First-principles study on S and N doping graphene/SnS2 heterostructure for lithium-ion battery

Highlights: • A dynamic mechanism of enhanced performance in graphene/SnS₂ LIB anode is proposed. • A high Li storage capacity of 1367 mAh g⁻¹ of graphene/SnS₂ LIB anode is predicted. • The capacity and diffusion of defective graphene and graphene/SnS₂ is discussed. Graphene/SnS₂ anode Lithium-ion battery (LIB) was reported with high energy capacity (initial capacities over 1500 mAh g⁻¹), long cycle life (532 mAh g⁻¹ after 600 cycles), and high rate performance (844 mAh g⁻¹ at 10A g⁻¹). The enhancement is due to the advantages of composite materials. However, the deeply dynamic mechanism remains undiscussed. Here using first-principles calculation and climbing image nudged elastic band method, we explored this question in the view of adsorption and diffusion, including the effect of defects in graphene and graphene/SnS₂ and the low diffusion energy (0.21 eV) and high capacity (~1367 mAh g⁻¹) brought by S and N doping.