Engineering Two-Dimensional Carbon Anodes for Enhanced Lithium Battery Performance

Abstract

In this study, we systematically investigated the structural, electronic, and lithium storage properties of seven distinct two-dimensional (2D) carbon allotropes (Graphyne, Dodecagonal, Kagome graphene, Porous graphene, GY-5, Haecklites (5–7), and T-graphene) using density functional theory (DFT). Cohesive and formation energy analyses of the 2D carbon structures, together with phonon dispersion and ab initio molecular dynamics simulations, confirmed the thermodynamic and dynamic stability of most of the examined structures. Lithium adsorption studies revealed that the GY-5 allotrope transformed into the Ψ-graphene structure during lithiation, while Porous graphene was found to be unsuitable as an anode material for Li-ion batteries due to its Li adsorption energy exceeding the cohesive energy of Li. In contrast, Graphyne, Dodecagonal, Haecklites (5–7), Kagome graphene, and T-graphene exhibited high theoretical storage capacities (ranging from 930 to 5208.28 mAhg −1 ), open-circuit voltages suitable for battery applications (0–2 V), and low diffusion barriers comparable to those of commercial anode materials. Furthermore, Li adsorption induced a semiconductor-to-metal transition in the Dodecagonal and Graphyne structures, thereby enhancing their electronic conductivity. These findings demonstrate that certain carbon allotropes hold strong potential as promising candidates for next-generation high-performance Li-ion battery anodes.