Tuning D‐Band Center of Vanadium in Constructing Lattice‐Matched Coherent Heterostructure for Enhanced Sodium Storage

Abstract A multiphasic K_0.147Na_4.853V₁₂O₃₂/NaV₆O₁₅@C (KNVO/NVO@C) heterostructure is realized to feature a lattice‐matched coherent interface with a strong interfacial electric field in the cathodes, thereby elevating the d‐band center and strengthening the adsorption and transportation of Na⁺ with enhanced adsorption capacity. The heterostructured KNVO/NVO@C cathode exhibits an exceptional rate capability (235.2 mAh g⁻¹ at 0.2 C and 151.7 mAh g⁻¹ at 10 C) and ultralong cycling stability with a high capacity retention of 95% after 1000 cycles at 5 C. It is found that the interfacial synergy between the coherent structural properties and the strong stress field generated by the work function difference at the heterointerface upshifts the d‐band center of vanadium toward the Fermi level, which effectively lowers the Na⁺ diffusion barrier, facilitates charge transfer, and accelerates reaction kinetics and electron/ion transport. It is calculated that the diffusion coefficient of KNVO/NVO@C reaches ≈10⁻¹¹ cm² s⁻¹, highly exceeding that of the KNVO electrode. These findings offered a robust framework for rational heterointerface engineering to develop next‐generation high‐performance energy storage devices.