MnCoP-Coated NiCo₂S₄ Nanostructures on Ni Foam for Aqueous Asymmetric Supercapacitors

This study presents a promising composite cathode prepared by electrodepositing MnCoP nanostructures on hydrothermally grown NiCo 2 S 4 on Ni foam. The cathode has a capacitance of up to 7780.0 mF cm –2 at 1 mA cm –2, good rate performance (6340.0 and 4464.0 mF cm –2 at 10 and 60 mA cm –2 ), as well as cycling stability with 81.8% maintenance of its original capacitance after 7000 cycles at 20 mA cm –2 . The energy density achieved by the supercapacitor, which consists of this cathode, an activated carbon anode (on carbon cloth), and 2 M KOH aqueous solution electrolyte, is 0.488 mWh cm –2 at 0.800 mW cm –2 . Furthermore, it exhibits good cycling stability as it retains 84.8% of its initial capacitance even after 20 000 cycles at 20 mA cm –2 .