Preparation and properties of PEO/LiClO₄/KH560-SiO₂ composite polymer electrolyte by sol-gel composite-in-situ method

Abstract

Composite polymer electrolytes based on polyethylene oxide(PEO) were prepared by using LiClO₄ as doping salt and silane-modified SiO₂ as filler. SiO₂ was formed in-situ in (PEO)₈LiClO₄ matrix by the hydrolysis and condensation reaction of Si(OC₄H₉)₄. The crystallinity, morphology and ionic conductivity of composite polymer electrolyte films were examined by differential scanning calorimetry, scanning electron microscopy, atom force microscopy and alternating current impedance spectroscopy, respectively. Compared with the crystallinity of the unmodified SiO₂ as inert filler, that of composite polymer electrolytes is decreased. The results show that silane-modified SiO₂ particles are uniformly dispersed in (PEO)₈LiClO₄ composite polymer electrolyte film and the addition of silane-modified SiO₂ increases the ionic conductivity of the (PEO)₈LiClO₄ more noticeably. When the mass fraction of SiO₂ is about 10%, the conductivity of (PEO)₈LiClO₄-modified SiO₂ attains a maximum value of 4.8×10⁻⁵ S·cm⁻¹.

Keywords

polyethylene oxide(PEO) / sol-gel / composite-in-situ / polymer electrolyte / ionic conductivity