EDLCs based on the modified coconut shell raw material were manufactured with 1-Ethy1-3-methylimidazolium tetrafluoroborate (EMImBF(4)) as an electrolyte and a typical organic electrolyte based on acetonitrile. Three types of modification of the carbon material with different micro- to mesopore ratios were applied as the positive or negative electrode and tested. Obtained results showed different characteristic capacitances of 150-350 Fg(-1), strongly dependent on the type of carbon material. Asymmetric EDLCs were manufactured from different carbon materials as positive and negative electrodes and a mass electrode fitting provided with an EDLC working at 3 V with a specific energy of 68.6 Wh kg(-1) and power density of 36 W kg(-1). (C) 2012 Elsevier B.V. All rights reserved.