A unique V-shaped MnO2 nanostructure is synthesized with a weak acid (acetic acid) using microwave-assisted hydrothermal technique. To improve the performance of MnO2 in supercapacitor application, its composite was prepared...
The enhanced specific surface area of electrode active materials provides a convenient way for the flow of electrolytic ions, resulting in improved electrochemical energy storage performance. In this study, synthesis of Cu-doped MnO 2 nanomaterials was demonstrated using the microwave-assisted hydrothermal method. Upon reducing the microwave power from 400 to 250 W, the morphology of Cu-doped MnO 2 nanostructures changed from nanorods (∼50−100 nm diameter) to nanoflowers with ∼10−20 nm thick petals on the surface. The flower-like morphology shows enhanced supercapacitor performance with a specific capacitance value of 433.15 F g −1 at 0.5 A g −1 current density. This feature is due to the synergistic effect of the enhanced conductivity by Cu doping and increased Brunauer−Emmett−Teller (BET) specific surface area (144.35 m 2 g −1 ). Further, a two-electrode asymmetric supercapacitor (ASC) device was developed and it showed a maximum energy density of 77.78 Wh kg −1 at a power density of 1000 W kg −1 . The device showed capacitance retention up to 102.86% after 20,000 charge−discharge cycles at 20 A g −1 current density. This study suggests that the Cu-doped MnO 2 nanostructure is a promising electrode active material for enhanced supercapacitor performance with excellent rate capability.
Efficient and flexible energy storage materials are the future of energy technology. Among the various energy storage devices supercapacitor which stores electrochemical energy with higher power density than battery and higher energy density than capacitor is a potential device. In the supercapacitor, electrode active material plays very important role for storage and transportation of electrolytic ions. Herein, we have synthesized substrate free cobalt oxide deposited nickel-foam with the help of microwave-assisted hydrothermal technique, which is novel and faster synthesis process than conventional synthesis processes. Morphological characterization of as-synthesized samples was investigated with FESEM. Electrochemical performance with specific capacitance (Cs) value of 98.31 F g1 at 0.25 A g1 current density and 93.59 F g1 at 1 mV s1 scan rate obtained from galvanostatic charge/discharge and cyclic voltammetry curves.
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