Effects of various LiPF6 salt concentrations on PEO-based solid polymer electrolytes

Abstract

In this research, various weight percents of LiPF6 are incorporated into PEO-based polymer electrolyte system. Thin film electrolytes are prepared via solution casting technique and characterized by FTIR, XRD and DSC analyses in order to study their complex behaviour. The amorphicity of the electrolytes are measured by DC impedance. The results reveal that the conductivity increases with increasing temperature when the salt concentration increases to 20 wt.%. The conductivity for 20 wt.% of salt remains similar to the conductivity of 15 wt.% of salt at 318 K. Impedance studies show that the conductivity increases with increasing LiPF6 concentration, whereas XRD studies reveal that the phase changes from crystalline to amorphous when LiPF6 concentration increases. DSC studies indicate a decrease in Tm with increasing LiPF6 concentration. Finally, the complexation process is examined using FTIR.