nanowerk | Aligned carbon nanotube/graphene sandwiches for high-rate lithium-sulfur batteries
(Nanowerk Spotlight) Sp2-bonded
carbon nanomaterials – such as carbon nanotubes (CNTs) and graphene –
have attracted enormous research interest over the past decades. Due to
their superior intrinsic physical properties, such as mechanical
strength, electrical and thermal conductivity, these nanocarbons find
numerous applications in areas such as catalysis, energy storage or
nanocomposites. In addition to these intrinsic physical properties, what
makes these materials so attractive are their tunable chemical
characters, such as functional groups, doping, and surface modification.
However, the demonstration of their intrinsic physical properties and
performances in as-fabricated materials and practical devices has been
suffering from the self-aggregation and re-stacking of nanocarbon
materials due to strong van der Waals interactions. This prevents the
full utilization of the active sites for catalytic reactions.
Researchers consider the rational combination of CNTs and graphene into
three-dimensional (3D) hybrids an effective route to amplify the
inherent physical properties at the macroscale. From post-treatment
methods to in situ growth, various strategies have been
explored to fabricate such CNTs/graphene hybrids. Most of these
approaches, though, still require barrier layers, which hinders the full
demonstration of the excellent properties of these hybrid materials.
By in situ nitrogen doping and structural hybridization of
carbon nanotubes and graphene, a team from Tsinghua University, led by
professors Qiang Zhang and Fei Wei, have now successfully fabricated
nitrogen-doped aligned carbon nanotube/graphene (N-ACNT/G) sandwiches.
In this work, aligned CNTs and graphene layers were anchored to each
other, constructing a sandwich-like hierarchical architecture with
efficient 3D electron transfer pathways and ion diffusion channels.
The researchers have published their findings in Advanced Materials ("Nitrogen-Doped
Aligned Carbon Nanotube/Graphene Sandwiches: Facile Catalytic Growth on
Bifunctional Natural Catalysts and Their Applications as Scaffolds for
High-Rate Lithium-Sulfur Batteries").
