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 ∼235.5 mAh g^-1 is maintained after 200 cycles at 0.5 C-rate, and ∼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)₂C₂O₄ 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.