Effects of a Block Copolymer as Multifunctional Fillers on Ionic Conductivity, Mechanical Properties, and Dimensional Stability of Solid Polymer Electrolytes

Abstract

Solid polymer electrolytes with high ionic conductivities, good mechanical properties, dimensional stability, and easy processability were obtained from poly(ethylene oxide)-block-polyethylene (PEO-b-PE)-loaded poly(ethylene oxide) (PEO)/lithium perchlorate (LiClO(4)). In this article, we reported that the ionic conductivity and mechanical properties were remarkably increased due to the addition of the PEO-b-PE compared to that of PEO/LiClO(4) electrolyte. Scanning electron microscope (SEM), optical micrograph, and X-ray diffraction (XRD) results indicate that the addition of the copolymer, PEO-b-PE, decreased the defects of the PEO electrolyte films. Good dimensional stability was observed by dynamic rheological techniques up to 100 °C (higher than the melting point of PEO, 65 °C). A bicontinuous phase structure, that is crystalline PE domains within a matrix of PEO/salt, was proposed as the mechanism for such comprehensive enhancements in the ionic conductivity, mechanical properties, and dimensional stability obtained simultaneously in this study through a facile approach based on incorporation of a copolymer.