Stone-Wales Defect Induced Performance Improvement of BC3 Monolayer for High Capacity Lithium-Ion Rechargeable Battery Anode Applications

Abstract

First-principles density functional theory (DFT) computations were adopted to assess the potential application of a boron carbide (BC<inf>3</inf>) monolayer with point and topological defects as an anode material in alkali metal-based lithium (Li) ion rechargeable batteries. Results show that point defects (mono and bi vacancies) induce a large structural deformation upon Li intercalation which restricts their use for anode application. However, the Stone-Wales defect filled BC<inf>3</inf> monolayer shows high structural stability with a negative Li binding energy of -1.961 eV in comparison with -0.930 eV of its pristine form. It is also noticed that after adsorbing the Li atom, the semiconducting characteristics of both the pristine and Stone-Wales defect filled BC<inf>3</inf> monolayers are transformed into metallic, electrically conductive states. More importantly, the Li alkali metal atom shows fast diffusion on the surfaces of both the pristine and the Stone-Wales defect filled BC<inf>3</inf> monolayers with low energy barriers of 0.34 and 0.33 eV, respectively. Besides, both the pristine and Stone-Wales defect filled BC<inf>3</inf> monolayers exhibit high theoretical specific capacities of 1144 and 1287 mAhg-1, which are much higher than that of a traditional graphite anode and stand among the highest values of anode materials detailed in literature. The Li alkali metal intercalated monolayers BC<inf>3</inf> show small average open-circuit voltages of 0.485 and 0.465 V for pristine and Stone-Wales defect cases, respectively. On the basis of the aforementioned details, the present study suggests that the Stone-Wales type topological defect incorporated BC<inf>3</inf> monolayer is a promising anode material for Li-ion based rechargeable batteries with high storage capacity, low Li diffusion energy barrier, and low average open-circuit voltage. © 2020 American Chemical Society.