Facile synthesis of new-type MnOOH/NiAl-layered double hydroxide nanocomposite for high-performance supercapacitor

MnOOH nanowires decorated with NiAl-LDH have been successfully prepared via in-situ growth of small NiAl-LDH nanosheets by hydrothermal method without using any organic reagents. The morphology and structure of the samples were characterized by a series of techniques, including scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis meter (TGA), Brunauer-Emmett-Teller (BET), and Fourier transform infrared spectrometer (FT-IR). The excellent electrochemical properties of the as-prepared products were obtained by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). The specific capacitance was 1331.11 F/g at current density of 1 A/g in 6 M of KOH electrolyte and still could keep good cycling stability after 1000 cycles. An asymmetric supercapacitor (ASC) was assembled by MnOOH/NiAl-LDH and activated carbon (AC), exhibited excellent electrochemical performances in energy storage. At a power density of 800 W/kg, the equipment could deliver a maximum energy density of 26.89 Wh/kg and maintain good cycling stability. The excellent results suggested that MnOOH/NiAl-LDH nanocomposite could be used as a promising material for supercapacitors. (C) 2018 Elsevier B.V. All rights reserved.