Amorphous Sn(2)P(2)O(7) thin film electrodes have been successfully fabricated by radio frequency (r.f.) magnetron sputtering. Reversible lithiation and delithiation processes occurring at 1.47V and 2.01 V versus lithium are observed in both discharge/charge curves and cyclic voltammograms of the amorphous Sn(2)P(2)O(7) thin film electrodes for the first time. Large reversible capacity around 887 mAh g(-1) is achieved when the cell is cycled between 0.01 V and 4.0 V, corresponding to 9.2 Li per Sn(2)P(2)O(7) unit. Based on X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) evidences, the reaction mechanism involving the reversible decomposition and regeneration of amorphous Sn(2)P(2)O(7) as well as alloying and de-alloying of tin with lithium is proposed. (C) 2011 Elsevier B.V. All rights reserved.