Investigation of Nitrogen Doping Effects on the Performance of Graphene in Lithium-Ion Batteries Using Density Functional Theory

Abstract

We performed first-principles calculations using density functional theory (DFT) with the CASTEP code in Materials Studio to investigate the adsorption behaviour of lithium (Li) on graphene featuring single defects. Our study employed the generalized gradient approximation (GGA-PBE) to analyse the adsorption and diffusion characteristics of Li on three distinct graphene structures: pristine graphene, graphitic nitrogen-doped graphene (NG), and pyridinic nitrogen-doped graphene (NG1). The results indicated that Li diffusion occurs significantly faster on N-doped graphene compared to pristine graphene. Specifically, the calculated diffusion energy barriers were found to be 0.82 eV for pristine graphene, 1.83 eV for NG, and 0.65 eV for NG1. This suggests that NG1, with its lower energy barrier, facilitates Li movement more efficiently than the other structures. Furthermore, NG1 demonstrated a remarkable theoretical specific capacity of 453.88 mAh/g, underscoring its potential as an advanced anode material for lithium-ion batteries (LiBs). Overall, our findings highlight that nitrogen-doped defect graphene not only improves lithium diffusion kinetics but also enhances the overall capacity for lithium storage, making it a highly promising candidate for next-generation LiB applications.