Magnetic‐Field Modulation of Na 3 V 2 (PO 4 ) 3 Crystal Orientation for Enhanced Sodium‐Ion Battery Performance

ABSTRACT Na 3 V 2 (PO 4 ) 3 (NVP) is a promising electrode material that exhibits magnetic anisotropy; however, the potential of this magnetic anisotropy to optimize battery performance has been largely unexplored. This study proposes a cost‐effective and efficient method to induce the alignment of NVP along the (113) crystal plane by applying a vertical magnetic field during the slurry coating process, thereby enhancing its battery performance. Comprehensive structural characterizations and theoretical analysis elucidate the structure‐activity relationship between the preferred crystal orientation and ion transport kinetics, facilitating the formation of more ordered Na + deintercalation pathways in NVP electrodes. This alignment reduces electrode tortuosity, enhances interfacial compatibility, and substantially improves battery performance, particularly in terms of high‐rate cycling capability. As a result, the magnetic‐field‐modulated NVP (NVP−M⊥) electrode exhibits a high capacity retention of 85.1% after 500 cycles at 5 C, significantly surpassing that of the pristine electrode. The NVP−M⊥ electrode also demonstrates considerable reversible capacity at 40 C and maintains excellent stability under high temperature and prolonged cycling conditions. Furthermore, superior battery performance is observed in the assembled NVP−M⊥||hard−carbon pouch cell and commercial NVP electrode following magnetic‐field modulation, thereby validating the efficacy of this method. Consequently, this magnetic‐field‐induced crystal‐orientation optimization strategy provides an innovative approach for low‐cost and high‐throughput preparation of high‐performance sodium‐ion batteries.