Synergistic Pre‐Intercalation and Architectural Tuning to Suppress Vanadium Dissolution for Enhanced Aqueous Zinc‐Ion Battery Performance

ABSTRACT The inherent dissolution and stability issues of pristine vanadium (V) based cathodes limit their performance in rechargeable aqueous zinc‐ion (Zn 2+ ) batteries (RAZIBs). Herein, we report a morphology‐controlled V‐based hollow microsphere cathode (hRVO‐G) conceived via guest pre‐intercalation (Ru), architectural tuning, and rGO encapsulation strategy. The Ru pre‐intercalation expands the interlayer spacing of the V host, promotes the Zn 2 + (de)intercalation, and induces the V─O─Ru interfacial bonding, which lowers the valence state of the V. The existence of reversible dynamic V─O─Ru bond and lower Zn diffusion barrier in hRVO‐G, is further confirmed by theoretical studies. The hollow microsphere architecture mitigates volume changes and internal stress, ensuring structural stability during prolonged cycling. The rGO functionalization improves conductivity, suppresses the Ru‐V oxide agglomeration, and explores the maximum active site. Consequently, hRVO‐G delivers a high specific capacity of 399.8 mAh g − 1 at a current density of 0.1 A g − 1 (vs. 170.8 mAh g −1 for pristine stacked V 2 O 5 ) and achieves 73.1% capacity retention over 1000 cycles, with the charge storage dominated by the capacitive contributions. This work highlights the synergistic interfacial modulation through pre‐intercalation and architectural tuning to address dissolution and stability concerns in the V‐based cathodes for RAZIBs.