A new type vanadium oxide deposit with a porous, three-dimensional (3-D) network architecture plated at 0.7 V (vs. Ag/AgCl) from 25 mM VOSO4 with 5 mM H2O2 shows capacitive-like behaviorat 250 mVs(-1) and Cs approximate to 167 Fg(-1) at 25 mV s(-1) in 3 M KCl for pseudocapacitor applications. This work also emphasizes that anodic deposition of vanadium oxide does occur at a potential much more negative to oxygen evolution from aqueous VOSO4 solutions due to the presence of V5+ by adding H2O2. Through the X-ray photoelectron spectroscopic analyses, this oxide deposit, mainly consisting of V5+ with 11 mol.% V4+, shows a hydrous nature. The unique power characteristics of this hydrous vanadium oxide are reasonably attributed to its intrinsic porous and crystalline structure produced by means of this novel anodic deposition process at a potential much more negative to the oxygen evolution reaction. (C) 2008 Elsevier B.V. All rights reserved.