Nanosized Bi2WO6 particles were successfully synthesized by sonochemical method with an objective to develop an inexpensive and eco-friendly electrode material for supercapacitors. The prepared material was subjected to various thermal, structural, morphological, compositional, electrical and electrochemical studies. Bi2WO6 nanoparticle with homogeneous distribution was achieved through sonochemical process. The lattice parameter and atomic positions of Bi2WO6 structure were refined through Reitveld analysis. The electrochemical performance of Bi2WO6 nanoparticles was investigated in various aqueous electrolytes such as 1 M NaOH, 1 M LiOH, 1 M Na2SO4, 1 M KOH and 6 M KOH solutions. Among these, the material exhibited an enhanced electrochemical performance in KOH electrolyte due to its smaller hydration sphere radius, high ionic mobility and lower equivalent series resistance. The charge-discharge studies rendered a specific capacitance of 608 F/g in 1 M KOH at a current density of 0.5 mA/cm(2). Bi2WO6 exhibited an excellent coulombic efficiency and specific capacitance of around 304 F/g at 3 mA/cm(2) in the potential range from -0.9 to 0.1 V vs Hg/HgO in 1 M KOH electrolyte. The above results assured that Bi2WO6 could be utilized as suitable negative electrode material for supercapacitor applications and 1 M KOH could be its desirable electrolyte. (C) 2013 Elsevier Ltd. All rights reserved.