Investigation of swelling phenomena in PEO-based polymer electrolytes: II. Chemical and electrochemical characterization

New types of Polyethyleneoxide (PEO)-based gel electrolyte membranes, prepared by swelling a PEO-LiX (e.g., X=ClO4) dry polymer membrane containing a nanosize SiO2 ceramic filler in a 25 mol% ethylene carbonate (EC)/75 mol% diethylcarbonate (DEC) solvent mixture, are discussed. The basic characteristics of these membranes are reported in terms of (i) electrochemical stability, (ii) role of the storage time and liquid content in determining the ionic conductivity and (iii) evaluation of the limiting diffusion current density. The extent of dissolution of the PEO host in the EC/DEC mixture during the swelling process is also investigated.