Nitrogen-doped TiO2(B) nanorods as high-performance anode materials for rechargeable sodium-ion batteries

Abstract

To achieve better anode materials for sodium ion batteries, a nitrogen-doped TiO₂(B) nanorod structure is developed utilizing hydrothermal treatment, ion exchange and a subsequent low temperature calcination process. Transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction are employed to characterize the structure and properties of the nitrogen-doped TiO₂(B). Compared with anatase TiO₂ powder (325 mesh) raw materials and the TiO₂(B) nanorods without N-doping, the as-fabricated nitrogen-doped TiO₂(B) nanorods with a nitrogen-doping amount of 1.23 atom% exhibit higher specific capacity (224.5 mA h g⁻¹), good cycling stability (the capacity retention ratios after 200 cycles at 2C is 93.4%) and enhanced rate capability (110 mA h g⁻¹ at 3.35 A g⁻¹), which is likely to be associated with enhanced conductivity due to N-doping.