We report the synthesis of a soluble, amorphous, and adhesive electrolyte based on poly(ethylene glycol). A high molecular weight poly(PEGMA-co-MMA-co-IBVE) random copolymer with the lithium ion conductivity of 4.8 x10(-5) S/cm at room temperature was synthesized through a facile statistical copolymerization of poly(ethylene glycol) methyl ether methacrylates (PEGMA), methyl methacrylate (MMA), and isobutyl vinyl ether (IBVE). The polymer composition, thermal properties, adhesion, and electrochemical properties are presented. Such a copolymer has the adhesion strength to permanently hold 800 times its own weight, and high solubility in water and organic solvents for easy material processing. Its unique and versatile properties belong to a class of multifunctional soft matter electrolytes. (C) 2012 Elsevier B.V. All rights reserved.