Acepentalene Membrane Sheet: A Metallic Two-Dimensional Carbon Allotrope with High Carrier Mobility for Lithium Ion Battery Anodes

The assembly paths of a 2D porous carbon allotrope designed with acepentalene organic molecules are rationally proposed in theory. The polymerized acepentalene membrane sheet with hexagonal conjunction (h-PAMS) shows high stability. Its pi-bands hold Dirac fermion-like characteristics, with the Dirac point located below the Fermi level at the Gamma point, crossing the Fermi surface to enable high mobility charge carriers. In addition, it has anisotropic in-plane mechanical properties and can withstand strain loading as large as 0.9 eV/atom energy cost against structural collapse. The synergistic effects of Li adsorption and Li surface clustering result in 676 mAh/g capacity with a low average open-circuit voltage, making h-PAMS a promising lithium ion battery anode material. Furthermore, the barriers for Li diffusion on the h-PAMS and penetration through the porous hole are only 0.35 and 0.61 eV, respectively. The space expansion during the charge-discharge process is only about 10% of the stacked multilayer. Our studies show the possibility of bottom-up fabrication of the h-PAMS and its fascinating properties for high-performance nanoelectronics and Li ion battery anodes, calling for further investigations in both theory and experiment.