(618bg) A Solid Polymer Electrolyte with Comprehensively Enhanced Performance for Lithium Ion Battery

It is a compelling challenge to both improves ionic conductivity and mechanical properties in polymeric electrolytes, and to accomplish it through a simple processing method. This study reveals that poly(ethylene oxide) -block- polyethylene (PEO-b-PE) possesses a capability for enhancing the multiple performances of PEO-based polymer electrolyte, i.e. it functions as a multi-functional miscible filler for obtaining poly(ethylene oxide)(PEO)/lithium perchlorate (LiClO₄) having such enhanced performances. Analyses revealed that the ionic conductivity of a ternary polymer electrolyte, PEO/PEO-b-PE/LiClO₄, was enhanced by an order of magnitude with the addition of this copolymer. Tensile tests showed the ultimate stress of the ternary polymer electrolyte increased to 7.29 MPa, modulus 114.21 MPa, and breaking strain 1142.53%, which are 2252%, 688% and 274% higher than that of PEO/LiClO₄, respectively. Scanning electron microscope (SEM), optical micrograph and X-ray diffraction (XRD) results indicate 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 bi-continuous phase structure, i.e. 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.