Mechanism of ionic conductivity in poly(ethylene glycol 400)/(MgCl2)(x) polymer electrolytes: studies based on electrical spectroscopy

In this paper, eight solvent-free polymer electrolytes PEG400/(MgCl2)x (0.00329 less than or equal to x less than or equal to 0.7000) were prepared in order to investigate the mechanism of ionic motion and the interactions existing in these systems. The study was carried out by impedance spectroscopy in the 20-Hz to 1-MHz range at different temperatures. Real and imaginary components of conductivity spectra in terms of equivalent circuit analysis (EC) and correlated ionic motion analysis based on a generalized universal power law (UPL) were investigated. Results revealed that in the PEG400/(MgCl2)x, the ionic species formed in the bulk materials are crucial for the overall conductivity. Indeed, in PEG400/(MgCl2)x, conductivity is ionic and takes place through hopping of the cationic species Mg2+ and [MgCl]+ between the coordination sites present along the polyethereal chains.