Conducting polymer/transition metal carbide nanocomposite treated graphite felt as positive electrode in all-vanadium redox flow battery

Abstract

Vanadium redox flow battery (VRFB) has been attractive and created attention in energy storage technology. In this study, graphite felt (GF) coated with conducting polymer/transition metal carbide nanocomposite (NPTiC) used to examine the electrochemical behavior for battery applications. Chemical oxidation has been employed to create the polyaniline (PANI) powder. Through a Mechano-chemical technique, nano-Titanium Carbide (NTiC) and nanocomposites (PANI with various proportions of 2 %, 4 %, 6 %, 8 % and 10 % of TiC) were created. XRD, FTIR, SEM, TEM and TGA are used to characterize them. Studies of electrochemical performance such as Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were carried out for PANI, NTiC and all nanocomposites. The results revealed excellent reversibility of an electron transfer and low impedance between the electrode and vanadium electrolyte compared to PANI and NTiC. Utilizing a 132 cm2 electrode, the study of charge-discharge for PANI, NTiC and NPTiC6 nanocomposite materials treated on GF (named as PANI/GF, NTiC/GF and NPTiC6/GF) as a positive electrode and untreated graphite felt (UTGF) retained as a negative electrode was done using a vanadium electrolyte and Nafion 117 membrane. The best performance is at 30 mA/cm2 current density and showed enhancements in coulombic efficiency (ղC), voltaic efficiency (ղV) and energy efficiency (ղE) than PANI and NTiC electrodes on GF. High Coulombic efficiency of 98.89 % was calculated for the NPTiC6/GF electrode. Even after 50 cycles, there was only 12 % coulombic efficiency decay, confirming the nanocomposite electrode's stability. The findings suggest that the electrochemical performance of the NPTiC6 nanocomposite is excellent.