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 ‐MnO 2 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 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.