Tuning electronic structure of ultrathin V6O13 nanobelts via nickel doping for aqueous zinc-ion battery cathodes

Zinc-ion batteries (ZIBs) have gained significant attention for their high theoretical capacity, safe operation and low cost. However, the sluggish kinetics of Zn2+ diffusion in cathode materials hampers the further development of ZIBs. In this study, the interlayer spacing of V6O13 crystals was tuned by doping with Ni2+ to obtain Ni-doped V6O13 (NixV6-xO13) nanobelts with high performance for cathodes in ZIBs. The effect of the amount of Ni precursors on the morphology and the electrochemical properties of the NixV6-xO13 nanobelts was also investigated. The NixV6-xO13 nanobelt cathodes exhibited a high discharge capacity of 302.6 mAh g−1 at 1 A g−1 as well as an excellent specific capacity of 96.5 mAh g−1 after 10,000 cycles at high current density of 8.0 A g−1. By combining various in-situ and ex-situ characterization technologies, the electrochemical mechansims of the NixV6-xO13 nanobelt cathode were revealed. This work offers fundamental guidelines for tuning the electrochemical activities of cathodes in ZIBs.