Abstract: Titanium oxide has recently drawn much attention as anode material for sodium ion batteries. Nevertheless, its application is highly restricted by poor electronic conductivity and sluggish Na+ reaction kinetics. Herein, we report nitrogen(N)-doped-TiO2 nanotubes (N-TiO2-NTs) through a facile and cost-effective anodization process and annealing at NH3/Ar flow. XPS analysis investigates that the ratio of doped N element is 2.1 at% mainly in interstitial sites, which can effectively improve intrinsic electronic conductivity and enhance Na+ diffusivity of the TiO2 bulk. Due to the hetero-N doping and high specific area of nanotube structure, the kinetic activity of N-TiO2-NTs is observably enhanced. Therefore, the anode delivers high capacitive-controlled behaviors up to 80.3% and 86% of whole capacities at scanning rates of 0.6 and 1 mV s−1. The N-TiO2-NTs anode exhibits good and stable capacity (216.1 mA h g−1 at 0.2 C after 300 cycles) and high rate performance (114 mA h g−1 at 20 C). Moreover, the long-term cycling test after 5000 cycles obtains nearly 100% capacity retention at an ultrahigh current density of 10 C. Thus, we offer a facile strategy to develop N-TiO2-NTs as a hopeful product for the anode materials in sodium ion batteries.

https://doi.org/10.1016/j.jallcom.2021.161612