Hybrid polymer electrolytes based on linear siloxane networks and crosslinked polyether domains: Interplay between composition and properties

In this study, a new class of hybrid polymer electrolytes was prepared and characterized. The materials consisted of a matrix based on linear oligosiloxane networks and partially crosslinked polyether domains, doped with Lithium bis(trifluorosulfonyl)imide (LiTFSI). These materials are characterized by a maximum conductivity of 8∙10-5 S/cm at 30 °C, and high thermo-mechanical stability, with decomposition temperature of 250 °C and a storage shear modulus of almost 105 Pa at 100 °C. Compositional parameters such as salt, cross-linker concentration, and polyether chain length were varied, and the materials were characterized by several analytical techniques. Vibrational spectroscopy provided details of the hybrid structure and the effect of salt doping. The thermo-mechanical properties were studied by thermogravimetric analysis, differential scanning calorimetry and rheological analysis. Finally, the transport properties were analyzed by means of broadband electric spectroscopy. The study made it possible to describe the relationships between composition, morphology, thermo-mechanical and transport properties of the synthesized hybrid electrolytes, with particular emphasis on the interplay between polymer dynamics and conduction mechanism.