMMA/PC system that has the highest value of ionic conductivity. In current investigations, four combination systems: Pure PMMA, (PMMA + PC) systems, (PMMA + LiCF3SO3) and (PMMA + PC + LiCF3SO3) systems were prepared using the solution cast method. Solutions were stirred for numerous hours to obtain a homogenous solution before it is poured into the petri dishes under ambient temperature to form the solid electrolyte thin film. The films were then removed from petri discs and transferred into the dessicator for further drying prior to the different tests. From the characterization done through the a.c impedance spectroscopy, the highest room temperature ionic conductivity in the pure PMMA sample, (PMMA + PC) system and (PMMA + LiCF3SO3) system is 2.83 x 10(-12) Scm(-1), 4.39 x 10(-11) Scm(-1) and 3.93 x 10(-6) Scm(-1) respectively. The conductivity for (PMMA + PC + LiCF3SO3) system was obtained with the 30wt% of lithium triflate, which is 2.48 x 10(-5) Scm(-1). Infrared spectroscopy shows that complexation occurred between the polymer and the plasticizer, and the polymer and plasticizer and salt. The interactions have been studied in the C=O band, C-O-C band and the O-CH3 band.