Orbital hybridization engineering, a built-in electric field, and simultaneous carbon layer charge rearrangement...

To address the sluggish carrier kinetics of Na₃V₂(PO₄)₃ (NVP), we developed a multi-pronged synergistic modification strategy integrating "V3d-Pr4f" orbital hybridization to optimize the electronic structure, oxygen-vacancy-enriched heterogeneous NVP/NVPO to generate a built-in electric field, and an N/Br-codoped carbon layer that enables charge rearrangement. Notably, we introduce "V3d-Pr4f" orbital hybridization engineering to reconstruct the V3d electronic state, thus inducing modification of the "V-O" bond to accelerate carrier migration. EXAFS and simulation demonstrate the shortened bond length of V-O; ICOHP reveals that substituted Pr-O possesses stronger covalent bond energy than the primitive V-O bond, indicating a more stable Pr-VO₆ framework. Meanwhile, ²³Na-NMR and EPR together confirm the successful formation of an NVP/NVPO heterojunction with abundant oxygen vacancies, suggesting that lattice reconstruction has been achieved. Moreover, the difference in work function between NVP and NVPO promotes the spontaneous built-in electric field established at the interface, which has been comprehensively investigated by multiple spectroscopic and DFT calculations. Furthermore, charge rearrangement engineering is introduced into the coated carbon skeleton. ELF shows that charges accumulate at the N/Br sites after N/Br occupies C sites. The enriched charge is relatively attractive for O and induces O vacancies inside NVP. The optimized NVP/C@Pr-4% delivers a high capacity retention of 99.31% after 3000 cycles at 30C.