Title : Synergistic effect of Nickel ferrite decorated laser-induced graphene nanocomposite as an electrode material for high-performance supercapacitor
Abstract:
Electrochemical Energy Storage Devices such as Supercapacitors (SCs) are efficient technologies to tackle the ongoing energy crisis due to high power density, rapid charge-discharge kinetics, and prolonged life span. Despite numerous advantages, researchers are actively engaged in enhancing specific capacitance and energy density of supercapacitors. Generally, the charge storage mechanism in SCs takes place via the formation of an electric double layer at the electrode-electrolyte interface which requires a large specific surface area of electrodes, high porosity, and excellent electrical conductivity. However, the electrochemical performance of SCs is affected by structural deterioration and poor contact between the electrode and the current collector. Therefore, the development of novel electrode materials that can provide superior specific capacitance without any structural degradation is of utmost importance. Graphene-based electrodes have drawn a lot of attention, owing to their larger surface area, higher porosity, and excellent electrical conductivity. Usually, these materials use active carbon and a binder, which results in lower specific capacitance. Recently, binder-free electrode materials have gained significant attention due to their possibility to be used as direct electrodes without any additional variations. Laser-induced Graphene is a potential candidate for supercapacitor electrodes.
Herein, we have developed a facile and economical approach to synthesize NiFe2O4 (NFO) doped LIG electrodes using CO2 laser scribing. The as-synthesized electrodes were characterized using Raman spectroscopy, and Fourier transform-infrared spectroscopy (FT-IR), which confirmed the presence of Raman active modes of NFO i.e. T2g, Eg, and A1g along with highly intense D, G, and 2D bands in graphene. Field emission scanning electron microscopy (FESEM) reveals the 3-dimensional sheet-like structures along with embedded NFO nanoparticles. Furthermore, the X-ray photoelectron spectroscopy (XPS) core spectrum indicates the presence of C 1s, Ni 2p, Fe 2p, and O1s peaks. Furthermore, the supercapacitor performance of NFO/LIG nanocomposites was studied using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements using a typical three-electrode configuration in 1M KOH electrolyte solution. The electrodes demonstrate a remarkable improvement in specific capacitance (Cs) from 51 mF cm-2 to 198 mF cm-2 at 1 mA cm-2. Furthermore, a symmetric supercapacitor device was designed using Swagelok cell assembly which also demonstrated a significant increment in Cs from 23 mF cm-2 in pure LIG to 43 mF cm-2 in NFO/LIG nanocomposite. Additionally, electrodes exhibit excellent cyclic stability retaining 93% specific capacitance after 2000 cycles at 1 mA/cm2. This study not only presents high-performance SC but also provides a charge storage mechanism in NFO/LIG electrodes unlocking its potential as a cutting-edge electrode material in SC applications.
