A simple, reproducible, and versatile procedure for synthesizing mesostructured 12-phosphotungstic acid thin films with large spaced mesostructures (< 17 nm) using amphiphilic block copolymers as structure-directing agents is reported. The morphology of the mesostructure can be controlled by adjusting the m/n ratio of poly (ethylene oxide)(1/2)/poly (propylene oxide) (EO1/2/PO) in the tri-block copolymer (EO)(m)(PO)(n) (EO) This synthetic approach was adapted to prepare mesoscopically ordered heteropoly oxometalates (HPOMs) films, including 12-phosphomolybdic acid and 12-tungsto (IV) silicic acid. The electrochemical properties of the calcined HPOMs films as electrodes in Li-ion batteries were also investigated. (c) 2006 Elsevier B.V. All rights reserved.