Porous mixed transition metal oxides/graphene nanocomposites for high performance hybrid energy storage devices

Recently, hybrid material has been under intense investigation to fulfill a broad range of requirements posed by various applications. In this regard, a variety of graphene-based composites with single or mixed metal oxides have been successfully synthesized and studied as electrode materials for hybrid/asymmetric devices and supercapacitors with enhanced performance Porous-structured nickel manganese cobalt ternary metal oxide flakes with reduced graphene oxide (NCMO/RGO) has been obtained through a hydrothermal synthesis method. The effect of reaction time on composition and morphology was studied using transmission electron microscopy and X-ray diffraction. The obtained nanoporous structure has been employed as a novel and low-cost electrode material in construction of supercapacitor. Different electrochemical methods including cyclic voltammetry (CV), galvanostatic charge–discharge (CD) and electrochemical impedance spectroscopy (EIS) methods are carried out to characterize electrochemical performance of this nanocomposite. Based on the obtained charge–discharge results, high specific capacity and specific energy values of 115 mAh g-1 and 27 Wh kg-1, respectively, have been calculated at 1 A g-1. The present study introduces new facile hydrothermal synthesis method of novel porous NCMO/RGO for aqueous energy storage devices with voltage window up to 1.6 V.