Salt concentration and temperature dependent dielectric properties of blend solid polymer electrolyte complexed with NaPF6

Abstract

Solid polymer electrolytes consisted of poly (ethylene oxide) (PEO) and poly (vinyl) pyrrolidone (PVP) with sodium hexafluorophosphate (NaPF6) salt has been prepared by solution cast technique. The influence of salt concentration and temperature on the complex permittivity, complex conductivity, loss tangent, and complex modulus have been analyzed systematically. The complex permittivity decreases with the increase of frequency and high value of dielectric permittivity in the low-frequency window is attributed to the electrode polarization effect. The peak in the loss tangent plot shift toward high frequency with the addition of salt and increase of temperature clearly indicates the decrease of the relaxation time. The temperature dependent analysis suggests that dielectric properties, dc conductivity, and the molecular chain segmental dynamics increase with the increase of temperature owing to the thermal activation of dielectric properties. The ion migration and dc conductivity are effectively improved by the addition of salt. Aforementioned estimated results strongly convincing its use for the device applications