Effect of carbon nanotube dispersion on electrochemical and mechanical characteristics of poly(methyl methacrylate)‐based gel polymer electrolytes

Abstract

Polymer‐based electrolyte of lithium ion batteries and other devices have shortcomings of low ionic conductivity and inadequate mechanical strength. The study presents the preparation of polymethyl methacrylate (PMMA)‐based three‐layered nanocomposite gel polymer electrolytes (NCGPEs) having multiwalled carbon nanotubes (MWCNTs) dispersed in the middle layer of the composites and the effect of dispersoid quantities on the ionic, mechanical, and thermal characteristics of the electrolytes. The NCGPEs were synthesized by solution cast process with the various MWCNTs contents of 0.5, 1.0, 1.5, and 2.0 wt%. Morphology of the NCGPEs has been observed by scanning and transmission electron microscopes (SEMs). Interactions between the constituents of the composite and structural changes of the base polymer were investigated by Fourier transform infrared (FTIR) spectroscopy and X‐ray diffraction (XRD) techniques. The mechanical strength of the NCGPEs increases considerably owing to the dispersion of MWCNTs and the highest strength was found for the dispersion of 2.0 wt% of MWCNTs. The thermal stability of the nanocomposites was investigated by thermo‐gravimetric analysis (TGA). The chemical decomposition temperature of the nanocomposites increases considerably as compared to the gel polymer electrolyte. Ionic conductivity of the composite electrolyte increases with the increase in addition of MWCNTs and the maximum ionic conductivity (10−3 S cm−1) of the nanocomposite has been found with the dispersion of 2.0 wt% MWCNTs among all the dispersoid. POLYM. COMPOS., 37:1936–1944, 2016. © 2015 Society of Plastics Engineers