Porous Carbon Induced Anatase TiO2 Nanodots/Carbon Composites for High-Performance Sodium-Ion Batteries

The anatase TiO2 nanodots/carbon composites were prepared by an in-situ grown method induced by 3D porous carbon. Compared with the pure TiO2, the hybrid material of anatase TiO2 nanodots/carbon composites (denoted as AT@3DC) exhibited a smaller particle size with a diameter range from 5 nm to 10 nm and better electronical conductivity. When utilized as anode material for sodium-ion batteries (SIBs), the AT@3DC electrode showed ultrahigh cycling performance and ultrafast charge/discharge performance. A reversible sodium-ion storage capacity of similar to 235.5 mAh g(-1) is maintained after 200 cycles at 0.5 C-rate, and similar to 112.8 mAh g(-1) could be obtained at 20 C-rate after 5000 cycles with almost no decay, which indicate the high stability of the AT@3DC. The excellent rate capacity and ultralong cycling life are attributed to the unique 3D porous carbon support, which can assist the nucleation of Ti(OH)(2)C2O4 and limit their growth, effectually inhibit the aggregation of titanium dioxide nanodots, enhance the charge transfer rate and increase the mass transfer rate of Na+. Considering the excellent Na+ storage performance and ultrahigh cycling stability, the AT@3DC might be a promising anode material for the SIBs in the future. (C) 2016 The Electrochemical Society. All rights reserved.