One-Dimensional FeVO4/MWCNT composite electrode to procure an asymmetric supercapacitor device with superior parameters in Na2SO4 electrolyte: Synthesis and energy applications

Abstract

The present piece of work portrays the preparation of composite material FVC by blending the precursors FeVO4 (FV) and multi-walled carbon nanotubes (MWCNT) or C, further procured for energy accumulation purposes. The precursor FeVO4 is synthesized via hydrothermal exposure with controlled morphology of nanorods and the composite material with the addition of MWCNT is synthesized along with hydrothermal route. To validate the synthesis of all the compounds, their structural and morphological characterizations were examined, accompanied by energy accumulation data procured, via electrochemical studies comprising potentiostatic frequency analyzer (FRA), cyclic voltammetry (CV), and galvanostatic charge-discharge (GCD). Further, pore volume, area, and diameter distribution concurred via BET investigations which came up with a pore volume of 0.3802 cm3/g, a surface area of 89.770 m2/g, and a pore diameter of 16.313 nm suggesting the synthesis is done in nano-scale. From electrochemical findings low impedance and high value of specific capacitance (Cs) attained with a value of n-factor of 0.82 for FVC2 exhibiting least deviation from 1 out of all the samples. The Cs values exhibited for FVC2 composite from CV running is 1246.12 F/g gathered with a potential rate of 2 mV/s and 1147.06 F/g with an applied current of 0.001 A respectively. The calculated energy density and power density for the sample FVC2 is 159.31 Wh/kg and 415 W/kg which signifies good values for energy accumulation purposes along with good cyclic retention % of 97.23 after continuous exposure to 5000 cycles, further an asymmetric device was formulated FVC2//AC (AC as activated carbon) to check real-life application and the specific capacitance values obtained from it at 10 mV/s is 711.53 F/g with specific energy 96.1 Wh/kg and the respective power density is 669.2 W/kg with a retention of 90.24 % in specific capacitance after exposure to 5000 continuous cycles.