Graphene antidot lattices as potential electrode materials for supercapacitors

• Graphene antidot lattices show a formation energy per length of 0.50 ~ 0.60 eV/nm.
• Within a hole density of 10%, graphene antidot lattices are almost metallic.
• An optimum pore diameter of ~0.86 nm was found for penetration of K and Cl atoms.

Thermodynamic stabilities and electronic properties of graphene antidot lattices with hexagonal holes were examined using density functional theory calculations and several crucial factors related to the applications of supercapacitors were discussed. For the graphene antidot lattices with different hole sizes, the formation energy per edge length is about 0.50∼0.60 eV/nm, which is comparable to that of graphene nanoribbon edges. Within a hole density of 10%, the graphene antidot lattices can maintain the excellent electronic properties of perfect graphene due to negligible intervalley scattering. Further increasing the hole density will open a band gap. Taking the potassium chloride (KCl) electrolyte as an example, we further investigated the diffusion behaviors of potassium (K) and chlorine (Cl) atoms through the graphene antidot lattices. It was shown that K and Cl atoms can go through the holes with nearly no barrier at an appropriate hole size of 0.54 nm, which gives an optimum pore diameter of ∼0.86 nm. Therefore, the excellent graphene-like electronic properties and good penetrability for ions suggest promising applications of graphene antidot lattices in the field of supercapacitors.

Compared with perfect graphene, porous graphene antidot lattices facilitate the diffusion of ions in passing through the graphene layers, which should be promising electrode materials for supercapacitors.Figure optionsDownload as PowerPoint slide