Network structures of fullerene-like carbon core/nano-crystalline silicon shell nanofibers as anode material for lithium-ion batteries

Abstract

Fullerene-like carbon (FLC) nanoparticles were prepared by depositing soot of burning castor oil. FLC core/nano-crystalline silicon (nc-Si) shell nanofibers with network structures have been fabricated by electrospinning and plasma enhanced chemical vapor deposition techniques. The morphologies and structures of the materials were characterized using scanning electron microscopy, transmission electron microscopy, and micro-Raman spectroscopy. It was demonstrated that the FLC core/nc-Si shell nanofibers on nickel foam can be used as electrode for lithium-ion batteries without adding any binding or conducting additives. High reversible specific capacity of 1164mAhg−1 is retained after 50 discharge/charge cycles at a constant current density of 100mAg−1. The electrode delivers prolonged cycle life and enhanced rate capability compared to pristine nc-Si film. The improved electrochemical performance could be attributed to that the FLC core provides facile strain relaxation to accommodate the large Si volume expansion and shrinkage during lithium-ion insertion and extraction.