Structural and AC impedance studies on nanocomposite polymer electrolytes based on poly(ε‐caprolactone)

Abstract

Nanocomposite polymer electrolyte (NCPE) films of [75 wt % poly(ε‐caprolactone) : 25 wt % zinc triflate] + x wt % nanofiller Al2O3 (x = 1, 3, 5, 7) were prepared by solution cast technique. Such NCPE films were characterized using Fourier transform infrared and AC impedance spectroscopic techniques. Complexation of polymer with salt and nanofiller was revealed from FTIR analysis. On the other hand, an apparent increase in the number density of charge carriers upto 5 wt % loading of the nanofiller was also confirmed. Furthermore, AC impedance spectroscopic studies have shown that ionic conductivity increases with the addition of Al2O3 and reaches a maximum of 2.5 × 10−5 S cm−1 at room temperature for 5 wt % loading of nanofiller. The dielectric behavior of all the synthesized samples has also been analyzed and presented. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40524.

Preparation, zinc ion transport properties, and battery application based on poly(vinilydene fluoride-co-hexa fluoro propylene) polymer electrolyte system containing titanium dioxide nanofiller

“…At the high-frequency region, the observed increasing trend of conductivity with TiO 2 content of the NCPE system up to 5 wt% loading and beyond which the decreasing feature of conductivity noticed may be attributed as due to the possible agglomeration of the excess inorganic nanofiller TiO 2 . Sownthari and Suthanthiraraj 13 have also reported that the observed ionic conductivity behavior arises mainly due to the interaction of Zn 2+ ions with the polymer. Ultimately, the observed frequency dependence of AC conductivity could be carefully viewed in Figure 3 wherein the mid-frequency region of the conductivity spectrum shifts toward the high-frequency region with an increase in the loading of TiO 2 filler.…”

“…The fact that R b decreases with increase in filler concentration may be due to the increase in the number of free ions available for the conduction process. 13 The electrical conductivity ( σ ) may be calculated using the relation:…”

“…In view of the above fact, on increasing the filler concentration, the conductivity relaxation time decreases up to 5 wt% TiO 2 loading, beyond which it increases, and therefore this feature may also be correlated with an increase in the ionic conductivity. 12,13 As the concentration of filler particles increases above 5 wt% within the chosen polymer electrolyte system, the conductivity tends to decrease because of the fact that any reduction in the interparticle distance may lead to an overlap of immobile polymer regions around the nanoparticles. It is therefore quite evident that the observed modulus spectrum shows the existence of a non-Debye type of relaxation phenomenon with a distribution of relaxation times (more than one relaxation time) in the case of present NCPEs.…”

“…Therefore, the present analysis of electric modulus behavior confirms the non-Debye type of relaxation occurring in all these specimens of NCPEs. 13…”

Structural and Electrochemical Properties of Nanocomposite Polymer Electrolyte for Electrochemical Devices

“…17 It is also been reported that an increase in the content of fillers after a certain level leads to a decrease in conductivity. 18,19 Among the fillers studied, SiO 2 plays a crucial role in terms of enhancing ionic conductivity. To our best knowledge, the effect of concentration added to the polymer electrolyte [70PEO:30AgI], and its electrochemical properties in particular, on its potential use for electrochemical double-layer capacitor has not been explored until now.…”