Abstract: The gel nanocomposite polymer elect rolyte (NCPE) was prepared by UV radiation curing based on poly(ethylene glycol) diacrylate ( PEGDA) monomer containing nanosize SiO₂ in the presence of liquid elect rolyte. ThePEGDA monomer containing nanosize SiO₂ was synthesized using aqueous colloidal silica as one of starting materialsthrough a solvent exchange process and the partial surface groups of SiO₂ were modified into acrylic group during theprocedure by employing methacryloxypropyl t rimethoxysilane (MAPTMS) , which made the nanosize SiO₂ havingthe UV-curable acrylate groups. Compared with the gel polymer elect rolyte based on PEGDA without nanosize filler , the ionic conductivity is higher and the improvement s in the elect rochemical stability and interfacial stability arenoticeable for the gel NCPE.