Influences of ultrasonic- and microwave-irradiated preparation methods on the structural and dielectric properties of (PEO–PMMA)–LiCF3SO3–x wt% MMT nanocomposite electrolytes

Abstract

The novel solid polymeric nanocomposite electrolytes (SPNEs) consisted of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) blend with lithium triflate (LiCF3SO3) as ionic salt and montmorillonite (MMT) clay as inorganic nanofiller have been prepared by classical solution cast, ultrasonic assisted, microwave irradiated and ultrasonicated followed by microwave-irradiated solution cast melt-pressed methods. The X-ray diffraction studies reveal that the amorphous phase of PEO–PMMA blend and the exfoliated/intercalated MMT structures in the electrolytes vary significantly with MMT concentration and the sample preparation methods. The complex dielectric function, electrical conductivity, electric modulus and impedance spectra of these materials have been investigated over the frequency range 20 Hz–1 MHz. It is observed that the microwave-irradiated prepared electrolytes have relatively high ionic conductivity. The conductivity values confirm their correlation with the dielectric strength and the relaxation times, and suggest the suitability of these electrolytes for lithium-ion batteries and electrochromic devices.