Ultrasmall TiO₂ Nanoparticles in Situ Growth on Graphene Hybrid as Superior Anode Material for Sodium/Lithium Ion Batteries

To inhibit the aggregation of TiO₂ nanoparticles and to improve the electrochemical kinetics of TiO₂ electrode, a hybrid material of ultrasmall TiO₂ nanoparticles in situ grown on rGO nanosheets was obtained by ultraphonic and reflux methods. The size of the TiO₂ particles was controlled about 10 nm, and these particles were evenly distributed across the rGO nanosheets. When used for the anode of a sodium ion battery, the electrochemical performance of this hybrid TiO₂@rGO was much improved. A capacity of 186.6 mAh g^–1 was obtained after 100 cycles at 0.1 A g^–1, and 112.2 mAh g^–1 could be maintained at 1.0 A g^–1, showing a high capacity and good rate capability. On the basis of the analysis of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), the achieved excellent electrochemical performance was mainly attributed to the synergetic effect of well-dispersed ultrasmall TiO₂ nanoparticles and conductive graphene network and the improved electrochemical kinetics. The superior electrochemical performance of this hybrid material on lithium storage further confirmed the positive effect of rGO