Pyrolytic carbon-coated silicon/Carbon Nanotube composites: promising application for Li-ion batteries

Abstract

Carbon Nanotubes (CNTs) were grown on silicon nanoparticles by Chemical Vapour Deposition (CVD) method and then the as-prepared Si-CNT hybrid was coated by pyrolytic carbon through pyrolysis of sucrose, as anode material for Li-ion batteries in this study. After 20 cycles, the pyrolytic carbon-coated silicon/CNT composite achieved a discharge capacity of 727 mAh/g. However, for the simple mixture of silicon and CNTs coated by a layer of pyrolytic carbon through pyrolysis of sucrose, the discharge capacity after 20 cycles was only 363 mAh/g. The CVD growth of CNTs on silicon suppresses the structure destruction of pyrolytic carbon-coated silicon/CNT composite during cycling, resulting in the improvement of cyclability.