Fabrication of 3D graphene-CNTs/alpha-MoO3 hybrid film as an advance electrode material for asymmetric supercapacitor with excellent energy density and cycling life

Recently, three-dimensional (3D) architectures of graphene-carbon nanotubes (CNTs) have attracted a lot of attention due to their multifunctional properties. In this study, we have reported a novel 3D graphene-CNTs/MoO3 hybrid film as a binder free electrode material with unique morphology and outstanding electrochemical performance. The optimized 3D graphene-carbon nanotubes (GF-CNTs) framework was fabricated by a chemical vapor deposition (CVD) process on Ni foam skeleton. Further, controlled loading of MoO3 nanoplates were grown on the GF-CNTs framework as a hybrid film, using an easy and low cost hydrothermal method. The as-fabricated hybrid electrode exhibits remarkable specific capacitance of 1503 F g(-1) at 1 A g(-1) and 798.93 F g(-1) at a current density of 10 A g(-1), as well as exceptional capacitance retention of 96.5% after 10,000 cycles. The excellent electrochemical performance of the electrode material can be attributed to the combination of pseudocapacitance and electric double layer capacitance contributed by the MoO3 nanoplates and graphene foam/CNTs in the hybrid system, respectively. The asymmetric supercapacitor (ASCs), assembled from GF-CNTs/MoO3 and GF-CNTs as positive and negative electrode, respectively, delivers excellent specific capacitance of 211.71 F g(-1) at current density of 1 A g(-1). The ASCs device also exhibits a maximum energy density of 75.27 W h kg(-1) at a power density of 816.67 W kg(-1) with excellent cycling ability of 94.2% of the initial capacitance after 10,000 cycles. These results suggest that the as-fabricated GF-CNTs/MoO3 hybrid architecture can be used as a promising electrode material for the next generation supercacitor devices.