Bioinspired tailoring of nanoarchitectured nickel sulfide@nickel permeated carbon composite as highly durable and redox chemistry enabled battery-type electrode for hybrid supercapacitors

Abstract

Rational design of highly conductive and redox-active electrode materials composed of metal chalcogenides and carbon composites has attracted promising attention for the development of high-performance energy storage devices. Herein, cost-effective in situ design of carbon sheets with nickel sulfide shielded nickel (NiS–Ni@C) nanocomposite is prepared using biomass precursor with subsequent pyrolysis and sulfurization, respectively. Initially, highly conductive nickel nanospheres are permeated into carbon sheets (Ni@C) by the pyrolysis of carbon-rich wheat snacks and nickel salt. Following, core–shell-like hierarchical NiS flowers on Ni@C were derived in situ using various thiourea concentrations under hydrothermal treatment. Utilizing the hierarchical NiS–Ni@C as an electrode material, the highly conductive composite enables rapid diffusion of electrolyte ions into their interiors and accelerates redox chemistry during electrochemical measurements. Specifically, hierarchical NiS–Ni@C nanocomposite demonstrates dominant battery-type behavior with a maximum specific capacity of 430 C g⁻¹ and excellent cycling stability of 92%. Moreover, a hybrid supercapacitor is assembled using hierarchical NiS–Ni@C as a positive electrode and wheat-snack derived porous carbon as a negative electrode, which exhibits superior energy and power densities with good cycling stability. The designed composite using biomass sources promotes the way for the development of highly active electrode materials for energy storage and electrocatalytic applications.