Facile synthesis of nano-structured Ni(OH)2-MnO2-rGO composite VIA gelation method for potential super capacitor electrode material

Abstract

This research work represents the facile synthesis of self-assembled hybrid Ni(OH)2-MnO2-rGOcomposite by a simple gel formation technique. The electrochemical study was conducted to evaluate the supercapacitor performance of the as-prepared Ni(OH)2-MnO2-rGO electrode material using 0.5 M Na2SO4. Due to the abundant self-assembled layered nanostructure of rGO and hydrothermally grown Ni(OH)2 as well as MnO2 on rGOsurface, the composite exerts relatively high surface area and well-defined spherical morphology. The synergetic effect of Ni(OH)2, MnO2, and rGO in Ni(OH)2-MnO2- rGO ternary hybrid as active materials exhibited significantly enhanced specific capacitance (320 Fg-1) and energy density (11.11 Whkg-1) at 1 Ag-1 current density, based on the total mass of active materials. In addition, the Ni(OH)2-MnO2-rGO hybrid structure-based symmetric supercapacitor also showed satisfying power density (250 Wkg-1) and electrochemical cycling stability (2000 cycles). The solution resistance (Rs) for the Ni(OH)2-MnO2-rGO was found 4.7 Ω and after 2000 cycles the capacitance retention was 92 % of the initial value.As a result of those outstanding features, the hybrid composite of Ni(OH)2-MnO2-rGOis considered as a highly prospective electrode material for supercapacitor applications. KEYWORDS:Hybrid Supercapacitor, Gel formation, Ni(OH)2-MnO2-rGO, Self-assembled, ternary hybrid.