Green Large-Scale Preparation of Na₃V₂(PO₄)₃ with Good Rate Capability and Long Cycling Lifespan for Sodium-Ion Batteries

Sodium-ion batteries are recognized as a more cost-effective choice for large-scale energy system storage compared to lithium-ion batteries. Na3V2(PO4)(3) exhibits a structure as a Na superionic conductor, displaying outstanding thermal stability and notable energy density. Whereas conventional preparation process of Na3V2(PO4)(3) emits harmful gases such as nitrogen oxides and sulfur dioxides, which not only pollute the environment but also escalate material production costs, rendering it unsuitable for large-scale industrial applications. In this work, we successfully synthesized a carbon-coated Na3V2(PO4)(3) material via spray drying using vanadium oxide (V2O5), oxalic acid (H2C2O4), and sodium dihydrogen phosphate (NaH2PO4). Importantly, our production process does not involve the emission of nitrogen oxides and sulfur dioxides, effectively mitigating environmental pollution. The NVP/C-Na sample demonstrates a noteworthy initial capacity of 109.3 mA h g(-1) at 1 C. After 5000 cycles at a high rate of 10 C, the material exhibits exceptional cycling stability, maintaining a substantial capacity of 88.4 mA h g(-1). These results underscore its excellent electrochemical performance of the NVP/C-Na, indicating its promising potential for large-scale energy storage in sodium-ion batteries.