Carbon nanotube surface modification with the attachment of Si nanoparticles in a thermal plasma jet

Abstract

The nanocomposite of carbon nanotube and silicon is a promising anode material for a high-capacity lithium-ion battery, because it can improve electrode performance by decreasing the pulverization and swelling of the electrode. In this work, the nanocomposite of multiwalled carbon nanotube and silicon (MWCNT–Si) was synthesized by attaching silicon nanoparticles to the surface of MWCNT in a thermal plasma jet generated from a nontransferred arc plasma torch. The effects of the input power of plasma, the injection position of Si feedstock, and the mass ratio of silicon to MWCNT on the characteristics of nanocomposite were examined. The structure of the nanocomposite and the chemical species in the product were analyzed by electron microscopy and X-ray diffraction, respectively. Although a small amount of SiC was found, MWCNT–Si nanocomposite was synthesized at a relatively high input power. The size and content of silicon nanoparticles in MWCNT–Si nanocomposites were controllable by changing the mass ratio of silicon to MWCNT raw materials. On changing the silicon feedstock injection position, MWCNT–Si nanocomposite was found when the feed position of silicon was at the inside of plasma torch due to the high heat flux and the long residence time.