Enhancement in Electrical Properties of PEO Based Nano-Composite Gel Electrolytes

Vol. 2  Issue 3
Year: 2014
Issue:Oct-Dec
Title:Enhancement in Electrical Properties of PEO Based Nano-Composite Gel Electrolytes
Author Name:Rajiv Kumar
Synopsis:

The nano-composite polymer gel electrolytes containing polyethylene oxide (PEO), triflic acid, dimethylacetamide (DMA), propylene carbonate (PC), ethylene carbonate (EC) and nano-porous alumina filler (Al2O3) have been synthesized. The AC impedance has been studied to evaluate Ionic conductivity of the electrolytes. pH, viscosity and thermal properties of these electrolytes have also been studied. The increase in conductivity has been observed with the addition of polymer to liquid electrolytes which has been explained to be due to the breaking of ion aggregates present in electrolytes. The increase in free H+ ion concentration upon breaking of ion aggregates has also been observed in pH measurements. It was observed that the conductivity increases with an increase in the concentration of nano filler and two maxima in conductivity have also been observed. The maximum conductivity of 1.02 × 10-2 S/cm has been observed at 8 wt% concentration of nano filler. A possible mechanism for the increase in conductivity could be the creation of additional hopping sites and favorable conducting pathways for migrating ionic species though Lewis acid- base type interactions between ionic species and O- sites on the filler grain surface. Temperature dependence conductivity of polymer gel electrolytes follows Arrhenius behaviour. The gels containing DMA are stable over upto 125o C range of temperature, while gels based on PC and EC are stable only upto 40oC temperature range which looses their gelling nature above 40o C. The conductivity does not show any appreciable change with temperature which is desirable for their use in smart electrochemical applications at low temperature.