High performance electrochemical capacitors based on MnO2/activated-carbon-paper

In this research, the surface of commercial carbon paper was firstly activated with potassium dichromate lotion and then MnO2 nanoribbons were anchored onto the activated carbon paper (denoted as ACP) through an electrodeposition route. The as-prepared composite MnO2/ACP possessed a specific capacitance as high as 640.8 F g(-1) calculated from the discharge curve with a current density of 10.0 A g(-1) and this observation was deemed to originate from its enlarged specific surface area and improved electronic conductivity. Accordingly, the specific capacitances calculated from cyclic voltammograms were 617.0 and 395.0 F g(-1) at a potential scan rate of 20 and 50 mV s(-1), which kept 81.5% and 52.2% specific capacitance at 10 mV s(-1) (757.0 F g(-1)). This indicated that the composite MnO2/ACP possessed good rate capability as an active electrode material for pseudo-capacitors. In a word, for the first time the composite MnO2/ACP has been reported as a promising electrode material for efficient supercapacitors.