A novel poly(ethylene oxide) (PEO)-based nanocomposite polymer electrolyte (NCPE) has been developed by using nanosized, high surface area ZnAl2O4 With a mesopore network as the filler. X-ray diffraction (XRD), differential scanning calorimetry (DSC), and field emission scanning electron microscopy (FESEM) were used to characterize the NCPE. The results showed that the presence of the nanosized ZnAl2O4 powder leads to a reduction in the crystallinity of the PEO phase. The ionic conductivity and lithium ion transference number of the PEO-based polymer electrolyte were enhanced by the addition of the nanosized ZnAl2O4 powder. A broad electrochemical stability window suggests that the PEO-LiClO4-ZnAl2O4 NCPE is a viable candidate for the electrolyte material in lithium polymer batteries. (C) 2009 Elsevier B.V. All rights reserved.