Core–shell anatase anode materials for sodium-ion batteries: the impact of oxygen vacancies and nitrogen-doped carbon coating

• Published in: Nanoscale Vol. 11; no. 38; pp. 17860 - 17868
• Main Authors: Bai, Yu-Lin, Xarapatgvl, Raxidin, Wu, Xue-Yan, Liu, Xin, Liu, Yu-Si, Wang, Kai-Xue, Chen, Jie-Sheng
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 14.10.2019
• Subjects: Anatase; Anodes; Batteries; Carbon; Coating; Electrochemical analysis; Electrode materials; Infrared radiation; Ion storage; Lattice vacancies; Nitrogen; Oxygen; Rechargeable batteries; Sodium; Sodium-ion batteries; Synergistic effect; Titanium dioxide
• ISSN: 2040-3364; 2040-3372; 2040-3372
• DOI: 10.1039/C9NR06245A

In this work, the impact of oxygen vacancies and nitrogen-doped carbon coating on the sodium-ion storage properties of anatase TiO 2 has been demonstrated. Oxygen vacancies and nitrogen-doped carbon coating were introduced simultaneously by the calcination of core–shell structured TiO 2 spheres in a reducing atmosphere. Compared to the anatase TiO 2 with and without oxygen vacancies, TiO 2−x @NC exhibits much better electrochemical performance in the storage of sodium ions. A high reversible capacity of 245.6 mA h g −1 is maintained at 0.1 A g −1 after 200 cycles, and a high specific capacity of 155.6 mA h g −1 is achieved at a high rate of 5.0 A g −1 . The significantly improved electrochemical performance of the core–shell structured anatase TiO 2 spheres is attributed to the synergistic effect of the oxygen vacancies in the anatase lattice and surface nitrogen-doped carbon coating. This work provides an efficient strategy for improving the electrochemical performance of metal–oxide-based electrode materials for sodium-ion batteries.