Revealing the potential of graphene-embedded Na₃Fe₂(PO₄)₃ for enhanced sodium-ion battery performance

In this study, pure sodium iron phosphate [Na₃Fe₂(PO₄)₃, abbreviated NFP] and graphene-embedded sodium iron phosphate [Na₃Fe₂(PO₄)₃/graphene, abbreviated NFP/G] were effectively produced through a facile sol–gel method followed by physicochemical and electrochemical characterization for sodium-ion batteries. The resulting NFP nanoplates exhibited an even distribution and firm attachment to the graphene sheets of the NFP/G nanocomposite. The nanocomposite displayed superior sodium storage capacity, achieving 115.1 mAh g⁻¹ at a 0.1 C rate, closely approximating the theoretical capacity of pure NFP. As a SIBs cathode, NFP/G stands out for its exceptionally long cycle life and high capacity. It surpasses the capacity of pure NFP, and its derivatives studied at these charge/discharge rates, delivering high capacities of 103.7 mAh g⁻¹ (96.4%) and 86.8 mAh g⁻¹ (93.7%) after 50 and 500 cycles at 0.5 C and 1 C, respectively. The interaction between the NFP nanoplates evenly distributed on the graphene sheets established active sites, promoting the fast and efficient diffusion of sodium ions, leading to reduced diffusion lengths and enhanced electronic conductivity. These results emphasize the promising potential of these nanocomposites for sodium-ion energy storage applications.