Novel ZIF67/Mn/MWCNTs decorated with layer double hydroxide supercapacitor electrodes

Nanoflakes of bimetal metal-organic framework (MOF) with different multiwall carbon nanotubes (MWCNTs) contents decorated by layer double hydroxide (LDH) (Ni-ZIF670.75(1-X%)/Mn0.25(1-X%)/MWCNTX%-LDH) were synthesized using solvothermal technique as supercapacitor electrodes. The structural properties, adsorption/desorption of surface area, porosity, morphology and elemental analysis of these nanocomposites were investigated by Fourier transforms infrared spectrum (FTIR), X-ray diffractometer (XRD), Brunauere-Emmett-Teller (BET) test, Barrett-Joyner-Halenda (BJH) test, scanning electronic microscope (SEM), and energy dispersive X-ray analysis (EDX), respectively. SEM image of Ni-ZIF6772.75%/Mn24.25%/MWCNT3%-LDH nanocomposite electrode showed an agglomeration of hollow nanoflakes shape of LDH with high porous structure and an average diameter of 1.15 µm. The electrochemical performance of the fabricated nanocomposites was assessed by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrical impedance spectroscopy (EIS). It was found that the Ni-ZIF6772.75%/Mn24.25%/MWCNT3%-LDH electrode provided a superior specific capacitance of 2395 Fg−1(1077 C/g) at 1 Ag−1 and 2732 Fg−1 (1639 C/g) at 5 mV/s. The stability of this electrode had capacitance retention of 92% after 1000 cycles with energy density of 70 Wh/kg and power density of 244 W/kg.