One-Step Fabrication of Ultrathin Porous Nickel Hydroxide-Manganese Dioxide Hybrid Nanosheets for Supercapacitor Electrodes with Excellent Capacitive Performance

摘要

A facile one-step hydrothermal co-deposition method for growth of ultrathin Ni(OH)_2-MnO_2 hybrid nanosheet arrays on three dimensional (3D) macro-porous 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 MnO_2, the as-fabricated Ni(OH)_2-MnO_2 hybrid electrode exhibits an ultrahigh specific capacitance of 2628 F g~(-1). Moreover, the asymmetric supercapacitor with the as-obtained Ni(OH)_2-MnO_2 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.