• Electrode;
  • Graphene;
  • NFR;
  • Supercapacitor

Three-dimensional graphene networks (3DGNs) with a controllable number of layers (from monolayer to few layers) are fabricated by CVD on a Ni foam rod (NFR) template. The special morphology of the NFR and accompanying concentration gradients of CH4 gas provide the necessary conditions to deposit the 3DGNs with varied thicknesses on different areas of one substrate. The high conductivity, large Brunner-Emmett-Teller (BET) area, and three-dimensional network of the 3DGNs make it a potential material for use in the electrochemical field. Supercapacitors with the 3DGNs-based electrode show a high energy density ∼34.2 Wh kg−1 at a current density of 100 mA g−1, and a specific capacitance of 246 F g−1 is obtained in a 30 wt.-% KOH aqueous electrolyte solution. Moreover, the resultant devices maintain high performances under high current density conditions, indicating the outstanding stability of the prepared 3DGNs.