N, P dual-doped carbon nanotube with superior high-rate sodium storage performance for sodium ion batteries

Herein, we demonstrate an effective strategy to prepare N and P co-doped carbon nanotubes (NPC) using pyrrole monomer and phytic acid as precursors. Importantly, density functional theory (DFT) and pseudocapacitance contribution calculations certify that the electron mobility and electrochemical kinetics of the carbon nanotubes are enhanced by P-doping. Furthermore, the co-effect of the special hollow nanotubes structure and dual N, P doping endows the NPC with excellent rate performance and long-term cycling stability when it is used as an anode material for sodium ion batteries. Even tested at a high current density of 5000 mA g(-1), a high reversible capacity of 180.3 mA h g(-1) can be obtained after 3000 cycles for the NPC electrode. (C) 2019 Elsevier B.V. All rights reserved.