Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5438314 | Ceramics International | 2017 | 17 Pages |
Abstract
To improve the electrochemical performance of silicon-based anode material, lithium fluoride (LiF) and pitch carbon were introduced to co-modify a silicon/graphite composite (SG), in which the graphite acts as a dispersion matrix. The pitch carbon helps to improve the electronic conductivity and lithium ion transport of the material. LiF is one of the main components of the solid electrolyte interphase (SEI) formed on the silicon surface, helping to tolerate the large volume changes of Si during lithiation/delithiation. The modified SG sample delivered a capacity of over 500 mAÂ h gâ1, whereas unmodified SG delivered a capacity of lower than 50 mAh gâ1 after 100 cycles at 100Â mAÂ gâ1. When performed at 4Â AÂ gâ1, the reversible capacity of the modified SG was 346 mAh gâ1, much higher than that of SG (only 37 mAÂ h gâ1). The enhanced cycling and rate properties of the modified SG can be attributed to the synergetic contribution of the pitch carbon and LiF which help accommodate the volume change, reduce the side reaction, and form a stable solid electrolyte interface layer.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Yong Yang, Zhixing Wang, Guochun Yan, Huajun Guo, Jiexi Wang, Xinhai Li, Yu Zhou, Rong Zhou,