Ultrathin MnO2 nanosheets supported on cellulose based carbon papers for high-power supercapacitors

3D carbon materials-supported MnO2 have promising application in energy storage as supercapacitor electrode materials. Here, we demonstrate a simple and scalable method to fabricate 3D carbon paper-supported MnO2 nanosheets, which can be used as supercapacitor electrode materials with low cost and high capacitance performance. MnO2 nanosheets with thickness about a few nanometers are grown on the carbon paper substrate through the reaction between aqueous KMnO4 and carbon. With the present method, the self-supported MnO2 composites can be fabricated into supercapacitor electrodes directly without any binder and conductive agents. It is found that MnO2 content in the composites increases with the increasing of KMnO4 concentration. The supercapacitor based on the hybrid with a MnO2 content of 7.9% exhibits the largest specific capacitance of 306.6 F g(-1) at 0.5 A g(-1), and a high power density of 67.8 kW kg(-1) at the maximum current density of 300 A g(-1). Moreover, the supercapacitors exhibit capacitance retention above 95% after 6000 cycles, demonstrating high stability of the carbon paper-supported MnO2 nanosheets for supercapacitors. Such 3D carbon paper-based architectures have promising application in energy storage devices with high power density and stability. (C) 2013 Elsevier B.V. All rights reserved.