Ab Initio Investigation of Graphene–Polythiophene Nanocomposite as Electrode Material for Mg-Ion Batteries: A Computational Perspective

Abstract

By using the ab initio computational methods, this study delves into the feasibility of utilizing graphene–polythiophene (G/PTh) nanocomposites as electrode materials for magnesium-ion (Mg-ion) batteries. The research employs the DMol³ and CASTEP modules within Materials Studio software to systematically analyze the electronic and structural characteristics of G/PTh nanocomposites, shedding light on their potential to enhance energy storage in Mg-ion batteries. The investigation encompasses an in-depth exploration of the interaction between Mg adatoms and the nanocomposites, focusing on the electronic properties, specific capacity, Mg adatom diffusion kinetics, structural and thermal stability, and the underlying mechanisms that govern energy storage. The loading of Mg atoms onto the G/PTh nanocomposite yields a notable maximum specific capacity of 815 mAh/g, indicative of weak adsorption energy (−1.51 eV) and highlighting the potential of the resulting battery as an efficient energy storage device. The nanocomposite exhibits a remarkably low Mg diffusion barrier of 5 meV, facilitating a rapid Mg ions diffusion across its surface. A bandgap of 0.019 eV suggests the promising potential of G/PTh nanocomposites as suitable electrode materials for Mg-ion batteries.