Propylene carbonate uptake and conductivity of lithiated short side chain perfluorinated sulfonic ionomeric membranes

Short Side Chain (SSC) ion-conducting polymers have revealed a better electrochemical behaviour compared to the long-side-chain (LSC) NAFION (R)-like polymers in the Polymer Electrolyte Membrane Fuel Cell (PEMFC) application (1). The relevance of the lithium form of HYFLON (R) ION as polymer electrolyte for lithium ion batteries has also been investigated. Starting from these SSC ionomers and utilising a particularly straightforward methodology for the preparation and dehydration of the lithium ion membrane in nonaqueous media, it has been possible to achieve a high ionic conductivity in the range of 10-3 S/cm at room temperature(2). The high concentration of lithium ions and the high polymer swelling in propylene carbonate solvent are not sufficient to explain the high ionic conductivity observed.