Deep Layer Pillaring Reinforced Electronic States and Structural Defects Toward High‐Performance Sodium Ion Battery

Abstract Although layered vanadium oxides are extensively studied for sodium‐ion batteries (SIBs), their broader application is hindered by the instability of their bulk‐phase structure, sluggish electron/ion‐transfer kinetics, and insufficient active sites. Herein, a novel synergistic strategy is proposed to modulate the electronic structure of VO by incorporating Na + cations into deep V─O layers (D‐NVO x ), resulting in significant structural modifications such as enlarged lattice spacing, the generation of abundant oxygen vacancies, and disordering of the V─O layers. Comprehensive analytical characterizations and theoretical calculations reveal that this synergy induces reversible Na + pseudocapacitive intercalation and reconstructs low‐energy barrier channels, thereby accelerating Na‐ion diffusion kinetics. Moreover, the oxygen vacancies dramatically boost electronic conductivity and reinforce structural stability. The reduced crystallinity and lattice distortion result in dense nanointerfaces, potentially widening diffusion channels and providing additional active sites for fast surface Na‐ion storage. Owing to these merits, the D‐NVO x electrode achieves a high specific capacity (505 mAh g ‒1 at 0.05 A g ‒1 ), outstanding cyclic stability (96% capacity retention over 2000 cycles at 2.0 A g ‒1 ), and superior rate performance (280 mAh g ‒1 at 5.0 A g ‒1 ). This work provides in‐depth insights into enhancing electrochemical energy storage in SIBs by modulating electronic structure and structural defects.