Preparations and Electrochemical Performances of Carbon Coated Silicon/Graphite Composites

Authors

Tian-yi GAO, College of Energy, Xiamen University, Xiamen 361005, Fujian, China;
Zheng-liang GONG, College of Energy, Xiamen University, Xiamen 361005, Fujian, China;Follow

Corresponding Author

Zheng-liang GONG(zlgong@xmu.edu.cn)

Abstract

In this work, the carbon coated silicon (Si@C) composite materials were synthesized based on the industrial silicon powder (600 meshes) via a high energy ball milling combing with in-situ carbon coating (carbonization) method. The Si@C/graphite (Si/C) composite anode materials were prepared by a simple mechanical ball-milling approach. The effects of carbon coating and the ratio of Si to graphite on electrochemical performances of Si/graphite composite materials were investigated systematically. Compared with the nano-Si/graphite composites, the Si/C composites showed higher reversible capacity, better rate capability and cycle performance. The Si@C materials composited of amorphous carbon and crystal silicon with the primary particles size of 100 ~ 200 nm. The Si/C-2-1 composite also revealed high reversible specific capacity, good rate performance and cycling stability. The Si/C-2-1 exhibited the reversible capacity of 492 mAh·g^-1 with a capacity retention of 85.8% after 100 cycles at 0.1C. Moreover, the reversible discharge capacity reached 369.7 mAh·g^-1 when cycled at 1C, corresponding to 73.9% of that at 0.1C. The Si/C-2-3 which contained 20% silicon displayed a higher reversible capacity of 600.4 mAh·g^-1 when cycled at 0.1C. However, the cycling stability of these composites decreased with increasing Si content, indicating that the graphite content played an important role to improve the cycle performance of the composite.

Graphical Abstract

Keywords

lithium ion battery, anode materials, silicon-based composite materials, carbon coating

DOI Link

https://doi.org/10.13208/j.electrochem.170728

Publication Date

2018-06-28

Online Available Date

2017-09-19

Revised Date

2017-09-17

Received Date

2017-07-28

Recommended Citation

Tian-yi GAO, Zheng-liang GONG. Preparations and Electrochemical Performances of Carbon Coated Silicon/Graphite Composites[J]. Journal of Electrochemistry, 2018 , 24(3): 253-261.
DOI: 10.13208/j.electrochem.170728
Available at: https://jelectrochem.xmu.edu.cn/journal/vol24/iss3/7