Nitrogen-Doped TiO(2)–C Composite Nanofibers with High-Capacity and Long-Cycle Life as Anode Materials for Sodium-Ion Batteries

Nitrogen-doped TiO(2)–C composite nanofibers (TiO(2)/N–C NFs) were manufactured by a convenient and green electrospinning technique in which urea acted as both the nitrogen source and a pore-forming agent. The TiO(2)/N–C NFs exhibit a large specific surface area (213.04 m(2) g(−1)) and a suitable nitrogen content (5.37 wt%). The large specific surface area can increase the contribution of the extrinsic pseudocapacitance, which greatly enhances the rate capability. Further, the diffusion coefficient of sodium ions (D(Na+)) could be greatly improved by the incorporation of nitrogen atoms. Thus, the TiO(2)/N–C NFs display excellent electrochemical properties in Na-ion batteries. A TiO(2)/N–C NF anode delivers a high reversible discharge capacity of 265.8 mAh g(−1) at 0.05 A g(−1) and an outstanding long cycling performance even at a high current density (118.1 mAh g(−1)) with almost no capacity decay at 5 A g(−1) over 2000 cycles. Therefore, this work sheds light on the application of TiO(2)-based materials in sodium-ion batteries. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40820-018-0225-1) contains supplementary material, which is available to authorized users.