Solid polymer electrolytes (SPEs) of poly(ethyleneoxide) and magnesium trif
late, which are plasticized with propylene carbonate (PC), ethylene carbona
te (EC) and a mixture of PC and EC, are studied for their conductivity, ac
impedance of the Mg I SPE interface, cyclic voltammetry, infrared spectrosc
opy and differential scanning calorimetry. in the presence of plasticizers,
the ionic conductivity (a) increases from a value of 1 x 10(-8) S cm(-1) t
o about 1 x 10(-4) S cm(-1) at ambient temperature. The a is found to follo
w a VTF relationship with temperature. The values of the activation energy,
pre-exponential factor and equilibrium glass transition temperature are sh
own to depend on the concentration of plasticizer. Ac impedance studies ind
icate lower interfacial impedance of Mg/plasticized SPE than stainless stee
l/plasticized SPE. The impedance spectra are analyzed using a non-linear le
ast square curve fitting technique and the interfacial resistance of Mg/pla
sticized SPE is evaluated. The cyclic voltammetric results suggest a quasir
eversible type of Mg/Mg2+ couple in plasticized SPE. (C) 2000 Elsevier Scie
nce B.V. All rights reserved.