Nickel/Cobalt phosphate ultrathin nanosheets grown on the surface of Fe(PO3)3 nanosheets for high performance supercapacitors

Using as-prepared Fe(PO3)3 nanosheets as the precursor, nickel phosphate-coated Fe(PO3)3 ([email protected](PO3)3) and cobalt phosphate-coated Fe(PO3)3 ([email protected](PO3)3) with unique structures (ultrathin nanosheets grown on the surface of Fe(PO3)3 nanosheets) were successfully prepared via the hydrothermal method. Their unique structures and the synergistic effect between Ni-Fe and Co-Fe enable their performance in terms of pseudocapacitance as electrodes. The capacitances of [email protected](PO3)3 and [email protected](PO3)3 in a traditional three-electrode system were larger than those of pure Fe(PO3)3. Subsequently, asymmetric supercapacitors were also constructed. When compared with those of a Fe(PO3)3//AC aqueous supercapacitor, the specific capacity, specific energy, and specific power of the [email protected](PO3)3//AC and [email protected](PO3)3//AC aqueous supercapacitors showed an increase. This improved performance threfore demonstrates that [email protected](PO3)3 and [email protected](PO3)3, with their unique structures, are promising electrode materials for use in supercapacitors.