One-step fabrication of ultrathin porous nickel hydroxide-manganese dioxide hybrid nanosheets for supercapacitor electrodes with excellent capacitive performance

Abstract

A facile one-step hydrothermal co-deposition method for growth of ultrathin Ni(OH)2-MnO2 hybrid nanosheet arrays on three dimensional (3D) macroporous nickel foam is presented. Due to the highly hydrophilic and ultrathin nature of hybrid nanosheets, as well as the synergetic effects of Ni(OH)2 and MnO2, the as-fabricated Ni(OH) 2-MnO2 hybrid electrode exhibits an ultrahigh specific capacitance of 2628 F g-1. Moreover, the asymmetric supercapacitor with the as-obtained Ni(OH)2-MnO2 hybrid film as the positive electrode and the reduced graphene oxide as the negative electrode has a high energy density (186 Wh kg-1 at 778 W kg-1), based on the total mass of active materials. Highly porous hybrid films composed of ultrathin Ni(OH)2-MnO2 hybrid nanosheets with ultrahigh specific capacitance (2628 F g-1) are successfully fabricated using a facile one-step hydrothermal co-deposition method. The Ni(OH) 2-MnO2 hybrid nanosheet-based asymmetric supercapacitor exhibits a high energy density (186 Wh kg-1 at 778 W kg-1) based on the total mass of the active materials. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.