Cage-like carbon nanotubes/Si composite as anode material for lithium ion batteries

Coiled carbon nanotubes with different length were grown on superfine silicon particles via a chemical vapor deposition method. As anode active materials for Li-ion batteries, this CNTs/Si composite shows a reversible specific capacity of 940 mAh/g, a coulombic efficiency of 80% for the first-cycle and good cyclic performance. The improvement of the cyclic performance for silicon particles is related to the maintaining of the electronic contact during cycling and forming a thick SEI film on it.