One-pot hydrothermal synthesis of amorphous FeOOH on Ni foam for high performance supercapacitors

In this work, we developed a facile method to prepare FeOOH directly deposited on the Ni foam through one-pot hydrothermal route. The as-prepared FeOOH/Ni foams (FN) were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM). Electrochemical performances of the as-prepared FN as electrodes were also evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectrometry (EIS) in 1M KOH aqueous solution. The results indicate that the flocculent amorphous FeOOH flakes homogeneously grown on the surface of Ni foams construct a three-dimensional (3D) porous structure, which not only provides easy penetration of liquid electrolyte, facilitating fast electron transfer and ion diffusion, but also alleviates the volume change of FN electrodes during the charge-discharge process. The optimized FN electrode exhibits a high specific capacitance of 1300 F/g at a current density of 2 A/g, and excellent capacitance retention of 91% after 2000 cycle tests at a current density of 4 A/g. This work would open an avenue for designing high-performance amorphous electrode materials for supercapacitors. (C) 2018 Elsevier B.V. All rights reserved.