Core-Shell VN@PCNs Nanoreactors as Cathode Materials for High-Performance Aqueous Zinc Ion Batteries

Aqueous zinc ion water batteries (AZIBs) have attracted much attention due to their high safety, lo w cost, and environmental friendliness, but their cathode materials still face challenges in terms of volume change, reaction kinetics, and structural stability. In this study, vanadium nitride/nitrogen-doped carbon (VN@PCNs) nanoreactors with a core-shell structure were successfully constructed by encapsulating VN nanorods in porous hollow carbon spheres through a synergistic optimization strategy of interfacial engineering and structural modulation. This structure of the nanoreactor significantly reduces the dissolution and structural collapse of the active material, thus maintaining the stability of the electrode structure during multiple charge/discharge cycles. Meanwhile, the concentration gradient formed inside and outside the core-shell structure significantly enhances the diffusion of hydrated zinc ions, effectively improving the slow desolvation rate. Thanks to these advantages, the electrode can still maintain a specific capacity of up to 328 mAh g−1 after 500 cycles at a current density of 3 A g−1, which provides a valuable research direction for the subsequent development of zinc ion batteries.