Investigating the effect of Carbon Nano Tube Properties on the Lithium Ion Storage Capacity

Abstract

Nowadays, lithium ion batteries have been attracted researchers attentions for energy storage in portable electronic devices. In comparison to alternative battery technologies, Li ion batteries provide one of the best energy to weight ratios, exhibit no memory effect and experience low self-discharge when not in use.To improve the performance of Li ion batteries, the development of new materials including nano and macro scale structures are likely to contribute for both electrodes and electrolyte. One of the nanomaterialscandidates for anode section is carbon nanotube (CNT) due to its unique set of electrochemical and mechanical properties.According our knowledge, there is not any specific researches related to the CNT properties effects on the Li ion storage. The diameter, length and number of CNTs layers are the most important factors on the Li ion storage capacity. Hence, in this study, lithium ion storage inside various types of CNTs has been investigated using molecular dynamics simulation method. Also, adsorption energy of the lithium ions inside various types of CNTs has been calculated. Results show that lithium ions are tend to adsorb on the outside surface of CNT with the Li ion storage capacity of about 0.015 ions.(number of carbon atoms)-1. Moreover, results indicate that increasing the diameter and the length of CNT enhances the Li ion storage capacity, but ion adsorption mechanism on the CNTs with higher length is more stable than that on the CNTs with larger diameter. While increasing the number of internal layers of CNT does not have any significant effect on the ion storage capacity.