High Power Density Supercapacitors Based on the Carbon Dioxide Activated D-Glucose Derived Carbon Electrodes and Acetonitrile Electrolyte

Abstract

The electrochemical impedance spectroscopy, the cyclic voltammetry, and the constant power charge/discharge methods have been applied to establish the electrochemical characteristics for the electrical double–layer capacitor consisting of the 1 M (C2H5)3CH3NBF4 electrolyte in acetonitrile. The microporous carbon electrodes prepared from D-(+)-glucose by the hydrothermal carbonization method and subsequent pyrolysis and carbon dioxide activation steps. The total Brunauer-Emmett-Teller specific surface area (SBET ≤ 1539 m2 g−1), micropore surface area (Smicro ≤ 1534 m2 g−1), total pore volume (Vtot ≤ 0.694 cm3 g−1) and the size distribution of the pores, obtained from the N2 sorption data and using the non–local density functional theory, have been correlated with the electrochemical characteristics for electrical double–layer capacitors as the region of ideal polarizability (ΔE ≤ 3.0 V), characteristic time constant (0.34 s) and the high series capacitance (126 F g−1), dependent on the carbon activation conditions, have been calculated.