Suppressing Vanadium Dissolution via Synergistic Lattice Substitution and Heterointerface Engineering for Ultrastable Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (AZIBs) have attracted considerable attention for grid-scale energy storage, yet the practical application of vanadium-based cathodes is severely hindered by vanadium dissolution and sluggish reaction kinetics. Here, we develop a theory-guided dopant screening strategy that simultaneously considers dopant formation energy and vanadium vacancy formation energy to identify effective lattice stabilizers. Density functional theory (DFT) calculations reveal that Al is the optimal dopant, where strong Al-O bonding increases the energy barrier for vanadium detachment and enhances intrinsic lattice stability. Guided by these insights, we rationally construct an Al-VO2/V2C heterostructure cathode. In this system, Al substitution stabilizes the bulk lattice and facilitates Zn2+ diffusion, while the conductive V2C MXene heterointerface accelerates electron transport. As a result, the Al-VO2/V2C cathode delivers a high capacity of 429.2 mAh g-1 after 200 cycles at 0.1 A g-1 and achieves 96.3% capacity retention over 10,000 cycles at 10 A g-1. This work establishes a thermodynamics-guided design principle for stabilizing vanadium-based cathodes while enhancing reaction kinetics in AZIBs.