Three-Sodium Ion Activity of a Hollow Spherical Na₃V₂(PO₄)₂F₃ Cathode: Demonstrating High Capacity and Stability

Na₃V₂(PO₄)₂F₃ (NVPF) is a promising cathode material for sodium ion batteries, owing to its high voltage and promising cycling profile. Nevertheless, most previous reports demonstrated only approximately 100 mAh g⁻¹ at limited operating voltage. Using a solvothermal synthesis route, we synthesized the NVPF cathode with a controlled architecture and spherical morphology. We used this electrode as the cathode for a sodium-ion battery and managed to intercalate/deintercalate the third Na⁺ ion from the structure, demonstrating a high specific capacity (197 mAh g⁻¹). Long-term stability challenges of these electrodes under a wide potential regime are also presented here in.