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Gel polymer electrolytes employing the co-polymer poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) as the polymer host were prepared by soaking the PVdF-HFP films in a liquid electrolyte of 1.0M 1- methyl-3-propyl imidazolium iodide (MPII) ionic liquid dissolved in a mixture of propylene carbonate (PC) and 1,2- dimetoxyethane (DME) (v/v=7:3). Conductivity of PVdF-HFP-MPII-PC/DME electrolyte was investigated as a function of temperature. Conductivity enhancement with temperature is attributed to the increase in the number, n and mobility, μ of free ions. The n and μ of free ions have been determined quantitatively by impedance spectroscopy. [ABSTRACT FROM AUTHOR]

Micro porous gel type polymer electrolytes composed of 80 Wt% PVDF-HFP polymer - 20 Wt% LiBF4 salt in different concentrations of EC plasticizer (10Wt% - 70 Wt %) plasticizer have been synthesized by Solution cast technique. The effect of plasticizer in polymer-salt matrix, structural, morphological and ionic conductivity is studied. Structural and morphological studies showed increase in amorphous nature and recrystallization after a certain limit of EC plasticizer. The highest ionic conductivity of 1.510 x 10-3 Cm-1 is found for 40 Wt% of EC plasticizer at 303K. Addition of plasticizer increase free volume enables segmental motion of polymer and free mobility of ions. Also it provides more number of charge carriers in turn enhances the ionic conductivity up to certain limit of 40 Wt% of EC plasticizer. Further increase of plasticizer content creates ion-pair aggregation and recrystallization which reduces the ionic conductivity. The ionic conductivity obeys the VTF relationship for Gel type polymer electrolyte system. [ABSTRACT FROM AUTHOR]

Initial study on nano composite polymer electrolyte of PVdF-HFP/MG49-ZrO2 has been done. The zirconium was synthesis via in-situ sol-gel method in a dissolved polymer blends. The effects of different concentrations of zirconium and pH values have been investigated on nano composite polymer (NCP). Analysis impedance show that only at 6 wt. % of zirconium for all pH values show a semi-circle arc which have lowest value of bulk resistance. No ionic conductivity value is obtain due to the absent of ion charge carriers. Analysis of XRD revealed that crystallinity phase of the nano composite polymer was affect by different pH values. However, no significant changes have been observed in IR bands. This could well indicate that different pH medium did not affect the chemical bonding in the structure. [ABSTRACT FROM AUTHOR]

Membranes based on PVdF-HFP have been prepared by solution-casting methode. Lithium perchlorate (LiClO4) and lithium trifluoromethane sulfonate (LiCF3SO3) were used as lithium salts, and ethylene carbonate and a mixture of ethylene and propylene carbonate (1:1 wt. %) as plasticizers. The ionic conductivity was determined by means of impedance spectroscopy. The Nyquist plot was fitted with a general equivalent circuit. The ionic conductivity increases to plastificizer content. The membrane consisting of 50 w% PVdF-HFP, 35 w% PC+EC and 15 w% LiCF3SO3 has the highest conductivity with a value of 6.892×10-3 S/cm at room temperature. [ABSTRACT FROM AUTHOR]