Fe-based phosphate nanostructures for supercapacitors

Fe-based phosphates with excellent physical and chemical features are potential electrode materials for supercapacitors. In this work, we successfully synthesized Fe-based phosphates with different dimensions, morphologies, and compositions by one-step hydrothermal method. Influence factors on the chemical composition and morphology of the as-prepared materials were explored and the energy storage performance of the as-prepared samples were tested under the traditional three electrode system. Two-dimensional (2D) iron metaphosphate (Fe(PO3)3) showed the best electrochemical performance. For Fe(PO3)3 electrode materials, the layered structure can provide a larger specific surface area than the bulk structure, which is conducive to the diffusion and transport of electrolyte ions during charging-discharging and further improves the rate performance and cycle stability of supercapacitor. 2D Fe(PO3)3 and activated carbon were used as electrode materials to construct a 2D Fe(PO3)3//AC supercapacitor. The supercapacitor showed high energy density, high power density, and excellent cycling stability, which indicates 2D Fe(PO3)3 is a promising electrode material for supercapacitors.