On the basis of sol-gel methodology, a novel degradable hybrid electrolyte, poly(lactic acid) (PLA)/poly(methyl methacrylate) (PMMA)/silicon dioxide (SiO2) hybrid electrolyte, was prepared from PLA, methyl methacrylate, and tetraethoxylsilicon with 3-methacryloxypropyl trimethoxysilane as a coupling agent. As observed from Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy spectra, the PLA, PMMA, and silica units were linked by covalent bonds through the coupling agent in a hybrid network. Differential scanning calorimetry results show that the heat-resistance properties of the hybrid electrolyte improved with increasing SiO2 content. The hybrid electrolyte was shown to be amorphous by the X-ray diffraction results. From study of ionic conductivity by alternating-current impedance, the ionic conductivity of the PLA/PMMA/SiO2 hybrid electrolyte increased with increasing silica content, reached a maximum value of 2.42 x 10(-4) S/cm at 2 wt SiO2, and then decreased. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 2790-2794, 2010