title: High Ionic Conductivity of Composite Solid Polymer Electrolyte via In Situ Synthesis of Monodispersed SiO2 Nanospheres in Poly(ethylene oxide).
abstract: High ionic conductivity solid polymer electrolyte (SPE) has long been desired for the next generation high energy and safe rechargeable lithium batteries. Among all of the SPEs, composite polymer electrolyte (CPE) with ceramic fillers has garnered great interest due to the enhancement of ionic conductivity. However, the high degree of polymer crystallinity, agglomeration of ceramic fillers, and weak polymer-ceramic interaction limit the further improvement of ionic conductivity. Different from the existing methods of blending preformed ceramic particles with polymers, here we introduce an in situ synthesis of ceramic filler particles in polymer electrolyte. Much stronger chemical/mechanical interactions between monodispersed 12 nm diameter SiO2 nanospheres and poly(ethylene oxide) (PEO) chains were produced by in situ hydrolysis, which significantly suppresses the crystallization of PEO and thus facilitates polymer segmental motion for ionic conduction. In addition, an improved degree of LiClO4 dissociation can also be achieved. All of these lead to good ionic conductivity (1.2 × 10(-3) S cm(-1) at 60 °C, 4.4 × 10(-5) S cm(-1) at 30 °C). At the same time, largely extended electrochemical stability window up to 5.5 V can be observed. We further demonstrated all-solid-state lithium batteries showing excellent rate capability as well as good cycling performance.
authors.forename: Dingchang
authors.initials: D
authors.lastname: Lin
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Yayuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Hye Ryoung
authors.initials: HR
authors.lastname: Lee
authors.forename: Po-Chun
authors.initials: PC
authors.lastname: Hsu
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.affiliation: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
keywords: Solid composite polymer electrolyte; in situ synthesis; ionic conductivity; poly(ethylene oxide); silica nanosphere