Single-phase, chemically pure vanadium pentoxide (V2O5) powders are prepared by co-precipitation and further calcination at 300 degrees C. The materials obtained are agglomerated in sub-micron particles, and BET analysis shows that the as-prepared V2O5 powders have a high specific surface-area of 41 m(2) g(-1). V2O5 shows the highest capacitance in 2 M KCl electrolyte when compared with other electrolytes such as 2 M NaCl and 2 M LiCl. It yields a maximum specific capacitance of 262 F g(-1). The higher specific surface-area may be the reason for the high capacitance compared with previously published results. (c) 2006 Elsevier B.V. All rights reserved.