Hydrothermally Synthesized Zinc Vanadate Rods for Electrochemical Supercapacitance Analysis in Various Aqueous Electrolytes.

Zinc vanadate (Zn₃V₂O₈) rods have been prepared using easy and economical hydrothermal technique and are explored for supercapacitor electrode application. X-ray diffraction (XRD) and Field emission scanning electron microscopy (FESEM) were analysed for the structure and morphology of the sample. The electrochemical performance of the Zn₃V₂O₈ electrode was investigated using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge test. The performance of Zn₃V₂O₈ in water soluble electrolytes, such as K₂SO₄, Na₂SO₄ and KOH were analysed, and the results demonstrated unique double layer properties of the material. The electrode material tested in 0.5 M K₂SO₄ showed good supercapacitive performance in terms of specific capacitance and efficiency when compared to other electrolytes. We have obtained a specific capacitance of 213 F g⁻¹ at current density of 1 A g⁻¹. This electrode exhibits very less charge transfer resistance (3.3 Ω) in potassium sulphate electrolyte and is lower than other electrolytes. Moreover, Zn₃V₂O₈ provided enhanced rate capacity, with (77%) of retention capacity for charge–discharge up to 1000 cycles. [ABSTRACT FROM AUTHOR]