New α-Zn2V2O7/carbon nanotube nanocomposite for supercapacitors

This study synthesized alpha-(ZnVO7)-V-2-O-2 nanopowders using a hydrothermal approach followed by annealing treatment. The resulting powders were then mixed with multi-walled carbon nanotubes and electrochemically characterized as new nanocomposite electrodes for supercapacitors. The structure and surface morphology of the powders were characterized by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Plus, the capacitive behavior of the composite electrodes was evaluated by cyclic voltammetry and galvanostatic charge-discharge cycles in different molar aqueous KCl solutions. The alpha-(ZnVO7)-V-2-O-2/multi-walled carbon nanotube composite electrodes were prepared using three different ratios and screened for their use in supercapacitors. As a result, the alpha-(ZnVO7)-V-2-O-2/multi-walled carbon nanotube composite electrode with a 1 : 2 ratio was identified as the best electrode with a specific capacitance value of 44.8 F g(-1) in 0.5M KCl. Notwithstanding, all the tested composite electrodes demonstrated an excellent cycle stability and showed a less than 4% change in their specific capacitance values when compared to the initial values.