A Low-Cost Nano/Micro Structured-Silicon-MWCNTs from Nano-Silica for Lithium Storage

Despite the fact that silicon material can be synthesized from various sources, deriving them from silica resources is of strategic significance for the industrial processing. Here a low-cost nano/micro structure of Si–CNT was derived from nano-SiO 2 and multiwall carbon nanotubes (MWCNTs) with simple methods. By employing table salt (NaCl) as a heat scavenger for the magnesiothermic reduction, the nano/micro structure of the material was remained effective. Comparing to ball milling, a combination of SiO 2 , MWCNTs and NaCl by spray drying achieved the long cycle life for Si–CNT composite. This material presented a stable capacity above 968.1[Formula: see text]mAh g[Formula: see text] with excellent capacity retention of 85.4% at the 150th cycle versus the 2nd one. The Si nanoparticles, very small particle size in 10–20[Formula: see text]nm, homogenously dispersed in electronically conductive network of MWCNTS, which accommodate the volume change of Si and reinforce highly conductivity of the Si–CNT composite during repeated cycles. Combined with its low-cost and up-scaling technologies, Si–CNT composite is a promising anode material in rechargeable lithium batteries with high electrochemical performance.