Biomass Based Carbon Nanospheres as Electrode Materials in Lithium Ion Batteries

In the past decades, the development of nano- carbon materials with well-defined characteristics such as fullerenes, nanotubes and graphene have been a very active area of research. Carbon nanospheres (CNSs) is other class of nanostructured carbon materials, and have shown good prospects for application as alternative LIB anodes. CNSs possess some remarkable characteristics such as high specific capacity and good rate capability as anode materials in LIB. Those specific characteristics are attributed to a combination of several factors, including a short diffusion paths for Li⁺ ions; good porosity and high surface area. CNSs can be synthesized by various techniques which influence the characteristics of resulting carbons in terms of sphere size, size distribution, crystallinity and microstructure. The synthesis process of CNSs include the chemical vapor deposition, hydrothermal carbonization, laser ablation and polymerization –carbonization. Carbon based materials have been initially synthesized from petroleum-derived compounds. Because of the depletion of carbon deposits and very serious concerns on global climate change and environmental pollution, the use of renewable natural resources such as biomass for production of carbon materials has been intensively explored in recent years. In this work, the synthesis of carbon nano-spheres onto the surface of activated carbon support was carried out by thermal assisted catalytic pyrolysis technique and utilizing palm oil as renewable and eco-friendly carbon source. The structure and morphology of the resulting nano carbons are examined with X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). Cyclic voltammetry (CV) and cyclic test of the carbon product as an anode material for lithium ion batteries are also investigated. From TEM observations, it can be shown that CNSs has turbostratic structure in the presence of  Fe-metal catalyst. The CNSs have a stable cycle performance up to 100 cycles at a constant current density of 100 mA/g, showing its potential as an anode material in lithium-ion batteries.