▎ 摘　　要

Supercapacitors are promising alternative energy storage systems due to their relatively fast rate of energy storage and delivery. We describe a simple and scalable method to fabricate three-dimensional (3D) few-layer graphene/multi-walled carbon nanotube (MWNT) hybrid nanostructures on industrial grade metal foam foils (nickel foam) via a one-step ambient pressure chemical vapor deposition (APCVD) process. The as-grown few-layer graphene/MWNT nanocarbon foams are in the form of a homogeneous and densely packed hierarchical nanostructures and possess a very large surface area of 743 m(2) g(-1). Symmetrical electrochemical double-layer capacitors (EDLCs) of 3D hybrid hierarchical few-layer graphene/MWNT nanostructures show a high specific capacitance of 286 F g(-1) which leads to an energy density of 39.72 Wh kg(-1) and a superior power density of up to 154.67 kW kg(-1). Moreover, the capacitance retention of 99.34% after 85000 charge-discharge cycles demonstrates the very high stability of the electrode architectures for supercapacitors. These merits enable the innovative 3D hierarchical few-layer graphene/MWNT foam to serve as high performance EDLC electrodes, resulting in energy storage devices with very high stability and power density. (C) 2012 Elsevier Ltd. All rights reserved.