Co-axial carbon nanotubes and Ni-Si nanowire as anode material for high performance Li Ion battery

• Main Author: Chen, Ivan Weide.
• Other Authors: Tay Beng Kang
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Microelectronics
• Online Access: http://hdl.handle.net/10356/53227
• Institution: Nanyang Technological University

In this technological advanced age, electronic gadgets have become necessities and its services have been embedded into our daily life routine. However with miniaturization for better mobility and the increasing additional features, battery life for performance had since been deteriorating. Si, with its higher theoretical specific capacity, has been investigated for the replacement of the conventional anode material of the widely used Li ion battery. However recent studies have shown that Si itself is not an appropriate anode material. Stress induced by huge volume change during charging and discharging causes cracks and pulverization of the Si material, fast fading of the capacity, and hence the failure of the batteries. Nano-compositing and nano-structuring of Si are now considered as the most important strategies to alleviate stress and withstand pulverization during charging and discharging. On one hand, compositing Si with metal material is found to be an effective way to reduce the damages during cycling and prolong its capacity over longer cycles. On the other hand, an emerging trend in Li ion battery research is the nanostructure of co-axial CNT-Si heterogeneous nanowires, utilizing the extraordinary properties of CNTs for improved battery performance. In this project, we investigate the performance of co-axial CNT-Si nanowire as anode material. Furthermore, through modification of the Si shell with Ni, we obtained CNT-Ni Si (NiSi) with further improved capacity retention. This novel anode structure combines the merits and nano-compositing and nano-structuring and provides a promising routine towards high capacity as well as long life time Li ion batteries.