One-pot sonochemical synthesis of hierarchical MnWO₄ microflowers as effective electrodes in neutral electrolyte for high performance asymmetric supercapacitors

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>In this article, manganese tungstate (MnWO<SUB>4</SUB>) microflowers as electrode materials for high performance supercapacitor applications are prepared by a one-pot sonochemical synthesis. The crystalline structure and morphology of MnWO<SUB>4</SUB> microflowers are characterized through X-ray diffraction, field emission scanning electron microscopy. The electrochemical properties of the MnWO<SUB>4</SUB> microflowers are investigated using cyclic voltammograms, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The MnWO<SUB>4</SUB> microflowers as electrode materials possess a maximum specific capacitance of 324 F g<SUP>−1</SUP> at 1 mA cm<SUP>−2</SUP> in the potential window from 0 to +1 V and an excellent cycling stability of 93% after 8000 cycles at a current density of 3 mA cm<SUP>−2</SUP>. An asymmetric supercapacitor device is fabricated using the MnWO<SUB>4</SUB> and iron oxide (Fe<SUB>3</SUB>O<SUB>4</SUB>)/multi-wall carbon nanotube as the positive and negative electrode materials, it can be cycled reversibly at a potential window at 1.8 V. The fabricated ASC device can deliver a high energy density of 34 Wh kg<SUP>−1</SUP> at a power density of 500 W kg<SUP>−1</SUP> with cycling stability of 84% capacitance retained after 3000 cycles. The above results demonstrate that MnWO<SUB>4</SUB> microflowers can be used as promising high capacity electrode materials in neutral electrolyte for high performance supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hierarchical MnWO<SUB>4</SUB> assembled microflowers via one-pot sonochemical synthesis. </LI> <LI> MnWO<SUB>4</SUB> nanoflakes deliver a maximum specific capacitance of 324 F g<SUP>−1</SUP> at 1 mA cm<SUP>−2</SUP>. </LI> <LI> Excellent cycling stability of 93% its initial capacitance after 8000 cycles. </LI> <LI> Asymmetric device delivers high energy density of 34 Wh Kg<SUP>−1</SUP> at 500 W kg<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>