Hierarchically Porous Nanostructured Nickel Phosphide with Carbon Particles Embedded by Dielectric Barrier Discharge Plasma Deposition as a Binder-Free Electrode for Hybrid Supercapacitors

Three-dimensional (3D) metal phosphides are promising superior electrode components for supercapacitors. In this study, 3D porous nickel phosphide nanoarrays are successfully enrooted on the surface of nickel foam (Ni2P/NF) by low-temperature hydrothermal treatment. Subsequently, a nanocarbon was embedded over Ni2P@NF by efficient utilization of the environmental pollutant ethylene gas via a dielectric barrier discharge plasma reactor. This nanocarbon was deposited on porous Ni2P/NF nanoarrays (Ni2P-C/NE) as a positive electrode sandwiched with peanut shell-derived porous activated carbon (ENS-AC) as a negative electrode for the fabrication of a hybrid supercapacitor device. The hybrid supercapacitor device (Ni2P-C/NF//PNS-AC) delivers an enormous amount of areal and gravimetric capacities values at a 1 A g(-1) current density of 318.8 mu Ah cm(-2) and 106.2 mAh g(-1), respectively. Moreover, the hybrid supercapacitor device achieved outstanding energy and power density with excellent cyclic durability (90.1%) even after 5000 cycles at 7 A g(-1), which are 108.1 Wh kg(-1) at 1 A g(-1) and 14,370.4 W kg(-1) at 15 A g(-1), respectively. These results evidenced that the novel nanostructured Ni2P/NF with embedded carbon nanoparticles has excellent potential as the supercapacitor electrode material.