V<sub>2</sub>O<sub>3</sub>/VN@C Heterostructures with\nFast Charge Transfer as High-Performance Cathodes of Zinc-Ion Batteries

Zinc-ion batteries (ZIBs) are promising\ncandidates for\nnext-generation\nenergy storage systems due to their high energy density and low cost.\nHowever, challenges such as poor cycling stability and sluggish kinetics\nhinder their practical application. In this study, we propose a novel\nheterostructure composed of microsphere V<sub>2</sub>O<sub>3</sub> integrated with vanadium nitride (VN) and uniformly coated with\ncarbon (V<sub>2</sub>O<sub>3</sub>/VN@C) to address these challenges.\nThe optimized V<sub>2</sub>O<sub>3</sub>/VN@C heterostructure exhibits\nexcellent stability during cycling within a voltage window of 0.1–1.3\nV (vs Zn/Zn<sup>2+</sup>). The V<sub>2</sub>O<sub>3</sub>/VN@C electrode\nexhibits a large specific capacity (278 mA h g<sup>–1</sup> at 200 mA g<sup>–1</sup>), remarkable cycling stability (96%\ncapacity retention after 400 cycles at 200 mA g<sup>–1</sup>), improved rate capacity (141 mA h g<sup>–1</sup> at 15 A\ng<sup>–1</sup>), and higher energy density besides. Furthermore,\nthe investigation of the Zn-ion storage mechanism in the V<sub>2</sub>O<sub>3</sub>/VN@C electrode reveals that the heterostructure effectively\nenhances the conductivity and inhibits the phase transition of V<sub>2</sub>O<sub>3</sub> to a high-valence state. During charging and\ndischarging, the heterostructure facilitates the desolvation process\nof Zn[H<sub>2</sub>O]<sub>6</sub><sup>2+</sup> and accelerates the\ncharge transfer kinetics of the electrodes. The proposed strategy\nprovides new opportunities for designing long-cycling and high-energy\ncathodes for AZIBs and beyond.