Advanced three-dimensional hierarchical Pr6O11@Ni-Co oxides-based core-shell electrodes for supercapacitance application

Abstract

A facile solvothermal method is used to fabricate hierarchical core-shell nanostructures based on praseodymium, nickel and cobalt oxides supported on nickel foam. The Pr6O11 nanoparticles were first grown on the nickel foam and then utilized as a backbone for anchoring NiO, Co3O4 and NiCo2O4 nanostructures to form a core-shell structure. The core-shell electrodes exhibit superior electrochemical performance than single Pr6O11 nanoparticles electrodes. A superior specific capacitance of 1635 F/g at a current density of 0.5 mA/cm2 with good cycling stability was obtained for the Pr6O11@NiCo2O4 electrode. Moreover, a solid-state supercapacitor was fabricated by assembling Pr6O11@NiCo2O4 electrodes using KOH/PVA as the solid electrolyte. The as-prepared solid-state device demonstrated impressive energy density of 6.6 W h/kg and a power density of 150 W/kg. This optimal performance could be attributed to the high conductive nickel foam current collector and synergistic effects generated from the core-shell architecture of NiCo2O4 and the Pr6O11 nanoparticles.