Synthesis and electrochemical properties of silicon/carbon composites prepared by high temperature pyrolysis
Silicon/carbon composites as anode materials for lithium batteries with high power capacity were synthesized by a high temperature pyrolysis method. The performances of the silicon/carbon composites were investigated by X-ray diffraction,thermogravimetric analysis,scanning electron microscopy,transm...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | zho |
| Published: |
Science Press
2015-08-01
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| Series: | 工程科学学报 |
| Subjects: | |
| Online Access: | http://cje.ustb.edu.cn/article/doi/10.13374/j.issn2095-9389.2015.08.011 |
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| Summary: | Silicon/carbon composites as anode materials for lithium batteries with high power capacity were synthesized by a high temperature pyrolysis method. The performances of the silicon/carbon composites were investigated by X-ray diffraction,thermogravimetric analysis,scanning electron microscopy,transmission electron microscopy,galvanostatic cell cycling,and cyclic voltammetry. It is found that the silicon/carbon composites consist of silicon,carbon and few silicon dioxide phases,and the carbon content is about 39%. Electrochemical cycling tests of button cells show that the specific capacity is far more than that of carbon materials. The initial charge capacity of the silicon/carbon composites is 768 m Ah·g-1 at a current of 0.2 m A and the initial coulombic efficiency is 75.6%.After 70 cycles the reversible specific capacity is 529.0 m Ah·g-1 and the average capacity deterioration rate of each cycle is 0.44%.These improvements can be attributed to the introduction of carbon in the Si/C composites and carbon coatings on the Si surface,which provide a rapid lithium transport pathway,reduce the cell impedance and stabilize the electrode structure during charge/discharge cycles. |
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| ISSN: | 2095-9389 |