Study on graphene and its derivatives for efficient supercapacitor applications

Abstract

The main aim of this research work is to develop energy storage devices that are efficient, reliable, cost effective, and environmentally friendly. These devices are crucial for storing energy generated from renewable sources and addressing energy scarcity issues. Supercapacitors, batteries, and fuel cells are the examples of next generation energy storage devices capable of storing large amounts of energy. The advent of nanotechnology has played a significant role in enhancing the capacity of batteries and supercapacitors to store energy. It has also enabled the development of advanced materials for these devices. In comparison with batteries, supercapacitors exhibit some interesting features like fast charging, low maintenance cost, high power density, longer life span, eco friendly nature and higher safety Graphene, a type of carbon nanomaterial, is a popular choice for supercapacitor applications due to its exceptional properties, such as high surface area, electrical conductivity, lightweight nature, and mechanical strength. Traditional graphene based supercapacitors face challenges due to the agglomeration of graphene nano sheets, which can negatively impact performance. Functionalization, introduction of pores in graphene nano sheets and hybridization with metal oxides can address agglomeration issues and hence enhance charge storage capacity of graphene. Existing chemical methods to achieve these forms of graphene are expensive, complex, time consuming, and have adverse environmental effects. Green chemistry and microwave irradiation can overcome these limitations. These methods are cost effective, environmentally friendly, and easier to handle. The present thesis work includes the synthesis and characterization of various graphene-based materials, such as graphene oxide, holey graphene, graphene foam, and graphene composites with carbon nanotubes and metal oxides (CuO, MnO2 and Fe3O4) composites. newline