One-step facile fabrication of N, S co-doped carbon modified NiS/MoS2 heterostructure microspheres with improved sodium storage performance

Abstract

Metal sulfides are considered potential anode materials for sodium ion batteries (SIBs) due to their unique structure and high theoretical capacities. Nevertheless, the low intrinsic electrical conductivity and sluggish electrochemical reaction kinetics lead to inferior electrochemical performance, which greatly limits their practical application. In this work, we successfully constructed N, S co-doped carbon modified NiS/MoS2 heterostructures (denoted as NiS/MoS2) via a simple one-step hydrothermal method. The as-prepared sample was corroborated as an advanced anode for SIBs that simultaneously achieved high reversible capacity (670.2 mA h g−1 at 0.5 A g−1), excellent rate capability (249 mA h g−1 at 40 A g−1), and long-term cycling stability (573.8 mA h g−1 after 1000 cycles at 2 A g−1). Furthermore, the superior cycle and rate performance are also reflected in the sodium-ion full cell, which demonstrates the potential value of the NiS/MoS2 anode in practical applications. The bimetallic sulfide heterostructure distinctly lowers the Na + diffusion energy barrier and elevates the reaction kinetics by a built-in electric field effect. In addition, the doping of N, S elements can form a strong bond with carbon to accommodate the volume change and boost the electron transfer. This work provides a valuable reference to develop advanced anode materials for SIBs for practical applications.