Nie, S.; Liu, L.; Liu, J.; Xie, J.; Zhang, Y.; Xia, J.; Yan, H.; Yuan, Y.; Wang, X. Nitrogen-Doped TiO2–C Composite Nanofibers With High-Capacity and Long-Cycle Life As Anode Materials for Sodium-Ion Batteries. Nano-Micro Lett 2018, 10, 71.