Stepwise MXene-Derived VN Intermediate Conversion N-Doped Carbon-Coated Amorphous VO _<i>x</i> for Ultrafast and Durable Zinc-Ion Storage

Aqueous zinc-ion batteries (AZIBs) show great promise for large-scale energy storage applications thanks to their excellent safety performance and low cost. However, their development is hindered by the limited availability of high-performance cathode materials. In this study, amorphous vanadium oxide (A-VOx/NC) coated with nitrogen-doped carbon was produced using a nitriding strategy and subsequent electrochemical oxidation process with delaminated V2CTx MXene as the precursor. Material characterization confirmed that the resulting A-VOx/NC had inherited the MXene precursor’s desirable layered morphology and formed a disordered amorphous structure. Within this tailored structure, the layered structure provides a large accessible site for the Zn redox reaction, while the amorphous structure offers isotropic ionic migration pathways for Zn-ion intercalation/deintercalation. Meanwhile, the nitrogen-doped carbon layer boosts the material’s conductivity and acts as stable “armor” to suppress vanadium dissolution in electrochemical reactions. Consequently, the A-VOx/NC material exhibits exceptional electrochemical properties when used as a cathode in AZIBs, delivering a high specific capacity of 527.35 mAh g–1 at 0.2 A g–1, maintaining excellent rate capability (117.14 mAh g–1 even at 50 A g–1), and demonstrating outstanding cycling stability, retaining 91.67% of its capacity after 3000 cycles at 50 A g–1. Further strong evidence confirms the conventional H+/Zn2+ cointercalation/deintercalation charge storage mechanism in the A-VOx/NC cathode. This work expands the application of MXene-derived materials in electrochemical energy storage and provides a general strategy for regulating the crystallinity and microstructure of cathode materials. This is useful for designing advanced AZIB cathodes.