Preparation of Tunable 3D Pillared Carbon Nanotube–Graphene Networks for High-Performance Capacitance

We have developed a rational strategy for creating the 3D pillared vertically aligned carbon nanotube (VACNT)-graphene architectures by intercalated growth of VACNTs into thermally expanded highly ordered pyrolytic graphite (HOPG). By controlling the fabrication process, the length of the VACNT pillars can be tuned. In conjunction with the electrodeposition of nickel hydroxide to introduce the pseudocapacitance, these 3D pillared VACNT–graphene architectures with a controllable nanotube length were demonstrated to show a high specific capacitance and remarkable rate capability, and they significantly outperformed many electrode materials currently used in the state-of-the-art supercapacitors.