Optimized Electrochemical Behavior of Carbon‐Coated Ti‐Doped Na₃V₂(PO₄)₂F₃ Cathodes for Sodium‐Ion Batteries

Na₃V₂(PO₄)₂F₃ (NVPF) has emerged as a very promising cathode material for sodium‐ion batteries (SIBs), on account of its durable structural reliability and impressive electrochemical performance. However, their practical use is limited by low capacity, poor conductivity, slow Na‐ion transport, and capacity fading, requiring structural and surface modifications. To overcome its inherent low conductivity, carbon‐coated Ti‐doped NVPF (designated as NVPF‐Ti‐x) is prepared via a sol–gel process, with x values of 0, 0.01, 0.02, 0.03, 0.04, and 0.05. Among these variants, NVPF‐Ti‐0.02 demonstrates the most remarkable electrochemical behavior of high reversible capacity and rate capability. NVPF‐Ti‐0.02 achieves an exceptional stabilized specific capacity of 133 mAh g⁻¹ at a current density of 50 mA g⁻¹ after the first cycle onward. It shows a high reversible capacity retention of 94.76% after 100 cycles and 81% after 300 cycles. These results highlight the effectiveness of Ti doping and carbon coating in significantly boosting the conductivity and mechanical stability of NVPF. The improved performance of NVPF‐Ti‐0.02 underscores its potential as a leading candidate for advanced SIB technologies, offering both high capacity and robust cycling stability.