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

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 angstrom 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 243.31 mAh/g and 212.38 mAh/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.

Automated summary

The theoretical study compared the capabilities of self-passivated porous phosphorene and perfect phosphorene nanosheet as anode materials in fast rechargeable Li/Na ion batteries. The creation of nanopores inside the perfect phosphorene nanosheet led to increased band gap and higher susceptibility to absorb Li/Na atoms, with enhanced adsorption energy around the pores. Storage capacities of porous phosphorene were calculated to be lower than perfect phosphorene, with a significant charge transfer needed for electrical conductivity as an anode material.