A Novel Two-Step Hydrothermal Approach for Synthesizing α -NaVOPO 4 Cathode Materials in Sodium-Ion Batteries

α-NaVOPO ₄ has emerged as a highly promising cathode material for sodium-ion batteries, thanks to its impressive theoretical capacity (144.9 mAh g ^− 1 ) and elevated operating voltage. However, its practical application is hindered by poor electronic conductivity. In this study, we successfully synthesized α-NaVOPO ₄ with small particle size and exceptional uniformity using a two-step hydrothermal method. This approach preserves the intrinsic advantages of α-NaVOPO ₄ while improving particle microstructure, effectively boosting the electrochemical performance of the cathode. The successful synthesis of pure-phase α-NaVOPO ₄ , along with its desired structural and morphological properties, was rigorously confirmed through X-ray diffraction and scanning electron microscopy. To assess the material's sodium storage performance, we evaluated its electrochemical behavior in a Na||NaVOPO ₄ half-cell, employing both galvanostatic charge/discharge cycling and cyclic voltammetry for comprehensive analysis.