Microwave-assisted synthesis of Fe-doped NiMnO3 as electrode material for high-performance supercapacitors

Fe-doped NiMnO3 nanosheet electrode material was successfully synthesized by convenient and efficient microwave-assisted hydrothermal method. The crystal structure, chemical composition, morphology, and specific surface area of the electrode material were analyzed by X-ray diffraction, Fourier transform infrared, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and Brunner-Emmet-Teller testing. Results showed that Fe doping changed not only the crystal structure but also the morphology of the NiMnO3 nanosheet electrode material. Moreover, the electrode material exhibited a high specific surface area and outstanding conductivity. Electrochemical performance was analyzed by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The outcome of these experiments demonstrated that the Fe-doped NiMnO3 electrode material exhibited optimum electrochemical performance when the mass ratio was 15wt%. The specific capacitance reached 732.7Fg(-1) at a current density of 1Ag(-1), and capacitance retention was approximately 78.3% after 10,000cycles at 3Ag(-1). The Fe-doped NiMnO3 electrode material is thus a promising next-generation supercapacitor material because of its high specific capacitance and long cycle life.