Polyether-grafted SnO2 nanoparticles designed for solid polymer electrolytes with long-term stabilityElectronic supplementary information (ESI) available: XPS results and in situ IR spectra. See http://www.rsc.org/suppdata/jm/b4/b405179c/

Polyether-grafted SnO2 nanoparticles are prepared through a hydrothermal method and exchange reactions. X-ray diffraction (XRD) and transmission electron microscopic (TEM) results illustrate that these nanoparticles are uniform, mono-dispersed and about 3 nm in diameter, while thermo-gravimetric and differential thermal analyses (TG-DTA) and infrared (IR) data prove that poly(ethylene glycol methyl ether) (PEGME) groups are bound tightly on SnO2 surfaces. The composites of such PEGME-SnO2 nanoparticles and LiClO4 exhibit ionic conductivity over 10−5 S cm−1, and the PEGME–SnO2–LiClO4 composites act as the main conductive component when PEGME–SnO2 fillers are incorporated in the prototypical PEO–LiClO4 films. The PEO–(PEGME–SnO2)–LiClO4 films exhibit improved conductivities with long-term stability, enhanced Li+ transference numbers and better mechanical properties.