Ion-by-Ion Adsorption Process and Reaction for the Synthesis of Hierarchical Manganese Tungstate (MnWO4) Microflowers as an Energy-Efficient Electrode for Supercapacitors

초록

For the first time, manganese tungstate (MnWO4) electrodes are successfully synthesized by the successive ionic layer adsorption and reaction (SILAR) method. This study is mainly focused on synthesized hierarchical MnWO4 microflowers (MFs) for electrochemical supercapacitor application. The crystalline structure, morphology, presence of functional groups, stretching and bending vibration, and availability of chemical states present in the MnWO4 MFs are investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared, Raman, and X-ray photoelectron spectroscopy, respectively. In addition, the resultant materials undergo electrochemical analysis using a three-electrode system. As a result, the MnW-50 electrode reveals a maximum specific capacitance (Cs) and capacity (Csp) of 698 F/g and 87 mAh/g at 5 mA/cm2 with moderate energy density (ED) and power density (PD) of 19 Wh/kg and 700 W/kg, respectively. Furthermore, the aqueous hybrid device is fabricated using MnWO4 MFs as a cathode and reduced graphene oxide (rGO) as an anode material, which reveals the maximum performance of the Cs and Csp of 206 F/g and 87 mAh/g at 5 mV/s and 185 F/g and 70 mAh/g with sufficient ED, and PD of 45 Wh/kg and 1960 W/kg at 5 mA/cm2, respectively. The aforementioned results indicate the benefits and improved electrochemical efficiency of MnWO4 MFs as cathodes for hybrid supercapacitors.

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