Our research group at the University of Pavia is involved in the preparation and characterization of gel electrolytes for lithium batteries, based on PVDF homopolymer and copolymers. In this paper our most recent developments are reviewed and particular emphasis is given on the physico-chemical properties which strongly influences their utilization in electrochemical devices.

First of all we discuss the structure and microstructure of these complex multi-phase gels, in terms of some basic parameters, for example the nature and the morphology of the pristine polymer matrix. Our attention is then focused on the ionic transport mechanisms involved in these systems, which are described by means of a percolative approach and compared with the ionic diffusive processes. The final part of this paper will review the cation dynamics, outlining the level and the nature of the ion-ion and ion-polymer interactions.