High-performance pouch-type hybrid supercapacitor based on hierarchical NiO-Co3O4-NiO composite nanoarchitectures as an advanced electrode material

Abstract

The core-shell-like architectures consisting of NiO nanosheet arrays grafted Co3O4-NiO fish thorns-like nanostructures (NiO NSAs@Co3O4-NiO FTNs) were successfully prepared by a simple solution-based method. With an aid of ammonium fluoride (NH4F), the morphological evolution of Co3O4-NiO FTNs was elaborated effectively. Subsequently, the NiO NSAs were uniformly decorated on the Co3O4-NiO FTNs to form a core-shell-like composite material for positive electrode in hybrid supercapacitors (HSCs). The core-shell-like composite exhibited a large surface area with high open porous channels, which intends to deliver high areal capacity of 313.9 μA h/cm2 (at 4 mA/cm2) in 1 M KOH, and it is 1.84 and 3.9 times higher than the Co3O4-NiO FTNs and solitary NiO NSAs electrodes. Furthermore, we fabricated a pouch-type HSC with core-shell-like NiO NSAs@Co3O4-NiO FTNs as a positive electrode and activated carbon as a negative electrode in aqueous alkaline electrolyte. At a current density of 2 mA/cm2, the fabricated HSC provides high areal capacitance of 623.5 mF/cm2 with a maximum energy density of 216.1 μW h/cm2 and power density of 27.7 mW/cm2. In addition, the HSC showed superior cycling stability with a capacity retention of 126% after 5000 cycles, indicating the great promise of practical applications. Thanks to the comprehensive electrochemical performance, the pouch-type HSCs effectively operated a toy motor fan and light-emitting diode bulb for real-life applications.