| Popis: |
Abstract Sodium‐ion batteries (SIBs) have been considered as promising replacements to lithium‐ion batteries (LIBs) for large‐scale energy storage applications. For anode materials, titanium dioxide (TiO2) as a typical insertion‐type anode material have been extensively investigated as a safety, stable, cheap and environmental‐friendly anode materials for SIBs. Constructing suitable TiO2 crystal structure is a common modification strategy for improving the diffusion kinetics of sodium ion within TiO2 and its intrinsic electronic conductivity. Herein, a multi‐atomic doped oxygen‐deficient TiO2/C composites (N, S‐NTC) was successfully synthesized with excellent electrochemical performance. Synergistic effect of N, S and Ni elements on the structure, morphology and electrochemical performance was investigated. Electron Paramagnetic Resonance (EPR) spectroscopy, Raman spectroscopy and X‐ray photoelectron spectroscopy (XPS) analysis indicated that the Ni, N, S doping can introduce oxygen deficiency, narrow the bandgap of TiO2 and facilitating Na+ diffusion, further providing higher electronic/ionic conductivities and faster electron transport channel. As a consequence, the anode materials delivered ultrahigh rate performance and cycling performance of a high reversible capacity of 128.6 mA h g−1 at 1 A g−1 after 3000th cycles. |
Plný text