Two-dimensional mesoporous carbon sheet-like framework material for high-rate supercapacitors

Two-dimensional mesoporous carbon sheet-like framework (MCSF) material has been prepared using mesoporous SiO2 nanosheet as template and coal tar pitch as carbon precursor. MCSF sheets consisting of numerous mesopores have a specific surface area of 582.7 m(2) g(-1). As a result, the MCSF electrode possesses a maximum specific capacitance of 264 F g(-1) at 5 mV s(-1), excellent rate capability (74% retention ratio at 1000 mV s(-1)), and impressive cycling stability with 91% initial capacitance retained after 5000 cycles at 200 mV s(-1) in 6 mol L-1 KOH. MCSF symmetric supercapacitor exhibits a maximum energy density of 9.6 Wh kg(-1) at 5 mV s(-1) and a maximum power density of 119.4 kW kg(-1) based on the total mass of the two electrodes in 1 mol L-1 Na2SO4 electrolyte. (C) 2013 Elsevier Ltd. All rights reserved.