TiO2nanotubes grown on graphene sheets as advanced anode materials for high rate lithium ion batteries

Abstract

Here, we propose a unique architecture based on directly growing TiO2 nanotubes on graphene sheets. This work establishes the benefits of combining nanotubular TiO2 with conductive graphene to achieve a significant enhancement in capacitive energy storage. The TiO2 nanotubes possess a porous structure and a higher surface area compared with its bulk material. The graphene sheets play an important role in the conductive substrate for charge collection. In the preparation process, amorphous TiO2 colloids coated on graphene oxide (GO) sheets serve as the seeds to realize the growth of nanotubes, and ensure the robust contact between graphene and TiO2 nanotubes to benefit charge transfer. When used as anodes for lithium ion batteries, the graphene–TiO2 nanotubes (Gr–TNTs) manifest excellent rate capability and cycling performance, indicating that the nanotubes, graphene and their synergistic effect can prompt fast charge transfer in such a composite structure.