Organic Macromolecule regulated the structure of vanadium oxide with high capacity and stability for aqueous Zinc-ion batteries

The phytic acid coated/inserted V2O5 nano-composites (PHVO) obtained by one-step hydrothermal method present excellent electrochemical performance and stable long cycle life. [Display omitted] •The phytic acid coated/inserted V2O5 were prepared by one-step hydrothermal method.•The outer phytic acid serves as a stabilizer to enhance the structural stability of PHVO.•The inserted phytic acid plays as the intercalary spacer to expand the interlayer space of V2O5.•Long cycle life and excellent electrochemical performance can be achieved. The aqueous zinc-ion rechargeable batteries (AZIBs) have become a promising alternative for large-scale energy storage applications and triggered a great deal of scientific research due to low cost, high security, and eco-efficiency. Here, we report the successful synthesis of phytic acid coated/inserted V2O5 nano-composites (PHVO) by one-step hydrothermal method. On one hand, the surface of V2O5 nanosheets is uniformly coated by phytic acid to form an ultrathin layer, serving as a stabilizer to greatly enhance the structural stability by restraining the exfoliation of active materials during the cycling process. On the other hand, the phytic acid plays as the intercalary spacer to expand the V2O5 interlayer distance to 13.5 Å, which is beneficial to the diffusion kinetics of Zn2+ by offering expedited channels. With the abovementioned advantages, the overall electrochemical performance of PHVO has been significantly improved. It showed an excellent specific capacity of 406 mAh g−1 at 0.1 A g−1, and the capacity retention rate was 97.3% after 6000 cycles at 5 A g−1. This work paves the way to the design and fabrication of stable cathodes for AZIBs with excellent electrochemical performance.