N/Br co-doped C coating Zn2VO4 as excellent electrochemical performance cathode material for aqueous zinc ion batteries

Rechargeable aqueous zinc-ion batteries are considered promising candidates for large-scale energy storage due to its low cost and high safety. However, the strong electrostatic forces between the Zn2+ ions and the host material, low conductivity and slow ion diffusion kinetics of cathode materials hinder its development. Zn2VO4 coating with N and Br co-doped C was successfully prepared using CTAB as N/Br co-doped C source. The coating of N/Br co-doped C improves the electrical conductivity and electrochemical activity of the material. As cathode material for ZIBs, it displays an initial discharge capacity of 181 mAh g−1 at 1 A g−1, and a high capacity of 120 mAh g−1 with 0.8 % capacity delay rate over 5000 cycles at high current density of 5 A g−1. Meanwhile, the material electrode displays fast ionic diffusion as well as excellent charge transfer kinetics which are favorable for fast energy storage and conversion.