Density functional theory study of molecular pillared graphene for High-Performance Sodium-Ion batteries

Abstract

This study investigates the potential of molecular pillared graphene (MPG) as anode materials for Na-ion batteries using density functional theory (DFT) calculations. Two distinct MPG structures were designed by varying the organic pillar molecule’s chemical composition. The investigated MPGs comprise two parallel graphene layers linked by naphthalene or pyrene via the formation of five-membered boroxine rings. Cohesive energy analysis and ab-initio molecular dynamics simulations confirm the structural stability of these materials. The results demonstrate high Na mobility within the MPG structures due to the low energy barrier for diffusion. Furthermore, the layered structure facilitates Na-ion insertion, leading to exceptional theoretical capacitances calculated to be 832 and 858 mAh/g. The combination of low diffusion barriers and high theoretical capacities suggests MPG as a promising candidate for Na-ion battery anodes. Additionally, Na adsorption induces metallic behavior in the MPG structures, a crucial prerequisite for efficient ion diffusion in anode materials.