First-principles study of penta-graphene/MoS2 vdW heterostructure as anode material for lithium-ion batteries

The development of two-dimensional heterostructure materials as anode materials has been proved to be a promising method to significantly improve the performance of Lithium-ion batteries. In this work, by using first-principles method, we have extensively studied the electronic structure, stability, and the Li adsorption preferences of penta-graphene (PG)/MoS2 van der Waals heterostructures. The structural and thermal stability are proved by the formation energy, phonon spectrum and ab-initio molecular dynamics (AIMD) simulations. The calculation shows that the system changed from semiconductor to metal after the insertion of Li. The barrier energy of lithium-ion diffusion can be as low as 0.13 eV, and the open-circuit voltage (OCV) of PG/MoS2 system can be as low as 0.37 V. In addition, it is found that lithium storage capacity can reach 751 mA·h/g with overall OCV reaching 0.592 V. More than two-thirds of the total capacity change happened within the ideal OCV window of 0.2–1.0 V. Therefore, PG/MoS2 heterostructure composite system can be a promising anode material with high efficiency.