High mass-loading NiCo-LDH@MnCoP nanostructures on Ni foam as an advanced cathode for aqueous supercapacitors

Abstract

This study presents an advanced composite cathode (NiCo-LDH@MnCoP) with a high mass-loading nanostructures on Ni foam through facile hydrothermal and electrochemical deposition techniques. The cathode demonstrates exceptional capacitance, achieving a level of 18511.1 mF cm⁻² at 1 mA cm⁻², commendable rate performance (11244.4 and 8874.7 mF cm⁻² at 10 and 16 mA cm⁻²). The supercapacitor was assembled using AC/CC as the anode, 2 M KOH as the electrolyte and NiCo-LDH@MnCoP/NF as the cathode. Consequently, the device achieved an impressive energy density of 0.610 mWh cm⁻² at 0.775 mW cm⁻² and exhibited excellent cycling stability, with a retention of 80.8 % of its initial capacitance after 20,000 cycles at 20 mA cm⁻², while maintaining an approximate Coulombic efficiency of 100 % throughout the cycling process. Furthermore, assembling supercapacitors into two series-connected coin-cells lights up a red LED for up to 44 min.