Researchers has devised new two-dimensional carbon based materials – called Graphydiyne.
Carbon is the anode material in lithium-ion batteries. Its
layered structure allows lithium ions to travel in and out of the spaces
between layers during battery cycling. Carbon has a highly conductive
two-dimensional hexagonal crystal lattice, and they form a stable, porous
network for efficient electrolyte penetration. However, the fine-tuning of the
structural and electrochemical properties is difficult as these carbon
materials are mostly prepared from polymeric carbon matter in a top-down
synthesis.
Graphdiyne being a hybrid two-dimensional network made of
hexagonal carbon rings bridged by two acetylene units, has been used as a
nanoweb membrane for the separation of isotopes. However, its distinct
electronic properties and web-like structure also make graphdiyne suitable for
electrochemical applications. Changshui Huang from the Chinese Academy of
Sciences, Beijing, and colleagues have investigated the lithium-storage capabilities
and electrochemical properties of tailor-made, electronically adjusted
graphdiyne derivatives.
The scientists synthesized the graphdiyne derivatives in a
bottom-up approach by adding precursors on a copper foil, which self-organized
to form ordered layered nanostructures with distinct electrochemical and
morphological properties.
Among these functional groups, those exerting
electron-withdrawing effects reduced the band gap of graphdiyne and increased
its conductivity, the authors reported. The cyano group was especially
effective and, when used as an anodic material, the cyano-modified graphdiyne
demonstrated excellent lithium-storage capacity and was stable for thousands of
cycles, as the authors reported.
The authors conclude that modified graphdiyne can be prepared by
a bottom-up strategy, which is also best suited to build functional
two-dimensional carbon material architectures for batteries, capacitors, and
other electrocatalytic devices.
