Some physicochemical properties of PAN-based electrolytes: solution and gel microstructures

The mechanical and electrochemical properties of gel electrolytes, formed by immobilizing ethylene carbonate (EC)–propylene carbonate (PC)/lithium perchlorate (LiClO4) solutions in a polyacrylonitrile (PAN) matrix, were investigated by oscillating rheological experiments, conductivity measurements and 1H-NMR spectroscopy. The gelʹs rheological behaviour showed two thermoreversible structural transitions in the temperature range 25–120 °C independent from the salt content in the membranes but can be attributed to the only polymeric matrix. In this paper, we also report a study of the EC–PC/LiClO4 solutions in a wide concentration range performed by pulsed gradient spin–echo NMR (PGSE–NMR) technique. The solvent self-diffusion coefficient measurements have allowed elaborating a model to describe the solvation mechanism of the lithium ions in these solutions.