Single-ion-conducting nanocomposite polymer electrolytes based on PEG400 and anionic nanoparticles: Part 1. Synthesis, structure and properties

The synthesis and the properties of single-ion-conducting nanocomposite polymer electrolytes (nCPEs) are described. The nCPEs are obtained by doping polyethylene glycol 400 (PEG400) with different amounts of a fluorinated TiO2-based nanofiller (LiFT®) that is surface-functionalized with Li+ cations. Electrolytes with general formula [PEG400/(LiFT)y] and y = nTi/nPEG ranging from 0 to 26.4 are obtained. The materials are characterized by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Fourier-Transform Infrared Spectroscopy in both the medium (FT-MIR) and far infrared (FT-FIR). In the [PEG400/(LiFT)y] electrolytes the concentration of LiFT nanofiller strongly affects the thermal stability and transitions of PEG400. In addition, vibrational measurements allow us to reveal the interactions occurring between: (a) different PEG400 chains; (b) PEG400 and Li+ cations; and (c) PEG400 and LiFT nanoparticles (NPs). On LiFT nanofiller concentration, results show three compositional regions in [PEG400/(LiFT)y] electrolytes which are correlated to the presence of three different interaction environments between LiFT NPs and PEG400 chains.