• • Carbon coating at 600 °C (NVPOF@C-600) increased electronic conductivity by three orders of magnitude compared to uncoated or lower-temperature treatments, directly addressing the material's low intrinsic conductivity bottleneck.
• • The ~4.5 nm carbon layer effectively suppressed grain growth and secondary crystallization at high temperatures, maintaining a uniform particle size of ~0.36 μm, which is critical for consistent electrochemical performance and long-term cycling stability.
• • NVPOF@C-600 achieved a high-rate discharge capacity of 102.5 mAh g−1 at 20 C, demonstrating excellent rate capability essential for high-power applications.
• • In full-cell configuration with hard carbon anode, NVPOF@C-600//HC retained 89.3% capacity after 9,000 cycles, indicating exceptional durability for grid-scale energy storage.