New composite polymer electrolytes composed of polyurethane acrylate (PUA), nano-size SiO2 as a ceramic filler, and LiN(CF3SO2)(2) as a lithium salt were examined in an all-solid-state lithium-polymer battery (Li/PUA-SiO2/Li0.33MnO2). The addition of hydrophobic SiO2 could increase the ionic conductivity of polymer electrolyte about one-fold. The dynamic modulus of polymer electrolyte increased 50 and 150% by adding 9.1% hydrophobic and hydrophilic SiO2, respectively. The addition of nano-size SiO2 powders enhanced greatly the interfacial stability between polymer electrolytes and lithium electrode. The capacity fading of the cell could be improved by the addition of nano-size SiO2 powders. The cycling performance of the cell reached about 75 and 45% of initial capacity (192 mAh g(-1)) after 100, and 500 cycles, respectively, with an efficiency of charge-discharge of about 100% at 60degreesC. (C) 2004 Elsevier B.V. All rights reserved.