Coppey Nicolas, Noé Laure, Monthioux Marc, Caussat Brigitte
Laboratory of Chemical Engineering, University of Toulouse, ENSIACET/INP Toulouse/UMR CNRS 5503, 4, allée Emile Monso, BP84234, 31432 Toulouse, Cedex 4, France.
J Nanosci Nanotechnol. 2011 Sep;11(9):8392-5. doi: 10.1166/jnn.2011.5078.
Silicon was deposited on balls of entangled multi-walled carbon nanotubes (CNT) with a mean diameter of several hundreds of microns, by Fluidized Bed Chemical Vapor Deposition from silane (SiH4). The weight total percentage of deposited silicon was between 30 and 70%, to test their efficacy in Li-ion battery anodes. TEM and SEM imaging revealed that silicon deposits were of the form of nanoparticles uniformly dispersed on the whole CNT surface. The diameter of these nanoparticles increases with the deposited silicon percentage from 18 to 36 nm whereas their density remains constant at 5 10(22) nanoparticles/g of CNT. This indicates a low affinity of chemical species born from silane pyrolysis with the CNT surface for nucleation. The increase of the silicon nanoparticles diameter leads to the decrease of the specific surface area and the porous volume of the balls, probably due to the filling of the pores of the CNT network by silicon. A slight increase of the mean diameter of the balls was observed for the two highest silicon percentages, certainly due to the ability of the CNT network to be deformed under the mechanical stress induced by the silicon nanoparticles growth.
通过硅烷（SiH₄）的流化床化学气相沉积法，在平均直径为数百微米的缠结多壁碳纳米管（CNT）球上沉积硅。沉积硅的总重量百分比在30%至70%之间，以测试它们在锂离子电池阳极中的功效。透射电子显微镜（TEM）和扫描电子显微镜（SEM）成像显示，硅沉积物呈纳米颗粒形式，均匀分散在整个碳纳米管表面。这些纳米颗粒的直径随着沉积硅的百分比从18纳米增加到36纳米，而它们的密度在每克碳纳米管5×10²²个纳米颗粒时保持恒定。这表明硅烷热解产生的化学物质与碳纳米管表面的成核亲和力较低。硅纳米颗粒直径的增加导致球的比表面积和孔隙体积减小，这可能是由于硅填充了碳纳米管网络的孔隙。对于两个最高的硅百分比，观察到球的平均直径略有增加，这肯定是由于碳纳米管网络在硅纳米颗粒生长引起的机械应力下发生变形的能力。
