Oxygen-Vacancy-Rich V2O5@NC Composite with Enhanced Zinc-Storage Performance for Aqueous Zinc-Ion Batteries

The practical application of vanadium-based cathode materials in aqueous zinc-ion batteries (AZIBs) is severely hindered by vanadium dissolution, low electronic conductivity, and sluggish reaction kinetics in aqueous electrolytes. In this work, a three-dimensional confined V2O5@ nitrogen-doped carbon (V2O5@NC) composite was rationally designed and constructed through a dual-regulation strategy combining oxygen-vacancy engineering and conductive network enhancement. In this architecture, the nitrogen-doped carbon framework provides a highly conductive network and robust structural support, while in situ carbonization induces the generation of oxygen vacancies within V2O5. These oxygen vacancies cause lattice distortion and expand the interlayer spacing, thereby accelerating Zn2+ diffusion and improving reaction kinetics. Benefiting from this synergistic effect, the V2O5@NC electrode exhibits an excellent specific capacity of 437 mAh g−1 at 0.1 A g−1 and maintains a remarkable 89.3% capacity retention after 2000 cycles at 3 A g−1, demonstrating outstanding rate performance and cycling stability. This study provides new insights and an effective design strategy for developing high-performance cathode materials for next-generation aqueous zinc-ion batteries.