Effect of Al 2O 3 nanoparticles on the electrochemical characteristics of P(VDF-HFP)-based polymer electrolyte

Abstract

Alumina (Al 2O 3) nanoparticles have been used as fillers in the preparation of poly(vinylidenefluoride-co-hexafluorpropylene) (P(VDF-HFP))-based porous polymer electrolyte. The degree of crystallization of polymer film filled with Al 2O 3 nanoparticles decreases with increase of the mass fraction of Al 2O 3 nanoparticles and the amorphous phases of polymer film expand accordingly. The Al 2O 3 nanoparticles play the role of solid plasticizer for polymer matrix. Nevertheless that excessive Al 2O 3 nanoparticles existing in polymer matrix leads to micro-phase separation between polymer matrix and fillers. As a result, both ionic conductivity and lithium ions transference number reduces whereas the activation energy for ions transport increases. When the polymer film is filled with 10% of the mass fraction of Al 2O 3 nanoparticles, polymer electrolyte possesses the ionic conductivity up to 1.95 × 10 −3 S cm −1 and the lithium ions transference number to 0.73 while the activation energy for ions transport of them falls to 5.6 kJ mol −1. Effect of Al 2O 3 on the electrochemical properties of polymer electrolyte has been investigated in this paper. Analysis of FTIR spectra shows that there is the interaction between Al 2O 3 nanoparticles and polymer chains.