Novel silicon-oxygen-carbon composite with excellent cycling steady performance as anode for lithium-ion batteries

The novel anode material for lithium-ion batteries, silicon-oxygen-carbon (Si-O-C) composite, is prepared by a liquid solidification combined with following pyrolysis process, in which silicon dioxide (SiO2) is used as an additive agent to enhance the electrochemical performance of the composite. While the structure of the composite is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR), the morphology and microstructure were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. SEM and TEM observations reveal that the Si-O-C powders are about 1 mu m in diameter, and there is a homogenous pyrolyzed carbon layer about 5 nm thick on the surface of the particle. The Si-O-C sample as anode material can deliver a high initial charge capacity of 753.4 mAh g(-1), and the capacity keeps above 500.0 mAh g(-1) after 40 cycles at 100.0 mA g(-1). The electrochemical impedance spectroscopy results show that the composite exhibits lower charge transfer resistance and higher lithium-ion diffusion rate compared with the Si-C anode, which indicates that the composite Si-O-C could be used as a promising anode material for lithium-ion batteries.