This work describes the first steps towards fabrication and characterization of a novel hybrid nanostructure comprised of carbon nanotubes (CNTs) grown out-of-plane from graphene layers for supercapacitor applications. Graphene is a promising material for supercapacitors, due to outstanding theoretical specific surface area (~2630 m2/g), and an intrinsic capacitance of up to 21 μF/cm2, the theoretical limit of carbon materials. The key idea of this work is to minimize graphene self-aggregation by growing CNTs spacers directly on and between the graphene layers. To this end, we have fabricated a CNT-graphene architecture, in which CNTs were grown out-of-plane on a graphene layer. The measured average capacitance of a graphene-CNT sample was 653.7 μF/cm2 at 10 mV/s. The graphene-CNT capacitance was maintained at 490.3 μF/cm2 at charging/discharging rates of 300 mV/s, implying very rapid current response on voltage reversal at each end potential. This indicates that there is a stable, low-resistance electric interconnection between CNTs grown on a non-aggregated graphene layer. The growth of novel graphene-CNT and graphene-CNT-graphene architectures is a milestone towards fabricating structures of alternating graphene and CNTs layers for 3D hybrid electrode architecture.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2013: Advanced Materials, CNTs, Particles, Films and Composites (Volume 1)
Published: May 12, 2013
Pages: 228 - 230
Industry sector: Advanced Materials & Manufacturing
Topics: Carbon Nano Structures & Devices, Graphene & 2D-Materials