Polyether-grafted SnO₂ nanoparticles designed for solid polymer electrolytes with long-term stability

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-SnO ₂ nanoparticles and LiClO₄ exhibit ionic conductivity over 10^-5 S cm^-1, and the PEGME-SnO₂-LiClO ₄ composites act as the main conductive component when PEGME-SnO ₂ 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.