Chinese Journal of Applied Chemistry ›› 2017, Vol. 34 ›› Issue (1): 76-82.DOI: 10.11944/j.issn.1000-0518.2017.01.160101

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Synthesis of Porous Silicon Oxide/Silicon/Carbon Composite Material from Micro-SiO for Lithium Storage

FENG Xuejiaoa,CUI Hongminb*(),XIAO Zhengqianga,YAN Nanfub,LI Mina   

  1. aInstitute of Science and Technology Strategy
    bInstitute of Applied Chemistry,Jiangxi Academy of Science,Nanchang 330029,China
  • Received:2016-03-09 Accepted:2016-05-17 Published:2017-01-03 Online:2017-01-03
  • Contact: CUI Hongmin
  • Supported by:
    Supported by the Doctoral Project of Jiangxi Academy of Science(No.2014-YYB-27, No.2014-YYB-20)

Abstract:

Porous silicon oxide/silicon/carbon composite was derived from micro-silicon monoxide with simple calcination, chemical vapor deposition and HF etching. The obtained c-SiOx/Si/C(c-refers to calcination) composite after etching possesses a high specific surface area of 32.9 m2/g and an average/mean pore distribution of 3 nm. The atomic ratio of Si/O in c-SiOx/Si/C is increased comparing to that of c-SiO/C without etching. The Si nano-crystallites were embedded in porous Si-suboxide, and the particles are covered by a uniform carbon layer with a thickness of 6 nm on the surface. The c-SiOx/Si/C with this particular structure exhibits a stable reversible capacity of ca. 645.1 mA·h/g after 50 cycles with the current density at 0.3 mA/g. In contrast, c-SiO/C composite without pores presents a reversible capacity of only ca. 466 mA·h/g under the same carbon coating condition. The different cycling performances of c-SiOx/Si/C and c-SiO/C may be consequences of their structural differences. It is believed that the rich nanopores of the c-SiOx/Si/C can endure and buffer the severe volume change of silicon upon lithium insertion and extraction and improve the mechanical integrity of composite.

Key words: silicon monoxide, porous structure, electrochemical performance, lithium ion battery