Ab-initio study of nanoporous phosphorene as anode material in rechargeable Li/Na ion batteries

Abstract

We have examined theoretically the capability of self-passivated porous phosphorene as anode material in fast rechargeable Li/Na ion batteries comparing to the perfect phosphorene nanosheet by performing density functional theory calculations. Creating nanopores with the diameter of about 6.5 Å inside the perfect phosphorene nanosheet, the band gap grows and the susceptibility to absorb Li/Na atom increases, extracted from electronic calculations. The adsorption energy of Li/Na around the pore enhances respected to the perfect phosphorene. Open circuit voltage changes with adatom concentration for Li/ Na intercalation on porous phosphorene have also been discussed. Storage capacities of porous phosphorene have been calculated to be 243.31mAh/g and 212.38mAh/g for LIB and SIB respectively which are lower by the factor of 0.6 with respect to the reported values for perfect phosphorene. A significant charge of nearly one electron is transferred from Li/Na atom to perfect and porous nanosheets which make them electrically conductive required for a good anode material. Employing nudged elastic band theory revealed that both perfect and porous phosphorene have an open channel along zigzag direction for Li/Na diffusion due to low diffusion barrier while they have a forbidden channel along armchair orientation.