Enhanced cycling performance of silicon/disordered carbon/carbon nanotubes composite for lithium ion batteries

A composite anode material of silicon/disordered carbon/carbon nanotubes (Si/DC/CNTs) was prepared by pyrolyzing the mixture of silicon (Si), carbon nanotubes (CNTs), and polyvinyl chloride (PVC) as carbon source. The X-ray diffraction (XRD) analysis confirmed that the phase transition of Si from crystalline to amorphous form occurred during the first cycle. The field-emission scanning electron microscopy (FESEM) observation revealed that Si particles wrapped by a CNTs network were homogeneously embedded into the carbonaceous matrix. The Si/DC/CNTs composite showed a discharge capacity of 1254 mAh/g in the first cycle, and a discharge capacity of 821 mAhig after 20 cycles, which is much higher than that of Si/DC composite (658 mAh/g). It was found that the excellent resiliency of the CNTs can assist the carbonaceous matrix derived from PVC to restore the volumetric changes of the Si. (C) 2010 Elsevier B.V. All rights reserved.