Synthesis of interlayer expanded MoS2 by sulfurization of MoO3 with enhanced sodium-ion storage.

• MoS 2 inherits the structure of the intermediate 1 T-MoS 2 with expanded interlayer distance. • The flower-like structure and few-layered MoS 2 promote the transport of sodium ions. • Increasing the storage site of Na+ leads to high specific capacity. • Faster kinetics of Na+ leads to significant C-rate performance. MoS 2 , high theoretical specific capacity (670 mAh g−1) and unique physical and chemical properties, is widely used as the anode of sodium-ion batteries (SIBs). However, the original MoS 2 , with its inferior inherent conductivity and serious volume variation during charge and discharge, often exhibits low actual capacity and poor rate performance. In this work, MoS 2 nanoflower was synthesized by sulfurization of molybdenum trioxide (MoS 2 -MT), which expanded interlayer distance without mixing with other materials. The expanded interlayer distance (about 0.68 nm) reduced the diffusion barrier of Na+. The larger specific surface area increased the contact area between the electrode material and the electrolyte, which provided more active sites for the insertion/extraction of Na+. As anode of SIBs, MoS 2 -MT achieved a high specific capacity of 535.3 mAh g−1 at 0.1 A g−1, and reserved 410 mAh g−1 at 1 A g−1 after 100 cycles with a capacity retention rate of 85.4%. At the same time, MoS 2 -MT also exhibited considerable rate performance that reserved 313.5 mAh g−1 at 5.0 A g−1. [ABSTRACT FROM AUTHOR]