Lithium Ion Concentration Dependant Ionic Conductivity and Thermal Properties in Solid Poly(PEGMA-co-acrylonitrile) Electrolytes

Abstract

The lithium ion concentration dependant ionic conductivity and thermal properties of poly(ethylene glycol) methyl ether methacrylate (PEGMA)/acrylonitrile-based copolymer electrolytes with LiClO 4 have been studied by differential scanning calorimetry (DSC), linear sweep voltammetry (LSV) and AC complex impedance measurements. In systems with 11 wt% of acrylonitrile all liquid electrolytes were obtained regardless of lithium ion concentration. Complex impedance measurements with stainless steel electrodes give ambient ionic conductivities 8.1 × 10 −6~1 .4 × 10 −4 S cm −1. On the other hand, a hard and soft films at ambient temperature were obtained in copolymer electrolyte system consists of 15 wt% acrylonitrile with 6 : 1 and 3 : 1 of [EO] : [Li] ratio, respectively. DSC measurements indicate the crystalline melting temperature of poly(PEGMA) disappeared completely after addition of LiClO 4 in this system due to the complex formation between ethylene oxide (EO) unit and lithium salt. As a result, free standing film with room temperature ionic conductivity of 1.7 × 10 −4 S cm −1 and high electrochemical stability up to 5.5 V was obtained by controlling of acrylonitrile and lithium salt concentration.

Hyperbranched Polyelectrolyte Copolymers as Novel Candidate Delivery Systems for Bio-Relevant Compounds

“…1 H-NMR spectra and peak assignments are depicted in Figure 2 . Based on the integrated intensities of the signal at δ 3.64 ppm, corresponding to the repeating methylene protons of OEGMA pendant chains [ 35 ], and the signal at δ 1.41 corresponding to the methyl protons in the tert-butyl groups of tBMA [ 27 ], the HCs chemical compositions are in complete accordance with the initial monomer feed compositions (the asterisk in the relative peak presented in Figure denotes the solvent signal).…”