Utilizing Titanium–Vanadium Coprecipitation for the Preparation of High-Performance Sodium Vanadium Phosphate Cathode Materials from Low-Purity Vanadium Sources

Na3V2(PO4)3 presents unique advantages for sodium-ion battery applications due to its excellent structural stability and rapid sodium-ion conduction. However, its commercial viability has been hindered by the high cost of purified vanadium raw materials. Therefore, utilizing low-purity vanadium sources containing impurities for the synthesis of Na3V2(PO4)3 is of great significance for developing cost-effective, high-performance cathode materials. In this study, vanadium-acid solutions containing varying concentrations of Ti impurities were treated via a hydrolysis-precipitation process to obtain low-purity vanadium precursors with different Ti/V ratios. These precursors were subsequently utilized to synthesize Na3V2(PO4)3 cathode materials with controlled Ti doping. The results demonstrate that the appropriate incorporation of Ti significantly modifies the structure and morphology of Na3V2(PO4)3, thereby enhancing the rate capability (75.26 mAh·g–1 at 20 C) and cycling stability of the battery (99.14% retention after 2000 cycles at 10 C). This simple, efficient, and low-cost synthesis strategy offers valuable insights for the scalable production of high-performance Na3V2(PO4)3-based cathodes.