Ionic conduction studies in P(VDF–HFP)–LiAsF₆–(PC + DEC)–fumed SiO₂ composite gel polymer electrolyte system

Abstract

Abstract In the present work, thin polymer electrolyte films of P(VDF–HFP) copolymer containing LiAsF 6 salt dissolved in PC and DEC and fumed SiO 2 submicron particles as dispersed phase prepared by solution casting technique are characterized by ac impedance measurements in the temperature range 303 K–373 K. Maximum ionic conductivity for P(VDF–HFP)–(PC + DEC)–LiAsF 6 –SiO 2 fumed composite gel polymer electrolyte is found to be of the order of 10 –3 S/cm at room temperature. XRD patterns show the increased amorphicity in the electrolytes. The degree of crystallinity is decreased from 30% in pure polymer to 17.7% in composite gel polymer electrolyte. Scanning electron micrographs show uniform dispersion of SiO 2 particles and suggest that SiO 2 supports formation of porous microstructures and increases the retaining capability of liquid electrolyte in the polymer gel network. FTIR spectral analyses confirm the polymer/salt/filler interaction. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)