Superior electrochemical properties of Na₃V₂(PO₄)₂F₃/rGO composite cathode for high-performance sodium-ion batteries

Na₃V₂(PO₄)₂F₃ has garnered attention as a promising cathode material, primarily due to its substantial theoretical capacity, high operating voltage, and high structural stability. Nonetheless, this material suffers from the low intrinsic electronic conductivity, resulting in a considerable impact on the material properties. To address this challenge, we employ a straightforward hydro-solvothermal reduction process to fabricate Na₃V₂(PO₄)₂F₃/reduced graphene oxide composites featuring a three-dimensional conductive structure. Through an integrated approach involving material synthesis, structural characterization, and electrochemical analysis, we elucidate the synergistic effects between Na₃V₂(PO₄)₂F₃ and reduced graphene oxide in facilitating sodium ion storage and transport. The Na₃V₂(PO₄)₂F₃/reduced graphene oxide cathode in a Na ion cell exhibits reversible capacities of 127 mAh.g⁻¹ at 0.1C and 74 mAh.g⁻¹ at 10C with a 99% retention after 100 cycles at 25 °C. Excellent capacity, reversibility, structure stability, and improved ionic diffusivity make novel composite material an advanced cathode material for sodium-ion batteries, contributing to the development of cost-effective and high-performance energy storage solutions for a sustainable future.