Effect of Plasticizer and Lithium Salt Concentration in PMMA-based Composite Polymer Electrolytes

Blended polymer electrolytes with poly(methyl methacrylate) (PMMA) were prepared with various propylene carbonate (PC) plasticizer concentrations and lithium perchlorate (LiClO4) ratio by the solution-casting technique. Fourier transform infrared studies show the evidence of the complexation between PMMA, LiClO4, and PC. The composite polymer electrolytes show good thermal property, which are confirmed by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). PC is added to the PMMA–LiClO4 blend polymer electrolytes as plasticizer to enhance the conductivity, and the highest conductivity obtained is 5.64×10−3 S cm−1 at 80 °C for PC mixture system. Moreover, the maximum conductivity of polymer electrolyte (PMMA:PC:LiClO4:SiO2 (wt. ratio) = 299:556:128:17) is up to 8.91 mS cm-1 at 90 °C by optimizing the composition of the polymers, salts, plasticizer, and filler, and the temperature dependence of the conductivity of polymer electrolytes obeys the Vogel–Tamman–Fulcher (VTF) relationship.