Single-phase, chemically pure vanadium pentoxide (V2O5) powders are prepared by co-precipitation and further calcination at 300°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 41m2 g−1. V2O5 shows the highest capacitance in 2M KCl electrolyte when compared with other electrolytes such as 2M NaCl and 2M LiCl. It yields a maximum specific capacitance of 262Fg−1. The higher specific surface-area may be the reason for the high capacitance compared with previously published results.