The synthesis, chemistry, local structure and electrochemical properties of vanadium oxide xerogels and aerogels have much in common. The one difference in their respective synthesis routes, the means by which solvent is removed, has a significant influence on the resulting morphology. The high surface area, nanochmensional solid phase, short diffusion paths and interconnected mesoporosity of the aerogels exert a profound effect on their electrochemical properties Our studies with V(2)O(5) aerogels show that these materials offer the promise of achieving both high energy density and high power density because of a pseudocapacitive charge storage mechanism which develops. To cite this article: V Augustyn, B. Dunn, C. R. Chimie 13 (2010). (C) 2009 Academie des sciences Published by Elsevier Masson SAS. All rights reserved