Amorphous Carbon-Coated Silicon Nanocomposites: A Low-Temperature Synthesis via Spray Pyrolysis and Their Application as High-Capacity Anodes for Lithium-Ion Batteries
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- 作者：See How Ng ; Jiazhao Wang ; David Wexler ; Sau Yen Chew ; Hua Kun Liu
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：July 26, 2007
- 年：2007
- 卷：111
- 期：29
- 页码：11131 - 11138
- 全文大小：563K
- 年卷期：v.111,no.29(July 26, 2007)
- ISSN：1932-7455
文摘
This article introduces an effective, inexpensive, and industrially oriented approach to produce carbon-coatedSi nanocomposites as high-capacity anode materials for use in rechargeable lithium-ion batteries. Initially,nanosized Si particles (<100 nm) were mixed in a citric acid/ethanol solution via ultrasonication. This mixturewas further spray-pyrolyzed in air at low processing temperature (300-500 
C), resulting in a homogeneouslayer of carbon coating on the surface of the spheroidal Si nanoparticles. The effects of the processingtemperature on the amorphous carbon content, the thickness of the carbon-coating layer, and the homogeneityof the carbon coating were studied in detail. These parameters strongly influenced the electrochemicalperformance of the carbon-coated Si nanocomposites, as will be discussed below. Carbon-coated Sinanocomposites spray-pyrolyzed in air at 400 C show the best cycling performance, retaining a specificcapacity of 1120 mA·h g-1 beyond 100 cycles, with a capacity fading of less than 0.4% per cycle. Thebeneficial effect of the carbon coating in enhancing the dimensional stability of the Si nanoparticles appearsto be the main reason for this markedly improved electrochemical performance.
C), resulting in a homogeneouslayer of carbon coating on the surface of the spheroidal Si nanoparticles. The effects of the processingtemperature on the amorphous carbon content, the thickness of the carbon-coating layer, and the homogeneityof the carbon coating were studied in detail. These parameters strongly influenced the electrochemicalperformance of the carbon-coated Si nanocomposites, as will be discussed below. Carbon-coated Sinanocomposites spray-pyrolyzed in air at 400 C show the best cycling performance, retaining a specificcapacity of 1120 mA·h g-1 beyond 100 cycles, with a capacity fading of less than 0.4% per cycle. Thebeneficial effect of the carbon coating in enhancing the dimensional stability of the Si nanoparticles appearsto be the main reason for this markedly improved electrochemical performance.