The high energy supercapacitor from rGO/Ni(OH)2/PANI nanocomposite with methane sulfonic acid as dopant

Abstract

The low energy densities of supercapacitors limit their utilization as energy storage and energy conversion devices. To overcome this limitation, here we present a ternary nanocomposite of reduced graphene oxide (rGO)/nickel hydroxide (Ni(OH)<inf>2</inf>/polyaniline (PANI), with methane sulfonic acid as dopant, having weight percentages of 14%:14%:72% (G14NP), respectively, as an electrode material for supercapacitor. With 1 M sulfuric acid (H<inf>2</inf>SO<inf>4</inf>) as the electrolyte, the supercapacitor yields a high energy density of 120.48 W h kg?1, comparable with those of Li-ion batteries. The G14NP also exhibits good electrochemical performance with a specific capacitance of 602.40 F g?1 and a power density of 2584.83 W kg?1, at a current density of 1 A g?1. The G14NP also exhibits a promising stability of its electrochemical performances even after 16,500 cycles at a potential scan of 400 mV s?1. Remarkably, the composite performs exceptionally well at a potential window available in an aqueous electrolyte. The sustainability to high current loading while charging and its power backup application is satisfactorily demonstrated, by charging with a commercial 9 V battery. © 2019 Elsevier Inc.