Four kinds of silicon-metals (Cu, Ni, Sn)-graphite composites for anode active materials of lithium secondary batteries were prepared by sequential employment of PECVD (Plasma enhance chemical vapor deposition) and RF(Radio-frequency)-magnetron sputtering method. The silicon-copper-graphite composite showed the highest reversible capacity and cyclability among the silicon-metal composite graphite samples prepared. The enhanced electrochemical performance of silicon-copper-graphite composite is attributed to the formation of copper silicide on the surface of graphite. The copper silicide plays an important role as a buffering layer against volume change of silicon during the intercalation/deintercalation due to the chemical bonding of silicon and copper, and has lower interfacial impedance than that of other silicon-metal-graphite composites which may lead to low irreversible capacity.
Bibliographical noteFunding Information:
Acknowledgement This research was supported by a grant(code #05K1501-01920) from ’Center for Nanostructured Materials Technology’ under ’21st Century Frontier R&D Programs’ of the Ministry of Science and Technology, Korea.
Copyright 2008 Elsevier B.V., All rights reserved.
- Lithium ion battery
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Mechanics of Materials
- Electrical and Electronic Engineering
- Materials Chemistry