Electronic and Ionic Dynamics Coupled at Solid-Liquid Electrolyte Interfaces in Porous Nanocomposites of Carbon Black, Poly(vinylidene fluoride), and γ-Alumina

Better fundamental understanding of the transport properties within nanocomposite materials consisting of interpenetrated percolating networks and used as electrodes is needed to improve their performance for a variety of devices. The. simultaneous measurement of their effective ionic and electronic conductivities requires a sophisticated experimental set up. Here, the reciprocal influence of ionic and electronic transfers at different scales of model porous nanocomposites made of carbon black-poly(vinylidene fluoride)-gamma alumina wetted by a nonaqueous electrolyte is investigated by broadband dielectric spectroscopy (BDS) from 40 to 10(10) Hz, between 223 and 293 K. Experimental results show that the coupling of electronic and ionic dynamics at interfaces in the nanostructured composite material results in significant decrease of the electronic conductivity compared to the dry state and increase of the ionic conductivity compared to the bulk electrolyte.