Rambutan-pitaya-like structured TiO2@Co-CNT-NC nanocomposite as high-performance lithium ion battery anodes

Abstract Titanium dioxide (TiO2) is considered to be one of the most promising materials utilized as anode materials for lithium ion batteries (LIBs) due to cycling stability, low cost and nontoxicity. Nevertheless, the intrinsic drawback of TiO2 limiting its practical application is the poor electronic conductivity leading to the undesired rate capability because of the inferior electron transport. Therefore, in the study, we construct a rambutan-pitaya-like structured 3D porous framework containing TiO2 nanoparticles embedded into nitrogen-doped carbon framework and carbon nanotubes on the surface (namely TiO2@Co-CNT-NC) by a facile method. In the unique structure, the whole electrical conductivity of TiO2@Co-CNT-NC anode can be effectively heightened by the improvement of the intergranular electrical conductivity because of the formation of the CNTs on the surface of the composite. The porous structure with numerous micropores and mesopores can effectively promote the electrolyte penetration, retard the volume change and provide high contact area between electrolyte and electrode. As a result, after 1100 cycles, the capacity of the TiO2@Co-CNT-NC anode at 6 C gradually increases from 228 mA h g−1 to about 300 mA h g−1 with the capacity growth rate of 0.026%.