Three Dimensional Graphene Aerogel Encapsulated NiCo₂O₄ Sea Urchin-like Nanospheres for Supercapacitor Application

NiCo 2 O 4 nanostructures have emerged as a promising candidate for high-performance supercapacitor electrodes. In this study, we synthesized NiCo 2 O 4 nanoarchitectures via a hydrothermal method and further enhanced their electrochemical properties by integrating a three-dimensional graphene (3DG) network. This 3DG coating effectively prevents the aggregation of NiCo 2 O 4 nanoparticles, creates hierarchical porous channels, and significantly expands the active surface area at the nanoscale. The optimized 3DG/NiCo 2 O 4 nanocomposite demonstrates exceptional charge storage capabilities, achieving a high specific capacitance of 700.73 F/g at 1 A/g and outstanding cycling stability with 96.24% capacitance retention after 5000 cycles. When configured as an asymmetric supercapacitor (3DG/NiCo 2 O 4 //AC) for energy storage applications, the device delivers an impressive energy density of 16.35 Wh/kg at a power density of 749.81 W/kg, while maintaining 85.63% capacity retention after 6000 cycles. These results highlight the crucial role of nanoscale structural engineering in developing advanced energy storage materials.