Activated carbons (ACs) prepared from rice husk (RH), an agricultural byproduct, have mesoporosity that is obtainable from leaching of the mineral component of silica. To verify the suitability of RH-derived ACs for the use of electrode materials of electrical double-layer capacitors, we evaluated the electrochemical performance of three RH-derived ACs (two micro-and mesoporous ACs and one mesoporous AC). Evaluation was done by using the non-aqueous ionic electrolyte solutions 1 mol dm(-3) triethylmethyl ammonium tetrafluoroborate/propylene carbonate (PC) solution, 1.5 mol dm(-3) spiro-(1,10)-bipyrrolidinium tetrafluoroborate/PC (SBP.BF4/PC) solution, and the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIm.BF4). Under low voltage scan rate (1 mV s(-1)) and low current density (<1 mA cm(-2)), mesoporous AC, which had the highest specific surface area, showed the highest specific capacitance (120 F g(-1)) in EMIm.BF4. However, its specific capacitance considerably decreased because of the increase in scan rate and current density. Under high scan rate (10 and 100 mV s(-1)) and high current density (>10 mA cm(-2)), micro-and mesoporous AC in 1.5 mol dm(-3) SBP.BF4/PC showed the highest specific capacitance and highest retention of specific capacitance, even though its specific surface area was not the highest. Mesoporous AC showed voltage-dependent specific capacitance, indicating that ionic transport in the mesoporous structure was sensitive to electric field. It was finally shown that micro-and mesoporosity developed by utilizing natural structure and composition of RH was useful for the electrode materials of advanced electrical double-layer capacitors requiring more viscous nonaqueous electrolytes. (C) 2015 Elsevier Ltd. All rights reserved.