Electrical and electrochemical properties of poly (methyl methacrylate) based nanocomposite gel electrolytes dispersed with dedoped (insulating) polyaniline nanofibers

In this work, we have investigated the effect of dedoped (insulating) polyaniline (PAni) nanofibers on the electrical and electrochemical properties of poly(methyl methacrylate) (PMMA)-based gel electrolytes. PAni nanofibers have been synthesized using interfacial polymerization technique. By analysis of X-ray diffraction (XRD) and impedance spectroscopy results, it has been demonstrated that the incorporation of dedoped PAni nanofibers up to a moderate concentration (4 wt%) to PMMA-(PC + DEC)-LiClO4 gel polymer electrolyte system significantly enhances the ionic conductivity of the electrolyte system, which can be attributed to the inhibition of polymer chain reorganization upon dispersion of high aspect ratio nanofibers in PMMA matrix resulting in reduction in polymer crystallinity, which gives rise to an increase in ionic conductivity. At higher concentration, dedoped nanofibers appear to get phase separated and form insulating clusters, which impede ionic transport. The phase separation phenomena at higher fraction of nanofibers are confirmed by XRD. Studies on electrochemical behavior reveal that electrochemical potential window increases with the increase of nanofibers loading.