Synthesis of carbon-SiO2 hybrid layer @ SiO2 @ CNT coaxial nanotube and its application in lithium storage

Abstract

To alleviate the volume variation upon the silicon oxide during the lithium ion storage process and improve its cyclic stability as well as rate performance in the application of anode material in LIBs, a silicon oxide, carbon and carbon nanotube hybrid material with coaxial structure is developed here in a two-step manner. The formed Carbon-SiO2@SiO2@CNT coaxial nanotube material carries 644 mAh g−1 stable capacity under 0.1 A g−1 as the anode material in LIBs. After over 5000 operating cycles under 1 A g−1, 242 mAh g−1 reversible capacity is clearly demonstrated. The enhanced electrochemical performances can be mostly attributed to the inner carbon nanotube and outer carbon layer, both of which can relief the stress arising from the change of volume and improve the conductivity. The coaxial structure may also benefit to the lithium ions transportation.