Enhanced Energy Storage and Conversion through Carbon Nanostructured Composites

Abstract

Experts rank climate change and energy shortage as the most important issues that we confront over the next 50 years. These problems are connected, since non-regenerative fossil fuels are responsible for greenhouse gas emission thanks to the CO2 they produce during combustion. From all the observations, it is evident that these two major global problems concerning energy and the environment must be faced together. Hence, this doctoral work aims to tackle sustainable energy production, conversion, and storage challenges. Graphene and carbon nanotubes (CNTs) have been considered as promising electrode materials for energy conversion and storage due to their unique physical and electrical properties. Considering this fact, a novel nanostructured composite synthesised consisting of graphene and carbon nanotubes (CNTs), each pre-doped with nitrogen (N). This unique composite demonstrated remarkable electrocatalytic activity toward the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and Hydrogen evolution reaction (HER) compared to commercial platinum on supported carbon (Pt/C) catalyst. Therfore, replacing the expensive noble metal catalysts, which offer relatively short service life, with this composite produced from cheap and readily available materials, opens up a new avenue to target sustainable energy production and conversion issues. Employing of this composite to impregnate sulfur into its structure to be used as a cathode in Li-S batteries, and as a support to grow iron and cobalt Oxide (Fe3O4, Co3O4) nanoparticles on its body to be applied in anode for Li-ion batteries, exhibited superior electrochemical performances, including relatively low irreversible capacity loss, high specific capacity, and satisfactory cyclability. This carbon nanostructured composite proved to have a promising potential in sustainable energy storage applications.