PREPARATION AND CHARACTERIZATION OF FLUORINATED HYBRID ELECTROLYTES

Hybrid polymer electrolytes based on copolymers of vinylidene fluoride , (VdF) and different molar ratios of hexafluoropropylene (HFP), and a n electrolyte solution ethylene carbonate (EC)/propylene carbonate (PC )/ LiN(CF3SO2)(2) have been prepared by the solvent casting technique. Thermal analysis showed that small or no interactions exist between t he electrolyte solution and the host polymer matrices. Conductivities in excess of 10(-3) S/cm at room temperature were obtained. However, o n isothermal heating at 55 degrees C under vacuum, the samples showed relevant losses of the electrolyte solution, that caused the conductiv ity to drop by 1-2 orders of magnitude. Cationic transport numbers, t( +), ranging between 0.2 and 0.3 have been measured by the Hittorf meth od. (C) 1998 Elsevier Science Ltd. All rights reserved.