Effect of Filler-Polymer Interactions on the Crystalline Morphology of PEO-Based Solid Polymer Electrolytes by Y2O3 Nano-Fillers

A novel lithium solid polymer electrolyte (SPE) based on polyethylene oxide (PEO) matrix and yttrium oxide (Y2O3) as nano-filler was prepared by solution casting technique. The Lewis acid-based filler-polymer coordination interactions between the surface of Y2O3 and the ether oxygen of PEO were proved by FTIR, which induced an obvious modification of crystalline morphology of the PEO-based SPEs. Polarized optical microscope (POM) analysis shows that the induced nucleation and steric hindrance effects of Y2O3 nano-filler result in the increased amount as well as decreased size of spherulites in the PEO matrix, respectively. Atomic force microscope (AFM) images indicate the surface morphology of PEO gets rougher as Y2O3 content increases. X-ray diffractomer (XRD) and differential scanning calorimetry (DSC) results demonstrate the crystallinity of SPEs decreases from 51.1% to 32.5% with the Y2O3 weight ratio [m(Y2O3)/m(PEO+LiI)] increasing from 0 to 0.15. POLYM. COMPOS., 32:511-518, 2011. (C) 2011 Society of Plastics Engineers