Lithium-storage properties of SiO2 nanotubes@C using carbon nanotubes as templates

Abstract

Silica-based anode material is the most concerned material at present, which has the advantages of good cycle stability, high theoretical specific capacity and abundant reserves. However, silica suffers from inherent low conductivity, severe volume expansion effect and low initial coulombic efficiency, which limits its application in lithium-ion batteries. Nanotubes structure can mitigate the volume expansion during lithiation/delithiation. In this article, silica nanotubes (SNTs) were prepared using carbon nanotubes (CNTs) as a template, and then the uniform carbon layer was coated on their surface by carbonization of citric acid. The hollow structure of nanotubes provides more sites for the insertion of Li+ during lithiation and additional channels for Li+ migration in the cycles, which improves the electrochemical performance. Conductivity can be enhanced by coating carbon layer. The specific capacity of the composite material is about 650 mAh g−1 at 0.1 A g−1 after 100 cycles. With a specific capacity of 400 mAh g−1 even at 1 A g−1 after 100 cycles. The silica-based material is a competitive anode material for lithium-ion batteries.