Metal organic framework/layer double hydroxide/graphene oxide nanocomposite supercapacitor electrode
Ahmed Elsonbaty, Mohamed E. Harb, Moataz Soliman, Shaker Ebrahim, Ayman Eltahan
Abstract
Layered Double Hydroxide (LDH) based on Metal Organic Framework (MOF) structures has attracted a great deal of attention due to their high surface area, tailoring structure of the MOF, and high pseudocapacitance of LDH. Herein, an Ni-ZIF-67/Mn-LDH supercapacitor electrode was prepared via the solvothermal method at room temperature. A supercapacitor electrode based on Ni-ZIF-67/GO-LDH by replacing active metal Mn with graphene oxide (GO) was also synthesized to enhance the capacitance retention and stability from 78% to 97% after 1000 cycles. The morphology of these electrodes was characterized by scanning electron microscopy (SEM). It was found that the specific surface areas of Ni-ZIF-67/GO-LDH and Ni-ZIF-67/Mn-LDH are 82 and 20 m2 g−1. The electrochemical performance of the two nanocomposite supercapacitor electrodes was observed by cyclic voltammetry, charge–discharge, and electrochemical impedance spectroscopy measurements. The Ni-ZIF-67/GO-LDH electrode produced a specific capacitance (Cs) of 1036 F/g at 1 A/g, while the Ni-ZIF-67/Mn-LDH electrode results in a superior Cs value of 1420 F/g at 1 A g−1 with an energy density of 44 Wh/kg and a power density of 3.5 kW/kg.