Synthesis characterization and electrochemical studies of metal sulfide with graphene nanocomposites for super capacitor applications

Abstract

The present scenario posses the urgent demand for renewable and sustainable energy has inspired considerable efforts to build the energy storage systems. Thanks to their interesting features such as high power density, fast charging/discharging operation, long cycle life, and limited environmental impact, supercapacitors form a significant energy storage device in the society. Supercapacitors are widely known in two forms namely, electrical double layer (EDL) capacitors and pseudocapacitors based on their energy storage mechanism. The capacitance of the EDL capacitors is dependent on the charge accumulated at the interface of the electrode/electrolyte. However, the capacitance of the pseudocapacitors resulted from the fast faradic redox reactions in the electrode material. The electrode material is the determinant of capacitor performance, whether it is EDL capacitors or pseudocapacitors. Therefore, considerable effort is made to explore the materials for the electrodes with improved capacitive efficiency. Due to its extraordinary electrical properties, superior mechanical properties, and ultra-large specific surface area, graphene, the novel carbon material, graphene with two-dimensional (2D) nanostructure has attracted enormous interest in recent years. Significantly, these properties make graphene the best candidate electrode material for the supercapacitor among other related carbon materials. In addition to the graphene for supercapacitor applications, various graphene-based 2D materials and their composites have been investigated to improve the efficiency of supercapacitors. In recent decades, the production of hybrid electrode materials with superior performance has addressed growing concerns in energy and environmental issues, helping us to address the potential energy demand as well. Owing to their suitability in energy and environmental applications newline newline newline newline