Fabrication of 3D graphene-CNTs/Α-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.