Fabrication of rGO based ZnFe2S4 nanostructured electrode for high-performance supercapacitors

The electrode materials with an elevated specific capacitance, energy density, and stability are crucial to create robust and effective energy storage devices (ESDs). Herein, we have synthesised zinc iron sulfide (ZnFe2S4) accumulated granular-like structures across the graphene sheet (ZnFe2S4/rGO) by using an easy hydrothermal technique. The physicochemical characteristics of the all-synthesised electrode materials has been ascertained using various analytical techniques. A variety of electrochemical experiments have been employed to ascertain the pseudocapacitive behaviour of the manufactured materials. The ZnFe2S4/rGO nanocomposite superior supercapacitive performance over pristine ZnFe2S4 is because of its strong conductivity and enormous surface area, that promotes electrolyte diffusion. Thus, the ZnFe2S4/rGO electrode demonstrated higher specific capacitance (C-s) of 1664 F/g with current density (C-d) of 1 A/g and profound stability (2500th charge-discharge cycle). Furthermore, the fabricated ZnFe2S4/rGO nanocomposite yields an extraordinary energy density (E-d) of 92.40 Wh/kg at a power density (P-d) of 316.15 W/kg, leading to improved electrochemical efficiency. The EIS analysis showed that ZnFe2S4/rGO exhibits superior charge-transfer characteristics compared to pure ZnFe2S4. These findings suggest that porous hierarchical ZnFe2S4/rGO nanocomposite could potentially be employed as an electrode material with excellent rate performance in modern supercapacitors.