Institution: | aDepartamento de Química and CQ-VR, Universidade de Trás-os-Montes e Alto Douro, 5001-911 Vila Real, Portugal bDepartment of Experimental Physics, Chalmers University of Technology, 41296 Göteborg, Sweden cUnidade de Microscopia Electrónica, Universidade de Trás-os-Montes e Alto Douro, 5001-911 Vila Real, Portugal |
Abstract: | Fourier Transform infrared (FT-IR) and Raman (FT-Raman) spectroscopies and Scanning Electron Microscopy (SEM) were used to investigate ionic association, hydrogen bonding and morphology in a family of sol–gel derived lithium triflate (LiCF3SO3)-doped di-urethane cross-linked poly(ε-caprolactone) (PCL(530))/siloxane hybrid electrolytes. The materials studied, with compositions ∞ > n 0.5 (where n – composition – expresses the molar ratio of PCL(530) ester repeat units per Li+ ion), are non-porous and homogeneous. The Li+ ions interact with the urethane and ester carbonyl oxygen atoms within the whole range of salt concentration analyzed, promoting the formation of hydrogen-bonded aggregates. The composition dependence of the relative concentration of “free” anions and coordinated anions (weakly coordinated anions, ion pairs or Li(CF3SO3)2]− triplets, aggregates I (Li2(CF3SO3)]+) and aggregates II (Li3(CF3SO3)]2+) in all the samples is in perfect agreement with the values of the room temperature ionic conductivity reported previously. |