A Study on the Electrochemical Characteristics of Kerosene Derived Carbon Nanospheres As Anode Materials of Lithium Secondary Batteries

Abstract

Spherically shaped carbon materials have been explored for decades, and their characteristics have been applied for instance in the various energy-related industries such as batteries, capacitors or fuel cells. It can be said that the term of carbon spheres refers to all carbon materials that possess a spherical or near spherical shape but do not include the fullerene family of carbons. In general, spherical carbons have been prepared by various methods such as arc discharge, chemical vapor deposition, laser ablation, autoclave process, shockwave process and catalytic pyrolysis process. It can be observed that the different methods can produce carbon spheres with quite different structural and electrical characteristics. In this study, carbon nanospheres (CNSs) were synthesized by the nebulyzed pyrolysis process using kerosene as carbon precursors, ferrocene catalyst and activated carbon support at elevated temperature under an nitrogen atmosphere. Morphology and structure of as grown CNSs were characterized by Scanning Electron Microscope (SEM), High-Resolution Transmission Electron Microscope (HRTEM), Raman and X-ray photo electron spectroscopy. It was found that the carbon products had a turbostratic structures and high degree of disorder carbon structures. Preliminary electrochemical measurements of kerosene derived CNSs as anode materials of lithium secondary batteries were carried out using cyclic voltammetry and charge –discharge tests. Experimental results showed that a stable cycle performances until the 100th cycles was obtained with specific capacity of 400 mAh/g. However, the main problem is the high irreversible capacity at the first cycle due to the low purity and non uniform carbon nano-spheres.